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Recent advances in electrical stunning

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Abstract

This paper provides an overview of the electrical stunning systems and their implementation in modern-day broiler slaughter plants. The application of low voltage electrical stunning systems in the U.S. is reviewed and contrasted with European experiences within the context of differing slaughter technologies, practices, and regulatory constraints. Finally, the impact of electrical stunning on traditional carcass and meat quality attributes of broilers is examined.

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... These aspects produce carcass defects with downgrading of meat quality (Wilkins et al., 1999). Therefore, to ensure both carcass and meat quality, higher stunning frequencies (>300 Hz) have become more common in poultry slaughterhouses (Bilgili, 1999;Gazdziak, 2007). Several authors (Gregory and Wilkins, 1989;Wilkins et al., 1999;Raj at al., 2001) have reported the adverse effect of high stunning currents (especially at low frequencies) on meat quality. ...
... Raj found a significantly lower occurrence of broken bones and breast meat hemorrhages in broilers stunned with a sine wave AC of 1500 Hz compared to 50 Hz. A significant reduction of ventricular fibrillation and cardiac arrest was also observed with higher frequencies (Bilgili, 1999;Gazdziak, 2007). The Annex I of the Regulation (EC) N.1099/2009 establishes the minimum currents at which the animals shall be exposed in the water bath to guarantee an effective stunning. ...
... As variations in impedance (resistance) between the birds are significant, it is not possible to ensure constant electric current for each stunned chicken. Therefore, by using an average value, the risk is that some animals are not stunned effectively because they receive insufficient electric current to ensure unconsciousness and insensibility (Bilgili, 1999;Kettlewell and Hallworth, 1990;Shields and Raj, 2010). The problem could be resolved by increasing the average stunning currents in the recommendations of the Regulation (CE) N. 1099/2009(European Commission, 2009, but this can produce in some animals a poor meat quality with lesions on carcasses and meats. ...
Article
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Animal killing for food production and the related operations are events that may induce pain, stress, fear and other forms of suffering to the animals. To face this problem and guarantee the animal welfare, the EU has adopted the Regulation (EC) N. 1099/2009 on the protection of animals at the time of killing. Electrical water bath stunning is one of the methods used in commercial slaughterhouses to protect poultry welfare. In particular, this method induces unconsciousness into the birds due to run of electrical current through the head and body. The aim of the present work was to find an optimal setting of electrical parameters to obtain an effective water bath stunning in a commercial poultry slaughterhouse. Moreover, the influence of the tested electrical parameters on meat quality was evaluated. All the experiments confirmed that high stunning frequencies induce a lower occurrence of lesions on carcasses but, on the other hand, require greater current intensities to be effective. A frequency of 750 Hz and an average current intensity of 200 mA for each bird in the water bath resulted as the best combination of electrical parameters to obtain a proper stunning without any consequence on the meat quality.
... Kesim hattının hareket etmesiyle birlikte başı su banyosuna giren piliçlerin üzerinden geçen akım ile devre tamamlanmaktadır (Duncan, 2001). Özel olarak tasarlanmış bilinçsizleştirme panoları tarafından üretilen AC/DC akım, yüksek/düşük frekans, yarım/tam doğrultulmuş, sinus/kare dalga tipleri kullanılmaktadır (Kuenzel ve Ingling, 1977;Griffiths ve Purcell, 1984;Bilgili, 1992Bilgili, , 1999Heath ve ark.,1994;Lambooij ve Gerritzen, 2007). Kullanılan gerilim (volt) veya akım (amper) değerleri Ohm(Ω) kanunundan (Gerilim = Akım × Direnç) yararlanılarak piliç başına hesaplanmaktadır. ...
... Elektrik değerleri ABD'de 10-28 V, 10-45 mA ve 350-500 Hz (Bilgili, 1999;Gazdziak, 2007;Nunes, 2007;Shields ve ark., 2010), AB'de AC ve DC akımlar 50 -2000 Hz ve 70-150 mA akım aralığında kullanılmaktadır (Prinz, 2009). Elektrik uygulaması piliçlerde kalp ritminin bozulmasına (Richard ve Sykes, 1967;Lopes da Silva, 1983;Gregory ve Wotton, 1990;Bilgili, 1999;Anonim, 2004), beyine giden kanın azalmasına ve oksijen yetersizliğine neden olmaktadır (Raj, 1998). ...
... Elektrik değerleri ABD'de 10-28 V, 10-45 mA ve 350-500 Hz (Bilgili, 1999;Gazdziak, 2007;Nunes, 2007;Shields ve ark., 2010), AB'de AC ve DC akımlar 50 -2000 Hz ve 70-150 mA akım aralığında kullanılmaktadır (Prinz, 2009). Elektrik uygulaması piliçlerde kalp ritminin bozulmasına (Richard ve Sykes, 1967;Lopes da Silva, 1983;Gregory ve Wotton, 1990;Bilgili, 1999;Anonim, 2004), beyine giden kanın azalmasına ve oksijen yetersizliğine neden olmaktadır (Raj, 1998). Beynin yeterince beslenememesi sonucunda hareketsizlik ve bilinçsizlik oluşmaktadır. ...
Article
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Bu çalışma kesim öncesi etlik piliçleri bilinçsizleştirmek amacıyla uygulanan farklı akım (AC/pDC) ve dalga tipilerini (kare, üçgen ve chirp) içeren elektrikle sersemletmenin karkas kusurları ve göğüs eti kalite özellikleri üzerindeki etkilerini belirlemek amacıyla yürütülmüştür. Çalışmada ticari olarak benzer çevre koşullarında yetiştirilen ortalama 2350 g ağırlığında aynı sürüden temin edilmiş 39 günlük yaşta (Ross 308) etlik piliçler kullanılmıştır. Her birinde 10 piliç (5♀:5♂) bulunan altı deneme grubu oluşturulmuştur. Toplam 60 piliç, su banyosunda 5 sn süreyle 200 Hz frekans ve 120 mA/piliç değerlerinde AC ve pDC elektrik akımıyla sersemletilmiştir. Kesimden sonra piliçlerdeki kan kaybı miktarı, karkaslardaki damar kanamaları, spot lekeler ve kanat kemik kırıkları tespit edilmiştir. Ayrıca, göğüs etinin pH ve renk değerleri ve su kaybı incelenmiştir. Elektrik akımı uygulaması piliçlerde herhangi önemli bir karkas kusuruna neden olmamıştır. Üçgen ve chirp dalga tiplerinin, kare dalgaya göre piliçlerde daha fazla kan kaybına yol açtığı belirlenmiştir. AC akım uygulanan piliçlerin göğüs etinde pH15 değeri daha yüksek bulunurken, göğüs etindeki en düşük su kaybı chirp dalga tipinde meydana gelmiştir. Su banyolarında üçgen ve kare dalganın, bireysel uygulamalarda ise chirp dalga tipinin incelenen özellikler üzerinde daha fazla olumlu etkilerinin olduğu belirlenmiştir.
... Electrical stunning is the most common stunning method that is utilised in commercial poultry plants in both the United States and Europe (Bilgili, 1999;Goksoy et al., 1999). Electrical stunning is accomplished by passing a sufficient amount of electrical current through the brain to render the broilers unconscious (Bilgili, 1992). ...
... In their investigations on the comparison of amperages (60 versus 110 mA) used for electrical stunning, Gregory and Austin (1992) observed about a five-fold increase in ventricular fibrillation at greater amperage, thereby inhibiting the recovery of chickens subjected to stunning and consequently leading to death. However, insufficient currents may not prevent the perception of pain, stress or discomfort even though the broiler is physically immobilized (Bilgili, 1999). Low voltage stunning (US) is utilised in the United States, and high current stunning is used in Europe that results in electrocution (EU) (Bilgili, 1999). ...
... However, insufficient currents may not prevent the perception of pain, stress or discomfort even though the broiler is physically immobilized (Bilgili, 1999). Low voltage stunning (US) is utilised in the United States, and high current stunning is used in Europe that results in electrocution (EU) (Bilgili, 1999). ...
Article
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Broiler stunning is conducted to produce a rapid onset of insensibility prior to slaughter. Though most broiler plants use electrical stunning applications, gas stunning, and low-atmosphere pressure stunning are also available for commercial applications. All three of these stunning methods are able to meet animal welfare requirements and produce meat with acceptable quality. However, each method differs in their mechanisms of stunning, rigor mortis patterns, and physical meat characteristics. In addition, gas stunning and low-atmosphere pressure stunning have received interest over the past decade as part of an effort to further improve animal welfare. Researchers have reported that gas and low-atmosphere pressure stunning both have potential advantages over electrical stunning with respect to broiler welfare and deboning time, which has been attributed to shackling post-stunning. This review paper will focus on these three stunning methods and their impact on animal welfare, physiology, rigor mortis patterns, carcass characteristics, and meat quality.
... Turkeys are especially prone to prestun shocks (Gregory, 1994;Wooton & Gregory, 1991) because their wings hang lower than their heads when hung inverted on a shackle. In some slaughter plants, prestun shocks may occur because the ramp at the entrance to the stunbath is electrically live (Gregory, 1994), although newer entry designs in broiler chicken stunners may prevent overflow of electrically charged water onto the entry ramp (Bilgili, 1999). ...
... Depending on the length of the water-bath and the line speed (Wilkins et al., 1999), the duration of the electric stun usually lasts 10-12 s (Sams, 2001). U.S. stunners may be set at 10-28 volts, delivering 10-45 mA per bird, and the frequency of the current varies between 350 and 500 Hz (Bilgili, 1999;Gazdziak, 2007;Nunes, 2007). Although precise control of each of these electrical settings relative to the others is important, specific stun settings necessary for an effective and immediate stun are not mandated in the United States. ...
... Although the probability of inducing an effective stun increases as the frequency setting decreases, low-frequency settings cause intense muscle contractions and consequent rupture of small blood vessels in the skin and/or flesh, which causes carcass defects that lead to downgrading (Wilkins et al., 1999). Therefore, higher stunning frequencies (>300 Hz) have become more prevalent in U.S. slaughter plants (Bilgili, 1999;Gazdziak, 2007) to ensure carcass and meat quality despite the existing potential for an ineffective stun and/or for the bird to recover consciousness following stunning. However, even low-frequency pulsed DC settings are questionable on welfare grounds because although some broiler chickens may experience cardiac arrest at stunning, these birds may not show EEGs indicative of effective stunning (Raj et al., 2006a(Raj et al., , 2006b. ...
Article
Full-text available
The customary slaughter method of birds killed for human consumption involves the stunning of several live birds at one time using electrical water baths supplied with constant voltages. The birds are hung upside-down on shackles prior to conveyance through the electrified bath. This system, which is used globally, is increasingly under scrutiny as research suggests that it can be both inhumane and ineffective. Scientists have demonstrated that handling, inversion, and shackling are traumatic and stressful to birds and that shackling itself may be painful. In some cases, birds may also receive painful pre-stun electric shocks. There is growing evidence that the existing electrical water-bath stunner settings, including those used in U.S. slaughter plants, may not render birds immediately unconscious. Further, birds may miss the stunner completely and remain conscious when their throats are cut and possibly when they reach the scald vat. Since the existing, constant voltage, electrical water-bath systems that involve stunning several birds simultaneously are increasingly considered inhumane, alternative technologies that use gas mixtures to render birds unconscious have been developed to improve animal welfare. To date, the most effective and least aversive method of stunning birds prior to slaughter is Controlled Atmosphere Killing (CAK), which rapidly and efficiently gasses birds while they are in transport crates.
... These aspects produce carcass defects with downgrading of meat quality (Wilkins et al., 1999). Therefore, to ensure both carcass and meat quality, higher stunning frequencies (>300 Hz) have become more common in poultry slaughterhouses (Bilgili, 1999;Gazdziak, 2007). Several authors (Gregory and Wilkins, 1989;Wilkins et al., 1999;Raj at al., 2001) have reported the adverse effect of high stunning currents (especially at low frequencies) on meat quality. ...
... Raj found a significantly lower occurrence of broken bones and breast meat hemorrhages in broilers stunned with a sine wave AC of 1500 Hz compared to 50 Hz. A significant reduction of ventricular fibrillation and cardiac arrest was also observed with higher frequencies (Bilgili, 1999;Gazdziak, 2007). The Annex I of the Regulation (EC) N.1099/2009 establishes the minimum currents at which the animals shall be exposed in the water bath to guarantee an effective stunning. ...
