Abstract: The experiment was conducted to study the effect of castration on weight,body measurement index and serum biochemical indices of young Xinjiang brown cattle in different periods.62 Xinjiang brown cattle (21-months-old) were chosen and divided into the experimental group (castrated) and control group (non castrated).Experimental animals were measured weight and body measurement index and detected blood samples in 22,23,24,25 and 26 months.The pre-test period lasted for 10 days and the trial period lasted for 150 days,The results showed that the daily gain of control group was significantly higher than that of experimental group in 23 and 24 months (P<0.05).The daily gain of control group was highly significantly higher than that of experimental group in 25 and 26 months (P<0.01).The whole daily gain of control group,which was significantly increased by 13.40% than that of experimental group (P<0.05).The body height of control group was significantly higher than that of experimental group in 24,25 and 26 months (P<0.05).The body length,long body straight and chest circumference of control group were significantly higher than that of experimental group in 23,24,25 and 26 months (P<0.05).The tajiri long and sciatic wide of experimental group were significantly higher than that of control group in 23,24,25 and 26 months (P<0.05).The serum levels of urea nitrogen and albumin of experimental group were significantly higher than that of control group in 23,24,25 and 26 months (P<0.05),while the serum level of globulin was opposite trend.The serum activities of alanine aminotransferase and aspertate aminotransferase of control group were significantly higher than that of experimental group in 24,25 and 26 months (P<0.05).In conclusion,castration could reduced daily gain,growth rate and protein metabolism capacity of young Xinjiang brown cattle,but that could improved the ability of fat deposition.

Key words: castration; daily gain; body measurement; protein; serum enzyme