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Influence of production systems and sex on nutritional value and meat quality of native Malawian Muscovy ducks
Abstract
This study was conducted to assess effects of production systems and sex on nutritional value and meat quality of native Malawian Muscovy ducks. One hundred twenty ducks were randomly assigned to either an intensive (IS), duck-rice integration (DR) or free-range (FR) production system. A starter ration containing 20% crude protein and a finisher containing 17% crude protein were fed to ducks in IS (1 to 4 weeks), and provided as a supplement to ducks in DR and FR (5 to 10 weeks). Feed and water were offered ad libitum. At 10 weeks of age, 16 ducks per treatment were selected randomly, slaughtered and chilled at 4 °C for 24 hours. Carcass temperature, pH and meat colour were measured at 45 min, and at 3, 6, 12 and 24 hours post mortem. Tenderness, cooking loss, proximate and mineral composition were determined 24 hours post mortem. Production system and sex had no effect on carcass temperature, pH and proximate composition of duck breast meat. However, production system affected tenderness and mineral composition of the meat and sex influenced moisture and tenderness. Males were moister and had less tender meat than females. Carcasses from ducks in the FR system contained more zinc, copper, manganese, and potassium, but less iron while those in IS had the lowest mineral content of the three production systems. Thus, DR can be adopted to improve the current FR system of native Malawian Muscovy duck production with supplementation to produce duck with acceptable mineral composition and better meat quality. Keywords: cooking loss, meat colour, mineral, proximate composition
... Moreover, in 110-week-old Peking ducks, the cooking loss of males duck meat was higher than that of females (Kokoszyński et al., 2020). In contrast, sex did not influence cooking loss (Tanganyika & Webb, 2019). The cooking loss was closely corelated with meat final product; therefore, it became an essential indicator of meat quality in the food industry (Huda et al., 2011). ...
... A lower value of the cooking loss indicated a better meat quality (Patriani et al., 2021). Cooking loss is also an indicator of water holding capacity (WHC), which influences meat quality (Tanganyika & Webb, 2019). ...
... According to Tanganyika and Webb (2019), duck meat ranks third in poultry meat, which is widely produced worldwide after chicken and turkey. Asia is a leading producer and consumer of duck meat globally, with China as the main leader. ...
The duck meat industry in South Africa remains a niche yet steadily growing industry within the broader poultry market. While chicken continues to dominate with 93% of poultry production, duck meat has demonstrated strong growth rates, outpacing chicken in percentage terms over recent years. Between 2021 and 2023, commercial duck production increased by 14.2% and 3.3% consecutively, highlighting its potential as an emerging industry when others were experiencing a negative growth rate.
... At the start of the experiment Muscovy ducklings were vaccinated against Gumboro and Newcastle disease and were dewormed with Piperazine. Although ducks are resistant to most avian diseases and do not have standard vaccination programme, they are regarded as carriers of some poultry diseases [6]. Later they were individually weighed and tagged for identification. ...
A study to assess the effect of replacing Soybean with Pigeon pea on growth performance, meat quality and sensory characteristics of Malawian Indigenous Muscovy ducks was conducted at Bunda Campus of the Lilongwe University of Agriculture and Natural Resources (LUANAR). The study used forty-two (42) ducks which were assigned to two treatments (T1:21 ducks on Soybean meal based-ration, T2:21 ducks on Pigeon pea-based ration). Major feed ingredients were analyzed for nutrient composition before formulating ration. Starter of 20% CP and finisher of 17% CP was fed to ducks in an intensive system. Weekly body weights were measured and used to determine average daily body weight gain which showed better results on pigeon pea fed ducks. Feed conversion ratio were statistically significant with pigeon showing the best value of 2.0 ± 0.00 and Soybean 2.24 ± 0.00. At the 12 th week of age, six ducks from each treatment were selected with reference to mean weight and then slaughtered. Using the right breast muscle, Carcass temperature, and pH were measured at 45minutes, 3hours, 6hours, 12 hours and 24hours post-mortem. Cooking loss, drip loss, and color were determined at 24hours post-mortem. There was no difference between treatments on redness (a*) but the difference was observed on lightness (L*) and yellowness (b*). The left breast muscle was cut from each duck, labelled then chilled at 4 0 C for 24hours followed by cooking at 70 0 C for 15 minutes by boiling. Trained panelists scored the meat samples for sensory characteristics. The results showed that the panelists preferred duck meat from pigeon pea-based ration to Soybean based ration. Therefore, pigeon pea can replace soybean as a protein source since it has a positive effect on Malawian Indigenous Muscovy ducks.
... The male Muscovy duck is prioritized for the meat, while the female Muscovy duck is the egg production (Fouad et al., 2018). Gender determination from an early age needs to be done for the efficiency and effectiveness of duck production (Tanganyika and Webb, 2019). Sex differentiation using the cloacal inspection method is difficult for farmers to do on a duck that has not yet reached sexual maturity due to the difficulty in identifying the penis at a young age (Odwyer et al., 2006). ...
Gender determination of Muscovy duck as early as possible is essential for the efficiency and effectiveness of duck production. This study aimed to determine the morphometric differences in prepubertal male and female Muscovy duck (Cairina moschata) as predictors of gender. This study used a split-plot design, with the observed variables cranium length, width and height, mandibular length, and rostrum length and width. This study used a total of 80 samples of duck heads consisting of 40 male and 40 female Muscovy duck heads, with ten heads each in the age group of 2, 4, 6, and 8 weeks, respectively. Results showed that the length, width, and height of the cranium, mandibular length, and rostrum lengthand width were greater in males (p <0.05) than those of the females in all age groups. It could be concluded that the morphometric size of prepubertal male Muscovy ducks head was greater than those of the female ones at the same age; thereby, it could be used to distinguish gender. Based on the morphometrics, further study can also be conducted to measure other body parts of the Muscovy duck apart from the cranium. In addition, it is necessary to study the morphometric measurements of the cranium in other poultry as a basis for identifying sex.
... The decrease in pH measured 24 h postmortem compared to pH measured 45 min postmortem indicates normal biochemical changes in breast muscles, and also affects the ability of meat to retain water (water-holding capacity) (Tanganyika and Webb, 2019). This relationship was observed in our study when analysing breast muscles from ducks. ...
Duck’ meat is characterized by good nutritional properties and gaining popularity in the consumer market. Extruded soybean is potentially more digestible than commonly use soybean meal, and is expected to influence carcass traits and the quality of breast and leg muscles. The study’ aim was to compare meat quality from both sexes’ ducks fed a diet with extruded soybean (ESB) as a substitute for soybean meal (SBM). Cherry Valley ducks were divided into two groups. The control group (1) was fed an SBM-based diet, and the treatment group (2) with ESB. Each group was divided into sex subgroups with 50 birds in each (5 replicates, 10 ducks each). Dissection and analysis of meats’ pH, colour, water-holding capacity (WHC), drip loss and chemical composition of breast and leg muscles were done. Interaction of Diet and Sex was calculated. In group 2 higher carcass weight, dressing percentage, weight of wings, leg muscles, total muscles, and better WHC were found. Dressing percentage, the proportion of neck with skin, breasts’ and stomach’ weight, and the weight and proportion of fat, and pH45min were higher in females (p<0.05). The interaction was found for the pre-slaughter body weight, the weight of carcass remains, WHC in breasts (p<0.05). The ESB feed had no negative effect on the analysed traits and can be used in the ducks’ diet. Improved the WHC indicates the high suitability of meat for processing. A positive effect of diet on the muscles’ proportion and dressing percentage was noticed, which is important for consumers’ market. The sex-related differences and interactions between variables suggest separate rearing due to sex.