... As variations in impedance (resistance) between the birds are significant, it is not possible to ensure constant electric current for each stunned chicken. Therefore, by using an average value, the risk is that some animals are not stunned effectively because they receive insufficient electric current to ensure unconsciousness and insensibility (Bilgili, 1999;Kettlewell and Hallworth, 1990;Shields and Raj, 2010). The problem could be resolved by increasing the average stunning currents in the recommendations of the Regulation (CE) N. 1099/2009(European Commission, 2009, but this can produce in some animals a poor meat quality with lesions on carcasses and meats. ...
... In most countries, stunning of animals for slaughter is a legal requirement, where the animals for meat consumption should instantaneously be rendered insensible and remain insensitive to pain until the brain is completely unresponsive (Council Directive 93/119/ CEE, 1993). The most universally accepted means to immobilize birds before slaughter is electrical stunning (Bilgili, 1999). The state of unconsciousness induced by electricity results from the inhibition of impulses in both the reticular activating and the somatosensory systems (Heath et al., 1994). ...
... Several studies have examined the relationship between electrical stunning and animal stress with emphasis on meat quality (Lee et al., 1979;Craig and Fletcher, 1997;Northcutt et al., 1998;Bilgili, 1999;Alvarado and Sams, 2000;Gregory, 2005) however thus far, this has not been established. Thus, the objective of the present study was to investigate the influence of electrical stunning on the animal's stress and the subsequent effect on meat quality. ...
Article
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The objective of this study was to investigate the influence of electrical water bath stunning treatments (pulsed direct current) on stress conditions of poultry meat. This was carried out by evaluating meat quality measured through the incidence of PSE (pale, soft, exudative) in broiler breast fillet meat. We applied the randomized factorial design 22 with three replications at the central point, with independent variables, including voltage (40, 80, 120 V) and electrical frequency (100, 400, 700 Hz). The response functions under study were pH, L*, a*, b*, WHC and incidence of PSE meat. Samples presenting with pH of ≤5.80 and L* of ≥53.0 were classified as PSE whereas those with 5.80<pH<6.00 and 44.0<L*<53.0 were considered normal. The fillets taken from birds without stunning presented 54.14% of PSE meat samples, which decreased to 25.0% with stunning. The response functions L* and incidence of PSE showed regression (P≤0.05) with good adjustment of experimental data to the proposed model. The lowest incidence of PSE meat was observed when voltage and frequency were at their highest levels. In poultry slaughter, the applied electric stunning voltage of 120 V with a frequency of 700 Hz was determined to be the most effective for inhibition of PSE development.
... Usually, there are up to 20 birds at any one time in the water bath (Wilkins et al., 1999). In the United States, 10-28 volts are normally used in the stunners, dispensing 10-45 mA per bird, and the frequency of the current normally is between 350 and 500 Hz (Bilgili, 1999;Gazdziak, 2007). The total current is equivalent to the sum of the current flowing through each particular chicken. ...
... This is applied for constant-voltage multiple-bird stunners, which are the most commercial equipment (Sparrey et al., 1993). Two hundred and twenty chickens per minute have been reported as one of the highest processing speeds in a modern slaughter plant (Bilgili, 1999). ...
Chapter
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Increasing poultry production also means increasing energy and water use in poultry processing. Assessing these inputs is critical to develop more efficient systems and requires analysis of individual steps in processing. This chapter reviews way of measuring and reducing water and energy us at different stages in poultry processing.
... Although the degree of ecchymosis can be reduced by applying electrical current for a shorter period, the reduction may lead to ineffective stunning and excessive movement of animals pre-slaughter and post-slaughter (Berg et al., 2012;Cook et al., 1995;Gregory and Wotton, 1984). Moreover, in cases where the insufficient currents succeeded in immobilizing the stunned animal physically, the stun may not avert the stress, discomfort or pain experienced by the animal (Bilgili, 1999;Wenzlawowicz and Holleben, 2001). In contrast, the use of high current stunning is a humane method since there is less likelihood of the animal regaining consciousness before death (Gregory and Wilkins, 1989;Xu et al., 2011). ...
... They also observed high glycogen and lactate concentrations in birds subjected to 160 Hz stun which was related to increased glycolytic rate, meat paleness, and drip loss (Xu et al., 2011). Various electrical parameters and stunning methods differ in their effect on post mortem rigor development and pH (Bilgili, 1992(Bilgili, , 1999Hillebrand et al., 1996;Roth et al., 2002). Sante et al. (2000) examined the pH of turkey hens stunned with alternating current of various frequencies and found that increased rates of pH decline was associated with stunning at 480 and 600 Hz. ...
Article
The use of high and low electrical frequencies in pre-slaughter electrical stunning and their implications for meat quality and animal welfare in ruminants and poultry are reviewed. There are different views regarding the appropriateness of high and low frequency stunning with respect to religious and animal welfare requirements. High electrical frequency when applied head-to-back does not initiate cardiac arrest, reduces carcass damage, enhances bleeding efficiency and eliminates the need for subsequent electrical immobilization for operator's safety. Conversely, low frequency when similarly applied kills the animal, which has animal welfare advantages, but reduces bleeding efficiency and negatively affects the quality of meat. The ability of high frequency to effectively stun without killing the stunned animal enables the process to meet this fundamental requirement for halal slaughtering when used in head-to-back in ruminants and water bath electrical stunning in poultry. Thus, it is necessary to appraise the efficacy of high and low frequency stunning in order to optimize meat quality and animal welfare attributes vis-a-vis their compliance with halal requirements.
... If birds are not stunned prior to exsanguination, clonic-tonic convulsions (death struggle) will occur, leading to carcass damage (broken wings and clavicles) (Ali et al., 2007;Mackie and McKeegan, 2016). While high voltage-low frequency stunning systems that yield a minimum current of 100 mA per broiler at 50 Hz sine wave alternating current (AC) are required for use in the European Union, both direct current (DC) and AC low voltage-high frequency stunning systems are typically utilized in the United States, where stunning conditions are not mandated for poultry (Humane Methods of Slaughter Act, 1958;Humane Methods of Slaughter Act, 1978;Bilgili, 1999;Raj and O-Callaghan, 2004; Council of the European Union, 2008; Xu et al., 2011). These low-voltage DC water bath systems (approximately 15 V DC) sometimes include the addition of an AC plate (approximately 37 V AC) following the DC stun (2-phase stunner). ...
... These low-voltage DC water bath systems (approximately 15 V DC) sometimes include the addition of an AC plate (approximately 37 V AC) following the DC stun (2-phase stunner). The electrical stunning of broilers prior to exsanguination has significant positive effects on broiler carcass meat quality 3495 Downloaded from https://academic.oup.com/ps/article-abstract/96/9/3495/3869915 by guest on 04 December 2017 including increased breast muscle tenderness (Lee et al., 1979;Craig and Fletcher, 1997;Bilgili, 1999). Carcass defects, which include bruising, discoloration, broken or dislocated bones, damaged viscera, bruised wing joints, red wing tips, and breast fillet hemorrhaging, have all been attributed to stunning at excessively high voltages (Veerkamp and deVries, 1983;Heath, 1984;Veerkamp, 1988;Gregory, Austin and Wilkins, 1989). ...
Article
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Broilers in the United States are typically electrically stunned using low voltage-high frequency (12–38 V, ≥400 Hz) DC or AC water bath stunners. In the European Union, however, broilers are required to be electrocuted using high voltage-low frequency (50–150 V, 50–350 Hz) AC. Low voltage stunned broilers regain consciousness in the absence of bleeding. In contrast, high voltage stunned broilers die due to induction of cardiac fibrillation. For birds stunned with low voltage systems, concerns have been raised regarding animal welfare during bleeding. This work evaluated the impact of extended DC stunning duration and alternative stunning methods (DC+AC combination) on the recovery of bird consciousness and meat quality. In the absence of bleeding, broilers that were DC stunned for extended times (60, 90, or 120 s), 63, 10, or 0% of broilers, respectively, were able to recover consciousness. Alternative stunning protocols included water bath stunning broilers at 15 or 25 V DC for 10 s followed by plate stunning at 100, 110, or 120 V AC for 5 s. Prior to shackling, live body weight and shank width were measured and during stunning, maximum mA for both DC and AC stuns were recorded. All of the alternative stunning protocols (DC+AC) resulted in non-recoverable stunning. The maximum mA recorded during both DC and AC stunning were moderately/strongly (r = 0.54–0.81) correlated to body weight and poorly/moderately (r = 0.27–0.74) correlated to shank width. No significant differences for carcass or meat quality characteristics (hemorrhages, red wing tips, broken clavicles, pH, cook loss, a* and b* color values, and MORS shear energy) were detected between control (15 or 25 V DC only) and treatment groups (DC+AC combination stunning). The only significant different meat quality parameter was L* values where the lowest voltage group (15 V DC) had the darkest fillets (53.27) and the 15 V DC+100 V AC group had the lightest fillets (55.61) with all other groups intermediate. These data indicate that stunning parameters combining DC and AC stunning may be viable protocols when a stun-to-death is desired.
... At the time the animals are put up for slaughter within the abattoir, the pre-slaughter stress can influence the welfare of the poultry, as well as post mortem metabolism and quality meat (Gregory 1994;Ali et al. 2008). The most universally accepted method to immobilise the poultry before slaughter is by electrical stunning (Bilgili 1999). Council Regulation 1099/ 2009/EC (2009) recommended the use of a minimum current of 120 mA, which causes instantaneous and irreversible stunning, and a lack of consciousness and sensibility before, or at the same time, the animals are killed. ...
... The effects of electrical stunning on the final quality of meat are dependent on voltage, frequency, and duration of the treatment. Several studies have examined the relationship between electrical stunning and animal stress, with emphasis on the quality of meat (Lee et al. 1979;Craig and Fletcher 1997;Northcutt et al. 1998;Bilgili 1999;Alvarado and Sams 2000;Gregory 2005). The hanging operations, struggling on the shake line and exposure to heat can, in turn, lead to rapid glycolysis (pH drop), low ultimate pH, and muscle cytotoxicity (van Hoof 1979;Gregory and Bell 1987;Kannan et al. 1997;Loschi et al. 2004;El Rammouz et al. 2004;Debut et al. 2005;Petracci et al. 2010;Petracci and Cavani 2012). ...
Article
This study was designed to investigate physicochemical (pH, peroxides) and histological parameters (glycogen reserve, muscle damages), as pre-slaughter stress markers and quality meat evaluators. Ross commercial broilers was processed, either without stunning (NS Lot), or by combining two current levels of 200 mA, 67 V (HV Lot), and 200 mA, 53 V (MV Lot); with two frequencies of 1000 Hz and 800 Hz, using sinusoidal alternating current. The use of high frequency (800 and 1000 Hz) induced the fastest pH decline, already at 3 h postmortem, in Pectoralis major and Quadriceps femoris of MV and HV Lot carcasses (P < 0.05). Moreover HV carcasses showed a lesser production of superoxide free radicals than the NS Lot and MV Lot carcasses (P < 0.05). Changes in the glycogen reserve and the histological muscle damages did not show significant differences in the analysed Lots. The incidence of individual carcass defects, sufficient to cause downgrading or rejection was generally low in each Lot. To assess animal welfare and quality poultry meat the pH monitoring and measurement of superoxide radical production, as additional and feasible parameters, might be markers easier to use in practice at abattoir.
... Bunlardan birisi olan elektrikle bilinçsizleştirme yöntemi, uygulama kolaylığı, düşük maliyeti ve kısa zamanda göstermiş olduğu etki nedeniyle birçok ülkede uygulanmaktadır. Kullanılan elektrik akımı, özel tasarlanmış panolar tarafından; AC/DC akım şeklinde, yüksek/düşük frekansta, yarım/tam doğrultulmuş, sinus/kare dalga tipinde ve sürekli/pulslanmış olarak üretilebilmektedir (Kuenzel ve Ingling, 1978;Griffiths ve Purcell, 1984;Bilgili, 1992;Heath ve ark., 1994;Bilgili, 1999;Lambooij ve Gerritzen, 2007). Uygulanan elektrik akımı bir süreliğine piliçlerin beyin ve kalp fonksiyonlarını bozarak bilinçlerinin kaybolmasına yol açmaktadır. ...
... Ancak, elektrik uygulaması etin parlaklığının artırmasına yol açmıştır (P<0.05). Öte yandan, bilinçsizleştirmede kullanılan yüksek akım değerlerinin, piliç karkaslarında rigorun erken gelişmesini engellediği fakat olgunlaşmış etin toplam kalite değerini etkilemediği bildirilmiştir (Bilgili, 1999 Hz değeri duyusal yönden değerlendirildiğinde sertlik, aroma ve kabul edilebilirlik açısından en az beğenilen özelliğe sahiptir. pDC 400 Hz değeri ise çalışmada incelenen birçok parametre açısından daha doyurucu sonuçları ortaya çıkarmıştır. ...
