Effects of Castration at 6 Months Old on Growth Performance,Testosterone and Growth Hormone Levels in Blood of Yanbian Cattle

In order to study the effect of castration at 6 months old on growth performance and blood hormones of Yanbian cattle at 6 to 18 months of age, 20 Yanbian cattle that were 6 months old with similar body weight and body size indexes were randomly divided into 2 groups. The cattle in test group was castrated at 6 months old,and that in control group did not do any treatment,and the test period was 12 months. At the 12th of 6,8,10,12,14,16 and 18 months old,the body weight and body size indexes were measured,and the fasting blood sample were collected the day before 12th to detect the serum testosterone and growth hormone. The results showed that the body weight of the test group was lower than that of the control group,and there was a significant difference at 8 months old (P < 0.05). The body height,body length and chest circumference of the test group were lower than that of control group(P>0.05),and the increase of body height of test group was significantly lower than that of control group at the age of 6 to 8 months old (P < 0.05),while that was significant higher than control group at 12 to 14 months old (P < 0.05). The level of serum testosterone in the test group was extremely significantly or significantly lower than that in the control group after castration (P < 0.01;P < 0.05), and the level of serum growth hormone in Yanbian cattle was significantly lower than that in the control group at 8 months old (P < 0.05). In summary,the castration at 6 months old could reduce the growth of body weight,serum testosterone and growth hormone levels of Yanbian cattle,but had little effect on the body size.