Free-range chicken production has significantly increased in recent years and it often entails exposing birds to cyclic environmental conditions. The objective of the current study was to investigate the effect of bird strain and sex, and rearing system on the physiological responses of Potchefstroom Koekoek (PK), Ovambo (OV) and Naked Neck (NN) chickens reared in a hot environment. Body weight (BW), rectal temperature (RT), respiratory rate (RR) and heart rate (HR) were determined weekly for 4 weeks, in 3 slow-growing chicken strains under cyclic environmental conditions. A total of 288, 20-week old Potchefstroom Koekoek (PK), Ovambo (OV) and Naked Neck (NN) chickens were separated by sex and allocated to extensive and intensive rearing systems. Ambient temperature and relative humidity (RH) were used to compute a temperature humidity index (THI). A Proc MIXED model was used to analyze fixed effects and a linear regression model was fitted to test the relationship between THI and response parameters. All factors studied influenced (p<0.05) BW while none affected (p>0.05) RT. Higher BW (p<0.05) were obtained with OV in both rearing systems. Sex influenced (p=0.0021) HR but not RR (p>0.05). Week and rearing system affected (p>0.05) RR. THI showed significant correlation with RR and HR. THI was higher in intensive than extensive rearing. Physiological responses of PK, OV and NN are comparable under similar rearing conditions.
Objective:
The aim of this study was to compare carcass traits, meat quality and sensory attributes in two different genotypes of geese according to age and sex.
Methods:
The experiment was carried out on 160 birds of two genotypes of geese: the Czech Goose (CG) breed and a Eskildsen Schwer (ES) hybrid. One-d-old goslings were divided into four groups according to genotype and sex. Two dates for slaughtering (at 8 and 16 wk of age of goslings) were undertaken.
Results:
The slaughter weight, cold carcass weight and dressing percentage were affected by all the studied factors, and significant interactions between age, genotype and sex were detected in the slaughter weight (P < 0.001) and cold carcass weight (P = 0.004). The pH was not affected by any of studied factors, whereas in terms of meat colour parameters there were observed significant effect of age on L* and b* value and significant effect of sex on a* value. The meat fat content was higher (P = 0.002) in ES. Higher score for overalll acceptance of goose meat was detected in ES at both ages than in CG.
Conclusions:
ES had higher dressing percentage and better sensory attributes, whereas CG exceled in the favourable nutritional value of the meat.
• The post-mortem proteolysis and tenderisation between male and female duck breast muscles were compared.
• The results showed that μ-calpain activity, desmin content and shear force decreased more quickly in female than in male samples stored at 5°C.
• It is suggested that the post-mortem proteolysis and tenderisation are more rapid and extensive in female duck breast muscle.
A growing awareness of human health, nutrition, and animal welfare concerns has led to the development of specialty markets for organic food. Poultry produced in alternative systems, such as free-range or organic, are part of this trend. The aim of the present study was to evaluate the differences in growth performance, carcass traits, and meat quality of medium-growing chickens raised in three different raising systems: indoor-floor, cage, and free-range. One hundred and twenty female Lingnanhuang medium-growing birds were reared in each system. All birds were offered the same diets and were grown for 90 days. The body weight gain and feed conversion ratios (feed/gain) of birds from the cage and indoor-floor systems were superior to those kept in the free-range system. The raising system significantly affected eviscerated carcass, abdominal fat, breast muscle, and leg muscle yields as well as shear force value of muscle (P < .05). There was no difference in pH, water-holding capacity, intramuscular fat, and inosine monophosphate content among the systems (P > .05). In conclusion, in medium-growing chickens, the free-range raising system had significant negative effects on growth performance and abdominal fat content.
Consumer acceptance of meat is strongly influenced by the eating quality. Cooking method has great impact on eating quality of meat, and energy consumption is important parameter to consider while selecting the cooking method. Energy requirement for well-cooked meats varies with cooking method, appliances and consumer behaviour. Energy consumption reduction during meat cooking may have the influence on global energy requirement. This article critically reviewed the effects on quality characteristics of meat and meat products by different cooking methods. The different cooking methods including oven, frying, sous vide and ohmic cooking are discussed in detail, and their effects on meat quality parameters such as colour, tenderness, cooking loss, shrinkage and juiciness are also presented. Highlighting on the role of cooking process on meat quality, energy requirement for cooking were identified.
We investigated marinade absorption and physicochemical characteristics of vacuum-aged duck breasts that were halved and individually vacuum-packed for chiller aging at 4°C for 14 d. One half was marinated for 0, 7, or 14 d, while the other half was used as a control. Marinade absorption, cooking loss, cooking yield, texture profile, pH, color, protein solubility, and thiobarbituric acid reactive substances (TBARS) values were evaluated, and protein sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) was performed. Marinade absorption and pH did not vary significantly after 14 d of aging. Marination increased the pH, color (a* and b*) values, and cooking yield and reduced cooking loss. TBARS values significantly increased with aging time, but were significantly reduced by marination. Myofibril and total protein solubility increased with aging and marination, while SDS-PAGE showed protein degradation. Hence, aging and marination can be used simultaneously to improve physicochemical quality and cooking yield of vacuum-aged duck breast.
A series of experiments was conducted to determine muscle fiber type, area, and distribution, and muscle total collagen, color, proximate composition, total fatty acid profile, calories, and cholesterol content for Pekin duckling and broiler chicken Pectoralis muscle. Duckling Pectoralis contained approximately 16% white fibers and 84% red fibers compared with 100% white fibers in the chicken Pectoralis. Duckling white fibers were significantly (P < .05) smaller than broiler white fibers, 1,809 versus 3,346 μm², respectively. Duckling red fibers averaged 301 μm². Total collagen content of duckling Pectoralis muscle was 1.75 mg/g muscle and was significantly greater than chicken Pectoralis muscle (1.27 mg/g). The International Commission on Illumination redness (a*) value was higher for duckling than chicken, whereas lightness (L*) and yellowness (b*) values were lower. Moisture and lipid contents were greater for duckling Pectoralis, 77.7 versus 74.2%, and 2.3 versus 1.6%, respectively, but duckling muscle contained less protein and ash, 19.5 versus 23.3%, and 1.09 versus 1.14%, respectively. Duckling Pectoralis contained more saturated and less monounsaturated fatty acids than chicken, with no difference between species for polyunsaturated fatty acids. Duckling Pectoralis muscle was lower in calories than chicken, 1.2 versus 1.4 kcal/g of muscle, but higher in cholesterol, 99.1 versus 47.4 mg/100 g of muscle.
