The effects of different caponization age on growth performance and blood parameters in male Tibetan Chicken.

摘要

In this experiment, 40 triplets consisting of full-sib Tibetan Chicken cockerels were divided equally into two trial groups. In each group, the triplets were randomly assigned to caponization, sham treatment and intact groups. The birds of the two trials were caponized or sham-operated at either 6 weeks old (early) or 18 weeks old (late) and slaughtered at 24 weeks old. Results revealed that the birds in the early caponization group showed significant increases in terms of intermuscular fat deposits, subcutaneous fat thickness, liver weight, triacylglycerol concentration (p<0.05) and abdominal fat weight (p<0.01) at 24 weeks old when compared with the intact and sham groups. The later caponization resulted in significant increase in liver weight, abdominal fat weight, total cholesterol and triacylglycerol concentrations (p<0.05). In both trials, the capons exhibited lower leg muscle weight than the intact (p<0.05). There were no significant effects on breast muscle weight on either the early or late caponization group. It is concluded that late caponization accelerates the rate of fat deposition within the abdominal cavity when compared with other areas after sexual maturity. It is also suggested that the role of androgen on the growth of breast muscle is different from that on leg muscle in Tibetan Chicken cockerels, and the positive effects of androgen are reflected only on leg muscle growth.