This study was conducted to investigate the effects of cage stocking density on egg yield, some egg quality traits and plumage condition in laying hens. Eighteen weeks-old 264 ISA-Brown pullets were divided into four cage density groups. The densities were 2 000, 1 000, 667 and 500 cm 2 per hen (by allocating 1, 2, 3 and 4 hens per cage; floor area 40 × 50 cm) with 48, 30, 24 and 21 replicate cages, totally 123 three-tier battery cages. During the experimental period from 18 to 53 weeks of age, all birds were provided illumination for 16 hours a day. The hens were fed a diet containing 11.7 MJ ME/kg and 180 g CP during the period of 18 to 40 weeks of age and 11.3 MJ ME/kg and 170 g CP during the period of 41 to 54 weeks of age. Feed and water were available for ad libitum. Egg yield, mortality, live weights at 50% egg production age and at the end of experiment, pecking related mortalities, some egg quality traits and plumage condition were recorded weekly. Hen-housed egg production, egg mass, viability, and live weights were significantly decreased by higher densities. Most of the egg quality traits were not affected by cage densities. Pecking related mortalities increased in cage densities of 667 cm 2 and 500 cm 2 per hen compared to the other densities (P < 0.05) while plumage scores were higher in all body parts of hens kept in cages of 2 000 cm 2 and 1 000 cm 2 densities compared to the higher densities. The results showed that brown laying hens should be kept in cages having 1 000-2 000 cm 2 densities in order to improve their welfare and performance.
Certain meat quality traits of guinea fowl that were reared in two production systems were determined in this study. Grey guinea fowl were reared in free-range and barn conditions. Birds were slaughtered at 14, 16 and 18 weeks old to determine meat quality traits. Some digestive traits were also determined. The type of production system affected the yellowness of breast meat significantly, and guinea fowl reared in the freerange system had yellower breast meat. The pH of both breast and thigh meat increased at older ages. Water-holding capacity, cooking loss and drip loss of breast and thigh meat were not affected by production system. Drip loss of meat decreased at older slaughter ages. The ratios of digestive system organ weights to body weight mostly decreased at older ages.
To evaluate color [lightness (L*), redness (a*), and yellowness (b*)], water-holding capacity (WHC), and pH values, and for proximate analysis of breast and thigh meats from slow-growing (Bronze; B), fast-growing (Hybrid; H), and medium-growing (crosses; H × B) turkey genotypes raised with or without outdoor access, 36 turkeys (2 females and 2 males from each replicate) per housing system or 12, 16, and 8 turkeys per B, H, and H × B genotype, slaughtered at 17 and 21 wk of age, respectively, were used. Therefore, data were analyzed as a factorial arrangement (2 × 3 × 2 × 2) of treatments. All birds were provided with the same starter, grower, and finisher feeds. Muscle samples were collected at 12 h postmortem for evaluation of meat quality and proximate analysis. Outdoor access increased the a* value and protein content of the breast muscle (P < 0.05) and the b* value of the thigh muscle (P < 0.01). The B and H genotypes had higher (P < 0.01) L* values for the breast meat than did the H × B genotype, whereas the B genotype had lower a* (P < 0.01) and pH (P < 0.01) values for the breast meat or a higher (P < 0.05) pH value for the thigh muscle compared with the H genotype. The breast meat of the B genotype was more yellow (P < 0.01) than that of the H and H × B genotype. Thigh meat from the H genotype had a higher L* value and a lower a* value than did thigh meat from the other genotypes (P < 0.01). Thigh meat from the H × B genotype was higher in protein and lower in fat than was thigh meat from the B and H genotypes, respectively (P < 0.05). No interaction effect of housing system and genotype was observed on the parameters studied (P > 0.05). These results show that housing system did not affect the main quality parameters (pH, water-holding capacity, and L* values) of either muscle, and that genotype created more differences in terms of these parameters.
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