Meat quality attributes of male and female broilers from 4 commercial strains processed for 2 market programs

In recent times, meat quality has become a key aspect of poultry production. In the current study, 2,400 sex separate broilers from 4 commercial strains were placed in 6 replications to evaluate various meat quality characteristics when grown to 2 market weights. Broilers were fed 1 of 2 diets with varying degrees of amino acid inclusion to evaluate meat quality of broiler raised on varying planes of nutrition. Birds were processed to meet 2 specified target weights (2.5 and 3.8 kg) representing small bird and big bird debone markets in the United States, respectively. Birds were processed using commercial methods, deboned at 3-h postmortem, and meat quality was assessed. Myopathies (woody breast, white striping, spaghetti meat, along with tenderloin quality), fillet dimensions, color, water-holding capacity (e.g., drip loss, cook loss), and Meullenet Owens Razor Shear was determined. Data were analyzed using the Mixed Model platform of JMP Pro 15.2 (SAS Institute, Cary, NC). Diet had no effect (P > 0.05) on the key quality responses; data were then pooled resulting in main effects of sex, strain, and target weight (noted as carcass size). On the day of processing, high yielding (HY) strains produced higher breast and tender yields (P < 0.05) when compared to standard yielding (SY) strains. In addition, and as expected, females exhibited higher breast and tender yields (P < 0.05) than males. However, males had significantly thicker (P < 0.05) and longer (P < 0.05) fillets, higher incidences (P < 0.05) of white striping, and higher (P < 0.05) cook loss when compared to females. Differences were also observed in tenderness as SY strain A produced the lowest shear values, whereas SY strain B produced the highest shear values across parameters (P < 0.05). SY strains in the small bird (SB) market performed better than SY strains in the big bird (BB) market as indicated by lower incidences of breast and tender myopathies white striping, woody breast, spaghetti meat, woody-like tender, and tender feathering and improved quality attributes (P < 0.05). Similar trends were observed (P < 0.05) in HY strains as SB carcasses produced a better overall product than BB. Differences in carcass size directly impacted quality (P < 0.05) as SB markets showed improvements in most parameters assessed, but broilers representing BB markets had greater breast yield. Although strain had minimal impacts on quality measures, carcass size, and sex had a greater impact on muscle myopathies, water-holding capacity, and shear properties.

The Comparison between Tanzanian Indigenous (Ufipa Breed) and Commercial Broiler (Ross Chicken) Meat on the Physicochemical Characteristics, Collagen and Nucleic Acid Contents

The objective of this study was to characterize the meat quality traits that affect the texture and savory taste of Ufipa indigenous chickens by comparing the proximate composition, physical characteristics, collagen, and nucleic acid contents with those of commercial broilers. It was found that Ufipa chicken breast and thigh meat had a higher protein content (p<0.05) than broiler chicken meat, whereas the fat content was lower (p<0.01). The moisture content of thigh meat was lower in Ufipa chicken meat than in broiler chicken meat (p<0.05). Regarding meat color, broiler chickens had considerably higher L* and b* than Ufipa chickens in both the breast and the thigh meat, except for a* (p<0.01). Regarding water holding capacity, Ufipa chicken breast exhibited higher drip loss but lower thawing and cooking losses than broiler chicken (p<0.01). In contrast, its thigh meat had a much lower drip and thawing losses but higher cooking losses (p<0.01). The shear force of Ufipa chickens’ breasts and thighs was higher than that of broiler chickens (p<0.05), while the amount of total collagen in the thigh meat was higher than that of broiler chickens (p<0.05). Additionally, the inosine-5’-monophosphate (IMP) of Ufipa chicken breast and thigh meat was higher than that of broiler meat (p<0.05). The principal component analysis of meat quality traits provides a correlation between the proximate and physical-chemical prosperties of both breeds with some contrast. In conclusion, the present study provides information on healthy food with good-tasting Ufipa indigenous chickens, which offer a promising market due to consumers’ preferences.