Inheritance chickens are important in the developing countries, because of their meat quality. The present study was performed to investigate the effect of genetic background of Baetong, Black-boned, and Praduhangdum chickens. 30 chickens each and 4 replications of the chicken breeds were reared for 14 weeks. 10 chickens of each replication were sampled and analyzed, including carcass characteristics and meat quality as well as Shear’s value, water holding capacity, and color of their meat. No different marketable weight and hot carcass weight was found (P>0.05). Baetong chickens were lower hot carcass yield than Black-boned chickens and Praduhangdum chickens (P<0.05). Conversely, Baetong chickens were higher structural frame than Black-boned chickens and Praduhangdum chickens (P<0.05). Black-boned chickens and Praduhangdum chickens were edible portion, and wing yield than Baetong chickens (P<0.05). Black-boned chickens and Baetong chickens have more leg yield than Praduhangdum chickens (P<0.05). While, Praduhangdum chickens have more breast yield than the other chickens (P<0.05). Black-boned breast meat was more Shear’s force and Shear’s energy than Baetong breast meat and Praduhangdum breast meat (P<0.05). Black-boned breast meat and skin was darken than Baetong and Praduhangdum breast meat and skin (P<0.05). Black-boned breast meat was more drip losses than the others (P<0.05), while being lower cooking losses than the others (P<0.05). At the typical marketable weight, Black-boned chickens and Praduhangdum chickens have better meat quality compared with the carcass from Baetong chickens.
The current trial was conducted to determine the influence of different raising systems on the meat quality properties of male Turkish Pekin ducks. Ninety male ducklings were randomly allocated to three experimental groups: an animal-fish integrated farming group (IG), a non-animal-fish integrated farming group (NIG) and a poultry house group (PHG). All ducklings were fed a starter diet from weeks 2 to 6 and a finisher diet from weeks 6 to 10. Feed and water were offered ad libitum. At the end of the trial all ducks were slaughtered and the carcasses were stored at 3 °C for 24 hours, after which L*, a* and b* values of the carcass skins were measured. After standard dissection of carcasses, pectoralis muscles were obtained on which pH, colour (L*, a*, b*, C and H), total aerobic mesophilic, total aerobic psychrotrophic, lactic acid bacteria, Micrococcus/Staphylococcus, yeast-mould and Enterobacteriaceae counts were determined. The different raising systems of the ducks had significant effects on the pH, total aerobic mesophilic, Enterobacteriaceae, and L* and b* values of the pectoralis muscle. The lowest pH, total aerobic mesophilic and Enterobacteriaceae counts were found in the PHG group. The lowest L* values for the pectoralis muscle were found in the IG group while the highest a* value was recorded in the IG group. Significant differences in skin colour were observed between the experimental groups. For all production groups, all microbial counts were found to be within acceptable ranges. However, pH, total aerobic mesophilic and Enterobacteriaceae results were found to be lower in the PHG group than in the other groups. Different raising systems were thus found to affect the meat and skin colour of ducks, which may influence the preference of consumers.
Copyright resides with the authors in terms of the Creative Commons Attribution 2.5 South African Licence. See: http://creativecommons.org/licenses/by/2.5/za Condition of use: The user may copy, distribute, transmit and adapt the work, but must recognise the authors and the South African Journal of Animal Science. _____________________________________________________________________________ Abstract Demands for products of animal origin are increasing worldwide owing to the significant growth in the human population and changes in the health, wealth and life expectancy of people. The agricultural sector has the scientific knowledge, expertise and technology to respond to these challenges, but consumers are concerned about the methods used to meet these new challenges. They are also concerned about the environmental impact of modern technologies and intensification of production systems. Various combinations of pasture-based and intensive systems are employed to raise ruminant livestock, depending on resources and climate. The quality of animal products from production systems differs, but there are advantages and disadvantages for each. In South Africa, cattle and sheep are generally fattened for short periods to ensure efficient production and to meet market requirements. This is more easily achieved by feeding different proportions of concentrate diets, with or without feed additives and growth promotants that are approved for use in food-producing animals. Hormonal growth implants are strictly regulated for use in animal production systems. Production systems affect both the extrinsic and intrinsic aspects of carcass and meat quality of livestock. Extrinsic aspects that are affected include weight gain, age at slaughter and carcass weight. Concentrate feeding generally yields a more consistent carcass composition than pasture-fed animals, which addresses the necessity for more consistent meat quality. Intrinsic aspects of animal products that are affected include carcass composition and conformation, carcass fat content and colour, meat composition, colour, tenderness and flavour. Beef and lamb from pastures are darker, and carcass fat contains more yellow pigments, which may affect a consumer's choice to purchase. The typical pasture flavour in meat is because of the presence of branched-chain fatty acids, 3-methylindole and other oxidation products, and off-flavours are often detected. In many countries, the meat flavour of intensively fed livestock is preferred to pasture-fed animals, but certain consumers prefer the more intense pasture flavour. Pasture feeding has beneficial effects on n-3 fatty acids, notably eicosapentaenoic acid (EPA, C20:5n-3) and docasahexaenoic acid (DHA, C22:6n-3). Beef and lamb from pasture-fed animals are generally less tender, but shelf life is better, owing to the presence of antioxidants such as vitamin E.
This study was conducted to compare carcass characteristics and physico-chemical meat quality in two different genotype ducks raised under identical feeding and rearing conditions. A total of ninety 1-d-old Korean native ducks (KND, n = 45) and commercial meat-type ducks (Grimaud, n = 45) were fed same experimental diets during 56 d and 42 d, respectively to obtain similar slaughter weights. The experimental diet for starter period contained 20% crude protein (CP) and 2,900 kcal nitrogen corrected true metabolizable energy (TMEn)/kg of diet and that for grower period contained 17% CP and 3,050 TMEn/kg of diet. Average daily gain and feed efficiency of KND were inferior to those of commercial meat-type ducks (p<0.05). Carcass weight was not different between two genetically different ducks, but carcass yield of KND was significantly higher (p<0.05) than that of commercial meat-type ducks. There were no significant differences in cooking loss and pH of breast meat between two genetically different ducks, but water holding capacity of KND was significantly higher than that of commercial meat-type ducks. The linoleic acid and total polyunsaturated fatty acid of breast meat from KND were significantly higher (p<0.05) than the corresponding part from commercial meat-type ducks. Significant differences were detected in water holding capacity and the content of linoleic acid and polyunsaturated fatty acid, which were significantly higher in KND, whereas growth performance tended to be superior in commercial ducks. At the market weight, the meat from KND was judged to have better qualities with regard to higher water holding capacity and greater content of polyunsaturated fatty acid compare with meat from commercial meat-type duck.
