ArticlePDF Available

A Review: Influences of Pre-slaughter Stress on Poultry Meat Quality

Authors:
Md. Shawkat Ali at Bangladesh Agricultural University
Md. Shawkat Ali
Geun-Ho Kang
Geun-Ho Kang
Geun-Ho Kang
  • This person is not on ResearchGate, or hasn't claimed this research yet.
Seon-Tea Joo at Gyeongsang National University
Seon-Tea Joo
Download full-text PDF
Read full-text
Download citation

Abstract

Pre-slaughter conditions affect poultry meat quality. Therefore, stresses before slaughter like heat stress, struggle and shackling on the shackle line, crating and transport and feed withdrawal are very important for the poultry industry in respect of quality as well as welfare of the birds. However, exposure to heat in oxidative stress can in turn lead to cytotoxicity in meat type birds. Chickens exposed to heat stress before slaughter showed the lowest ultimate pH and birds shackled for a longer time the highest. The abdominal fat content was higher in heat stressed birds. Struggling on the shackle line hastened the initial rate of the pH drop and increased the redness of breast meat. Again, with increasing struggling activity, lactate concentration in breast muscle of chicken increased. Paler meat was found in birds that were transported for a longer time than in those after a small journey or not transported. The pre-slaughter and eviscerated weights were decreased as the length of feed withdrawal period increased.
Content uploaded by Md. Shawkat Ali
Author content
All content in this area was uploaded by Md. Shawkat Ali on Apr 12, 2021
Content may be subject to copyright.
912
INTRODUCTION
It is important to recognize that any of the
environmental stress factors discussed can result in changes
in the metabolites of muscle. These changes, in turn, are
responsible for differences in the ultimate properties of
meat. The nature of the changes depends upon the severity
of the stress, and the level of the animal’s stress resistance
at the time of death. In poultry, the quality of meat products
results from complex interactions between the genotype and
the environment, more especially the stresses undergone
before slaughter (Berri, 2000; Debut et al., 2003).
Pre-slaughter stressed animals have usually high
temperatures, rapid glycolysis (pH drop), and early onset of
rigor mortis in their muscles. Although the postmortem
changes are rapid, some degree of ante-mortem muscle
temperature rise, lactic acid buildup, and depletion of ATP
also occurs. This combination of conditions results in an
exaggeration of the muscle-to-meat transformation (rapid
pH decline and an elevated carcass temperature resulting in
protein denaturation) that normally occur. Muscles from
pre-slaughter stressed birds usually become pale, soft, and
moist or exudative (PSE) after a normal 18 to 24 h chilling
period condition. This condition most often results lower
possessing yields, increased cooking losses, and reduced
juiciness (Aberly et al., 2001).
Ante-mortem stress, including heat-stress (Babji et al.,
1982), struggle before slaughter (Ngoka and Froning, 1982;
Papinaho et al., 1995), have shown to accelerate glycogen
depletion, increase the rate of pH decline, and possibly
results in tough meat. Again, Glycogen deficiency usually
occurs when animal survive stress, such that associated with
fatigue, exercise, fasting, excitement, fighting or electrical
shock but are slaughtered before they have sufficient time
to replenish their muscle glycogen stores. Muscle glycogen
deficiency in these birds’ results in limited glycolysis in the
muscles after death and results in a high ultimate pH. As a
consequence of a high ultimate pH, changes in muscle color
that otherwise occur during the post-mortem transformation
of muscle to meat, do not occur. The pre-slaughter stresses
normally occur in poultry meat processing industry are heat
stress, pre-slaughter shackling, struggle, crating and
transportation and feed withdrawal.
DISCUSION
Heat stress before slaughter
Heat stress is a major concern for poultry, especially in
the hot regions of the world becau se of the resulting poor
Asian-Aust. J. Anim. Sci.
Vol. 21, No. 6 : 912 - 916
June 2008
www.ajas.info
A Review: Influences of Pre-slaughter Stress on Poultry Meat Quality
Md. Shawkat Ali, Geun-Ho Kang1 and Seon Tea Joo*
Division of Applied Life Science, Graduate School, Gyeongsang National University
Jinju, Gyeongnam 660-701, Korea
ABSTRACT: Pre-slaughter conditions affect poultry meat quality. Therefore, stresses before slaughter like heat stress, struggle and
shackling on the shackle line, crating and transport and feed withdrawal are very important for the
p
oultry industry in respect of quality
as well as welfare of the birds. However, exposure to heat in oxidative stress can in turn lead to cytotoxicity in meat type birds. Chickens
exposed to heat stress before slaughter showed the lowest ultimate pH and birds shackled for a longer time the highest. The abdominal
fat content was higher in heat stressed birds. Struggling on the shackle line hastened the initial rate of the pH drop and increased the
redness of breast meat. Again, with increasing struggling activity, lactate concentration in breast muscle of chicken increased. Paler meat
was found in birds that were transported for a longer time than in those after a small journey or not transported. The pre-slaughter and
eviscerated weights were decreased as the length of feed withdrawal period increased. (Key Words : Pre-slaughter Stress, Poultry Meat
Quality)
* Corresponding Author: Seon-Tea Joo. Tel: +82-55-751-5511,
Fax: +82-55-756-7171, E-mail: stjoo@gnu.ac.kr
1 Poultry Science Division, National Institute of Animal Science,
RDA, Korea.
Received October 24, 2007; Accepted February 6, 2008
Ali et al. (2008) Asian-Aust. J. Anim. Sci. 21(6):912-916
913
growth performance, immunosuppression, and high
mortality. Exposure to acute heat stress is likely to lead to
various metabolic changes in poultry meat. An early
reaction to high ambient temperature is the increased body
temperature (Sandercock et al., 1999). Furthermore,
according to Edens (1978), chicken exposed to high
environmental temperatures (43°C) showed a rising plasma
corticosterone concentration early in the heating episode
(before 90 min), afterwards a significant fall signifying the
Acute Adrenal Cortical Insufficiency (AACI) syndrome. As
reported by Edens and Siegel (1976) or Edens (1978), this
syndrome is associated with a loss of plasma glucose,
cholesterol, total calcium and inorganic phosphate and
decreased plasma sodium to potassium ratio. Debut et al.
(2005) stated that acute heat stress affected blood Ca2+ and
Na+ concentration and increased glycaemia and glycolytic
potential of thigh muscle also agreed the previous results.
Heat stress increases oxygen radicals, possibly by the
disruption of the electron transport assemblies of the
membrane (Ando et al., 1997). Heat-induced reactive
oxygen species (ROS) formation may be the factor that
causes molecular changes in DNA, proteins, lipids and
other biological molecules (Bruskov et al., 2002). ROS play
an important role in many biological systems, including the
body’s response to infection, heavy metal and ethanol
toxicity, and other conditions (Donati et al., 1990). However,
several studies have suggested that exposure to heat results
in oxidative stress, which in turn can lead to cytotoxicity
(Bernabucci et al., 2002). It was found that significantly
enhanced superoxide production in heat stress-treated
skeletal muscle mitochondria of meat type chickens,
whereas no such increase was observed in laying chickens.