Article
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Abstract This study was conducted to determine the effect of pre-slaughtering electrical stunning on some meat quality characteristics of broilers. In total, 144 broiler chickens were divided into 9 groups. Chickens were applied the electrical current in the different types (AC and pDC) in various frequencies (50, 200, 400 and 1000 Hz) of 120 mA during 4s. Then, pH and color in samples of breast meat taken from chickens were measured. Also, the sensory properties of these meats were evaluated by 49 panelists. The results had revealed that the effects of frequencies and current types applied during the slaughtering on the characteristics of pH and color of breast meat of chickens were not significant. But, when the values of pH and color of chicken meat were considered together with some sensory properties, it was determined that the most appropriate electrical value to be applied during the slaughtering was pDC 400 Hz. Özet Bu çalışma, etlik piliçlerin kesim öncesi bilinçsizleştirilmesinin bazı et kalite özellikleri üzerindeki etkilerini belirlemek için yürütülmüştür. Toplam 144 adet piliç 9 gruba ayrılmıştır. Piliçlere 4 saniye süreyle 120 mA seviyesinde, farklı tipte (AC ve pDC) ve farklı frekanslarda (50, 200, 400 ve 1000 Hz) elektrik akımı uygulanmıştır. Daha sonra, piliçlerden alınan göğüs eti örneklerinde pH ve renk ölçümleri yapılmıştır. Aynı zamanda, bu etlerin duyusal özellikleri de 49 panelist tarafından değerlendirilmiştir. Sonuçlar, kesim sırasında uygulanan akım tipi ve frekans değerlerinin piliç etlerinin pH ve renk özellikleri üzerinde önemli bir etki yaratmadığını ortaya koymuştur. Ancak, piliç etinin pH, renk ve bazı duyusal özellikleri birlikte değerlendirildiğinde, kesim sırasında uygulanabilecek en uygun elektriksel değerin pDC 400 Hz olduğu belirlenmiştir.
... Bunlardan birisi olan elektrikle bilinçsizleştirme yöntemi, uygulama kolaylığı, düşük maliyeti ve kısa zamanda göstermiş olduğu etki nedeniyle birçok ülkede uygulanmaktadır. Kullanılan elektrik akımı, özel tasarlanmış panolar tarafından; AC/DC akım şeklinde, yüksek/düşük frekansta, yarım/tam doğrultulmuş, sinus/kare dalga tipinde ve sürekli/pulslanmış olarak üretilebilmektedir (Kuenzel ve Ingling, 1978;Griffiths ve Purcell, 1984;Bilgili, 1992;Heath ve ark., 1994;Bilgili, 1999;Lambooij ve Gerritzen, 2007). Uygulanan elektrik akımı bir süreliğine piliçlerin beyin ve kalp fonksiyonlarını bozarak bilinçlerinin kaybolmasına yol açmaktadır. ...
... Ancak, elektrik uygulaması etin parlaklığının artırmasına yol açmıştır (P<0.05). Öte yandan, bilinçsizleştirmede kullanılan yüksek akım değerlerinin, piliç karkaslarında rigorun erken gelişmesini engellediği fakat olgunlaşmış etin toplam kalite değerini etkilemediği bildirilmiştir (Bilgili, 1999 Hz değeri duyusal yönden değerlendirildiğinde sertlik, aroma ve kabul edilebilirlik açısından en az beğenilen özelliğe sahiptir. pDC 400 Hz değeri ise çalışmada incelenen birçok parametre açısından daha doyurucu sonuçları ortaya çıkarmıştır. ...
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Abstract This study was conducted to determine the effect of pre-slaughtering electrical stunning on some meat quality characteristics of broilers. In total, 144 broiler chickens were divided into 9 groups. Chickens were applied the electrical current in the different types (AC and pDC) in various frequencies (50, 200, 400 and 1000 Hz) of 120 mA during 4s. Then, pH and color in samples of breast meat taken from chickens were measured. Also, the sensory properties of these meats were evaluated by 49 panelists. The results had revealed that the effects of frequencies and current types applied during the slaughtering on the characteristics of pH and color of breast meat of chickens were not significant. But, when the values of pH and color of chicken meat were considered together with some sensory properties, it was determined that the most appropriate electrical value to be applied during the slaughtering was pDC 400 Hz. Özet Bu çalışma, etlik piliçlerin kesim öncesi bilinçsizleştirilmesinin bazı et kalite özellikleri üzerindeki etkilerini belirlemek için yürütülmüştür. Toplam 144 adet piliç 9 gruba ayrılmıştır. Piliçlere 4 saniye süreyle 120 mA seviyesinde, farklı tipte (AC ve pDC) ve farklı frekanslarda (50, 200, 400 ve 1000 Hz) elektrik akımı uygulanmıştır. Daha sonra, piliçlerden alınan göğüs eti örneklerinde pH ve renk ölçümleri yapılmıştır. Aynı zamanda, bu etlerin duyusal özellikleri de 49 panelist tarafından değerlendirilmiştir. Sonuçlar, kesim sırasında uygulanan akım tipi ve frekans değerlerinin piliç etlerinin pH ve renk özellikleri üzerinde önemli bir etki yaratmadığını ortaya koymuştur. Ancak, piliç etinin pH, renk ve bazı duyusal özellikleri birlikte değerlendirildiğinde, kesim sırasında uygulanabilecek en uygun elektriksel değerin pDC 400 Hz olduğu belirlenmiştir
... The birds' heads are then dipped into an electrically charged water bath, closing the circuit and causing current to flow through the head and body to the shackle. As such, birds are potentially stunned as soon as their heads enter the water (Bilgili, 1999;Devos et al., 2018;Prinz et al., 2010a), which allows for automation and high throughput, but shackling is still done manually. While electrical water bath stunning can, in theory, result in immediate loss of consciousness, several major welfare concerns are associated with this approach. ...
... The opposition between carcass quality and humane electrical stunning appears to be unavoidable. While allowable electrical current and frequency parameters are set by law in the EU, the desire to promote meat quality has led to the global use of less effective currents that do not protect bird welfare (Bilgili, 1999;Hindle et al., 2010). For example, in the United States, electrical stunning for broilers routinely involves low current (10-45 mA per bird), high frequency (350-500 Hz), pulsed DC, which is unlikely to result in effective stunning (Shields and Raj, 2010). ...
... Stunning before slaughter is a statutory requirement in the EU to induce unconsciousness and insensibility (inability to perceive stimuli) in animals, so that slaughter can be performed without avoidable fear, anxiety, pain, suffering and distress (EFSA, 2004). The most widely used stunning system of poultry is electrical stunning (Bilgili, 1999). However, under certain conditions, electrical stunning can result in carcass and meat defects like haemorrhages and broken bones. ...
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The effect of stunning method (gas vs. electrical) on some breast meat quality traits was evaluated on 128 breasts (P. major muscles) of 106 day-old female BUT-Big6 turkeys (8.9 kg live wt) reared under intensive conditions. The birds were processed on a commercial processing plant using either electrical (E) or gas (G) stunning system. The birds from E group were shackled and electrically stunned with a constant voltage of 44V pulsating DC, 500Hz, for 22 sec (average of 18-20 mA/bird), while G group birds were stunned by CO2 exposure in their transport crates transiting through an underground chamber where birds encountered variable concentrations of carbon dioxide (from 10 to 60% CO2 going from the top to the bottom level, respectively) for 8 min and subsequently shackled (Linco® system). After stunning all turkeys were killed and processed following the same standard procedures. For both E and G group, 16 breasts were boned at 20 min, 6, 8 and 24 h post mortem (n = 128) and the incidence of blood- engorged wing veins and breast blood spots were evaluated. After boning, the samples were immediately analysed for muscle temperature (only 20 min post mortem), pH, R-value, and colour (L*a*b*), while at 24 h post mortem all collected samples were also analysed for pHu, drip loss, cooking yield and Allo-Kramer shear values of cooked meat. The gas stunning resulted in a lower incidence of blood-engorged wing veins (1.6 vs. 14.1%) and blood spots on breast meat (18.8 vs. 31.3%) as well as a lower redness (a*, 2.92 vs. 3.34; P
... The instrument used to perform slaughtering must be extremely sharp to facilitate the quick cutting of the blood vessels. The ensuring rapid drainage of blood causes anoxia and often prevents the bird from regaining consciousness during the subsequent 80 -90 s (BILGILI, 1999). BLACKMORE and DELA-NY, (1988) reported that in order to ensure that a slaughter process is humane, it is important to know the time taken for an animal to become insensible from the slaughtering procedure alone. ...
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Two experiments involving 420 birds were conducted to determine the influence of electrical stunning on meat quality and blood retained by chicken carcasses. The birds used in this study were 40-d-old (Ross 208) broiler chickens, from the same flock, hatched and raised commercially under similar environmental and nutritional conditions and weighing about 2 kg. In the first experiment, eleven treatment groups were set up with twenty mixed-sex birds each. In the second experiment, two hundred birds were allocated to ten groups with twenty male birds each. Birds in both experiments were individually stunned at 0, 23, 33, 38, 43, 48, 53, 58, 63, 103 and 193 Volt (only exp 1). The total blood volumes of the individual broilers were calculated. It was concluded that the applied electrical voltage for stunning significantly affects the rate of bleed out in broilers. Carcass defects were increased with the increasing of the electrical stunning voltages. With increased attention to the humane treatment of food animals during slaughter, the 50 - 63 V AC stun could prove to be more humane if it is combined with an effective method of slaughter that achieved a rapid bleeding. Stunning at 53 V AC for 10 s maximized bleed out to over 50%. Low electrical stunning voltages (0 to 23 V AC) resulted in poor bleeding (40%) and high incidence of carcasses defects that classified as B. High stunning voltages (103 to 193 V AC) sufficient to satisfy birds welfare issues but resulted in other side effects such as physical damage, breast blood spots, red wingtips and broken bones. High stun carcasses were classed as B. Moderate stunning (53 to 63 VAC) seems to be more effective in bleed-out (50%) and resulted in better carcass quality which obtained grade A. Finally, this study confirms that a beating heart is not necessary in order to ensure effective bleed-out. In addition, it is difficult to think of any scientific, religious, economic and humanitarian grounds for removing the last possible drop of blood.
... In commercial poultry processing plants, electrical water bath stunning is commonly applied. In this method, an electrical current is passed through the body and causes direct muscle stimulation [13][14][15]. ...
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With an emphasis on the global meat market and considering the ritual requirements and quality aspects, four types of slaughtering treatments were compared: (1) NSHS (without electrical stunning, halal neck cut, and subsequent bleeding for 180 s), (2) LSHS (electrically stunned at 250 mA for five seconds, halal neck cut, and subsequent bleeding for 180 s), (3) MSHS (electrically stunned at 500 mA for 10 s, halal neck cut, and subsequent bleeding for 180 s), and (4) HSHS (electrically stunned at 1000 mA for 20 s, halal neck cut, and subsequent bleeding for 180 s). Four hundred 36 day-old Ross 308 broiler chickens (body weights of 1.4 to 1.8 kg) were divided into four random groups of 100 birds each (ten replicated pens of ten birds). This study examined the liva- bility, bleeding out, Pectoralis major and Flexor cruris medialis proximate composition, cholesterol content, fatty acid profile and post-mortem pH, microbial loads, and oxidative stability. The livability and bleeding out were higher in NSHS and LSHS than MSHS and HSHS (p < 0.05). The Pectoralis major and Flexor cruris medialis proximate composition, cholesterol content and fatty acid profile, post-mortem pH, and microbial loads were unaffected by the slaughter treatments (p > 0.05), but the oxidative stability of Pectoralis major differed during the eight-day post-mortem period (p < 0.05). The results suggest that for capturing the global meat market, the meat industry can consider NSHS and LSHS because the ritual requirements are fulfilled, and there is no negative impact on the nutritional aspects.
... Con respecto al sistema de aturdimiento, solo se contaba como puntos de referencia con la información que existe a nivel internacional para pollos y pavos, y un trabajo de investigación donde se empleó un aturdimiento eléctrico en codornices (Tserveni Gousi et al., 1999). Así, con base en el estudio de estos autores y en los trabajos de Bilgili (1999) y Gregory (1989) se construyó un sistema, con materiales poco sofisticados, que funciona colocando al ave en un gancho metálico conectado a tierra, logrando así que el animal complete un circuito eléctrico. La corriente alterna es provista por un tablero equipado con breakers de modo que su paso puede ser regulado hasta una tina de acero inoxidable aislada con una capa de fibra de vidrio y que contiene agua. ...