This study was carried out to investigate the growth performance and the carcass ratio of meat-type Korean Native Ducks. Four hundred twenty Korean Native Ducks' chicks were selected and divided into four treatments (7 replications/ treatment, 15 birds/replication) by strains (A and B) and gender(male and female) with fractal factors. There was no significant difference between A and B on the body weight at 2, 4, 6, and 8 weeks old (P>0.05). However, body weight of female was higher at 2 weeks old than male while that of male was higher at the 8 weeks old (P
Year: 2014, Volumen: 64, No 2 , pages: 0-0
DOI: 10.2478/v10222-012-0096-y
Monika Michalczuk, Monika Łukasiewicz, Żaneta Zdanowska-Sąsiadek, Jan Niemiec
Comparison of Selected Quality Attributes of Chicken Meat as Affected by Rearing Systems
Keywords: slowly-growing chickens, meat quality, rearing system
Abstract:
The objective of this study was to establish the effect of rearing conditions of slowly-growing Hubbard JA 957 chickens on selected quality attributes of their meat. Birds from the control group (C) were kept on litter over the entire rearing period, whereas these from the experimental group (E) – with access to free range since the 4th week of life. The birds were slaughtered on day 63, and collected samples of breast muscles were assayed for proximate chemical composition, technological properties, and fatty acid profile in intramuscular fat. The study demonstrated no significant differences in the chemical composition of muscles depending on rearing systems. Meat of chickens using free range was characterised by higher shear force (P≤0.01). Which shows that it is tougher than the meat of chickens which do not use the free range. No significant differences were seen in physicochemical values when it comes to different systems of rearing. The access to free range does not also have any influence on the fatty acid formations. Lack of significant differences can show that the system of rearing has a minor effect when it comes to the quality of poultry meat.
Keywords: slowly-growing chickens, meat quality, rearing system
Analysed were 8-week-old males and females of duck paternal strains A44 and A55. The in vivo
weights of meat and fat with skin were estimated based on live body weight, breast bone length
and breast muscle thickness. Heritability coefficients for meat production traits and genetic and
phenotypic correlations between them were calculated. Carcasses were measured and dissected. In breast and leg muscles the pH and water holding capacity as well as water, protein, fat and ash were determined. Simple correlation coefficients were calculated between carcass weight with neck and carcass components, and body measurements. A55 ducks of both sexes showed greater meat and fat weight, but lower meat and higher fat content of carcass compared to A44 ducks. Based on the correlation coefficients between body measurements and body weight and carcass components, it is suggested that in order to increase the meat weight in the carcass, both strains should be selected for body weight, and strain A44 additionally for breast bone length and breast muscle thickness. Chest depth – which is positively and significantly correlated with the weight and content of breast and leg muscles of carcass, and negatively with the weight and content of subcutaneous fat with skin – can be used in selection for increased muscling and decreased carcass fatness. Also breast bone length and shank length, as well as chest and shank circumference can be used in the selection for increased meat weight and decreased fat weight in duck carcass. It is concluded, based on the pH, water holding capacity and chemical analyses of breast and leg muscles, that the culinary value of strain A55 meat is higher than of strain A44.
The aim of this work was to evaluate the moisture and ash content in meat of three
different local breeds of goat (Kamori, Pateri and Tapri). A total of 30 samples were randomly
collected from the local market of Tandojam- Pakistan. The results revealed that the average
moisture content in meat of Kamori breed was 76.56 ± 0.72% which is comparatively higher than
the mean moisture content in meat of Pateri and Tapri i.e. 72.63 ± 1.13% and 69.88 ± 0.93%
respectively. The over all moisture content in goat meat varied in a range of 65.92 and 80.02%
(mean 73.02 ± 0.732%). There were statistically highly significant differences (P< 0.001)
observed in meat of different breeds of goat. Further results of LSD (0.05) comparison of means
revealed that the moisture content in meat of different of goat are significant (P< 0.001) from
each other. The ash content in meat of all three breeds of goat meat was in a range of 0.87 and
1.97% (mean 1.40 ± 0.049%). Statistically there were highly significant differences (P< 0.001) in
average ash content in meat of these three different breeds of goat. LSD comparison of means
also showed significant differences (P >0.05) in average ash content in meat of different breeds of
goat.
This study was conducted to determine the effects of sex and age on meat quality characteristics of Turkish native geese raised under a free-range system. The range of least squares means for age and sex subgroups in terms of ultimate pH, water holding capacity (WHC), drip loss (DL), cooking loss (CL) and Warner-Bratzler shear force (SF) were 5.74-5.88, 8.99-9.69%, 3.36-3.63%, 27.67-29.97% and 3.15-3.38 kg/cm2, respectively. Least squares means for colour characteristics of breast skin were 61.97-62.60 for lightness (L*), 5.11-5.84 for redness (a*) and 11.18-12.26 for yellowness (b*) according to age and sex groups. Colour variables of breast meat were 40.15-40.59 for L*, 12.30-13.61 for a* and 0.83-1.16 for b* parameters. While the effect of age on breast meat quality characteristics were not significant (P>0.05), sex affected on ultimate pH and a* parameter significantly (P<0.05). Least squares means for age and sex subgroups in terms of ultimate pH, WHC and DL of thigh meat were 5.96-6.04, 5.97-6.90% and 2.51-2.68%, respectively. L*, a* and b* values for thigh skin were 62.57-63.16, 4.25-4.83 and 7.67-9.43, and also were 43.72-44.20, 9.79-10.38 and 0.84-1.23 for thigh meat. The effect of sex on yellowness of thigh skin was significant (P<0.05), but both sex and age did not affect on meat quality characteristics of thigh meat (P>0.05).
Thai indigenous chicken is one of the important chickens that are produced for consumption in Thailand. They make up almost 20 -25% of total chicken production in recent year. The quality attributes of this chicken meat are concordant with consumer demands for its unique taste and texture and nutritious meat. Factors affecting its quality characteristics should be reviewed to gain knowledge for developing or promoting this chicken meat in the future. Different breeds or genotypes of the indigenous chicken can cause a difference in the color of the meat. Rearing systems, such as intensive and extensive farming, promote differences in meat texture. The indigenous chicken reared under the intensive system has more tender meat and yellowish in skin color. The appropriate age of the indigenous chicken for consumption or further processing products is suggested to be 16 -18 weeks of age to ensure economical live weight and high meat quality. Aging condition, chemical composition and muscle protein properties are reflected in the quality of indigenous chicken meat. The indigenous chicken meat tends to have a longer time of rigor inset with lower ultimate pH compared to broiler meat resulting in lower water holding capacity. The high content of intramuscular collagen, but which is low in myofibrillar protein content, results in tough texture and high cooking loss in the meat during heating at 80 -100 o C. However, the indigenous chicken meat has high glutamic acid content but low fat and cholesterol contents. This, in concomitance with favorable fatty acid profiles, leads to the acceptably palatable meat that is desirable to consumers. The microstructure of muscle fiber and intramuscular connective tissue is the most important influence on the texture of indigenous chicken meat. Its muscle structure has very thick perimysium connective tissue and this is related to the high shear value of the meat.