The enhancement of superoxide production in meat type
chicken was associated with heat-induced increments in
rectal and muscle temperatures, leading to significant body
weight loss. In contrast, the layer chicken showed no
increase in temperatures, although there is a slight decrease
in body weight gain (Mujahid et al., 2005). Heat stress
increases oxygen radicals, possibly by the disruption of the
electron transport assemblies of the membrane (Ando et al.,
1997). However, in former study both meat and laying type
chicken were exposed to heat stress at 34°C. Therefore, it is
likely that increase of mitochondrial heat induced reactive
oxygen species (ROS) production was affected directly by
increase body temperature rather than the environmental
temperature. However it cannot be ruled out that laying-
type chickens have a unique regulatory mechanism
allowing the suppression of ROS production under heat
stress conditions or there is a possibility that laying-type
chickens are inherently immune to or better adapted to the
higher production of ROS.
Chicken exposed to heat stress before slaughter showed
the lowest ultimate pH and the birds shackled for a longer
time the highest, same trend also found in glycolytic
potential at 3 minutes of postmortem with the birds
(Rammouz et al., 2004). This decline in pH is a result of
glycolysis and ATP hydrolysis (Van Hoof, 1979). Acute heat
stress was chosen as pre-slaughter treatments as this is
commonly practiced and has a negative impact on animal
welfare (Gregory, 1994; Kannan et al., 1997) and meat
quality (Kannan et al., 1997; Debut et al., 2003).
Environmental regimen was a highly significant source of
variability for chilled carcass weight change; the cyclic
heat-stressed broiler carcasses gained more weight than the
thermoneutral (control) broiler carcasses during ice-water
chilling. Oven-cooked fillet yield was significantly affected
by environmental regimen; fillets from cyclic heat-stressed
broilers had lower yields than thermoneutral (control)
broiler fillets (Whiting et al., 1991). The abdominal fat
content was significantly higher under heat stress and the
meat quality showed no dependence on the climatic
conditions. However, the effect of heat stress was not
uniform in the fatty acid pattern and the sum of saturated
fatty acid was increased under heat stress (Amad et al.,
1992). Although, Shim et al.(2006) stated that heat stress
resulted in a significant reduction in total lipid and
triglyceride levels, but also increased the levels of total
cholesterol in the liver of broiler chicken (p<0.05).
Struggle and shackling on the shackle line during
processing
Hanging operations could induce severe struggling
(straightening up, wing flapping and vocalization) on the
shackle line (Gregory and Bell, 1987), increase plasma
corticosterone (Kannan et al., 1997; Debut et al., 2005) and
affect muscle peri-mortem metabolism and some meat
attributes (Debut et al., 2003). According to the last study,
struggling on the shackle line hastened the initial rate of the
pH drop and increased the redness of breast meat.
Furthermore, the behavioral response to shackling varied
between chicken types, the slow-growing line being more
reactive than the fast-growing line.
Most of the studies of struggling on the shackling line
have been investigated in the context of animal welfare
(Gregory and Bell, 1987; Gregory, 1994; Sparrey and
Kettlewell, 1994). Kannan and Mench (1996) reported that
hanging broilers in an inverted position is experienced as a
stressful event which leads to an increase in plasma
corticosterone concentration. Debut et al. (2005) and
Kannan et al. (1997) found that increasing the shackling
time led to higher plasma conticosterone in chicken.
Vigorous wing flapping can be seen as an escape behavior
and an indicator of discomfort (Sparrey and Kettlewell,
1994). Reaction of hanging has been already shown to be
intensified by environmental factors such as rough hanging,
noise, bright light, unsuitable shackles or separation from
Ali et al. (2008) Asian-Aust. J. Anim. Sci. 21(6):912-916
914
familiar counterparts (Gregory and Bell, 1987). Debut et al.
(2005) confirmed that the lactate concentration in breast
muscle of chicken at 15 min post mortem increased with
struggling activity. Similar results also found in chicken
(Papinaho et al., 1995) and turkey (Ngoka and Froning,
1982). Debut et al. (2005) also stated that breast muscle was
more sensitive to struggling activity than thigh muscle in
which lactate concentration was barely affected. This could
be related to the glycolytic status of the breast muscle and it
association with wing flapping activity.
Crating and transport
Crating causes an increase in plasma corticosterone
levels in broilers (Kannan and Mench, 1996). The duration
of crating (Kannan and Mench, 1996) and the method of
crating (Duncan, 1989) can also influence the stress
response shown by the bird. Although catching, crating, and
loading are the procedures that are most likely to cause
plysical injuries, transportation has also been reported to be
stressful to broilers. Duncan (1989), for example, found that
birds that were crated and transported on a vehicle for 40
min had higher plasma corticosterone concentrations than
birds that were crated and loaded onto the vehicle but not
transported. Further, Cashman et al. (1989) reported that
fear levels in birds were mainly determined by
transportation and not just by catching and loading. Ehinger
(1977) found that broiler meat tenderness and water holding
capacity were reduced after 2 h of transportation but
improved after 4 h of transportation. Cashman (1987)
assessed the ultimate pH, color, and water holding capacity
of broiler meat, and found that meat was paler in birds that
underwent a commercial 2-h journey than in birds that were
crated for only 10 min and not transported. These reports
suggest that transport stress can influence the color and
texture of broiler meat.
Feed withdrawal
Feed is normally withdrawn for several hours before
catching in order to reduce the danger of carcass
contamination. Total feed withdrawal times of 8 to 10 h
prior to slaughter are recommended (Wabeck, 1972),
although in practice longer periods sometimes occur. Feed
withdrawal affects a lot of metabolic processes. Feed
deprivation causes a shift from anabolism to catabolism,
from lipogenesis to lipolysis, and a reduced metabolic rate.
A study by Murray and Rosenberg (1953) revealed that the
plasma glucose concentration of fasted chickens declined
rapidly until a new equilibrium was reached and become
stabilized after 3 h of fasting for at least 16 h. Warriss et al.
(1988) stated that live glycogen depleted to negligible
amounts after feed withdrawal of 6 h.
Feed withdrawal induces behavioral and physiological
responses, indicating that broilers probably suffer from
stress (Freeman, 1984). An increase in corticosterone
concentrations has been shown in broilers after a feed and
water withdrawal of 24 h (Knowles et al., 1995). Also in
growing broiler breeders, feed restriction leads to plasma
corticosterone increases (De Jong et al., 2003). Withdrawal
of feed before catching is likely to increase corticosterone
as well (Nijdam et al., 2005).
Feed withdrawal before slaughter allows emptying of
the digestive system and reduces the likelihood of faecal
contamination during processing. The preslaughter and
eviscerated weights were decreased as the length of feed
withdrawal period increased (Veerkamp, 1978; Bartov,
1992). Food withdrawal periods of up to 24 h did not affect
the fat content in meat (Ang and Hamm, 1985; Bartov,
1992), the relative size of abdominal fat pad or the
composition of fatty acids in their meats (Bartov, 1992).
Dietary protein content, or energy-to-protein ratio,
besides it determinant effect on weight gain and feed
efficiency of broiler chicks, has a marked effect on the
quality of their carcasses (yield of edible meat, and carcass
fat content). Diet lower than protein recommended reduced
the yield of meat (Moran et al., 1992) and increased
fattening (Bartov and Bornstein, 1976; Moran et al., 1992).
The increased fattening was accompanied by increased
saturation of carcass fat (Marion and Woodroof, 1966;
Bartov and Bornstein, 1976). Increased fattening was also
observed when chickens were fed on diets in crumbled or
pelleted form (Marks and Pesti, 1984; Plavnik et al., 1997).
CONCLUSION
The conditions before slaughter affect meat quality
parameters, and these conditions are not only important in
respect of quality but also important as welfare of the birds.