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In order to evaluate the effect of the slaughter age of quail and the electrical stunning on some characteristics of the carcass, an electrical stunning system was designed and implemented with 117 V AC, 17 mA, 60 Hz during 4 s. As a result, appropriate stunning of the animals was achieved, showing the signs of electroplectic shock in the birds, absence of fractures in carcasses and a recovery time between 2 and 3 minutes. Male quails of 28-31, 42-45, and 56-59 days were slaughtered with and without the application of electrical stunning. It was observed that with age there was an increase in live weight (109.8 to 127.9 g), cold carcass yield (73.1 to 75.6%) and weight of the carcass meat (31.0 to 38.4 g) from 28-31 to the 42-45 days, but age did not influence other variables such as carcass water absorption and proportion of meat of the carcass. Results indicate that slaughter of quails is appropriate at 42-45 days, since it enables the producer to obtain profits while satisfying consumer’s expectations, with the application of the electrical stunning to guarantee the animal’s welfare without being detrimental to the characteristics of the carcass.
... Our recent survey (unpublished) of 24 slaughter plants in China showed that 15 of them use MS treatment. The LS method is commonly used in America because poultry are not specifically included in the legislation covering the humane slaughter of livestock and LS stunning has potential to improve meat quality (Bilgili, 1999;Xu et al., 2011). ...
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This study was designed to compare the effects of different stunning systems on the meat quality of broilers. This was done by investigating meat water-holding capacity, meat color, muscle glycogen, and lactate concentrations, as well as blood parameters, low-field nuclear magnetic resonance (NMR) transverse relaxation, and myofibrillar ultrastructures. A total of 160 broilers were divided into 4 treatment groups: a low-voltage stunning (LS) with a constant voltage of 15 V at 750 Hz for 10 s; a midvoltage stunning (MS) with a constant voltage of 50 V at 50 Hz for 10 s; a high-voltage stunning (HS) with a constant voltage of 100 V at 50 Hz for 5 s; and a control group with no stunning (NS). Blood samples were collected immediately after cutting the neck. Pectoralis major muscles were removed from the carcass after chilling and placed in ice. Breast muscle pH, meat color, glycogen, and lactate contents were determined at both 2 and 24 h postmortem. Drip loss, cooking loss, pressing loss, cooked breast meat shear values, low-field NMR, and ultrastructures of myofibrils were determined 24 h postmortem. The NS and MS treatments significantly increased (P < 0.05) blood plasma corticosterone, initial rate of glycolysis, and drip loss, and significantly reduced (P < 0.05) initial muscle pH and shear force values when compared with LS and HS. The results of low-field NMR reflect that NS and MS significantly decreased (P < 0.05) NMR transverse relaxation population 1 (T21) and increased (P < 0.05) NMR transverse relaxation population 2 (T22). The myofibrils of NS and MS samples showed significantly (P < 0.05) longer sarcomere length when compared with the LS and HS samples. The meat color, cooking loss, pressing loss, and final pH were not affected by the stunning methods. This study indicates that NS and MS treatments reduce meat water-holding capacity and decrease meat shear force when compared with LS and HS.
... • Animals developing bruising after hitting gateways and race fittings during passage to pens and restrainers • Pelt-burn in sheep during head-to-back stunning where the rear electrode makes contact on back of neck • Petechial haemorrhages in sheep can be seasonal and related to nutritional factors • DFD in cattle due to tiredness and long term stress, (Gregory, 1998) During electrical stunning blood pressure changes, muscle spasms and convulsions can cause ruptures and haemorrhages in vessels and muscle as well as fractures (Gregory 1998). Various stunning methods and electrical parameters have been reported to have a different effect on pH and Post mortem rigor development in various studies (Devine et al, 1984;Gregory, 1994;Bilgili, 1992;Hillebrand et al, 1996;Bilgili, 1999;Roth et al, 2002;Roth et al, 2003). Postmortem metabolism can be influenced by indirect stimulation by nerves. ...
... Con respecto al sistema de aturdimiento, solo se contaba como puntos de referencia con la información que existe a nivel internacional para pollos y pavos, y un trabajo de investigación donde se empleó un aturdimiento eléctrico en codornices (Tserveni Gousi et al., 1999). Así, con base en el estudio de estos autores y en los trabajos de Bilgili (1999) y Gregory (1989) se construyó un sistema, con materiales poco sofisticados, que funciona colocando al ave en un gancho metálico conectado a tierra, logrando así que el animal complete un circuito eléctrico. La corriente alterna es provista por un tablero equipado con breakers de modo que su paso puede ser regulado hasta una tina de acero inoxidable aislada con una capa de fibra de vidrio y que contiene agua. ...
Article
Full-text available
In order to evaluate the effect of the slaughter age of quail and the electrical stunning on some characteristics of the carcass, an electrical stunning system was designed and implemented with 117 V AC, 17 mA, 60 Hz during 4 s. As a result, appropriate stunning of the animals was achieved, showing the signs of electroplectic shock in the birds, absence of fractures in carcasses and a recovery time between 2 and 3 minutes. Male quails of 28-31, 42-45, and 56-59 days were slaughtered with and without the application of electrical stunning. It was observed that with age there was an increase in live weight (109.8 to 127.9 g), cold carcass yield (73.1 to 75.6%) and weight of the carcass meat (31.0 to 38.4 g) from 28-31 to the 42-45 days, but age did not influence other variables such as carcass water absorption and proportion of meat of the carcass. Results indicate that slaughter of quails is appropriate at 42-45 days, since it enables the producer to obtain profits while satisfying consumer's expectations, with the application of the electrical stunning to guarantee the animal's welfare without being detrimental to the characteristics of the carcass.
... Hamdy et al. (1961) suggested that 90% of all bruises on broilers occur within the last 12 h that the birds are alive and most of them are due to initial steps in slaughter processing, such as stunning. In this context, our results obtained for BUW incidences are in agreement with data reported by other authors who observed that using high voltage currents (over 100 V) resulted in significantly more hemorrhages in the breast (Veerkamp & Vries, 1983) and bruised wing joints (Heath, 1984;Bilgili, 1999). However, Ali et al. (2007) noticed that the application of an alternate current with moderate voltage (53 to 63 V) presented better results on carcass damage. ...
Article
The effect of electrical parameters (intensity and voltage) to obtain an effective water-bath stunning in a commercial poultry slaughterhouse was studied. A total of 390 broilers were randomly divided into six experimental groups according to the intensity (150 and 200 mA) and voltage (51-60, 61-80 and 81-100 V). Statistical analysis showed a significant (p<0.001) effect of electrical parameters on the cloacal reflex since the response rate was 8 s for 96% of broilers. On the other hand, the stunning treatments suppressed the palpebral reflex up to 12 s in 80% of broilers. All stun-treated broilers showed breathing response after 27 s with an average time between 45 and 50 s depending on voltage and intensity of the current. Regarding voltage, the percentage of complete neck cutting increased with the increase of voltage, presenting the highest levels in broilers stunned at 81-100 V (100 and 92.8%, for 150 and 200 mA, respectively). Concerning to intensity, the best results were obtained in broilers stunned at 150 mA, showing mean percentages of 94.83 and 87.30%, for 150 and 200 mA, respectively. The bruises on wings were significantly (p<0.001) affected by voltage, observing the highest values in broilers slaughtered at lower voltages. An opposite trend was observed on bruises under the wings since the lowest voltages showed (p<0.001) lower levels (1.34 and 1.42%, for 150 and 200 mA, respectively). Finally, bruises on dorsal winds and on back were significantly (p<0.001) influenced by intensity level, showing the lowest percentages in broilers stunned at 150 mA.
... Stunning before slaughter can be accomplished using modified atmosphere (MASK), low atmospheric pressure (LAPS), or electrical stunning (ES; Fletcher, 1999). Electrical stunning is the most commonly used method in commercial poultry plants within the United States (Bilgili, 1999;Göksoy et al., 1999). Low atmospheric pressures in the range of 150 to 230 mmHg are created in LAPS to render the broiler hypoxic (Cheek and Cattarazzi, 2010). ...
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Research was conducted to determine the effect of stunning method (low atmosphere pressure, LAPS, and electrical stunning, ES) and deboning time (0.75 and 4 h) on breast meat quality (n = 576, 144 birds per treatment) in a commercial processing plant. Breast meat quality was evaluated through determining pH, Commission Internationale d'Eclairage L*a*b*, cooking yield, shear force, and consumer acceptability. The onset of rigor mortis was more rapid (P < 0.05) in breast meat from LAPS-stunned birds compared with ES-stunned birds, but no differences existed (P > 0.05) among stunning methods with respect to final pH at 24 h. As expected, breast meat that was deboned at 4 h required less shear force (P < 0.05) to cut through the breast than samples that were deboned at 0.75 h postmortem, but no differences existed between breast meat from LAPS or ES broilers that were deboned at the same time postmortem. However, when samples were marinated with 2% NaCl and 0.5% phosphate, there was no difference in Allo-Kramer shear force between ES 4 h and LAPS 4-h samples, but the ES 0.75-h samples had lower shear force values (P < 0.05) than the LAPS 0.75-h samples. On average, the LAPS 4-h treatment had greater overall acceptability ratings (P < 0.05) than other treatments, and the ES and LAPS 4-h treatments had more acceptable (P < 0.05) texture than the ES and LAPS 0.75-h treatments. Cluster analysis revealed that the 2 largest consumer groups liked all chicken breast fillet treatments, but a larger proportion of consumers liked the 4-h LAPS and ES treatments compared with the 0.75-h LAPS and ES treatments. In addition, consumers who rated baked chicken breast as at least moderately acceptable preferred (P < 0.05) the 4-h LAPS samples over the 4-h ES samples. The present study revealed that both the LAPS and ES systems can be successfully used in commercial poultry plants without detrimental breast fillet quality problems with respect to color, texture, and consumer acceptance.
... The instrument used to perform slaughtering must be extremely sharp to facilitate the quick cutting of the blood vessels. The rapid drainage of blood causes anoxia and often prevents birds from regaining consciousness during the subsequent 80 to 90 seconds [17]. ...
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Slaughtering is an unavoidably sensitive issue among Muslim and Jews. This paper gives an outlook on possible detection methods in resolving the dilemma of religious slaughtering status. It will be rather easier to differentiate meat of different animal origins due to the exclusive genetic blueprint. However, in the case of adulteration in slaughtering procedure, the meat was taken from a similar source, thus, complicating the detection process. Therefore, an alternative approach employing proteomics were developed to identify protein expression patterns after external stimulation with electrical treatment. In the slaughtering process, the pain which is triggered by an external stimulus is expected to influence the protein profiles. Therefore, variations in stunning treatments which result in different patterns of protein profiles will pinpoint the specific biomarker for over stunned animals. This will inevitably help to detect adulterations in slaughtering procedure.
... Notwithstanding its short duration, slaughtering is a delicate step in meat production and its mishandling could render livestock production efforts useless (Farouk et al., 2014). Rendering birds unconscious and insensible to pain prior neck cut minimize struggling through a more accurate and speedy slaughtering process (Aberle et al., 2010) without adversely affecting meat quality (Bilgili, 1999;. The application of electrical water bath stunning is a common practice in poultry industry especially in Malaysia. ...
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The study examined the effects of pre-slaughter gas stunning and slaughter without stunning on meat quality and skeletal muscle proteome of broiler chickens. Fifty Cobb broiler chickens were randomly assigned to either a neck cut without pre-slaughter stunning (Halal slaughter) or pre-slaughter gas stunning followed by a neck cut. Samples of Pectoralis major muscle at 7 min, 4 h and 24 h postmortem were analyzed for pH, shear force, color, drip and cooking losses. Proteome profile of the 7 min samples was examined by two-dimensional polyacrylamide gel electrophoresis. Birds subjected to Halal slaughter had higher (P < 0.05) redness than those gas stunned at 4 and 24 h postmortem. Gas-stunned birds had lower (P < 0.05) muscle pH and shear force and higher (P < 0.05) drip and cooking losses compared with those subjected to Halal slaughter throughout postmortem storage. Gas stunning up-regulated (P < 0.05) the expression of beta-enolase, pyruvate kinase and creatine kinase compared with Halal slaughter. Results indicate that pre-slaughter gas stunning hastened postmortem energy metabolism and had detrimental effects on the water holding capacity and redness of broiler breast muscles.
