Comparison Studies On Meat Quality, Growth, Metabolism And Relationships Among Gushi, Broiler And Layer Chicks

The experiment compared the growth, nutrients deposition, nutrient apparent metabolic rate, digestive organs, digestive enzymes, serum biochemical values, meat quality indexes of male Gushi, Gushi hybrid, broiler and layer chicks during 0~8 weeks.The results showed that there were significance (p<0.01) for the live body weight, feed conversion efficiency and body composition among three strains. The born weight of broiler is 1.12 and 1.46 times of layer and Gushi chicks. The 8 week's weight become 3.17 and 4.08 times. The average daily feed intake of 0~8 weeks was 2.83 and 3.48 times. The fat and energy contents of broiler were higher than that of Gushi and layers. The ME and crude protein efficiency decreased with age. The fast growth chicks showed higher apparent crude protein metabolic rate and lower crude fat and apparent energy metabolic rate. Comparing with the broilers, the reason for low growth rate of gushi chicks was possibly related with lower protein efficiency and higher energy waste.The weights of digestive organs increased with the body weight. The 6th week's weights of broilers were above 20 times that of one day old. For layer chicks were 15 times and 10 times for Gushi hybrid chicks. The ratios of digestive organ weight to live body weight decreased as the chicks growing. The development of digestive organs for Gushi hybrid chicks was similar with broilers. The amylase activity in pancrea and duodenum chyme showed the character of the strain which the broiler was the highest and the layer was the lowest, the Gushi and Gushi hybrid were in between. The protein metabolic rate was relative to the trypsin activity in chyme. The increase from 4 to 6 week of fat metabolic rate was accordance with the change of lipase activity in pancreas and duodenum chyme.The contents of serum urea nitrogen, UA, total protein which were negative correlative with growth rate, were the sensitive indexes of difference for growth and protein metabolism between different strains of poultry. The activities of serum AST, LDH were negative correlative with live body weight. The activity of serum ALP increased with the increment of live body weight. They were also the sensitive indexes for the growth difference.The content of OH-proline was negative correlated with muscle tenderness and the activity of SOD was positive correlated with meat quality. Both of them are meaningful indexes for meat quality. The faster the growth rate was, the bigger for the muscle fiber diameter. The Gushi chicks presented the thinnest muscle fibers and it was the most tenderness muscle among three strains. The Gushi chicks showed higher muscle protein content, higher fat content in breast, lower fat content in thigh and better muscle water holding capacity than broilers.The character of growth and metabolism for Gushi chicks is similar to layer chicks. After led into new blood from fast growing strain, the Gushi chicks had a increase of growth rate, feed intake, feed conversion efficiency, trypsin activity and muscle fiber diameter.