A randomized complete block design within a factorial arrangement of treatments was used to evaluate the effect of strain and sex on carcass characteristics, meat quality, and sensory acceptability. Two broiler strains were reared: a commercially available strain (strain A) and a strain currently in the test phase (strain B) that has been genetically selected to maximize breast yield. Broilers were harvested in a pilot scale processing plant using commercial prototype equipment at 42 d of age. Carcasses were deboned at 4 h postmortem. The left half of each breast was evaluated for pH, color, cooking loss, shear force, and proximate analysis. The right side of each breast was used for consumer acceptability testing. Thigh meat was evaluated for proximate composition. No interactions were observed throughout the study. Male broilers had a higher (P < 0.05) live BW, carcass weight, and breast weight and lower (P < 0.05) dressing percentage and breast meat yield when compared with females. Broilers from strain B presented a higher (P < 0.05) breast yield and dressing percentage than those broilers corresponding to the commercially available broiler strain. At 24 h postmortem, female broilers presented a lower ultimate pH and higher Commission internationale de l'éclairage yellowness values (ventral side of the pectoralis major) when compared with male broilers. On average, no differences existed (P > 0.05) among treatments with respect to pH decline, cooking loss, shear values, and proximate composition. In addition, no differences (P > 0.05) existed among breast meat from the different strains with respect to consumer acceptability of appearance, texture, flavor, and overall acceptability, but breast meat from strain B was slightly preferred (P < 0.05) over that of strain A with respect to aroma. However, breast meat from both strains received scores in the range of "like slightly to like moderately." Overall data suggest that all treatments yielded high quality breast and thigh meat and strain cross did not present variability in terms of consumer acceptability.
Poultry production has risen rapidly due to the increased consumption of further processed chicken-based products such as sausages, nuggets and burgers. This increase in poultry consumption has been dominated by chicken meat. Duck meat is also widely available but less frequently utilized in further processed products due to certain limitations of its functional properties. Nonetheless, duck meat production has increased steadily over the years. One technology that may improve the functional properties of meat is surimi processing. This specialized washing process removes undesired components (e.g., fats, blood, enzymes and pigments) and increases the concentration of myofibrillar proteins that play important roles in the functional properties of meat. The successful development of fish surimi has inspired researchers to study surimi-like material made from other animal muscle. Several researchers have tested the properties of surimi-like material made from beef, pork, chicken, mutton and sheep and reported improved qualities compared with the original (untreated) raw meats. Surimi-like material also has been used in several product formulations for nuggets, frankfurters, sausages, restructured roasts and imitation crab sticks. Therefore, it is reasonable to assume that processing duck meat into surimi-like material could improve the functional properties of duck meat and allow its application in many further processed products.
Fifty-eight force-fed mule ducks were used to evaluate the variability of 'magret' (breast meat) colour. Trichromatic coordinates in the CIELAB system (L*, a*, b*) were measured at 4 and 24 h post mortem and after 6 days of storage at +4°C under an oxygen-permeable film. At 24 h post mortem, the colour of breast meat was visually assessed and the 'magrets' were assigned to one of three colour groups (normal, intermediate, pale). At 24 h post mortem, 22% of the magrets were classified as very pale, and showed higher L* and b* than those classified as normal. These differences were maintained over the 5 days storage but their magnitude was not increased. The L* and b* values were significantly and positively correlated with the content of intramuscular fat (r = 0.50, P < 0.01 and r = 0.29, P < 0.05, respectively). The different measurements could not clearly demonstrate that the abnormal colour was due to myoglobin and lipid oxidation and/or colour defects such as those encountered in PSE (Pale, Soft, Exudative) meat. These preliminary observations showed a high variability of breast meat colour in force-fed ducks. Further research is needed to elucidate the underlying mechanisms.
Experiments were conducted to evaluate the effect of free-range raising systems on growth performance, carcass yield, and
meat quality of slow-growing chickens. Slow-growing female chickens, Gushi chickens, were selected as the experimental birds.
Two hundred 1-d-old female chicks were raised in a pen for 35 d. On d 36, ninety healthy birds, with similar BW (353.7 ± 32.1g),
were selected and randomly assigned to 2 treatments (indoor treatment and free-range treatment, P > 0.05). Each treatment was represented by 3 groups containing 15 birds (45 birds per treatment). During the indoor treatment,
the chickens were raised in floor pens in a conventional poultry research house (7 birds/m2). In the free-range treatment, the chickens were housed in a similar indoor house (7 birds/m2); in addition, they also had a free-range grass paddock (1 bird/m2). All birds were provided with the same starter and finisher diets and were raised for 112 d. Results showed that the BW
and weight gain of the chickens in the free-range treatment were much lower than that of the chickens in the indoor floor
treatments (P < 0.05). There was no effect of the free-range raising system on eviscerated carcass, breast, thigh, and wing yield (P > 0.05). However, the abdominal fat yield and tibia strength (P < 0.05) significantly declined. The nutrient composition (water, protein, and fat), water-holding capacity, shear force,
and pH of the muscle were largely unaffected (P > 0.05) by the free-range raising system. The data indicated that the free-range raising system could significantly reduce
growth performance, abdominal fat, and tibia strength, but with no effect on carcass traits and meat quality in slow-growing
chickens.
1. The feasibility of killing 7-week old Peking ducks with gas mixtures and their effects on carcase and meat quality were evaluated and compared with killing in electrical waterbath under commercial conditions. 2. The prevalence of carcase appearance defects and broken bones in the carcases and haemorrhaging, pH, colour, cooking loss and texture of breast muscles were determined. 3. Ducks can be killed within 3 min by exposure to either 90% argon in air or a mixture of 30% carbon dioxide and 60% argon in air. 4. Gas or controlled-atmosphere killing of ducks, whilst they are still in their transport containers, would eliminate some of the welfare concerns associated with the conventional electrical waterbath stunning systems, without adversely affecting carcase and meat quality.
A case-control study (n = 130) was conducted on toms condemned for cyanosis. Color (CIE L*a*b*), pH, and physical characteristics were measured on the Pectoralis major at slaughter and after 24 h. Meat from carcasses condemned for cyanosis had dark, firm, dry-like traits. It was darker and redder and showed higher water-holding capacity, lower cooking loss, and higher gel strength than did controls. Perimortem pH was negatively correlated with the lightness (L*) of meat at the time of slaughter (r = -0.58) and at 24 h postmortem (r = -0.64), positively correlated with water-holding capacity (r = 0.73) and gel strength (r = 0.43) and negatively correlated with cooking loss (r = -0.50). Ultimate pH was negatively correlated with lightness (L*) of meat at slaughter time (r = -0.62) and at 24 h postmortem (r = 0.79) was positively correlated with water-holding capacity (r = 0.87) and gel strength (r = 0.61) and negatively correlated with cooking loss (r = -0.52). Tests based on pH and L* of the P. major were also assessed; tests based on pH had a sensitivity in the range of 0.79 to 0.89 and specificity (Sp) of 0.60 to 0.94. Tests based on L* showed sensitivity of 0.75 to 0.92, and specificity of 0.79 to 0.97. The repeatability of measurements varied from good (L*: rho = 0.6) to excellent (pH: rho = 0.92). Overall, turkey breast condemned for cyanosis showed dark, firm, dry-like traits. Tests based on color and pH are described as a means of identifying turkeys condemned for cyanosis.