Better understanding of these factors will help the modern
poultry industry peoples to obtain good quality products.
ACKNOWLEDGMENT
The authors acknowledge a graduate fellowship provide
by the Korean Ministry of Education through the BK-21
project. Also, the first author is grateful to Korea Research
Foundation (KRF) for giving scholarship for his Ph. D.
study.
REFERENCES
Aberle, E. D., J. C. Forrest, D. E. Gerrard, E. W. Mills, H. B.
Hedrick, M. D. Judge and R. A. Merkel. 2001. Principles of
Meat Science (4th edition), Kendall/Hunt Publishing Company,
4050 Westmark Drive, Dubuque, Iowa, USA. p. 94.
Amad, A., J. Poetschke, I. Muller and L. Chhum Pith. 1992.
Differentiation of fattening and slaughtering performance and
carcass quality of broiler genotypes with and without the dwarf
Ali et al. (2008) Asian-Aust. J. Anim. Sci. 21(6):912-916
915
factor and fast or slow feathering under heat stress. Beitr Trop
Landwirtsch Veterinarmed, 30:407-425.
Ando, M., K. Katagiri, S. Yamamoto, K. Wakamatsu, I. Kawahara,
S. Asanuma, M. Usuda and K. Sasaki. 1997. Age related
effects of heat stress on protective enzymes for peroxides and
microsomal monooxygenase in rat liver. Environmental Health
Prospectives 105:726-733.
Ang, C. Y. W. and D. Hamm. 1985. Influence of length of feed
withdrawal times on proximate composition and levels of
selected vitamins and minerals in broiler breast meat. Poult.
Sci. 64:1491-1493.
Babji, A. S., G. W. Froning and D. A. Ngoka. 1982. The effect of
preslaughter environmental temperature in the presence of
electrolyte treatment on turkey meat quality. Poult. Sci.
61:2385-2389.
Bartov, I. 1992. Effect of feed withdrawal on yield, fat content and
fatty acid composition of various tissues in broilers.
Proceedings of the 19th World’s Poultry Congress, Amsterdam,
Vol. 3. pp. 195-199.
Bartov, I. and S. Bornstein. 1976. Effects of degree of fatness in
broilers on other carcass characteristics: Relationship between
fatness and composition of carcass fat. Br. Poult. Sci. 17:17-27.
Bernabucci, U., B. Ronchi, N. Lacetera and A. Nardone. 2002.
Markers of oxidative status in plasma and erythrocytes of
transition dairy cows during hot season. J. Dairy Sci. 85:2173-
2179.
Berri, C. 2000. Variability of sensory and lipid oxidation in
broilers exposed to high temperature at an early age. Br. Poult.
Sci. 41:489-493.
Bruskov, V. I., L. V. Malakhova, Z. K. Masalimov and A. V.
Chernikov. 2002. Heat-induced formation of reactive oxygen
species and 8-oxoguanine, a biomarker of damage to DNA.
Nucleic Acids Research 30:1354-1363.
Cashman, P. J. 1987. An assessment of the fair levels of broilers
during transit. M. Sc. Thesis, University of Bristol, Bristol, UK.
Cashman, P. J., C. J. Nicole and R. B. Jones. 1989. Effects of
transportation on the tonic immobility fear reactions of broilers.
Br. Poult. Sci. 30:211-222.
Debut, M., C. Berri, E. Baeza, N. Sellier, C. Arnould, D. Guemene,
N. Jehl, B. Boutten, Y. Jego, C. Beaumont and E. Le Bihan-
Duval. 2003. Variations of chicken technological meat quality
in relation to genotype and preslaughter stress conditions.
Poult. Sci. 82:1829-1834.
Debut, M., C. Berri, C. Arnould, D. Guemené, V. Santé-Lhoutellier,
E. Baéza, N. Jehl, Y. Jégo, C. Beaumont and E. Le Bihan-
Duval. 2005. Behavioural and physiological responses of three
chicken breeds to pre-slaughter shackling and acute heat stress.
Br. Poult. Sci. 46:527-535.
De Jones, I. C., A. S. van Voorst and H. J. Blokhuis. 2003.
Parameters for quantification of hunger in broiler breeders.
Physiology and Behavior 78:773-783.
Donati, Y. R. A., D. O. Slosman and B. S. Polla. 1990. Oxidative
injury and the heat shock response. Biochem. Pharmacol.
40:2571-2577.
Duncan, I. J. H. 1989. The assessment of welfare during the
handling and transport of broilers. Pages 93-107 in:
Proceedings of the 3rd European Symposium of Poultry
Welfare (Ed. J. M. Faure and A. D. Mills). World’s Poultry
Science Association, Tours, France.
Edens, F. W. 1978. Adrenal cortical insufficiency in young
chickens exposed to a high ambient temperature. Poult. Sci.
57:1746-1750.
Edens, F. W. and H. S. Siegel. 1976. Modification of
corticosterone and glucose responses by sympatholic agents in
young chickens during acute heat exposure. Poult. Sci.
55:1704-1712.
Ehinger, F. 1977. The influence of starvation and transportation on
carcass quality of broilers (Ed. S. Scholtyssek). The quality of
poultry meat, pp. 117-124 (Munich, Germany, European
Poultry Federation).
Freeman, B. M., P. J. Kettlewell, A. C. C. Manning and P. S. Berri.
1984. Stress of transportation of broilers. Vet. Res. 114:286-
287.
Gregory, N. G. 1994. Preslaughter, handling, stunning and
slaughter. Meat Sci. 36:45-56.
Gregory, N. G. and J. C. Bell. 1987. Duration of wing flapping in
chicken shackled before slaughter. Vet. Rec. 121:567-569.
Kannan, G. and J. A. Mench. 1996. Influence of different handling
methods and crating periods on plasma corticosterone levels in
broilers. Br. Poult. Sci. 37:21-31.
Kannan, G., J. L. Heath, C. J. Wabeck and J. A. Mench. 1997.
Shackling of broilers: effects on stress responses and breast
meat quality. Br. Poult. Sci. 38:323-332.
Knowles, T. G., P. D. Warriss, S. N. Brown, J. E. Edwards and M.
A. Mitchell. 1995. Responses of broilers to deprivation of food
and water for 24 hours. Br. Vet. J. 151:197-202.
Marion, J. E. and J. G. Woodroof. 1966. Composition and stability
of broiler carcasses as affected by dietary protein and fat. Poult.
Sci. 45:241-247.
Marks, H. L. and G. M. Pesti. 1984. The roles of protein level and
diet form in water consumption and abdominal fat pad
deposition of broilers. Poult. Sci. 63:1617-1625.
Moran, E. T., R. D. Bushong and S. F. Bilgili. 1992. Reducing
dietary crude protein for broilers while satisfying amino acid
requirements by least-cost formulation: Live performance,
litter composition, and yield of fast-food carcass cuts at six
weeks. Poult. Sci. 71:1687-1694.
Mujahid, A., Y. Yoshiki, Y. Abika and M. Toyomizu. 2005.
Superoxide radical production in chicken skeletal muscle
induced by acute heat stress. Poult. Sci. 84:307-314.
Murray, H. C. and M. M. Rosenberg. 1953. Studies on blood sugar
and glucogen levels in chickens. Poult. Sci. 32:805-811.
Ngoka, D. A. and G. W. Froning. 1982. Effect of free struggle and
preslaughter excitement on color of turkey breast. Poult. Sci.
