The Studies On The Energy And Protein Requirements In Female Lambs Of Mutton Sheep At35~50kg

Thirty Polled Dorset×Small Tailed Han sheep crossed ewes，weaned at6monthswith mean weight about32kg, were selected to this study. The diet was madeaccording to granulation TMR based on recommendation of nutrients requirements ofsheep(NRC，2007).Energy and protein metabolism rules and requirement factorialmodels of mutton sheep at the growth of35~50kg were systematically studied by thefeeding test, comparative slaughtering test and digestion-metabolism experiment.Theaim of this study is to investigate the energy and protein requirement of F2generationsheep and provide the theoretical basis for feeding standard and the scientific basis forefficient feeding.The results showed as follows.The apparent digestibility of dry matter, ether extract, neutral detergent fiber and aciddetergent fiber of mutton sheep at the growth of35~50kg were69.35%~76.45%、61.20%~69.87%、40.87%~49.89%and34.85%~44.68%respectively.The digestibility of energy was75.89%~79.42%， the metabolizability of grossenergy(ME/GE) and digestible energy(ME/DE) were52.37%~60.78%，66.94%~76.53%.The digestibility of protein was73.74%~79.92%,the utilization of net protein was18.01%~33.73%.The net energy requirement of mutton sheep at35~50kg can be estimated by thefactorial models as follows.NER=216.27KJ/kgW0.75·d+NEg.Log10(ER)=0.428+1.219Log10(BW).The metabolizable energy requirement of mutton sheep at35~50kg can beestimated by the factorial models as follows.MER=296.108KJ/kgW0.75·d+NEg／0.294Log10(ER)=0.428+1.219Log10(BW).The net protein requirement of mutton sheep at20~35kg can be estimated by thefactorial models as follows.NpR=0.878g/kgW0.75·d+NpgLog10(NR)=2.778+Log10(BW).