Three replicate trials were conducted to determine the influence of raw breast meat color and pH on subsequent cooked meat color and pH. In each trial, approximately 50 breast fillets were obtained from a commercial processing plant based on being either normal, lighter than normal, or darker than normal. Color (L* = lightness, a* = redness, and b* = yellowness) of each fillet was determined in triplicate on the underside surface of the fillet (to avoid scalding effects), and the pH was determined on a tissue sample removed from the posterior portion of each fillet. Fillets were then cooked in steam at 98 C for 20 min and cooled to room temperature, and a second sample was removed from the posterior section for cooked meat pH. Cooked meat color was measured on an exposed surface, to avoid cooking-related discoloration. The data were subjected to linear regression analysis to determine the relationship between raw and cooked values. Results indicated a significant linear relationship between raw and cooked values for each color parameter as well as pH. Model R2 values were 0.43, 0.40, 0.64, and 0.78 for L*, a*, b*, and pH, respectively. There were also significant linear relationships between raw meat L* and raw muscle pH (R2 = 0.59) as well as cooked meat L* and raw meat pH (R2 = 0.36). These results indicate that raw breast meat color and pH affect cooked breast meat color and pH but that cooking reduces the degree of color variation. Moreover, cooked meat lightness is more closely associated with raw breast meat pH than with cooked meat pH.
This study utilizes an analysis technique commonly used in marketing, the conjoint analysis method, to examine the relative utilities of a set of beef steak characteristics considered by a national sample of 1,432 US consumers, as well as additional localized samples representing undergraduate students at a business college and in an animal science department. The analyses indicate that among all respondents, region of origin is by far the most important characteristic; this is followed by animal breed, traceability, animal feed, and beef quality. Alternatively, the cost of cut, farm ownership, the use (or nonuse) of growth promoters, and whether the product is guaranteed tender were the least important factors. Results for animal science undergraduates are similar to the aggregate results, except that these students emphasized beef quality at the expense of traceability and the nonuse of growth promoters. Business students also emphasized region of origin but then emphasized traceability and cost. The ideal steak for the national sample is from a locally produced, choice Angus fed a mixture of grain and grass that is traceable to the farm of origin. If the product was not produced locally, respondents indicated that their preferred production states are, in order from most to least preferred, Iowa, Texas, Nebraska, and Kansas.
The effect of age at slaughter on meat flavour, tenderness, drip loss, cooking loss and colour was studied in Malawian indigenous spotted (Kawangi) chickens. Thirty-two chickens (16 cocks and 16 hens) were slaughtered at 4 different ages: 16, 20, 24 and 28 weeks. There were equal numbers of cocks and hens in each age group. Meat tenderness and flavour were determined from the breast muscles and the drumstick using sensory evaluation by a trained taste panel.The increase in age at slaughter decreased tenderness and drip/cooking loss while increasing colour and flavour. The optimum age at slaughter was around 24 weeks of age.
1. The effects of age and sex on body weight, carcass traits, physical and chemical properties of breast muscle from chickens and helmeted guinea fowls managed under village free range conditions, were assessed in random sample of 48 guinea fowls and 48 chickens obtained from local markets.
2. Guinea fowls had higher body weight, hot carcass weight, cold dressed weight and breast weight than chickens.
3. Guinea fowls had more dry matter, protein and less fat than chickens. Ash content did not differ between guinea fowls and chickens. Protein and fat increased whereas dry matter and ash decreased with age (P < 0.05)
4. Chicken meat was lighter at, less red and more yellow than guinea fowl meat. Cooking loss was higher in guinea fowls, male and grower birds than chickens, females and adult birds, respectively. Shear force was affected by age, as mature birds had a higher value than growers.
5. Guinea fowl carcasses contained more meat that was leaner, higher in protein and redder compared with chicken meat. As age increased the meat increased in protein and fat content and shear force whereas colour became darker, redder and yellower.
Both, 50 Ross 208 (25 pullets and 25 cockerels) and 50 Prelux-bro (25 pullets and 25 cockerels) chickens were kept in extensive indoor rearing for 28 days. From the 28th to 56th day half of the chickens remained indoors while the others had access to free range during the day. Ross chickens weighed significantly more than the Prelux ones and the weight of extensive indoor reared chickens was not significantly higher than that of free range ones. Free range chickens were significantly less fatty (P = 0.0229; percentage of abdominal fat of body weight at slaughter) than extensive indoor reared chickens. Pullets were more fatty than cockerels (P = 0.0106 for percentage of abdominal fat of body weight at slaughter and P = 0.0207 for percentage of abdominal fat of carcass weight). Four cockerels and four pullets were chosen at random from each genotype (Ross 208 and Prelux-bro) from the extensive indoor and free range system of rearing for a comparative study of the chemical composition of meat. The system of rearing did not significantly influence the chemical composition of leg and breast muscle with skin. Genotypes and sex differed significantly only in the content of dry matter in breast muscle. Breast muscle of Prelux chickens contained more dry matter than breast muscle of Ross chickens and breast muscle of pullets contained more dry matter than breast muscle of cockerels.
Several factors may affect poultry breast meat quality, both intrinsic characteristics (age, sex, size and strain) and external influences (carcass aging time postmortem before deboning, fillet marination and cooking method). Commercial duck processors are now expanding into the deboned breast meat markets but very little research is available on duck meat quality as compared to other poultry species. Therefore, the following study was conducted to determine the effect of duck sex, size and fillet marination on breast meat quality. Duck rearing, processing and carcass deboning were conducted at a commercial facility. Carcasses were kept separate by sex and were then sized to 1.6 kg (S), 2.0 kg (M) and 2.5 kg (L) after chilling. After 6 h aging on the carcass, breast fillets were removed and half of the fillets from each sex-size category were marinated while the other half of the fillets (unmarinated) were held as controls. A total of 360 fillets were produced, 30 in each of 12 categories (2 sexes X 3 sizes X 2 treatments). At the laboratory, fillets were weighed, evaluated for raw color, cooked, reweighed, evaluated for cooked color and sheared via Warner- Bratzler (WB). Uncooked and cooked fillet weights were significantly affected by bird size (p<0.05). Marination increased fillet cook yield compared to control fillets (73.5% versus 69.1%, respectively) and decreased WB shear values (2.2 kg versus 3.2 kg, respectively). Less force was required to shear the first slice using WB as compared to the second WB slice (2.4 and 3.0 kg, respectively). Lightness (L*) and yellowness (b*) values were lower in uncooked fillets from females than males ducks and marination decreased raw fillet L* values and cooked b* values for both sexes. Results showed that sex, carcass size and marination affect duck breast meat quality.