61:2291-2293.
Nijdam, E., E. Delezie, E. Lambooij, M. J. A. Nabuurs, E.
Decuypere and J. A. Stegeman. 2005. Feed withdrawal of
broilers before transport changes plasma hormone and
metabolite concentrations. Poult. Sci. 84:1146-1152.
Papinaho, P. A., D. L. Fletcher and R. J. Buhr. 1995. Effect of
electrical stunning amperage and peri-mortem struggle on
broiler breast rigor development and meat quality. Poult. Sci.
74:1533-1539.
Plavnik, I., E. Wax, D. Sklan and S. Hurwitz. 1997. The response
of broiler chickens and turkey poults to steam-peleted diet
supplemented with fat and carcohydrates. Poult. Sci. 76:1006-
1013.
Ali et al. (2008) Asian-Aust. J. Anim. Sci. 21(6):912-916
916
Rammouz, R. El., C. Berri, E. Le. Bihan-Duval, R. Babile and X.
Fernandez. 2004. Breed differences in the biochemical
determinism of ultimate pH in breast muscles of broiler
chickens-A key role of AMP deaminase? Poult. Sci. 83:1445-
1451.
Sandercock, D. A., R. R. Hunter, G. R. Nute, P. M. Hocking and M.
A. Mitchell. 1999. Physiological responses to acute heat stress
in broilers: implications for meat quality? Proceedings of the
14th European Symposium on the Quality of Poultry Meat,
Bolonga, pp. 271-276.
Shim, K. S., K. T. Hwang, M. W. Son and G. H. Park. 2006. Lipid
metabolism and peroxidation in broiler chicks under chronic
heat stress. Asian-Aust. J. Anim. Sci. 19:1206-1211.
Sparrey, J. M. and P. J. Kettlewell. 1994. Shackling of poultry: is it
a welfare problem? World’s Poult. Sci. J. 50:167-176.
Van Hoof, J. 1979. Influence of ante- and peri-mortem factors on
biochemical and physical characteristics of turkey breast
muscle. Vet. Q. 1:29-36.
Veerkamp, C. H. 1978. The influence of fasting and transport on
yields of broilers. Poult. Sci. 57:634-638.
Wabeck, C. J. 1972. Feed and water withdrawal time relationship
to processing yield and potential fecal contamination of
broilers. Poult. Sci. 51:1119-1121.
Warriss, P. D., S. C. Kestin, S. N. Brown and E. A. Bevis. 1988.
Depletion of glycogen reserves in fasting broiler chickens. Br.
Poult. Sci. 29:149-154.
Whiting, T. S., L. D. Andrews, M. H. Adams and L. Stamps. 1991.
Effects of sodium bicarbonate and potassium chloride drinking
water supplementation. 2. Meat and carcass characteristics of
broilers grown under thermoneutral and cyclic heat-stress
conditions. Poult. Sci. 70:60-66.
... After fasting, with the nutritional supply of broilers stopped, the metabolic activity changes from anabolism to catabolism, from fat production to fat decomposition, and gluconeogenesis is strengthened [16]. This will lead to increased weight loss [17], resulting in economic losses for the slaughterhouse. ...
... In addition, serum biochemical parameters in broilers will change after fasting [13]. After slaughter, the oxygen supply of body is stopped while energy is still needed for cell activities under anaerobic conditions, which will lead to glycolysis and lactic acid accumulation, thus reducing the pH value of muscles and affecting the color and water retention of meat [16][17][18]. Excessive fasting before slaughter will lead to a large consumption of muscle glycogen while the bird is alive leading to less glycogen content in muscles after slaughter, and less lactic acid produced by glycolysis. Arbor Acres (AA) broilers are characterized by fast growth rate, high adaptability, high feed conversion rate and good carcass quality. ...
... Duncan's new multiple range test were used to analyze the difference between any two groups. The linear contrasts of one-way analysis of variance were further used to determine the effects of the different Fasting time (4,8,12,16, and 20 h). Statistical significance was set at p<0.05. ...
Effect of pre-slaughter fasting time on carcass yield, blood parameters and meat quality in broilers
Article
  • Nov 2023
Objective: The aim of this study was to evaluate the effect of pre-slaughter fasting time on carcass yield, meat quality, blood parameters and glucose metabolism in broilers. Methods: Four hundred and fifty Arbor Acres (AA) broilers at 42 days of age were divided into 5 groups with 6 replicates in each group and 15 chickens as one replicate. Following this period, broilers from each group were distributed among five groups according to pre-slaughter fasting period as 4, 8, 12, 16 or 20 h. Results: With increasing fasting time, the carcass yield (p<0.01), the breast muscles yield (p<0.01) and the thigh yield (p<0.01) of the broilers were all linearly increased. With increasing fasting time, the L* values (p<0.01), cooking loss (p=0.020), moisture content (p<0.01) in the leg muscles linearly downregulated, while the drip loss (p=0.043), pH45min (p<0.01) and pH24h (p<0.01) were linearly upregulated. A trend for a lower (p=0.071) shear force in the leg muscles was also observed in broilers fasted for longer time. Similar results were also found in breast muscles. The different fasting treatments did not influence the breast muscles glycogen content (p>0.10), while the increase of fasting time resulted in a linear decrease of the blood glucose (p=0.021) and, more specifically, the glycogen content of the liver and leg muscles (p<0.001). With increasing fasting time, the AST (p<0.01), UA (p<0.01) and TG (p<0.01) in serum linearly downregulated, while the ALT was linearly upregulated. Conclusion: The results of this study show a significant influence of fasting time on carcass yield and meat quality in broilers. Moderate fasting (8-12 h) before slaughter can reduce the weight loss of broilers. Avoid prolonged fasting (≥16 h) increased body weight loss, decreased slaughtering performance and fluctuating blood indexes of broilers.
View
... These legislated processes are in place to protect the welfare of the birds and ensure that the resulting meat is fit for human consumption. Indeed, it is also worth noting that as well as the potential negative impact on bird welfare, rough pre-slaughter handling can affect the quality of the resulting carcass and meat [25]. For instance, rough handling of birds in the abattoir can impede their welfare by causing acute stress, which then leads to the production of meat of inferior quality known commonly as pale soft exudative (PSE) meat. ...
... PSE meats are characterised by an abnormal meat colour with high drip loss, conditions that affect the saleability of meat. Ali and colleagues [25] outlined the main welfare issues before stunning and slaughter as heat stress, feed and water withdrawal, crating and transport, and inversion and live bird shackling. Figure 1 below outlines the mandatory processes for birds (in the UK and within the EU) during primary processing in abattoirs that use water bath stunning [26]. ...
... In this section, we discuss the impact of pre-slaughter handling and slaughter with and without stunning on the welfare of birds. In addition to impacting animal welfare, rough pre-slaughter handling has a significant impact on product quality and profitability [25] (as highlighted above, in relation to meat quality defects and the production of PSE meat). ...
Poultry Welfare at Slaughter
Article
Full-text available
  • Mar 2023
Billions of poultry are slaughtered globally each year to provide protein for a rapidly expanding human population. The large number of birds produced in conventional systems presents animal welfare issues during production, transport, and at the time of slaughter. While we recognise the significance of welfare issues during rearing and transport, this paper highlights the welfare of poultry at the time of slaughter. The impacts of manual handling, inversion and shackling, use of inappropriate electrical stunning parameters, and the use of aversive gas mixtures during controlled atmosphere stunning are some of the evident welfare lapses; if the entrance to the water bath is wet and not isolated, bird welfare can also be compromised during water bath stunning because of pre-stun shocks. We also highlight the use of aversive stunning methods such as carbon dioxide gas at high concentrations, which has been shown to compromise bird welfare. In conclusion, we offer some reflections on ways to improve the welfare of birds during pre-slaughter handling, stunning, and neck cutting.
