Effects of different crude protein levels in feed on production performance,nutrient apparent digestibility,and serum biochemical indexes of lactating Alashan Bactrian camels

JIAO Xinggang; ZHANG Hui; WANG Yuxin; WANG Xiaoshan; ZHAO Rigetu; WU Fang

doi:10.13557/j.cnki.issn1002-2813.2025.02.008

Abstract：The study aimed to investigate the effects of different dietary crude protein(CP)levels on the production performance,nutrient apparent digestibility,and serum biochemical indexes of lactating Alashan Bactrian camels.Twenty healthy,six to ten year old lactating Alashan Bactrian camels with similar milk yields(1.62±0.41)kg were randomly divided into five groups,with four replicates per group,and one camel per replicate.The camels in P1,P2,P3,P4 and P5 groups were fed the total mixed pellet feed with CP level of 12.26%,14.34%,17.99%,19.12%and 21.94%,respectively.The pre-test lasted for seven days and the formal experiment lasted for seven days.The results showed that dry matter intake significantly increased with increasing dietary CP(P＜0.05).The milk yield and apparent digestibility of dry matter(DM)in the P5 group were significantly lower than in other groups(P＜0.05).The apparent digestibility of CP in P1 to P4 groups increased with increasing dietary CP content,while the P5 group was significantly lower than the P4 group(P＜0.05).The apparent digestibility of ether extract(EE)showed an upward trend initially and then declined,with the highest value in the P3 group,which was significantly higher than the P1 and P5 groups(P＜0.05).The apparent digestibility of acid detergent fiber(ADF)in the P3 and P5 groups was significantly lower than in other groups(P＜0.05).The apparent digestibility of total energy in the P5 group was significantly lower than that in P2 to P4 groups(P＜0.05).Different dietary CP levels had no significant effect on milk quality or serum biochemical indexes of Alashan Bactrian camels(P＞0.05).The study show that dietary CP levels exceed 19.12%reduce the apparent digestibility of DM,CP,EE,ADF,and total energy,as well as milk yield in lactating Alashan Bactrian camels.Dietary CP levels between 17.99%and 19.12%is optimal for protein absorption and utilization in the short term in Alashan Bactrian camels.