... A constant electrical current stunner measures the impedance of the birds and adjusts the voltage in order to deliver the pre-set minimum electrical current to the birds (Sparrey et al., 1993;Wilkins et al., 1999). Although this is beneficial in terms of animal welfare, this system was not being used in any of the visited slaughterhouses, probably because of the high processing speed that makes it difficult to isolate each bird long enough to deliver the pre-set electrical current, as also previously shown by Bilgili (1999). ...
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Data on slaughter and stunning protocols in Belgian poultry abattoirs were collected, and subsequently the survival rate after electrical waterbath stunning in 1,400 animals across 7 selected slaughterhouses was determined. The majority of the abattoirs applied electrical waterbath stunning (72%), whereas the other methods were gas stunning (13%), head-only stunning (6%), and dry stunning (3%). In 6% of the slaughterhouses, the birds were killed without previous stunning, according to religious rites (i.e., ritual or religious slaughter). Although religious slaughter occurred in a substantial number of abattoirs, the customers of the majority of them allowed stunning, provided the animals were not killed by the stunning procedure. Substantial variation both in electrical waterbath devices and technical settings (electrical current type, wave type, voltage, frequency) combinations was observed. These settings did not only differ between slaughterhouses, but also between subsequent visits to the same slaughterhouse. Despite this variation, all systems comprised a constant voltage, multiple bird stunner. The minimum average electrical current that every chicken should receive at a certain frequency, as stated by the European Regulation No 1099/2009, was not achieved for each animal monitored due to the bird's characteristics and the different applied stunning settings, with the exception of all ISA laying hens and broiler breeders in one particular slaughterhouse. The survival rate ranged from 96.0 to 100%, 97.0 to 100%, 68.0%, 72.0 to 85.1%, and 5.6 to 52.4% in 5-wk-old broilers, 6-wk-old broilers, LSL laying hens, ISA laying hens, and broiler breeders, respectively. Monitoring of unconsciousness after passing through the waterbath was not always performed and when it was, there was no uniformity in the applied criteria. It was concluded that a large variation in slaughter and stunning practices exists among slaughterhouses in Belgium. Further research should explore the effect of the different settings on inducing a successful stun and on carcass quality, and assess if the observed variation also exists in other EU member states.
... Due to strong skeletal muscle contractions caused by the electrical current, this has been associated with meat quality defects such as breast muscle haemorrhaging and broken bones WILKINS, 1989, 1990). In the US low voltage stunning is a common method (BILGILI, 1999). A step-up stunner of SIMMONS ENGINEERING COMPANY consists of two stunning phases: In Phase I a high frequency pulsed DC with a very low voltage of 10-15 V is applied, immediately followed by Phase II with a sine wave AC of 50 Hz. ...
Article
Stunning efficiency of male and female broiler chickens was analysed in response to the two-phase Simmons step-up stunner. In Phase I, a pulsed DC of 550 Hz is applied in a shallow waterbath. This is immediately followed by Phase II, consisting of a metal plate with sine wave AC of 50 Hz. 120 male and female broiler chickens were randomly allocated to six stunning groups with 10 males and 10 females per group. In Phase I a voltage of 12 or 15 V was applied followed by 40, 50 or 60 V in Phase II. Stunning time was 10 and 5 s in Phase I and II respectively. The rms current per bird was recorded. To assess stunning efficiency the electroencephalogram (EEG) was recorded for 120 s post-stun. Simultaneously the occurrence of spontaneous eye lid blinking, breathing and wing flapping was assessed. The corneal reflex was tested every 20 s. The reduction of brain power in two frequency bands (2-30 Hz and 13-30 Hz) to less than 10% of the pre-stun level was analysed as indicator for adequate stunning. Female broilers showed a significantly lower rms stunning current as a result of higher electrical resistance. Phase II showed the biggest impact on stunning efficiency. Increasing voltage improved the stunning effect, but none of the analysed treatments induced unconsciousness in at least 90% of the animals. Voltage settings of more than 60 V AC in Phase II must therefore be applied. The majority of animals recovered from stunning in all groups. The occurrence of physical reflexes was suppressed in animals that were considered sensitive in the EEG analysis. Assessment of these reflexes for the evaluation of stunning efficiency can therefore not be recommended for this stunning method. No animal showed tonic-clonic convulsions following stunning and the level of severe wing flapping was very low in all groups. Meat quality advantages of this stunning method can therefore be expected, but this must be assessed in a separate study. It must be investigated if this effect can be maintained with higher voltage settings to ensure adequate stunning efficiency.
... Raj et al. (2001), for example, found a significantly lower occurrence of broken bones and breast meat hemorrhages in broilers stunned with a sine wave AC of 1,500 Hz compared to 50 Hz. A significant reduction of ventricular fibrillation and cardiac arrest was also observed with higher frequencies (Bilgili, 1999). ...
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The effects of different amounts and frequencies of stunning sine wave alternating current were investigated under field conditions. Seven hundred and fifty broilers were stunned in an electrical water bath with an average root mean square (RMS) current of 150, 200, and 250 mA and frequencies of 200, 400, 600, 800, and 1,200 Hz. The occurrence of corneal reflex, spontaneous eye blinking, and a positive response to a painful stimulus were monitored and recorded immediately after the stunning and at 20 s post-stun. Statistical analysis showed that the electrical stunning frequency (P = 0.0004), the stunning RMS current (P < 0.0001) and the interaction between stunning frequency and stunning current (P < 0.0001) had a significant effect on the occurrence of animals experiencing an abolition of corneal reflex at 20 s post-stun. At a current of 150 mA, the probability of a successful stun was over 90% at 200 Hz, approximately 40% at 400 Hz, and below 5% for frequencies greater than 600 Hz. So, stunning at frequencies greater than 600 Hz cannot be recommended when a RMS current of 150 mA is applied. The maximum probability of a successful stun was obtained for a current level of 200 mA at 400 Hz and for a current level of 250 mA at 400 and 600 Hz, whereas the stunning treatments at 1,200 Hz provided the lowest probability of a successful stun. Assessment of spontaneous eye blinking and responses to comb pinching confirmed the indications coming from the analysis of corneal reflex.
... The instrument used to perform slaughtering must be extremely sharp to facilitate the quick cutting of the blood vessels. The rapid drainage of blood causes anoxia and often prevents birds from regaining consciousness during the subsequent 80 to 90 seconds [17]. ...
Article
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Enzymatic reactions involving lipases as catalyst in transesterification can be an excellent alternative to produce environmental-friendly biodiesel. In this study, lipase extracted from Cocoa Pod Husk (CPH) and immobilized through cross linked enzyme aggregate (CLEA) technology catalysed the transesterification of Jatropha curcas oil successfully. Face centered central composite design (FCCCD) under response surface methodology (RSM) was used to get the optimal conditions of 3% (w/w) enzyme loading, 4 h reaction time and 1:6 oil/ethanol ratio to achieve the highest conversion of free fatty acid and glycerides into biodiesel (93%). The reusability of CLEA-lipase was tested and after seven cycles, the conversion percentage reduced to 58%. The results revealed that CLEA lipase from CPH is a potential catalyst for biodiesel production.
... In this way, the electric current is passed through the bird, from head-to-legs. The water bath is electrically live so that each bird is stunned the moment it makes contact with water (Bilgili 1999;Raj 2003). Scientists have long been searching for alternatives to electro-narcosis (ie electrical stunning). ...
Article
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This study was performed to identify whether non-focal transcranial magnetic stimulation (TMS) with an adapted coil for broilers has the potential for use as a non-invasive stunning method for broilers. Application of the TMS probe resulted in dominance of theta and delta waves and appearance of spikes in the electroencephalogram (EEG) after stimulation. Correlation dimension (CD) analyses of the EEG signals recorded prior to and following the application of TMS suggested that the birds might be unconscious for approximately 15 to 20 s assuming that a reduction in CD to 60% of the baseline value indicates unconsciousness. Other observations included loss of behavioural arousal or muscle tone (muscle flaccidity), and irregular heart rate after TMS. It can be suggested that TMS has the potential to be developed as a stunning method in the future. The technique, evaluated using small number of broilers in this study, requires further improvement and the use of a power supply optimised in future research. Transcranial magnetic stimulation of the brain has potential for application as a non-invasive stunning method for broilers, which could be acceptable to some religious groups opposed to the use of established or conventional stunning methods.
... Insufficient currents may physically immobilize the broiler, but cannot prevent the perception of pain, stress, or discomfort by the animal. Thus, if bleeding does not occur rapidly, broilers may recover consciousness (Bilgili, 1999). ...
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The objective of this study was to evaluate the efficiency of electrical stunning by electronarcosis in a medium-size poultry processing plant located in southern Brazil. The current measurement of this type of stunning is presented, and then improvements to this method are proposed. Data were collected for 90 days. A quality indicator was proposed: the Stunning Severity Index (SSI), which includes elements of Statistical Process Control (SPC) using a p-chart (proportion chart) and measures. This index comprises the variables “wing-flapping,” “arched head,” and “rhythmic breathing.” Using the proposed index, 5% of the birds, on average, presented inefficient stunning symptoms.
... Regardless of differences in cultural, religious or regulatory practices directing the slaughter of poultry, the application of electrical stunning principles in slaughter plants and the effects of stun killing on end-product quality are of concern to meat processors worldwide (1). In Europe, where applying electrical stunning with a minimum current of 100 mA with frequencies changing proportionally with the magnitude of the current, it is a legal obligation to irreversibly and immediately stun the bird according to the Council of the European Union regulation of 24 September 2009 (EC Regulation No: 1099/2009) on the protection of animals at the time of killing (Official Journal of the European Union 2009). ...
Article
This study assessed the effects of electrical water bath stunning process on the meat quality of broilers processed in a commercial slaughterhouse in Turkey. Twenty-five live broilers were electrically stunned while twenty-five live broilers were not. Electrical stunning (30 V, 30 mA, 220 Hz alternative current) was applied for 17 seconds (s) in a water bath. The percentage of the blood loss was determined at 150 s after slaughter. The electrical stunning significantly decreased the percentage of the blood loss in broilers (P≤0.01). Conversely, higher pH values were observed at 15 min and 24 h postmortem (PM) in muscle samples from broilers slaughtered following stunning compared to un-stunned controls (P≤0.01). Electrical stunning had no significant effect on L* a* and b* colour values (P≥0.05). The Water Holding Capacity (WHC) of meat taken from stunned broilers was significantly higher than controls (P≤0.01). Texture analysis revealed greater toughness and firmness values in the meat of stunned broilers (P≥0.05).
... Regardless of differences in cultural, religious or regulatory practices directing the slaughter of poultry, the application of electrical stunning principles in slaughter plants and the effects of stun killing on end-product quality are of concern to meat processors worldwide (1). In Europe, where applying electrical stunning with a minimum current of 100 mA with frequencies changing proportionally with the magnitude of the current, it is a legal obligation to irreversibly and immediately stun the bird according to the Council of the European Union regulation of 24 September 2009 (EC Regulation No: 1099/2009) on the protection of animals at the time of killing (Official Journal of the European Union 2009). ...
Article
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This study assessed the effects of electrical water bath stunning process on the meat quality of broilers processed in a commercial slaughterhouse in Turkey. Twenty-five live broilers were electrically stunned while twenty-five live broilers were not. Electrical stunning (30 V, 30 mA, 220 Hz alternative current) was applied for 17 seconds (s) in a water bath. The percentage of the blood loss was determined at 150 s after slaughter. The electrical stunning significantly decreased the percentage of the blood loss in broilers (P≤0.01). Conversely, higher pH values were observed at 15 min and 24 h postmortem (PM) in muscle samples from broilers slaughtered following stunning compared to un-stunned controls (P≤0.01). Electrical stunning had no significant effect on L* a* and b * colour values (P≥0.05). The Water Holding Capacity (WHC) of meat taken from stunned broilers was significantly higher than controls (P≤0.01). Texture analysis revealed greater toughness and firmness values in the meat of stunned broilers (P≥0.05).
Chapter
Introduction Characteristics of a poultry carcass Factors affecting poultry carcass quality Cutting and yield of poultry carcasses Poultry carcass grading References
Chapter
Introduction Poultry-slaughtering plants Operations Equipment and machinery References References
Chapter
In most of the developed countries, excluding the United States of America, it is a statutory requirement that all animals including poultry slaughtered for human consumption are rendered immediately unconscious (stunning) and they remain so until death supervenes through blood loss (slaughter). The duration of unconsciousness induced by a stunning procedure must be longer than the sum of time that lapses between the end of stun and neck cutting and the time to onset of death following neck cutting. Since the effect of a stunning method is momentary, the onus of preventing resumption of consciousness thereafter relies on the efficiency of slaughter procedure (bleeding out); i.e. the prompt and accurate severance of blood vessels (neck cutting) supplying oxygenated blood to the brain. Some stunning procedures are therefore purposefully applied to induce humane death (e.g. killing with argon or nitrogen-induced anoxia), rather than mere unconsciousness, and other methods lead to death due to structural damage to the brain (e.g. penetrating captive bolts).