A total of 18 Qinchuan cattle, six intact males (IM), six castrated males (CM) and six females (FM), were used to investigate the effect of sex on the physicochemical characteristics (PCC) and fatty acid (FA) composition of the Longissimus dorsi muscle (LDM). Obvious sex differences were found in the PCC of LDM: the IM group had higher shear value, pH, drip and cooking losses, and contents of ash and hydroxyproline (Hyp) than the CM and FM groups, as well as lower ether extract content and lightness. Both the IM and CM groups had lower water content and higher protein content than the FM group. Sex differences were also observed in contents of C14:0, C14:1, C18:1, saturated fatty acids (SFA), monounsaturated fatty acids (MUFA) and unsaturated fatty acids (UFA) between the IM and both the CM and FM groups but not between the CM and FM groups. The results indicated that sex is an important source of differences in meat quality of Qinchuan cattle because the castration and the meat characteristics of the CM group were more similar to the FM than the IM group.
This article presents an overview of the primary chemical components of tissues comprising meat from common domestic species such as bovine, ovine, porcine, turkey, and poultry. Proximate analyses and other compositional values of edible tissues are given for various species. Physical characteristics as they affect chemical composition are described in the text and presented in tables.
The present study was conducted to evaluate the chemical composition of three genotypes of scavenging ducklings (Muscovy, Pekin and Desi White) in coastal areas of Bangladesh. Three ducks from each genotype were slaughtered at 6, 10 and 14 th week of age. The results indicated that dry matter yield was highest in Muscovy (40.91 and 44.40) followed by Pekin (39.30 and 44.31) and Desi White (35.67 and 41.82) for control and supplemental group, respectively at 14 th week of age. The concentration of crude protein was highest in Muscovy (18.76 and 19.90), intermediate in Pekin (18.40 and 19.66) and the lowest in Desi White (17.20 and 19.14) for two feeding regimes at 14 th week of age. The ether extract content varied from 17.21 to 23.16. Genotype and feed showed significant effect (p 0.05) effect on ash content at 14 th week of age. Genotypes and feed showed significant effect (p 0.05) on DM and moisture content of duck meat. DOI: http://dx.doi.org/10.3329/bjas.v43i1.19381 Bangladesh Journal of Animal Science, 43: 25-29
本研究は成長中の肉用アヒルにおける10週齢までの体重,体の各部位重量,体成分及び脂肪蓄積の推移について明らかにすることを目的として行った。肉用アヒルの成長は成長初期で速く,成長曲線の変曲点は雌で28日齢,雄で30日齢であった。肉用アヒルの出荷日齢は飼育効率の点から,現行の8から10週齢より6週齢まで早める方が飼育コストの面で有利であることが推察された。屠体重に対する皮•骨付き胸及び手羽の重量比は加齢に伴い増加するが,腿,ドラム•ステイック及び背の重量比には加齢による変化は認められなかった。屠体中の水分含量は加齢に伴い減少し,脂肪含量は増加した。蛋白質含量には加齢に伴う変化は認められなかった。加齢に伴い血清中トリグリセリド濃度は増加し,総コレステロール濃度は減少した。
Background
Baseline research investigating the toughness of Egyptian goose meat is required. To achieve this, the study therefore investigates the post mortem pH and temperature decline (15 min – 4 h 15 min post mortem) in the pectoralis muscle (breast portion) of this gamebird species. It also explores the enzyme activity of the Ca2+ dependant protease (calpain system) and the lysosomal cathepsins during the rigor mortis period.ResultsNo differences were found for any of the variables between genders. The pH decline in the pectoralis muscle occurs quite rapidly (c = -0.806; ultimate pH = ~5.86) compared to other species and it is speculated that the high rigor temperature (>20°C) may contribute to the increased toughness. No calpain I was found in Egyptian goose meat and the μ/m-calpain activity remains constant during the rigor period while a decrease in calpastatin activity was observed. The cathepspin B, B & L and H activity increased over the rigor period.Conclusions
Further research into the connective tissue content and myofibrillar breakdown during ageing is required in order to know if the proteolytic enzymes do in actual fact contribute to tenderisation.
A comparative study on the quality of meat from three breeds of goats reared in Bulgaria: Local Aboriginal (LA); Bulgarian White Dairy (BWD) and crossbreeds of local aboriginal with Saanen goats (LA S). Eight intact young male goats from each breed have been included in the experiment. The animals from the three breeds have been reared under similar conditions. The animals have been slaughtered at the age of 2 months (at weaning) and at the age of 6 months (upon reaching sexual maturity). The following tests have been performed on samples of m. longissimus dorsi between 5th and 6th ribs: pH 45 min post mortum, colorimetrically color of meat, water holding capacity and fatty acid composition of the fat. The thickness of muscle fibre and the proportion of muscle, connective and adipose tissue have been microscopically determined at m. longissimus dorsi, m. semitendinosus and m. iliopsoas. After deboning and separating the bigger tendons, the chemical composition of the meat from the left half of the carcass has been determined. The results reveal lack of statistically significant differences among the three breeds concerning pH, the water holding capacity, color of meat, thickness of the muscle fibre and fatty acid composition of the fat. The carcass meat of crossbreeds of LA S contains significantly more fat than the other two breeds. This influences the proportion of muscle, connective and adipose tissue in m. longissimus dorsi, m. semitendinosus and m. iliopsoas, resulting in more adipose tissue in the LA S compared to young goats of the LA or the BWD. There are differences in slaughtering 2-month-old goats (at weaning) and 6-month-old ones (upon reaching sexual maturity). At a greater age the content of fat in the carcass increases, as well as the quantity of the adipose tissue, the intensity of the colour of the meat and there is a tendency towards thickening of the muscle fibre and increasing the water holding capacity of meat. The moisture content in meat decreases due to the increase of fat.
A heat transfer model was used to simulate the temperature in 3 dimensions inside the meat. This model was combined with a first-order kinetic models to predict cooking losses. Identification of the parameters of the kinetic models and first validations were performed in a water bath. Afterwards, the performance of the combined model was determined in a fan-assisted oven under different air/steam conditions. Accurate knowledge of the heat transfer coefficient values and consideration of the retraction of the meat pieces are needed for the prediction of meat temperature. This is important since the temperature at the center of the product is often used to determine the cooking time. The combined model was also able to predict cooking losses from meat pieces of different sizes and subjected to different air/steam conditions. It was found that under the studied conditions, most of the water loss comes from the juice expelled by protein denaturation and contraction and not from evaporation.