Comparison of Physicochemical Characteristics and Sensory Attributes of Four Different Chicken Breeds from the Genuine and Selected Local Market

Village chicken is known as a high-quality product perception and sold at high prices. However, the authenticity of village chicken is doubted because colored chicken has been claimed as village chicken to fraud the consumers and to gain high profit. No stringent strategy has been implemented by the local authority on the authenticity of the claimed village chickens. Thus, the study aimed to determine the meat quality of different chicken breeds including village chicken, broiler chicken (Cobb), colored chicken (Hubbard), and layer chicken from genuine suppliers and chickens sold at different local markets based on the physicochemical characterization, textural properties, and sensory evaluation. Chicken breeds were obtained from genuine suppliers and slaughtered at the slaughtering house Universiti Putra Malaysia. Proximate composition, color, and textural properties were evaluated. Minitab-19 and SIMCA-13 software were used to analyze the results, applying analysis of variance and partial least squares discriminant analysis, respectively. The study revealed that some of the market-supplied chickens were not authentic based on the features studied. About 20% of market village chickens had possessed similar results as the control village chicken. It can be shown that 80% of the claimed village chicken sold in the market was not authentic village chicken. This study showed the differentiation in texture composition such as chewiness, hardness, gumminess, cohesiveness, resilience, and springiness, followed by protein content, ash content, and a ${}^{\ast }$ and b ${}^{\ast }$ values as an indicator to differentiate the authenticity of different chicken breeds.

The effect of light/dark cycles on performance and welfare in broiler

The purpose of this study was to compare a continuous lighting programme (23 hours of lighting (L) / 1 hour of darkness (D)) with intermittent lighting programmes (16L: 8D) and also to investigate the effects of the length of the dark cycle in the intermittent programme on the performance, carcass characteristics, water consumption, uniformity, metabolic parameters, and ammonia burns of chickens. Thus, five hundred Ross-308 male chicks were used. The 23L:1D was applied to the chicks for 7 days. On day 7, they were divided into four groups by balancing their live weight; group I: continuous 23L: 1D; group II: intermittent 4x (4L: 2D); group III: intermittent 2x (8L: 4D); group IV: continuous 16L: 8D. The study took place between days 7 and 42. At the end of the study, 10 chickens from each group were slaughtered, their carcass, blood, and bone properties were analysed. Body temperatures and ammonia burns were assessed for all broiler chickens. The mean live weight of group IV was the lowest. The difference among the groups in terms of live weight gains, feed intakes, feed conversion ratios, and survival rates was non-significant. Long-period darkness in group IV significantly dropped the water consumption. On day 21, group III’s best uniformity was calculated; but on day 42, the difference was non-significant. The highest breast ratio and the lowest wing ratio beloged to chicks in group I. Their free T4, glucose, and uric acid levels were lower; whilst their testosterone levels were higher. Body temperature and tibia ash levels were similar across all of the groups. The intermittent lighting programmes increased the number of ammonia burns. Consequently, the long-term darkness negatively affected both the chickens’ performance and well-being.

Do different vaccination regimes affect the growth performance, immune status, carcase characteristics and meat quality of broilers?

1. A vaccination regime is a schedule for the administration of vaccines which may vary according to country or even by farm. This study aimed to measure the production and health performance of broilers treated with different vaccination regimes. 2. A total of 108 Cobb 500 broiler birds were randomly divided into three treatment groups, with six replicates consisting of six birds per replicate. Each treatment group was administered with different vaccination regimes against Newcastle Disease (ND), Infectious Bronchitis (IB) and Infectious Bursal Disease (IBD). Treatment 1 (T1) broilers were vaccinated against ND+IB and IBD on days 7 and 14 of age, respectively (control); Treatment 2 (T2) broilers were vaccinated against ND+IB on days 3 and 7 of age, and IBD on day 14; and Treatment 3 (T3) broilers were vaccinated against ND+IB on days 7 and 21 and IBD on day 14. Throughout the 42-day study period, data and samples were collected to determine the growth performance, immune status, carcase characteristics and meat quality. 3. There were significant differences (P < 0.05) on growth performance (body weight, body weight gain, feed intake and cumulative feed conversion ratio), white blood cell count (heterophils percentage, lymphocytes percentage and heterophils to lymphocytes ratio), carcase characteristics (kill-out weight, de-feathered weight, dressing percentage, drumsticks and gastrointestinal tract weight) and meat quality (cooking loss and drip loss) between treatments. T1 broilers showed better growth, white blood cell count, carcase characteristics and meat quality compared to T2 and T3 broilers. 4. Based on findings from the current work, vaccination against ND+IB and IBD on days 7 and 14 proved to be the best vaccination regime for broiler production, due to the better production performance and health status of broilers.