Conference Paper
This paper presents an intelligent poultry stunner with parameter auto-tuning feature for improving carcass quality and animal welfare. In this stunner system, an active clamp flyback converter is used to increase conversion efficiency, and a dither voltage generator realized with a half-bridge inverter is adopted to fast breakdown the skin impedance of the poultry which can reduce poultry stress and improve carcass quality during stunning interval. To simplify the circuit structure of the proposed stunner, the switches in the active clamp flyback converter and the half-bridge inverter are integrated with the synchronous switch technique. With this approach, it can achieve higher conversion efficiency, less component count, lighter weight and smaller size. Compared with the one without switch integration, the proposed can raise efficiency of 5 % under full load condition. Under a fixed frequency of 400 Hz, its output voltage can vary from 60 V to 140 V and its duty ratio is from 0.3 to 0.7. Performance measurements from a prototype have verified the parameter auto-tuning feature and feasibility of the overall system design. The designed system has contributed a lot to improve animal welfare and has attracted much attention
Conference Paper
This paper proposes an interleaving forward converters with single-capacitor turn-off snubber associated with a full-bridge inverter for poultry stunning applications. The proposed converters can use the single-capacitor snubber to smooth out switch turn-off transient for reducing turn-off loss. As compared with the counterparts of the conventional converter topologies, the proposed converters have the merits of less component counts, higher efficiency over a certain load range, smaller size, and they are easier to implement. In the paper, mechanism of the stunning poultry is first reviewed and then, the desired stunning voltage waveforms and the stunning parameters with auto-tuning algorithm are proposed. Performance measurements from a prototype have verified the stunning parameters with auto-tuning algorithm and feasibility of the overall system design
Conference Paper
This paper presents an intelligent poultry stunner for improving carcass quality and animal welfare. In the stunner system, an active clamp circuit is used in a forward converter to reset the magnetizing energy and to recover leakage energy trapped in the transformer, increasing its conversion efficiency. In addition, a dither generator realized with a half-bridge inverter is adopted to fast breakdown the skin impedance of the poultry with which can reduce poultry stress and improve carcass quality during stunning interval. To simplify the circuit of the proposed stunner system, switches in the forward converter and the half-bridge inverter are integrated with the synchronous switch technique. With this approach, the proposed stunner system can achieve a higher conversion efficiency, less component counts, lighter weight and smaller size. Compared with the one without switch integration, the proposed one can raise efficiency of 5% under mil load condition. Under a fixed frequency of 400 Hz, its output voltage can vary from 60 V to 140 V and its duty ratio is from 0.3 to 0.7. Performance measurements from a prototype have verified the feasibility of the overall system design. The designed system has contributed a lot to improve animal welfare and has attracted much attention
Conference Paper
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Kesim öncesi etlik piliçlerin sersemletilmesi, piliçlerin sadece bilinçsiz bırakılması için değil aynı zamanda kan kaybını, tüy yolmayı ve et kalitesini de etkilediğinden önemli bir uygulamadır. Kesim öncesi etlik piliçlerin elektrik akımıyla bilinçsiz hale getirilmesinde yaygın olarak kare dalga tipine ait akım, frekans ve uygulama süresinin kombinasyonları kullanılmaktadır. Bu araştırma, kesim öncesi etlik piliçlerin 120mA’lik AC ve pDC akımın kare ve chirp dalga tiplerinde, 50 (düşük) ve 400 Hz’lik (yüksek) frekanslarda elektrik akımına maruz bırakılmasının, bazı refah parametreleri ve karkas kusurları üzerindeki etkilerini incelemek için gerçekleştirilmiştir. Çalışma her birinde ortalama ağırlığı 2628±333g olan, 44 günlük yaşta 10 piliç (5♀: 5♂) bulunan toplam 8 deneme grubu ile yürütülmüştür. Deneme gruplarında yer alan piliçlerde elektrik uygulamalarına bağlı solunumunun durması sırasında ortaya çıkan ayak ve kanat titreme tepkileri, kanat çırpma davranışları incelenmiş ve devamında kesilmişlerdir. Kesim işleminden sonra, akan kan miktarı ve karkas kusurlar saptamıştır. Kesim öncesi piliçlere uygulanan elektrik akımının, ayak-kanat titremeleri, kanat çırpma tepkisi ve kanattaki spot kanama miktarı üzerindeki etkileri önemli bulunmuştur (P<0.05). AC akımın kare ve chirp dalga tipinin 400 Hz’lik frekans düzeyinde piliçlerdeki bilinçsizlik etkinliğinin, uygulanan diğer elektrik değerlerine göre daha yüksek olduğu saptanmıştır (P<0.05). Kare dalga tipi piliçlerin göğüs, but ve tüy kökünde, chirp dalga tipi ise kanatlarda daha fazla kanamalara neden olmuştur. Chirp dalga tipinin incelenen bazı parametreler üzerinde daha olumlu sonuçlar ortaya koyduğu anlaşılmıştır
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The effects of ante-mortem stressors such as stunning, struggling, environmental temperature and feed withdrawal on the biochemical changes of broiler breast muscle are assessed in relation to post-mortem biochemical changes and the subsequent tenderness of broiler breast meat. The findings of investigations concerned with broiler meat are presented alongside more fundamental studies addressing such aspects as Ca2+ release and sequestration, endocrine changes during periods of stress and the role of fatty acids as regulators of membrane bound channels. An attempt is made to assimilate the pertinent facts associated with this topic and to give directions for future research. It is concluded, however, that, whilst tenderness in meat is often associated with a loss of ATP, glycogen breakdown and lactic acid accumulation within muscles, current data are insufficient to enable a definitive decision to be made as to which have adverse effects on broiler meat tenderness.
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Poultry are stunned immediately prior to slaughter to facilitate automated processing, to minimize the subsequent death struggle and thereby minimize carcass damage and down grades, and to render the bird unconscious and incapable of perceiving pain. A stunning method for slaughter should be considered ethical if the following criteria are attained. 1) Stunning results in a rapid onset of unconsciousness within a minimal time and with a minimal perception of pain. 2) The duration of the stun induced unconsciousness persists until death intervenes. 3) There is a near zero occurrence of "under stunned" and unstunned individuals. Stunning by definition must permit the stunned animals to recover consciousness. Electrically stunned broilers should recover consciousness to the level of regaining the ability to maintain an erect posture within 120 seconds following the stun. However, electrical stunning and exsanguination (bleeding) are integral steps in the slaughter of poultry and should be evaluated together in the progression to death. In contrast, poultry subjected to electrocution or gas stunning protocols are characterized as stun-kill because by design these birds will not regain consciousness at any time point even in the absence of exsanguination. There are distinct advantages and challenges to both electrical and gas stunning protocols which will be described and discussed.
Research
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report multibird electrical waterbath stunning of poultry, description of stunning parameters
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Halal slaughtered chicken is a major concern among Muslims. Currently, stunning methods has been adopted worldwide aiming at maximizing production. However, stunning treatment which is not in compliance with the Islamic teaching will end up with unlawful chickens for Muslim consumption. In this study, proteomics methods have been used to identify potential biomarkers for the effects of electrical stimulation on the protein profiles of chicken’s brain. The protein profiles were constructed in order to detect any differences in the protein expression and modifications. The electrical stimulation was conducted with different current and voltage. The different voltages studied were 10, 40, and 70 V while the values for current studied were 0.25, 0.5, and 0.75 A. The profiles from these electrically stimulated chicken were compared to the 0 A, 0 V non-stunned sample. After the proteomics analyses using 2D Platinum ImageMaster 6.0 and matrix-assisted laser desorption/ionization with time-of-flight mass spectrometry (MALDI-TOF) identification, aldolase C, actin-related protein 2 homolog (ARP2), and enolase 1 were identified to be positively present in the brain sample of electrically stimulated samples. The over expression of the proteins were further confirmed at the transcriptional level by real-time PCR. Results from MALDI-TOF and real-time PCR were in agreement. Therefore, this identification of biomarkers for electrically stimulated chicken’s brain provides a novel approach on differentiating the stunned chickens from the non-stunned ones.
Thesis
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Improved animal welfare during industrial slaughtering of fish is the aim of the scientific work presented in this thesis. The thesis is based on four publications that cover different stages of an automated industrial slaughtering line for fish. The publications are presented in a similar order to those on a slaughtering line. The results from paper I are relevant for all types of pre-chilling of fish before slaughtering and reveal the physiological effects of live chilling in Atlantic salmon (Salmo salar). Chilling of fish is commonly used in the industry, both during transportation and processing of the fish in the slaughtering house. The publication is based on two experiments where the first experiment included fish (mean weight 840 g) acclimatized to a water temperature of either 16, 8, or 4°C and which were directly transferred horizontally or vertically (9 combinations) to temperatures of 16, 8, 4, or 0°C using a dip net. In the second experiment, fish (mean weight 916 g) acclimatized to 16°C were exposed to four temperature-drop regimes (no physical handling): 16–4°C (over 5 h), 16–4°C (over 1 h), 16–0°C (over 5 h), and 16–0°C (over 1 h). Physical transfers in the first trial, i.e., temperature drops, resulted in immediate (1 h) increases in blood lactate concentrations at all three temperatures, but levels were significantly reduced and close to pretransfer levels after 6 h. Horizontal transfers, i.e. 16–16°C, 8–8°C, and 4–4°C, resulted in similar increases and were not significantly different from the groups exposed to temperature drops. The most severe vertical transfer (16-0°C) resulted in a swift loss of equilibrium and eventually death. In experiment No.2, temperature drops from 16 to 4°C and from 16 to 0°C over a period of one or 5 h, without physically handling the fish, resulted in no significant increases in any of the measured parameters 1 h post-transfer, except in the 16–0°C (1 h) group. The latter experienced a significant increase in blood sodium, glucose, lactate and cortisol levels compared to all other groups. The results suggest that salmon are capable of tolerating relatively steep temperature drops without any significant negative effects on blood stress parameters and that physical stress from gentle handling overrides the effect of thermal insults, which is important for the slaughtering procedure. The overall objective of the study in paper II was to find the optimal configurations for industrial percussive and electrical stunning by evaluating the methods under laboratory conditions. In an automated slaughtering line electrical and percussive stunning are common methods used to ensure unconsciousness, which is critical for fish welfare, before bleed out. The work described in this publication defines the settings, especially voltage and air pressure, needed for efficiently rendering the fish unconscious and also to verify the effect of the stunning machines. Evidence of unconsciousness and insensibility of Atlantic salmon was provided on the electroencephalogram (EEG) by the appearance of slow waves and spikes, followed by a strong depression in electrical activity. This phenomenon was observed in 17 salmon after percussive stunning using an air pressure of 8.1 to 10 bars, whilst 8 fish were considered conscious at pressures below 8.1 bars, although some were seemingly unconscious in behavior. Consequences were a haemorrhage in the brain cavity in 15 out of 17 fish, broken upper or lower jaws in 9 fish and eye burst in 8 fish. A general epileptiform insult (unconscious and insensible) was obtained by delivering a voltage, consisting of a direct current (DC) coupled with 100 Hz alternating current (AC) with a peak value of ≈112 volt (V), head to body, for approximately 0.5 s. The total duration of the insult was 62±44 s (mean±SD; n=25) which was followed by minimal brain activity in 19 fish. The heart rate was 20±7 beats/min prior to stunning. After stunning, the electrocardiogram (ECG) revealed fibrillation for 22±15 s and became irregular and showed extrasystolae (ventrical contraction) afterwards. Exposing the salmon for 5 s with electricity followed by a gill cut resulted in 1 out of 3 fish temporarily recovering after 3 min. Haemorrhages were not observed in the fillets. Average current for head to body electrical dry stunning was 668 milliampere (mA) root mean square (RMS) with an average stunning voltage of 107.9 Vrms. Electrical head to body stunning can be recommended when using coupled AC and DC current of 668 mArms and ≈107 Vrms. The salmon can be stunned in approximately 0.5 s. However, the experiment concluded that a correct bleeding procedure should be developed. For percussive stunning it was concluded that if sufficient force is used the fish will be rendered unconscious and insensible, however this resulted in damage to the carcass, whereas a combined AC and DC signal is recommended for dry electrical head to body stunning. The objective of paper III was to verify the optimal AC frequency range to be used during industrial electro stunning, i.e. electronarcosis, of Atlantic salmon by investigating the electrical impedance spectra of the combined fish and electro stunning device entity. This is an important task since the frequency of the electrical signals is crucial to the electro stunner’s effect. The electrical impedance and associated phase shift was measured in the frequency range 40 Hz to 1.0 MHz for individual fish (n = 11) placed in a regular electrical stunner. The results of the experiment showed that the average overall impedance of the combined fish and electrical stunning device increases with frequency from 40 to 60 Hz before leveling out in the range from 60 to 800 Hz. Thereafter the impedance decreases to a negligible value at 1 MHz. Measurements on impedance and phase angle showed that the highest average electrical impedance appeared at 100 Hz. Furthermore, there were individual peak impedance variations between 70 and 100 Hz. In all fish measured, the impedance at 900 Hz was observed to be lower than that at adjacent frequencies. Due to average measured impedance values and the expected influence of the alpha dispersions on the cell surface, as reported in previous research, it was concluded that the optimal AC frequency range for electro stunning of the Atlantic salmon brain is 70 to 100 Hz. The aim of paper IV was to understand the importance of electrical signal frequency spectrum on stunning, recovery and inflicting injuries. Hemorrhaging in the filet, caused by broken backbones, has been a quality problem for the industry when electro stunning is used to render the fish unconsciousness. The paper also shows the effect of chilling during bleed out. In this article Atlantic salmon were exposed for 5 seconds to either 217 Vrms, 50 Hz, AC or 107 Vrms coupled AC+DC at 200Hz, with and without a high frequency spectrum. Post stun the fish were placed back into water, either at ambient seawater temperature (10.4 °C) or cold water (-1.3 °C), to investigate recovery or mortality. The results showed that a high frequency spectrum, but low amplitude prevented the muscles from contracting and causing spinal injuries and hemorrhaging, for all individuals. Injury rates of 14 and 18% was observed when using electrical signals containing only low frequencies of 200 Hz AC+DC and 50 Hz, AC. The high frequency spectrum also reduced the stimulation of the brain as fish recovered faster with no mortality. Adding a cold shock post stunning delayed or prevented recovery of all groups within the time span required to kill the fish by exsanguination. Papers III and IV will potentially have relevance for other disciplines, such as medicine, where electroshock and electronarcosis are used.
