Effects of Different Grain Sources in Both Maternal and Offspring Diets on Pigmentation and Growth Performance in Yellow-Skinned Chickens

Carcass Characteristics and Meat Quality of Betong Chicken Fed with Diets Supplemented with Crude Glycerin

Experiments were conducted to evaluate the effect of crude glycerin inclusion in the diets of Betong chicken on the characteristics of their carcasses, internal organs, meat quality, lipid oxidation, and fatty acid profiles. One hundred 1-day-old chicks were raised for 8 weeks. Subsequently, the birds were sexed based on their morphological features, and weighed. Forty-eight male chickens, with comparable body weights, were randomly allotted to receive any of the three experimental diets, containing 0, 50 or 100 g crude glycerin/kg feed, on an as fed basis until they were 20 weeks old. A total of 24 chickens were slaughtered and their carcass characteristics and meat quality were studied. Results showed that carcass characteristics and internal organ parameters were not affected by crude glycerin supplementation (P>0.05). After chilling for 24 h, pH of the meat decreased in all groups (P>0.05), while shear force and cooking loss were not affected (P>0.05). Furthermore, crude glycerin did not affect the parameters such as crude protein, ether extract, ash, moisture and proportions of different fatty acid contents of meat of the Betong chicken (P>0.05). However, breast meat color and lipid oxidation were influenced by crude glycerin in diet (P<0.05). These results suggest that crude glycerin can be used at concentrations up to 10% in Betong chicken diet from 8 to 20 weeks of age. Nevertheless, its effect on breast meat color and lipid oxidation need to be considered.

Effect of chilling methods on the surface color and water retention of yellow-feathered chickens

This study was conducted to investigate the effects of air chilling (AC), water chilling (WC), combined chilling consisting of WC for 20 min and AC (CO₂₀), and combined chilling consisting of WC for 30 min and AC (CO₃₀) on the microbiological status, surface color, processing yield, and moisture content of yellow-feathered chicken carcasses. After chilling, the carcasses treated by AC exhibited the highest total viable counts (TVC) (4.7 cfu/cm²), followed by those treated by CO₂₀ and CO₃₀, whereas the carcasses treated by WC showed the lowest (P < 0.05) mean log TVC (4.2 cfu/cm²). Based on an instrumental color evaluation and photographs of carcass surfaces, the carcasses treated by AC showed a notable yellow color (P < 0.05), whereas no significant difference (P > 0.05) was found among the carcasses treated by CO₂₀, CO₃₀, and WC. The skin samples of carcass parts treated by WC (breast, thighs, drumsticks, back, neck, and wings) exhibited higher moisture contents than the skin samples of the carcasses treated by AC (P < 0.05), providing evidence that weight gain during WC is due to higher water absorption by the skin. The different parts of the broiler carcasses treated by AC had lower cooking losses than those of carcasses treated by combined chilling or WC (P < 0.05), except for the thighs and claws. In breast and drumstick muscles, the moisture contents of the superficial parts from carcasses treated by WC were higher than those of the carcasses treated by AC, whereas the internal parts were not significantly affected by the chilling methods (P > 0.05). The results of this work can be useful for understanding and improving the chilling process for yellow-feathered chickens.