View
... Glycogen stored in the animals' muscles will be converted into lactic acid, producing tasteful, tender, good quality, and colored meat. Stress during preslaughter handling and slaughtering procedures resulted in lactic acid in the muscle, thus reducing meat quality (Chambers et al., 2001;Ali et al., 2008;Gregory, 2008;Adzitey, 2011). Inappropriate action during preslaughter handling may cause the development of meat abnormalities in the carcasses, such as PSE or DFD. ...
... Inappropriate action during preslaughter handling may cause the development of meat abnormalities in the carcasses, such as PSE or DFD. Ali et al. (2008) stated that the initial pH would drop as the birds struggle on the shackle, increasing redness in breast meat. Xu et al. (2011) reported that the glycogen concentration in broilers subjected to 35 V of electrical current is higher than in broilers stunned at 65 V. Similar trend was observed when broiler chickens were stunned at a lower frequency (160 Hz); it exhibited a higher glycogen content compared to broilers subjected to 1,000 Hz of stunning frequency. ...
Are Spiritual, Ethical, and Eating Qualities of Poultry Meat Influenced by Current and Frequency during Electrical Water-Bath Stunning?
Article
Full-text available
  • Jun 2023
  • POULTRY SCI
With the continuous rise of Muslim and Jewish populations and their increasing preference for ritually slaughtered poultry meat, the industry is forced to redefine its existing product-centric quality standard toward a new consumer-centric dimension of quality. The new dimension is mainly attributed to ensuring animal welfare and ethical treatment (ethical quality), spiritual quality (such as halal status, cleanliness), and eating quality standards set by religion. To meet consumer quality requirements while maintaining high production performance, the industry has incorporated newer technologies that are compatible with religious regulations such as stunning methods like electrical water bath stunning. However, the introduction of new techniques such as electrical water bath stunning has been met with mixed reactions. Some religious scholars have banned the use of any stunning methods in religious slaughter, as halal status is believed to be compromised in cases where birds have been stunned to death before slaughter. Nevertheless, some studies have shown the positive side of the electrical water bath stunning procedure in terms of preserving eating, ethical, and spiritual quality. Therefore, the present study aims to critically analyze the application of various aspects of electrical water bath stunning such as current intensity and frequency on various quality attributes, namely, ethical, spiritual, and eating quality of poultry meat.
View
... The HPA axis plays an important role in maintaining the body's homeostasis to deal with various stressors (Sapolsky et al., 2000;Romero et al., 2009). The increase in HPA activity due to stress factors leads to an increase in corticosterone secretion, which in turn causes physiological and metabolic reactions such as an increase in blood sugar, a decrease in appetite, a change in carbohydrate metabolism, a decrease in muscle mass, a decrease in growth, an increase the activity of lipolysis enzymes, an increase in lipid peroxidation reactions and a deterioration in meat quality (Fellenberg and Apeisky, 2006;Honda et al., 2007;Ali et al., 2008;Ognik and Sembratowicz, 2012). ...
Dietary Omega-3 fatty acids affect the growth performance of broiler chickens reared at high stocking density
Article
Full-text available
  • Nov 2024
  • POULTRY SCI
The present study was conducted to investigate the effects of dietary omega-3 fatty acids in broiler chickens exposed to high stocking density (SD) on growth performance, carcass characteristics, breast meat quality, blood biochemical indices, nutrient digestibility and litter quality. A total of 420 one-day-old broilers were used in 2 × 2 factorial arrangements with 2 levels of SD (low: 9 birds/ m² and high: 17 birds/ m²) and 2 levels of omega-3 fatty acids (low and high omega-3; 0.057 and 0.5% of the diet, respectively) in a completely randomized design with 5 replicates for each treatment. Live body weight (LBW), feed intake (FI), and feed conversion ratio (FCR) were recorded periodically. The apparent metabolizable energy (AME), digestibility of crude protein (CP), organic matter (OM), and lipid of experimental diets, were measured from days 30 to 37 of age. The results showed that body weight gain (BWG) and FCR was improved (P < 0.05) in high SD broilers during the grower phase (days 15–24).The BWG of broilers under high SD and dietary omega-3 fatty acids was higher than others (P < 0.05) during the finisher phase (d 25-40). Carcass and total heart weight were higher in birds fed diets containing omega-3 fatty acids under high SD than in birds fed a diet low in omega-3 fatty acids at low or high SD (P < 0.05). The serum concentration of cholesterol in broilers with high SD fed diets high in omega-3 fatty acids was lower than broilers with high SD fed diets low in omega-3 fatty acids (P < 0.05). High SD decreased AME and CP digestibility (P < 0.05). Dietary omega-3 fatty acids, increased AME and digestibility of OM and lipid (P < 0.05). In broiler chickens raised at low stocking density, feeding a high-omega-3 diet reduced litter nitrogen levels compared to feeding a low omega-3 diet (P < 0.05). In summary, omega-3 fatty acid may have the potential to reduce negative effects of high SD on broiler production by enhancing the nutrient digestibility and litter quality.
View
... The increase in HPA activity due to stressful factors results in higher secretion of corticosterone. This leads to physiological and metabolic reactions such as increased blood glucose, decreased appetite, altered carbohydrate metabolism, reduced growth, heightened lipolysis enzyme activity, increased fat peroxidation reactions, heightened susceptibility to cardiovascular diseases, etc (Ali et al., 2008). Environmental stress in broiler chickens can lead to reduced growth rates and an imbalance between body weight and the relative weights of essential organs, such as the heart and liver, which are vital for overall growth. ...
Omega-3 fatty acids mitigate histological changes and modulate the expression of ACACA, PFK1 and ET-1 genes in broiler chickens under environmental stress: a pulmonary artery, cardiomyocyte and liver study
Article
Full-text available
  • Oct 2024
  • POULTRY SCI
The aim of this study was to investigate the effects of omega-3 fatty acids on blood biochemical parameters, histological changes in pulmonary artery, cardiomyocytes, and liver, as well as the expression of ACACA, PFK1, and ET-1 genes in broiler chickens under environmental stress (high stoking density). A total of 420 one-day-old male Ross broilers were used in a 2 × 2 factorial arrangements, with 2 levels of environmental stress (without and with stress; 9 and 17 birds/m², respectively) and 2 levels of omega-3 fatty acids (low and high; 0.057 and 0.5% of the diet, respectively) in a completely randomized design comprising 4 treatments and 5 replicates per each. The body weight decreased at d 40 because of environmental stress (P ≤ 0.05). The ascites heart index (AHI) in broilers fed high omega-3 fatty acids diets was lower (P = 0.062) than broiler fed low omega-3 fatty acids diet (0.279 vs. 0.316). Stressed birds showed a higher neutrophil: lymphocyte ratio compared to non-stressed birds (P ≤ 0.05). Broiler chickens receiving high omega-3 fatty acids diets exhibited elevated levels of hematocrit (HCT), hemoglobin (HGB), and lymphocytes (P ≤ 0.05). The neutrophil: lymphocyte ratio, and serum concentration of alanine aminotransferase (ALT), and aspartate aminotransferase (AST) decreased in broilers fed high omega-3 fatty acids diets (P ≤ 0.05). In stressed broilers on a high omega-3 diet, pulmonary artery wall thickness decreased (P ≤ 0.05). Additionally, under stress, myocardial cell diameter, hepatocyte and cell nucleus diameter significantly increased (P ≤ 0.05). Stressed broilers showed an increased relative fold change in PFK1 enzyme activity but reduced ET-1 mRNA expression in the liver compared to stressed birds on a high omega-3 diet (P ≤0.05). In conclusion, the results indicate that dietary omega-3 fatty acids have the potential to alleviate the adverse histological changes in the pulmonary artery, cardiomyocytes, and liver, while also modulating the expression of genes ACACA, PFK1, and ET-1 that are influenced by environmental stress in broiler chickens.