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Pre-slaughter stress can result in variations in the glycogen storage and metabolic changes of muscle, responsible for quality poultry meat. Aim of this study was to investigate, as preslaughter stress markers and quality meat, physicochemical (pH), biochemical (muscle glycogen content), and chemical (super oxides free radicals) parameters. The carcass quality, as incidence of individual carcass defects, also was evaluate. A number of 20 broilers was processed with two different electrical stunning: high (250 Hz; 640 mA; 60V) (Lot C or control) and low (150 Hz; 360 mA; 60 V) (Lot A) frequency and intensity, using sinusoidal alternating current. As preliminary results, the use of low frequency and intensity induced faster pH decline post mortem and adequate acidification of pH at 3 hours (6.49 Lot C; 6.37 Lot A), better muscle glycogen reserve (0.770 μl/50mL Lot C; 1.497μl/50mL Lot A), and lightly more rapid muscle oxidation (IDF: 0.109 Lot C; 0.122 Lot A), (FOX: 0.131 MeqO2/kg Lot C; 0.140 MeqO2/kg Lot A). The incidence of individual carcass defects sufficient to cause downgrading or rejection, both in Lot C and Lot A, was generally low. In a multidisciplinary approach, to assess animal welfare and quality poultry meat, additional and feasible parameters should be implemented. Monitoring of pH, muscle glycogen reserve and superoxide free radical production measurements might be markers easier to use, routinely, in practice at abattoir. Further studies are needed to evaluate the usefulness of these parameters.
Conference Paper
This paper presents a high step-up converter associated with a full-bridge inverter for livestock stunning applications. The proposed converter adopts a two stage converter and uses partial energy processing to reduce voltage stress and switching loss and then, its switches are operated in a complementary manner to reduce component counts and circuit structure complexity. To further improve its conversion efficiency, the proposed soft-switching converter is formed by introducing coupled inductors to the high step-up converter, which can achieve zero-voltage switching at turn-on transition. Compared with the conventional two-stage step-up converter and that with the switch integration, the proposed converter can improve conversion efficiency of 6~8% over that with two-stage hard switching under full load condition, and can reduce cost of that with the switch integration. In this research, the output voltage waveforms generated from the converter and inverter are with frequency varying from 50 Hz to 800 Hz, amplitude varying from zero to its breakdown voltage, as high as 200 V, and duty ratio changing from 0.3 to 0.7. Performance measurements from a prototype have verified the feasibility of the overall system design
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A variety of possible electrical circuits can be fabricated to stun poultry in processing plants. At the present time a lack of uniformity in terminology exists when describing the electrical features of stunners. Electrical output from several stunners is described including: AC, 60 Hz; AC, variable frequency; and pulsed DC. In addition sine wave and rectangular wave outputs are compared. When measuring the voltage output of sinusoidal and full-wave rectified sinusoidal waveforms, the average value is .63 6 times the peak value and the effective value is .707 times the peak value. For half wave rectified sinusoidal waveforms, the effective value is 0.50 times the peak value and the average is 0.318 times the peak value. For rectangular AC waveforms, with no off time, the peak, average, and effective values are all equal. A procedure is described for determining the output of a given stunner within a poultry processing plant. Two instruments are required, a multimeter and a cathode ray oscilloscope. The procedure includes an accurate description of the waveform output and a direct measure of the peak, average, and effective voltage used to stun poultry.
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Three electrical circuits were utilized to stun male broilers prior to the slaughter process. Before and after stunning, four physiological variables were measured: blood pressure, brain waves, and heart and respiratory rates. Based upon maximal bleed-out, the circuits were rated in the following order (maximal to minimal percent bleed-out): high frequency (HF), alternating current (AC), and direct current (DC). An attempt was made to correlate maximal bleed-out with the rate of change in heart rate and blood pressure following stunning for each electrical circuit. No correlation was found. It is suggested that the distribution of blood after stunning may be a more significant factor than the effect of a stun on heart rate and blood pressure. Perhaps both the high frequency and AC circuits effect better bleed-out by shunting more blood from peripheral regions to the viscera. Data suggest that the current industry practice of allowing a 10—15 sec. time interval between stunning and the severance of neck blood vessels is a reasonable one, in that it allows heart rate to return to normal levels prior to venesection. Brain waves were monitored before and after electrical stunning. In addition, simple sensory stimuli tests were conducted in an attempt to ascertain the humaneness of the slaughter process. The sharp decrease in brain activity following stunning and lack of response by broilers to painful stimuli suggest that it is a humane practice to electrically stun broilers as the initial step of processing poultry.
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IN PROCESSING poultry for market, the total and relative amount of blood lost through bleeding has always been of interest from the economic standpoint as well as with respect to the appearance of the dressed poultry. Since a large percentage of the blood of the chicken’s body is located in the small veins and capillaries, much of the blood remains in the body of the bird after death. This blood is present in the carcass of the bird when consumed, the larger blood vessels appearing as black strings. The accepted value for the loss of blood and feathers is 10 to 11 percent of the body weight. The loss due to blood alone is very seldom separated from total loss. Vernon (1923), quoting U.S.D.A. Bulletin 1052, shows a loss of 3.3 to 4.0 percent due to blood for hens and broilers, respectively. Mitchell, Card, and Hamilton (1926) report similar results . . .
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BIRDS incompletely bled during killing operations are often unacceptable to consumers. Blood trapped in the small blood vessels under the skin, and particularly in the larger veins and arteries in the wings, make the birds unattractive. Good bleeding has come to mean a step toward good quality. In commercial operations thorough bleeding within a very limited period of time is often difficult. It would thus seem that attention should be directed toward methods of draining more blood from the birds in this time interval. Latimer and Pederson (1923) cited Zaitschek’s studies to show that when the jugular vein of chickens whose average live weight was 1096.8±12.3 gm. was severed, they lost 3.8 percent of the average live weight as blood. Turner (1948) found that decapitated White Leghorn hens varying in weight from 1803 gms. to 2043 gms. lost from 3.2 to 2.3 percent of their live weight as blood. The . . .
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INTRODUCTION INTEREST in the removal of blood from animals which are to serve as food antedates the birth of Christ. Moses, among others, prescribed a ritual in order to obtain maximum blood loss when slaughtering animals. Orthodox Jews presently advocate that blood vessels be cut away from the forequarters and hindquarters of larger animals to further ensure adequate blood removal. These customs stem from the precept forbidding the consumption of blood. Some of the rituals of slaughter have persisted through the centuries while others have fallen victim to the expediency of newer techniques. Today the most economical slaughter technique, one that reduces time, labor, or product waste is likely to be adopted by processors as long as the volume of blood lost by the animal is considered adequate. A chicken carcass is considered adequately bled if it does not exhibit redness on the skin surface, engorgement of the visceral blood . . .
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Electrical stunning continues to be the method of choice for immobilizing broilers prior to slaughter. Recent research as well as personal observations in commercial broiler processing plants indicate a rather broad spectrum of ideas, concepts and approaches to stunning broilers with electrical currents. Basic concepts of electricity, electrical circuits and the physiology of electrical stunning are reviewed in parallel with current research data. Maintenance of humane slaughter conditions and carcass quality attributes of broilers require integration and application of this knowledge in modern-day processing plants.
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This study was designed to compare tenderness (shear force) and post-mortem metabolism at time of boning (R value) of broiler breast fillets harvested from a total of 200 electrically stimulated carcasses (840 V, 340 mA, pulsed 2 s on, 1 s off for 15 s) and 200 nonstimulated (control) carcasses at various times post-mortem up to 240 min. As on-carcass aging time was increased prior to fillet harvesting, shear force values decreased for fillets from both electrically stimulated and nonstimulated carcasses. However, regression analysis of the data indicated that fillets harvested 100 min post-mortem from electrically stimulated carcasses were as tender as fillets harvested at 240 min post-mortem from nonstimulated carcasses. For those processors currently holding broiler carcasses for 3 to 4 h after chilling prior to boning, electrical stimulation would provide a decrease of approximately 60% in the holding time to reach tenderness levels similar to those attained without electrical stimulation. Electrical stimulation did not have a significant effect on the rate of post-mortem metabolism as measured by R value.
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The Food Safety and Inspection Service (FSIS) conducted a 1992 telephone/FAX survey of all poultry slaughter establishments in the United States to determine the types and prevalence of stunning practices for each poultry class presently in use by the poultry industry. The survey revealed that electrical stunning was used in slaughtering greater than 90% of all birds except light fowl and geese. Low voltage-type electrical stunning devices (10 to 25 volts) were used in 216 of the 329 poultry slaughter plants, while 63 plants used electrical stunners set at a range of other voltages and amperages with unspecified waveforms and frequencies. Further studies monitoring voltage, amperage, and waveforms of electricity concurrent with somatosensory-evoked potentials are needed to determine the adequacy of electrical stunning as a humane practice.
