滩羊种公羊能量和蛋白质需要量研究OA

This study aimed to investigate the energy and protein requirements of Tan sheep breed rams at dif-ferent periods.Thirty-two 1.5-year-old Tan breed rams with similar body weight and good condition were se-lected and randomly divided into the energy group[initial body weight was(56.15±2.12)kg]and the protein group[initial body weight was(48.53±2.50)kg].Each group was further divided into 4 groups,with 4 rep-licates in each group and 1 sheep in each replicate.The experimental sheep in the energy groups were fed with diets with digestible energy(DE)levels of 8.50(group Ⅰ),10.00(group Ⅱ),11.50(group Ⅲ)and 13.00 MJ/kg(group Ⅳ),respectively,and the crude protein(CP)content in diets was 9.10%.The experi-mental sheep in the protein groups were fed with diets with CP contents of 6.99%(groupⅠ),8.25%(groupⅡ),9.49%(group Ⅲ)and 10.79%(group Ⅳ),respectively,and the dietary DE level was 9.0 MJ/kg.The experiment lasted for 120 days,and was divided into three periods as the mating preparation period(50 days),the mating period(40 days),and the mating recovery period(30 days).The digestion and me-tabolism experiment was conducted in the last 10 days of each period.The former 30 days of the mating period were divided into three phases(F1,F2 and F3 phases)with different frequencies of sperm collection.The re-sults showed as follows:1)with the increase of dietary DE level and CP content,the average daily gain(ADG)of experimental sheep was significantly increased(P＜0.05).With the increase of sperm collection frequency,the ADG was decreased,showing a negative growth.2)With the increase of dietary DE level,the serum glucose content of experimental sheep was significantly increased in each mating phase(P＜0.05),the serum urea nitrogen(Urea)content was significantly decreased at each mating phase and mating recovery peri-od(P＜0.05),the serum triglyceride(TG)content was significantly increased in the mating F2 phase(P＜0.05),and the serum contents of TG and total cholesterol were significantly increased in the mating F3 phase(P＜0.05).With the increase of dietary CP content,the serum Urea content of experimental sheep was signifi-cantly increased at each period(P＜0.05).3)The semen quality of experimental sheep in energy groupⅡwas relatively high.With the increase of dietary CP content,the ejaculation volume,sperm density and effective sperm count were significantly increased(P＜0.05).With the increase of sperm collection frequency,the se-men quality was significantly decreased(P＜0.05),and the serum testosterone content was significantly de-creased(P＜0.05).4)The dietary energy and protein requirements of Tan sheep breed rams at different peri-ods were as follows.The mating preparation period:DE(MJ/d)=0.557W0.75+0.071ADG(R2=0.802,P＜0.01)(W0.75 was metabolic body weight,the same as below),metabolic energy(ME,MJ/d)=0.450W0.75+0.061ADG(R2=0.799,P＜0.01);CP(g/d)=5.52W0.75+0.366ADG(R2=0.998,P＜0.01),digestible crude protein(DCP,g/d)=2.95W0.75+0.310ADG(R2=0.983,P＜0.01).The mating period:DE(MJ/d)=0.557W0.75+0.928 3n(n was the number of sperm collection,the same as below),ME(MJ/d)=0.450W0.75+0.765 6n;CP(g/d)=5.52W0.75+68.97n,DCP=2.95W0.75+47.84n.The mating recovery period:DE(MJ/d)=0.444W0.75+0.046ADG(R2=0.890,P＜0.01),ME(MJ/d)=0.359W0.75+0.039ADG(R2=0.891,P＜0.01);CP(g/d)=5.55W0.75+0.604ADG(R2=0.972,P＜0.01),DCP(g/d)=2.37W0.75+0.506ADG(R2=0.974,P＜0.01).In conclusion,it is recommended that the DE re-quirement for Tan sheep breed rams is 11.40 MJ/d and the CP requirement is 171.12 g/d.[Chinese Journal of Animal Nutrition,2026,38(3):2095-2112]