View
... These factors can lead to alterations in the metabolic rate of the poultry, resulting in a rapid postmortem pH decline. This decline can negatively impact meat quality, resulting in the pale, soft, and exudative characteristics associated with PSE meat (Ali et al., 2008). ...
Effects of broiler chilling methods on the occurrence of pale, soft, exudative (PSE) meat and comparison of detection methods for PSE meat using traditional and Nix colorimeters
Article
Full-text available
  • Jul 2023
  • POULTRY SCI
The aims of this study were to i) estimate the occurrence of pale, soft, and exudative (PSE) meat in modern commercial Ontario broiler flocks, ii) determine the effects of the chilling method (water vs. air) on PSE meat, and iii) investigate a new inexpensive colorimeter (10% of the price of traditional color meters), the Nix Color Sensor, as an objective color measurement of chicken meat. Between June 2019 to March 2020, a total of 17 different broiler flocks were processed. The color of 1,700 boneless skinless Pectoralis major muscles was randomly measured (100/flock), where 255 samples were also measured for pH, water-holding capacity (WHC), cooking loss, and penetration force. In addition, a traditional Minolta colorimeter was used to measure random 95 samples from a single water-chilled flock and subsequently compared the values obtained with the Nix Color Sensor. Strong correlations of L* values (rho = 0.75; P < 0.001), a* values (rho = 0.72; P < 0.001), and b* values (rho = 0.80; P < 0.001) were observed. When an L* value of 43 was used as the cut-off for the Nix, 12.5% of fillets were classified as PSE meat. Statistical differences (P < 0.05) were observed between the air and water-chill methods for L*, pH, and WHC. However, there were no significant differences observed between the 2 methods for cooking loss and penetration force values. The study indicated that PSE meat is still a challenge in Ontario broilers, and that the L*, pH, and WHC of breast meat (all indicate meat quality) are affected by the chilling method. In addition, the Nix was found to be an affordable, objective, and convenient sensor for measuring chicken meat color.
View
... This process is mainly related to the glycogen stock of muscle tissues before slaughter. Feed withdrawal and the other pre-slaughter stresses (excitement, struggle, fighting) can cause a glycogen deficiency due to rapid glycogen depletion, which causes high pH u (Ali et al. 2008). Similar to the result of the present study, Kim et al. (2007) showed an increased pH u in the breast meat of broilers that experienced FW. ...
Effect of chamomile (Matricaria chamomilla L.), linden (Tilia cordata Mill.), and green tea (Camellia sinensis L.) aqueous extract administration in the drinking water during pre-slaughter feed withdrawal period in broiler chickens
Article
Full-text available
  • Jun 2023
  • TROP ANIM HEALTH PRO
Feed withdrawal (FW) and other pre-slaughter stressors have detrimental effects on the meat quality of broiler chickens. Herbal extracts can be used for their sedative effects to reduce the harmful impacts of pre-slaughter stress on broiler chickens. This study aimed to investigate the effect of chamomile (CAE), linden (LAE), and green tea (GAE) aqueous extracts (AE) in drinking water during the pre-slaughter FW period on the meat and liver quality, serum corticosterone level, and some cecal microorganisms of broilers. A total of 450 male and female 42-day-old chickens were allocated to a completely randomized design with five treatment groups and two sexes in six replicates, 12 birds (six male and six female) for each replicate. Treatment groups were chickens offered ad libitum feed and drinking water (control, CT), broilers exposed to FW for 10 h before the slaughter with unsupplemented drinking water (FW), with drinking water supplemented 50 ml/L CAE, LAE, and GAE. Chickens that experienced FW had lower (P < 0.001) slaughter body weight, carcass, gastrointestinal tract (GIT) and inner organ weights, and GIT length (P = 0.002). However, the dressing percentage was higher (P < 0.001) in FW and AE groups than CT group. The FW increased (P < 0.001) the ultimate pH of thigh meat compared with the CT group. The FW also decreased (P = 0.026) the lightness (L*) value of thigh meat of broilers, although CAE and LAE did not change the L* value compared with the CT group. Similarly, the redness (a*) value of thigh meat was lower (P = 0.003) in chickens exposed to FW but was not affected by GAE administration. However, FW or AE did not impact the serum corticosterone level and cecal microbial loads in broiler chickens. The obtained result showed that CAE, LAE, or GAE can be used in drinking water to reduce the harmful effects of FW on the meat quality of broiler chickens.
View
... Although quail egg and meat production is growing rapidly, quail farming practices and welfare aspects are not well established (El Sabry et al., 2022). In addition to issues related to welfare, pre-slaughter stressors can influence carcass weights and meat quality indicators, such as colour change (Ali et al., 2008;Hussnain et al., 2020). ...
The Effect of Space Allowance During Pre-Slaughter Transport of European Quail Breeders on Welfare, Carcass Traits and Meat Quality
Article
Full-text available
  • Mar 2023
The objective was to evaluate whether space allowance during pre-slaughter transport of European breeding quail affects welfare, carcass traits and meat quality. A total of 248 quails (body weight = 344.90 ± 2.09 g) were used. During pre-transport, the quails were fasted for 5 hours and 30 minutes. The poultry were caught and placed in plastic transport crates with an area of 0.40 m². The treatments consisted of a different space allowance in each crate: 22, 28, 34 or 40 quails per crate. Immediately upon arrival at the slaughterhouse, the quails were stunned. During bleeding, blood samples were collected. The carcasses were individually weighed. The meat quality was measured. Data were analysed using the effects of space allowance during transport of quails and pickup truck as dependent variables. Death on arrival increased as the space allowance in transport crates decreased (p=0.08). Glucose and uric acid levels were not significantly different between groups (p≥0.14). The cold carcass weight presented the maximum value when the crates contained 31 quails (p=0.03). The meat pH, intensity of red, intensity of yellow and cooking losses were not different between groups (p≥0.12). The meat lightness value presented the maximum value when the crates contained 31 quails (p=0.04). In view of the above, the number of European breeding quails transported in crates must not exceed 30 animals. Keywords: Crate density; crating; space; stocking density; transportation
View
... In agreement with these findings, PBC supplementation quadratically increased 45-min yellowness, linearly increased 24-h pH value, quadratically decreased 24-h lightness, and linearly and quadratically reduced 24-h drip loss in pectoralis major muscle, which together imply an improved meat quality. After slaughter, muscle buffering capacity dramatically reduces, and muscle energy consumption continues postmortem with the generation of large amounts of lactate and protons due to the anaerobic carbohydrate metabolism, leading to a decline in pH value (P€ os€ o and Puolanne, 2005;Ali et al., 2008;Le Bihan-Duval et al., 2008). The direct regulatory effects of zinc and essential oils, 2 major components of PBC, on muscle glycolytic metabolism and subsequent pH value have been reported previously. ...