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A study was conducted to determine the influence of electrical stimulation (50,200, or 350 V ac) on biochemical and textural changes in broiler breast muscle. Sixty-four broilers were stunned (50 V ac) prior to kill, and all but a control group were pulse stimulated during bleeding. After processing, carcasses were held in 10-C water for 1 h, then in 2-C ice/water slush for 1 h prior to muscle removal at 2 h post-mortem (PM). Bagged samples were held at 2 C for 24 h, then cooked. The pH, R value (ratio of adenine nucleotides to inosine nucleotides), cook yield, fluids and solids lost (F&S), and objective texture were measured. In addition, 16 broilers processed in the same manner were used in producing a profile of sarcoplasmic protein/enzyme changes in the breast muscle by cation exchange fast protein-liquid chromatography at 10 min, 2, and 24 h PM. The R values and soluble protein were also determined. Stimulation at 200 and 350 V accelerated the onset of rigor noted by lower pH values at 10 min and 1 h PM, and higher R values at 2 h PM. Muscle stimulated at 350 V exhibited the lowest cook yield and highest percentage of F&S lost, suggesting both the loss of functional properties and muscle integrity due to this treatment. All control and stimulated samples exhibited shear values in excess of what would be considered tender. Hardness and chewiness values increased as stimulation voltage levels increased. Only one of the seven principal chromatographic peaks decreased in response to increased electrical stimulation.(ABSTRACT TRUNCATED AT 250 WORDS)
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Two experiments were conducted to determine the effects of constant amperage (as opposed to constant voltage) electrical stunning on broiler blood loss, post-mortem breast muscle (Pectoralis major) rigor development, and breast meat quality. Broilers were individually stunned for 5 s at 0 (unstunned control group), 50, 100, 150, and 200 mA in Experiment 1 and at 0, 50, and 125 mA in Experiment 2. Breast muscle pH and R-value (ratio of adenosine to inosine nucleotides) were determined at 15 min and 24 h post-mortem; breast meat shear value and color were determined at 48 h post-mortem. Stunning amperage had no effect on percentage blood loss in either experiment. The most rapid post-mortem reactions were observed for the unstunned control group as determined by pH and R-value at 15 min post-mortem. Birds stunned with 50 mA were intermediate with regard to rate of rigor development. The slowest post-mortem reactions occurred in broilers stunned from 100 to 200 mA. There were no differences in pH, R-value, or color between stunning treatments after carcasses were aged for 24 h. Stunning amperage did not affect Allo-Kramer shear value for breast muscles deboned at 15 min post-mortem. In Experiment 2, 24 h aged breast meat from broilers stunned with 125 mA required significantly higher shear value (4.5 kg/g) than breast meat from broilers stunned at 0 or 50 mA (3.8 and 3.6 kg/g, respectively). Results indicate that stunning amperages between 0 and 200 mA had effects on the rate of early rigor development but there were no consistent effects on final breast meat quality.
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Five trials were conducted to determine the effects of various alternative stunning and restraining methods on the quality of chicken broiler meat. The stunning methods used were electrical whole-body and head-only stunning with different voltages (25 vs 100 V) and frequencies (50 vs 200 Hz), and mechanical captive bolt stunning. Before being stunned, the broilers were restrained either by shackling them by the feet, restraining their heads while they were standing, or placing them in a cone. Convulsions during and after stunning were subjectively scored. At 1 d post-mortem, the pH, color, and the intensity and number of hemorrhages, of breast and thigh muscles were measured. Convulsions were, in order of increasing intensity, observed after whole-body stunning using 50 Hz, whole-body stunning using 200 Hz, head-only stunning, and captive bolt stunning. No differences in ultimate pH were measured. A consistent difference in color was observed between whole-body and head-only stunning. Head-only stunning resulted in darker and more red (P ≤ 0.01) breast muscles. Head-only and captive bolt stunning resulted in hemorrhages that were located more distal in the breast muscle than those observed after whole-body stunning. Captive bolt stunning (in a cone) resulted in fewer (P ≤ 0.01) hemorrhages in breast and thigh muscles than whole-body stunning (100 V, 50 Hz, shackled), and in a similar level of hemorrhaging as electrical head-only stunning (25 V, 200 Hz, in a cone).
Article
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Hemorrhages in muscle tissue can be considered as major quality defects of broiler carcasses. They can be induced by stunning, especially electrical stunning. The underlying mechanism, however, is considered to be multifactorial. In this study, the effect of blood circulation disturbances on the severity of hemorrhages induced by electrical stunning was investigated. The disturbances were evoked in two genetically different, fast-growing broiler strains, Ross and Hybro, by rearing the broilers at low ambient temperatures. The broilers were slaughtered by two different electrical stunning methods. Broilers reared at low temperatures showed changes in blood variables and heart weight known to be associated with blood circulation disturbances. There was no effect of rearing temperature on hemorrhage severity. Ross broilers, being the most susceptible to low temperatures, had less severe hemorrhages than Hybro broilers. There was, however, a clear effect of the stunning method on hemorrhage severity. Whole body stunning caused more severe hemorrhages than head stunning in thigh and breast muscles. These results suggest that factors interfering with blood circulation have little or no effect on the occurrence of hemorrhages induced by electrical stunning.
Article
Full-text available
Experiments were conducted to compare the effects of a high current (HC) stunning system to a low voltage (LV) stunning system on broiler carcass and meat quality. A total of 360 broiler chickens were individually stunned using either 125 mA, 50 Hz, constant AC for 5 s (HC) or using 10.5 V, 500 Hz pulsed DC for 10 s (LV). Birds were individually weighted, killed by conventional neck cut, bled for 150 s, and reweighed to determine blood loss. Breast fillets (Pectoralis major) were removed from the carcass immediately after picking (0 h) or after aging for 24 h in a static ice-water slush. Breast muscle pH was determined at both 0 and 24 h. Raw breast meat color (CIELAB) and cooked breast meat Allo-Kramer shear values were determined on samples held at 2 C for 48 h. The LV stunning treatment significantly increased (P < 0.05) blood loss (4.0 vs 3.7%) and significantly reduced initial muscle pH (6.47 vs 6.67) when compared to the HC stunning treatment. There were no significant differences between the stunning systems for 24 h pH, raw breast color, and Allo-Kramer shear. High current stunning reduced initial blood loss and delayed early rigor development compared to the LV treatment, but appeared to have little effect on final meat quality.
Article
The regulations for the slaughter of poultry for human consumption in the United Kingdom and in European countries which export to members of the EEC are reviewed. Physical methods of killing are described. The advantages and disadvantages of electric hand-stunning devices and high voltage and low voltage automatic stunners are discussed. It is suggested that the use of carbon dioxide and oxygen mixes for the anaesthesia of poultry in processing lines prior to venesection could be of economic advantage.
Article
This study investigated the parameters involved in the stunning of market weight chickens. Researchers used a prototype constant current stunner, designed and produced by the Department of Electrical Engineering of Virginia Polytechnic Institute and State University, to electrically stun broilers with 8, 29, or 50 mA/bird. Three weight classes existed, controlled by age: Broiler males grown for 34, 43, or 50 days or females for 37, 44, or 51 days. Pre-stun levels of 3, 5, or 8 hr of feed and water withdrawal were used for each weight class and sex. The effects of sex, weight, and feed and water withdrawal on stunning efficiency, recovery time, blood splatter, and bone breakage were determined. The experimental unit, determined by sex, weight, and feed withdrawal, was a “pen” of ten birds. A total of 130 birds of each sex were used for each of two repetitions. Results indicated a significant (P≤.001) gender difference in resistance, recovery time, and prevalence of defects in broilers.
Article
1. The effects of age at sexual maturity, age at culling, and stunning frequency and current on the incidence of broken bones were examined in end‐of‐lay hens. In addition comparisons were made between 4 different egg‐laying breeds, and between battery, perchery and free range husbandry systems.2. High frequency stunning (1500 Hz) caused a reduction in the incidence of broken bones compared with 50 Hz.3. Battery birds had a higher incidence of recently broken bones in comparison with perchery and free range birds. However, there were more old breaks in the perchery and free range systems than in the battery system.4. Breed of bird, age at sexual maturity and age at culling had no effect on the incidence of broken bones.
Article
1. The paper explains the use and method of operation of electrical water bath stunners, and explains the possible current pathways through a single bird and through a number of birds.2. A mathematical model has been formulated to demonstrate the effects of bird resistance and physical attitude of the bird on the current received by individual birds in a water bath stunner.3. The model shows that readings from ammeters installed in series with commercial stunners, or the values shown on voltmeters, are not an accurate indicator or a guarantee that individual birds are effectively stunned.4. The model demonstrates the need for a stunner to supply a constant current to each bird, rather than operate at a constant voltage where the current which the bird receives is dependant upon its own resistance.
Article
1. For a bird to be adequately stunned, sufficient electric current needs to reach the brain in order to induce an epileptic seizure. Methods are presented for determining the percentage of the stunning current which reaches the brain.2. A transverse section of the thorax was examined and tissues including epithelium, fat, muscle, liver, keelbone and heart, were tested for the percentage of current flowing through each tissue.3. It was found that the proportion reaching the brain varied from bird to bird whereas, with the exception of a slight variation in the proportion reaching the heart, that flowing through the other tissues located in the thorax was similar in all the birds tested.4. The variability in current reaching the brain and to some extent the heart may determine whether a bird is stunned, inadequately stunned or killed after having entered a water‐bath stunner.
Article
Experiments were conducted to determine the effect of electrical stunning duration on poultry breast meat postmortem biochemistry and texture. Broilers were stunned with 100 V AC for 0, 5, 10, 20, or 40 s, killed by conventional neck cut, and bled for 180 s to determine percentage blood loss. Breast fillets were removed from the carcass immediately after picking or following 24 h of aging in an ice-water bath. R-values and pH were determined at both deboning times and Allo-Kramer shear values were recorded after holding the samples for 48 h at 2 C. Stunning durations of 10, 20 and 40 s resulted in lower (P < 0.05) blood losses than birds stunned for 0 or 5 s. Stunning inhibited postmortem glycolysis as indicated by higher (P < 0.05) pH values and lower R-values at 15 min postmortem, but not after 24 h. Stunning had no effect on Allo-Kramer shear values. Stunning durations from 5 to 40 s at 100 V AC had no significant effect on postmortem rigor development, or meat quality.
Article
This review considers various aspects of electrical stunning of poultry, mainly broilers, with particular reference to electric water bath stunners. Since the welfare of the birds prior to slaughter is of prime importance, areas where this may be compromised are discussed. Factors concerning the quality of stunning, the effects on bleed out and the carcass quality are reviewed. The performance of electrical water bath stunners is discussed and suggestions are made for modifications which may improve the operation of this type of stunner.
Article
1. The effect of stunning current on the time to recovery of physical activity, and on somatosensory evoked potentials (SEPs) in the brain, was examined in broiler chickens. 2. Increasing stunning current was associated with an increase in the time to recovery of tension in the neck muscles and with an increase in the incidence of loss of SEPs. 3. Currents greater than 105 mA per bird provided 52 s or more of apparent insensibility; currents greater than 120 mA were associated with absence of SEPs following the stun.
Article
The spontaneous EEG and somatosensory evoked potentials (SEPs) were examined in chickens before and after electrical stunning using a waterbath stunner. Fifty-four per cent of the birds became epileptic and lost their SEPs, and 17% were non-epileptic and appeared to retain their SEPs. It was concluded that there was a reasonably close association between the presence of epileptiform activity in the EEG and the absence of SEPs following electrical stunning, but that the absence of SEPs could be preferred as an indicator of an effective stun on conceptual grounds.
Article
The effect of the stunning current at slaughter on carcase quality was examined in 1845 broiler chickens. As the current was increased there was an increase and then a decrease in the incidence of red wingtips and in haemorrhages of the wing veins and the shoulder joint. The incidence of deep breast muscle haemorrhages increased above about 130 mA, and the incidence of broken bones increased between 75 and 170 mA. The incidence of carcase defects was lowest when either less than 130 or greater than 190 mA was used to stun the birds.
Article
The failure of commercial pre-slaughter electrical stunning to stun effectively all birds may be, in part, a result of the current following slightly different paths through the tissues of different birds. Resistivity can be used to predict current pathways, and methods are presented for determining the resistivity of a tissue in freshly-killed or anaesthetized adult fowls. A variety of tissues were tested including comb, skeletal muscle, epithelium, brain, skull bone, heart and liver. The resistivity of a particular tissue varied little between birds, with the exception of skull bone in which resistivity differed markedly from bird to bird. This variation in skull bone resistivity may explain why some birds are inadequately stunned, since in these individuals the current density in the brain is likely to be insufficient to induce an adequate epileptic seizure.
Article
About 40 to 60 per cent of the total blood volume is lost at exsanguination. The loss can be influenced slightly by differences in traditional slaughter techniques and is considerably reduced after cardiac arrest in sheep and cattle. Blood not lost at sticking is probably largely retained in the viscera rather than the carcase. The residual blood content of lean meat is 2 to 9 ml/kg muscle. There is no evidence that this amount is affected by different slaughter methods or that large amounts of residual blood influence the microbiology of meat.
Article
Information was collected on the slaughter procedures used in 12 processing plants in Australia. The processing line speed varied from 25 to 125 birds/minute; the voltage in the electrified waterbath varied from 55 to 165 V; the duration of stunning was 2.0 to 7.5 seconds and the time allowed for exsanguination was 45 to 180 seconds. As a result of the variables, some birds were dead on leaving the stunner and prior to exsanguination, while it was probable that others were not dead before entering the scald tank.
Electrocution, stunning, and chicken carcase appearance
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Minimizing product loss in the hang, stun and kill areas
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Stunning of broilers. Pages 345–349 in: Proceedings World's Poultry Congress
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What is the right current to stun and kill broilers? Poult. Miss
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