The objectives of the present study were to ascertain the nutritional value (i.e., macro and microconstituents) of emu (Dromaius novaehollandiae, Latham) meat and a value-added product derived therefrom. The contents of creatine, creatinine and phosphocreatine in fresh emu meat and the impact of processing on these bioactives during the production of jerky were of particular interest. For comparative purposes, a beef counterpart was prepared. The proximate compositional data indicated that the macroconstituents of emu meat and the fabricated jerky product were not so different from their beef analogues. Analysis of the microconstituents in emu samples revealed that the levels of a number of nutritionally important oil- and water-soluble vitamins and minerals were typical of those for red meat species. The creatine content in emu meat (29.3 mg/g dry matter) was similar to that of beef; slightly higher creatine levels were detected, however, in the emu jerky (22.8 mg/g dry matter) compared to its beef counterpart, and these were significant (P < 0.01) when the data was analysed on a dry weight basis. This demonstrates a potential for the emu meat snack to be considered as a functional food for athletes looking for performance enhancement, and who are interested in consuming greater quantities of creatine from a natural food source.
In the first part of the paper, the Total Food Quality Model is used as a frame of reference for analysing the way in which consumers perceive meat quality, drawing mainly on European studies involving beef and pork. The way in which consumers form expectations about quality at the point of purchase, based on their own experience and informational cues available in the shopping environment, is described, as well as the way in which quality is experienced in the home during and after meal preparation. The relationship between quality expectations and quality experience and its implications for consumer satisfaction and repeat purchase intent is addressed. In the second part of the paper, and building on the insights obtained on subjective quality perception, possibilities for consumer-oriented product development in the meat sector are addressed. Issues dealt with here are branding, differentiation by taste, healthiness and convenience, and by process characteristics like organic production and animal welfare.
Low fat sausages were prepared with added hydrated oatmeal or tofu as texture-modifying agents at levels of 10%, 15%, and 25% (w/w), respectively. The effects of the type and level of texture-modifying agents on the physical and sensory properties of low fat sausages were investigated. The water-holding capacity in sausage products increased by increasing the hydrated oatmeal level, but no significant differences was observed by the addition of tofu. The higher level of the agents produced a sausage product with less cooking loss and with a softer texture. The moisture absorption measurements suggest that the decrease in hardness of oatmeal-added sausage products may be due to the higher water-retention properties of oatmeal in response to heat treatment, while that of tofu-added sausage products may be associated with a weaker internal structure of tofu than the pork loin. The sensory evaluations indicated that the greatest overall acceptability in a low fat sausage was attained when the hydrated oatmeal or tofu were at their 15% addition level, respectively.
1. Research in the field of poultry meat quality has become more varied during the last 50 years. Besides meat content and microbial condition, animal welfare issues during the slaughter process, muscle morphology, physiology of meat ripening, impact of slaughter process on meat quality, sensory attributes of meat and meat processing have come into focus. 2. The present review summarizes findings and developments in the fields of muscle physiology, meat ripening and meat quality aberrations (like PSE), nutrient composition and sensory qualities, effect of the slaughter process on carcass and meat quality, hygienic conditions and product safety during slaughtering, all based on selected papers published in British Poultry Science during the last 50 years. 3. Some special findings and conclusions are lifted out of the whole results presented in the papers to indicate their importance and to show their contribution to the development of knowledge in the respective field.
A total of 80 dry-cured duck breasts were used in this study. The gross composition, color and textural parameters, fatty acid and amino acid profiles, macro- and micromineral content, and sensory properties were analyzed. In comparison with other dry-cured meat products made from cuts of whole meat, dry-cured duck breast is characterized by low moisture and a higher protein content. Saturated, monounsaturated, and polyunsaturated fatty acid contents in intramuscular fat were approximately 35, 57, and 8% of the total fatty acid methyl esters, respectively. The main essential amino acids present in dry-cured duck breast were lysine and leucine, followed by valine, threonine, and isoleucine, with aspartic and glutamic acids being the most important in the nonessential fraction. Dry-cured duck breast proved to be a valuable source of iron, zinc, copper, and manganese (7.57, 4.66, 0.84, and 0.87 mg/100 g of edible portion, respectively), providing approximately 57, 45.2, 93, and 43.7% of the recommended daily allowances, respectively.
This study was conducted to determine degradation of the giant myofibrillar proteins titin and nebulin in postmortem aged beef, with known tenderness values, from animals differing in sex (steers vs bulls) and age (cows vs steers and bulls). Ten bulls and 10 steers (both groups were approximately 14 mo old) and 10 cows (44 to 108 mo old) were slaughtered. Longissimus muscle samples were removed for determination of Warner-Bratzler shear force, sensory panel tenderness evaluation, and SDS-PAGE analysis at 3, 7, 14, and 28 d postmortem. The SDS-PAGE analysis of titin and nebulin revealed that titin often migrated as three closely-spaced bands (T1, T1-2, T2, in increasing order of migration) in 3-d postmortem samples. With increasing time post-mortem, intact titin (T1) decreased and degraded titin (T2) increased in all samples. Within a class (i.e., steers, bulls, or cows) the rate of conversion of T1 to T2 was slower in the less-tender samples. The T1 to T2 conversion postmortem was slower in the intact males (bulls) than in the castrated males (steers). The T1 to T2 conversion postmortem also was slower in the older animals (cows) in comparison to the younger steers, but not in comparison to the younger bulls. Nebulin was degraded by 3 d postmortem in tender samples from steers, but some nebulin remained in the less-tender 3-d samples from steers and in all of the 3-d samples from bulls and older animals (cows). Intact nebulin was absent in all 7-d samples, regardless of the class of animal. Our results suggest that titin and nebulin are degraded at faster rates in more tender beef samples within each of the three classes of animals examined. The rate of degradation seems to differ when sex and age classifications are compared.
Performance and carcass characteristics of Dumyati, Muscovy, Peking and Sudani duck breeds
- A Galal
- W A Ali
- A M Ahmed
- K A Ali
Galal, A., Ali, W.A., Ahmed, A.M. & Ali, K.A. 2011. Performance and carcass characteristics of Dumyati, Muscovy,
Peking and Sudani duck breeds. Egypt. J. Anim. Prod. 48, 191-202.
Characterisation of local chicken in low input-low output production systems: Is there scope for appropriate production and breeding strategies in Malawi?
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Gondwe, T.N.P., 2004. Characterisation of local chicken in low input-low output production systems: Is there scope for
appropriate
production
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strategies
in
Malawi?
Cuvillier
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at:
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Growth performance, carcass yield and meat quality of Korean native duck
- E C Hong
- K N Heo
- H K Kim
- B S Kang
- C D Kim
- H J Choo
- H C Choi
- M M H Mushtag
- R Purnin
- J H Kim
Hong, E.C., Heo, K.N., Kim, H.K., Kang, B.S., Kim, C.D., Choo, H.J., Choi, H.C., Mushtag, M.M.H., Purnin, R. & Kim.
J.H., 2014. Growth performance, carcass yield and meat quality of Korean native duck. J. Agric. Sci. Tech. A4, 76-85.
Physicochemical analysis and mineral composition of duck meat (Peking, Muscovy and Local Java). Intern
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Local Java). Intern. J. Biol. Ecolog. Environ. Sci. 2(5), 2277-4394.
Child labour in livestock production in Malawi. Ministry of Gender
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