Effect of dietary protein levels on performance and serum biochemical indexes in Chongqing black goats

The current experiment was conducted to investigate the effects of different dietary crude protein levels(8.23%,10.42% and 12.52%) on the serum biochemical indexes in Chongqing black goat of 3～6 month old.The results showed that with the increase of dietary crude protein level,the daily weight gain of goat increased accordingly,and the high protein group was significant increased(P0.05 or P0.01).The daily feed intake in each group had a trend of increase,but not significant(P0.05).The feed efficiency had an improvemental trend.High protein group was significantly higher than low protein group(P0.01),there was no apparently difference between other groups(P0.05).The gross profit of low protein group was 13.83% lower than medium protein group,and the high protein group was 17.22% higher than medium protein group.In addition,with the increase of crude protein level,there was a tendency of increase in urea nitrogen and transaminase of the serum in goats.And the other serum biochemical indexes had no significant changes.