Effects of dietary supplementation with different levels of palygorskite-based composite on growth performance, antioxidant capacity, and meat quality of broiler chickens
Article
Full-text available
  • Mar 2023
  • POULTRY SCI
This study was conducted to investigate the effects of different levels of palygorskite-based composite (PBC) on growth performance, antioxidant status, and meat quality of broilers. A total of 320 one-day-old mixed-sex Ross 308 broiler chicks were allocated to 1 of 5 groups with 8 replicates of 8 birds each, and given a basal diet supplemented with 0, 250, 500, 1,000, and 2,000 mg/kg PBC for a 42-day trial, respectively. PBC quadratically increased feed efficiency during the late and overall experimental periods (P < 0.05). Compared with the control group, 1,000 mg/kg PBC increased feed efficiency during the overall period (P < 0.05). PBC linearly increased serum total superoxide dismutase (T-SOD) activity at 21 d and glutathione peroxidase (GSH-Px) activity at both 21 d and 42 d (P < 0.05). Compared with the control group, PBC supplementation, regardless of its level, increased 21-day serum SOD activity (P < 0.05). The 21-day serum GSH-Px activity was increased by PBC when its level exceeded 250 mg/kg (P < 0.05). PBC linearly increased 42-day total antioxidant capacity (T-AOC) activity, but linearly decreased 42-day malondialdehyde level in liver (P < 0.05). An addition of PBC, irrespective of its level, increased 42-day hepatic T-AOC activity (P < 0.05). PBC quadratically increased 45-min yellowness value and linearly increased 24-h pH value, but quadratically decreased 24-h lightness value and linearly and quadratically reduced 24-h drip loss in breast muscle (P < 0.05). Compared with the control group, the 24-h drip loss of breast muscle was decreased by PBC, regardless of its dosage (P < 0.05). An addition of PBC linearly increased 42-day T-AOC and T-SOD activities of breast muscle (P < 0.05). Compared with the control group, muscle T-SOD activity was increased by PBC, regardless of its administration level (P < 0.05). These results suggested that PBC could improve growth performance, antioxidant capacity, and meat quality of broilers, and its recommended dosage is 1,000 mg/kg.
View
Quality of poultry meat- the practical issues and knowledge based solutions
Article
  • Feb 2023
Animal protein is the most demanded and expensive source of nutritive protein, globally. Taking into account various types of poultry, the broiler (meat-type poultry) is widely accepted by various religious societies and relatively cheap amongst others animal protein sources. In particular, the chicken and turkey product is perceived to be healthier and of better quality due to a low content of fat, cholesterol and sodium compared to red meat. In order to maintain an unabated development and competitiveness of poultry industry, the priority is to focus on quality and safety of meat, during whole production and processing route. Consumers awareness of what should be considered a high quality product is constantly increasing, especially in the light of European and worldwide strategies to meet the common societal and environmental challenges, i.e. addressing the Zero Hunger goals, Green Deal and One Health concept. In this chapter, a common area of interest for a dialogue of poultry scientists and industrial practitioners is drawn from the background given on the consumer (demands and health)-centered issues.
View
Reducing Dietary Crude Protein for Broilers While Satisfying Amino Acid Requirements by Least-Cost Formulation: Live Performance, Litter Composition, and Yield of Fast-Food Carcass Cuts at Six Weeks
Article
Full-text available
  • Oct 1992
A dietary regimen employing the CP, ME, and essential amino acid (EAA) levels advocated by National Research Council in 1984 for broilers from 0 to 3 and 3 to 6 wk was compared with one in which only the CP was reduced from 23 to 20 and 20 to 17%, respectively. Corn, soybean meal, corn gluten meal, and fish meal analog were used together with the commercially available free EAA in least-cost formulation. Males and females from Peterson × Arbor Acres and Ross × Arbor Acres were grown in floor pens simulating commercial conditions. Live body weights were unaffected by dietary CP level throughout production; however, feed conversion was increased during the 3- to 6-wk interval when the CP was reduced. Reducing the dietary CP substantially decreased N content of the litter. Processing the birds revealed an increase of depot fat in the abdominal cavity when low CP had been fed. Removal of this fat depot led to a lower chilled carcass weight than when the 1984 National Research Council levels were employed. Cutting the carcass into fast-food portions indicated that reduced CP also decreased the proportion of split breast with back using an eight-piece cut and keel portion of the breast based on a nine-piece cut whereas thigh with split back increased. Both sexes and each strain responded similarly. Although reducing dietary CP reduces N content and, therefore, pollution potential of the resulting litter, adverse effects occur in live performance and the yield of breast pieces with two fast-food cutting procedures.
View
Effect of Free Struggle and Preslaughter Excitement on Color of Turkey Breast Muscles
Article
Full-text available
  • Nov 1982
The color changes produced in turkey muscle by excitement prior to slaughter and free struggle during slaughter were further characterized using reflectance analyses. The reflectance spectra of raw samples indicated that the darker color in breast muscle from birds exposed to excitement prior to slaughter and allowed to struggle freely during slaughter may be due to a higher concentration of cytochrome c. Cytochrome c may contribute to pink color problems in further processed turkey products.
View
Feed and Water Withdrawal Time Relationship to Processing Yield and Potential Fecal Contamination of Broilers
Article
Full-text available
  • Jul 1972
Trials were conducted to determine feed and water withdrawal times for broilers prior to slaughter which would result in lowest loss in eviscerated yield and lessen potential for fecal contamination of carcasses. Percent loss in live weight expressed as shrink showed a linear relationship with time. Loss at the twenty-four hour period was approximately double that at the twelfth hour. Eviscerated yield when based on initial weight showed a tendency for loss in yield with increasing withdrawal time whereas the opposite trend was shown when yield was based on weight at time of slaughter. Least differences were noted from the eighth to tenth hour of holding. Fecal contents were lowest at the eighth to tenth hour of withdrawal. This would be conducive to a lessened possibility for fecal contamination. The data points out the need for more precise scheduling of withdrawal and holding period prior to slaughter to reduce losses due to yields and fecal contamination of carcasses.
View
Studies on Blood Sugar and Glycogen Levels in Chickens
Article
Full-text available
  • Sep 1953
IT HAS been reported that mature New Hampshire pullets will tolerate high concentrations of low-grade sugar (Rosenberg, 1953a) and B-grade molasses (Rosenberg, 1953b) for at least 20 weeks. No adverse physiological effects, denoted by unthriftiness and mortality, were observed even when all the cereal grains in their rations were supplanted by either low-grade sugar or B-grade molasses. However, efficiency of feed utilization progressively worsened as the concentration of these byproducts from the sugar industry was increased. It has been reported, also, that Ingram et al. (1950) obtained good egg production during a 4-week trial with chickens fed purified diets in which sucrose was the principal source of carbohydrate. Since sucrose is the principal sugar in low-grade sugar and B-grade molasses, questions have been raised regarding the ability of the chicken to utilize efficiently these carbohydrate feedstuffs. Golden and Long (1942), in their excellent review of carbohydrate metabolism in avian species, …
View
The Influence of Fasting and Transport on Yields of Broilers
Article
Full-text available
  • May 1978
Yields of the components of carcasses were measured on broilers fasted different periods of time prior to slaughtering. The total wt losses after 4 hr of fasting are .353%/hr. These losses are mainly caused by the losses of the edible parts, which are .24%/hr. The results of measuring the losses of dry solids, water, and fat of the edible parts without giblets are hard to interpret due to the great variation in the chemical composition of the edible parts of individual broilers.