Effects of stock, sex, and muscle type on carcass characteristics and meat quality attributes of parent broiler breeders and broiler chickens

This study aimed to investigate the effect of using breeder parents (434-days-old) and broiler chickens (37 D of age) from Ross 308 on meat quality parameters and carcass characteristics; sex and muscle type were also estimated. Carcass assessment involved hot carcass weight, carcass yield, and cuts (breast, legs, wings, back, and shoulder). A total of 120 birds were divided into 2 groups (60 birds from each stock), each stock contain equal number of sexes (30 males and 30 females), and further divided into 6 replicates, so that there were 5 birds in each replicate. The birds were fed ad libitum. A sample of 30 birds (male, n = 15 and female, n = 15) from each group was slaughtered for assessing carcass and physical characteristics. Sensory analysis was carried out on each group after boiling or roasting the bird. Live weight, carcass weight and yield, breast weight, legs, wings, and back weights and yield were higher (P < 0.001) for breeder parents when compared to broilers, with the exception of breast percentage. Moreover, better carcass characteristics were observed in males than in females. Parent stock had better water-holding capacity and myofibrillar fragmentation whereas broilers had more tender meat than breeders. Moreover, cooking loss and other sensory characters were not significant between the two groups; however, females had more tender pectoral muscles and more myofibrillar fragmentation than males. We concluded that parent breeders had better carcass characteristics than broiler chickens. The broiler chickens of Ross 308 and female birds had better meat quality than parent breeders.

Thermotolerance of Broiler Chicks Ingesting Dietary Betaine and/or Creatine

The present study aimed to assess the effect of dietary betaine (B) and/or creatine (C) on performance and thermoregulatory responses of broiler chicks. Indian River broiler chicks, fitted with compact thermosensors, were reared to market age (five weeks). The chicks were randomly distributed into four treatment groups, in a 2 × 2 factorial arrangement of treatments-basal control diet (Control group: CONT; B-/C-); 1 g betaine/kg feed (Betaine group: BETA; B+/C-), 1.2 g creatine monohydrate/kg feed (Creatine group: CRET; B-/C+), and combination (Betaine and Creatine group: COMB; B+/C+) of both supplements. At 31 days of age, 20 chicks from each group were exposed to acute heat stress (A-HS) for 3 h (34.45 ± 0.20 °C), and hemogramic profiles were screened before and after. Performance parameters (feed intake, body weight gain, and feed conversion ratio) were reported on a weekly basis, and carcass meat quality was evaluated at the end of experiment. Redness of breast was higher due to B and C treatments separately than the CONT group (B by C interaction; p < 0.05). Compared to the CONT, dietary supplements alleviated hyperthermia responses, with B alone being more efficient than C or COMB treatments. The mitigation of hyperthermia is likely mediated by enhancement of water balance indicators. Although not efficient in improving growth performance, dietary B and/or C are efficient in improving thermophysiological performance and survival of finishing broiler chicks under A-HS.