View
Influence of Length of Feed Withdrawal Times on Proximate Composition and Levels of Selected Vitamins and Minerals in Broiler Breast Meat
Article
Full-text available
  • Aug 1985
The length of time broilers are off feed and water prior to slaughter may influence processing yield and fecal contamination. This study was undertaken to determine if lengthy withdrawal times have any effect on the composition of broiler breast meat. Three groups of broilers, off feed for 8, 20, or 32 hr (water was withdrawn 2 hr after feed withdrawal) were conventionally processed. At least 20 carcasses per group were randomly selected and the breast meat analyzed for proximate composition, five minerals (phosphorus, potassium, sodium, magnesium, and calcium), and three vitamins (riboflavin, niacin, and B6). Results showed no significant differences (P<.05) between treatments in any of the components determined except for protein. However, the difference was only .6% and should be of little concern in human nutrition.
View
The Effect of Preslaughter Environmental Temperature in the Presence of Electrolyte Treatment on Turkey Meat Quality
Article
Full-text available
  • Dec 1982
Ninety torn turkeys at 26 weeks of age, given Dawelyte electrolyte at .10% level in the drinking water 3 days prior to slaughter, were equally randomized into three preslaughter temperature environments for 4 hr: 1) control chamber at 21 C, 2) heat chamber at 38 C, and 3) cold chamber at 5 C. The birds were then processed using standard processing procedures and kept at −29 C until needed for further analyses. Carcass yield, quality attributes, chemical composition, and color of the breast muscles were evaluated. Under the conditions of this study, preslaughter administering of electrolytes did not prevent changes in muscle characteristics after exposure to preslaughter stress. Holding birds at high temperature (38 C) prior to slaughter resulted in meat with a lower pH, water holding capacity, cooking yield, and a higher shear value. Meat color from heat stressed birds was also pale compared to the control or cold preslaughter treatments. A cool preslaughter environment seems to produce meat with better carcass quality characteristics. Chemical composition was not significantly affected by the short-term preslaughter environmental temperature stress.
View
Age-related effects of heat stress on protective enzymes for peroxides and μsomal monooxygenase in rat liver
Article
  • Jul 1997
To evaluate the age-related response of essential cell functions against peroxidative damage in hyperthermia, we studied the biochemical response to heat stress in both young and aged rats. Passive hyperthermia was immediately observed in rats after exposure to hot environments. In aged rats, the rectal temperature maintained thermal homeostasis and increased to the same degree as in young rats. In these aged animals, the damage from heat stress was more serious than in young animals. In aged rats under normal environmental conditions, hepatic cytosolic glutathione peroxidase (GSH peroxidase) activities were markedly higher than those activities in younger rats. Hepatic cytosolic GSH peroxidase activities were induced by heat stress in young rats but were decreased by hot environments in aged rats. Hepatic catalase activities in young rats were not affected by hot environments, whereas in aged rats, hepatic catalase activities were seriously decreased. Catalase activities in the kidney of aged rats were also reduced by hot environments. Lipid peroxidation in the liver was markedly induced in both young and aged rats. Because the protective enzymes for oxygen radicals in aged rats were decreased by hot environments, lipid peroxidation in the liver was highly induced. In aged rats, lipid peroxidation in intracellular structures such as mitochondria and microsomes was also markedly induced by hot environments. In both young and aged rats, hyperthermia greatly increased the development of hypertrophy and vacuolated degeneration in hepatic cells. In aged rats, both mitochondria and endoplasmic reticulum of the hepatic cells showed serious distortion in shape as a result of exposures to hot environments. Microsomal electron transport systems, such as cytochrome P450 monooxygenase activities, were seriously decreased by heat stress in aged rats but not in young rats. Although the mitochondrial electron transport systems were not affected by acute heat stress in young rats, their activities were simultaneously inhibited after long-lasting heat exposure. In isolated hepatic cells and polymorphonuclear leukocytes in animals, the 70-kDa heat shock-induced proteins were markedly increased by heat stress. In conclusion, the heat stress-inducible oxygen radical damage becomes more severe according to the age of rats. Because aging and hyperthermia have a synergistic effect on lipid peroxidation, protective enzyme activities for oxygen radicals may be essential for surviving and recovering from thermal injury in aged animals and also in humans.
View
Lipid Metabolism and Peroxidation in Broiler Chicks under Chronic Heat Stress
Article
  • Aug 2006
The effects of taurine supplementation on growth performance, serum and liver concentrations of lipid, fatty acid composition and lipid peroxidation in the livers of broilers under chronic heat exposure conditions were investigated. The chicks with a similar body weight were equally assigned to one of three controlled-environment chambers. The brolier chicks, which were kept at 34°C were fed either with a control diet or the control diet supplemented with 0.8% taurine, whereas broiler chicks kept at 22°C were fed a control diet. Both of the BW and BW gains of broilers maintained at a temperature of 34°C were significantly lower than those of the control group, which was maintained at a temperature of 22°C (p<0.05). However, taurine addition in the diet of birds submitted to heat stress siginficantly improved BW gain (p<0.05). The feed intake of chicks declined with increases in temperature. The relative liver and gall bladder weights of chicks fed the control diet and maintained at 34°C were significantly lower than those measured in the control birds (p<0.05). However, dietary taurine was found to compensate for these reductions in liver and gall bladder weights. Relative weights of abdominal fat did not differ significantly among the three groups. Serum triglyceride concentrations were significantly lower in the chicks fed the control diet and maintained at 34°C compare to those measured in the chicks fed the control diet at 22°C (p<0.05). Heat stress resulted in a significant reduction in total lipid and triglyceride levels, but also increased the levels of total cholesterol in the liver (p<0.05). However, dietary taurine supplementation under the heat stress condition resulted in the recovery, to control levels, of serum triglyceride concentrations, as well as the amounts of total lipids, triglycerides, and cholesterol in the liver. The livers of chicks fed on taurine diets at 34°C showed significantly higher proportions of C14:0, C16:1, C18:1, C18:2, and 20:3. and lower C18:0 and C20:4 proportions than those of chicks fed on control diets at the same temperature (p<0.05). The total levels of saturated fatty acids decreased, but monounsaturated fatty acids and unsaturated fatty acid levels increased in chicks fed the taurine diet, as compared to chicks fed the control diet at 34°C (p<0.05). Peroxidizability indices were significantly lower in the heat-exposed chicks fed the taurine diet than in the non-taurine heat-exposed groups (p<0.05). In conclusion, dietary taurine results in an increase in the growth performances of chicks under heat stress conditions via improvements in lipid absorption and metabolism, as well as an induced reduction in lipid peroxidation.
View
Shackling of poultry: Is it a welfare problem?
Article
The slaughter of poultry differs from the slaughter of all other meat-producing animals in that the live birds are hung upside down in shackles prior to slaughter. There is concern from animal welfare organizations such as the United Kingdom Farm Animal Welfare Council that this practice, although necessary for present methods of humane slaughter, causes possible distress and pain to the birds. This paper reviews the regulations on the provision for the welfare of poultry at slaughter as it affects shackling, the equipment involved in shackling, and the physiological and psychological effect of shackling on birds.
View