Impacts of Graded Levels of Metabolizable Energy on Growth Performance and Carcass Characteristics of Slow-Growing Yellow-Feathered Male Chickens

A dose-response study was conducted to investigate the metabolizable energy (ME) requirement for Lingnan chickens from 9 to 15 weeks of age. One thousand two hundred 8-week-old slow-growing yellow-feathered male chickens were allotted to five dietary ME levels (2805, 2897, 2997, 3095 and 3236 kcal/kg). The results revealed that the daily metabolizable energy intake increased (p < 0.01), whereas the feed intake and feed:gain ratio decreased linearly (p < 0.01) with the increment in dietary ME level. The final body weight and daily gain of the highest ME treatment tended (p > 0.05) to be greater than those obtained with the lower ME levels. The fat content in breast muscle showed a quadratic response (p < 0.05) to the increase in dietary energy level. The shear force values of breast muscle in the 2897, 3095 and 3236 kcal/kg treatments were lower (p < 0.05) than those of the 2997 kcal/kg treatment. In conclusion, among the tested ME levels, 3095 kcal/kg was adequate for feed intake, shear force, and plasma uric acid, and 3236 kcal/kg tended to increase the body weight, body gain, and feed conversion ratio of Lingnan males between 9 and 15 weeks of age; further studies are still required for testing higher levels.

Effect of gender on breast and thigh turkey meat quality

1. The influence of gender on chemical composition, physicochemical parameters, fatty acid profile, amino acid and mineral composition of turkey breast and thigh meat was studied in order to assess nutrient requirements. 2. Chemical composition showed that only intramuscular fat in breast meat was significantly affected by gender (p < 0.05). The results showed a higher percentage of intramuscular fat in male samples, almost double the amount found in females (0.73% vs. 0.38%). 3.For meat colour parameters, only a* showed different results between sexes, with male samples (breast: p < 0.01; thigh: p < 0.001) having the highest values. 4. Fatty acid profiles showed that medium chain unsaturated fatty acids were the most abundant. The significant differences (p < 0.05) found in both breast and thigh muscle could be linked to a difference in metabolism between males and females. 5.There were higher levels of C16:1n-7 in females (breast: p < 0.001; thigh: p < 0.01) compared with male muscle sample (5.05 vs. 2.67 g/100 g in breast and 4.95 vs. 3.27 g/100 g in thigh). Nutritional indices (n-6/n-3 and thrombogenic index) were more favourable in female samples demonstrating that female turkeys had better fatty acid profile than the others. 6. Turkey meat is an important source of dietary amino acids, and female samples had the highest contents both of essential and non-essential amino acids. Furthermore, gender had a numeric effect (p > 0.05) on amino acid composition. 7. Mineral composition showed that Na, Zn and Fe were the minerals most affected by turkey gender.

Gene Effects on Body Weight, Carcass Yield, and Meat Quality of Thai Indigenous Chicken

The selection of rapidly growing animals in breeding programs has had inadvertent detrimental effects on meat quality. Thus, the aim of the present study was to investigate the relationship between body weight (BW) and meat quality traits, and the effects of genes encoding insulin-like growth factor I (IGF-I), insulin-like growth factor II (IGF-II), melanocortin-4 receptor (MC4R), and calpain 1 (CAPN1) on BW, carcass yield, and meat quality of the Thai indigenous chicken, Leung Hang Khao. Five hundred and ten chickens were used for genotyping. PCR-restriction fragment length polymorphism and PCR-single strand conformation polymorphism were used to determine the genotypes of IGF-I, IGF-II, MC4R, and CAPN1. BWs were collected from 0–16 weeks of age. The chickens were sacrificed at 16 weeks and individual carcass yields and meat qualities (drip loss, cooking loss, and shear force) were recorded. The correlations between BW and meat qualities were determined. Significant correlation between BW and cooking loss and shear force of breast meat and between BW and drip loss of thigh meat were detected (P<0.05); however, the magnitude of the association was low (−0.1–0.1). IGF-I was eliminated from the association analysis because genotype AA was lost and the frequency of occurrence of the AC genotype was low (0.04). Significant associations between IGF-II, CAPN1, and BW, and CAPN1 and meat quality were detected, while non-significant association between MC4R and BW was observed. The results indicated a low, negative relationship between BW and meat quality, and that the IGF-II and CAPN1 could be used as genetic markers in Leung Hang Khao chickens to improve growth and meat quality through breeding.