Study On The Appropriate Intatke Of Energy And Protein Of Small Fat-Tail Sheep During Pregnancy And Lactation

Experiments were conducted to test different levels of metabolizable energy, rumen degradable protein and undegradable dietary protein on the performance of ewes during each period of pregnancy and lactation l~50d by feeding trial, digestion and metabolism experiments and determination of feed degradation in rumen. The test is conducted to find the appropriate intake of ME , RDP and UDP of ewes during pregnancy and lactation 1-50d.The pregnancy period is divided into two stages-early pregnancy and later pregnancy-according to the physiological stages. A2+3 factorial experiment was performed . Energy was to planed to two levels-low (100% NRC) and high(120%NRC) .Protein was to planed to three levels -low (80%NRC), moderate(100%NRC) and high (120%NRC) .100 small-fat-tail sheep was selected to make to have the same oestrus and be mated by artificial fertilization. During early pregnancy and late pregnancy , 42 small-fat-tail sheep was divided randomly into 6 groups of 7 each, and fed with 2 levels of energy (100% and 120 % of recommended content of NRC (1978 ) ) and 3 levels of protein ( 80%, 100% and 120% of recommended content of NRC(1978)) .The treatments were adjusted to have 5 ewes and 10 lambs each group during lactation l-50d.Through comparison among productive performance of the ewes ( weight gained , the weight of lambs at birth , the changes of ewes during lactation l-50d, the growing speed of lambs and mild yield), the result could be concluded that the appropriate ME, RDP and UDP intake of ewes during early pregnancy, later pregnancy and lactation l-50d was 0.674 MJ/kgW0.75, 4.20g/kgW0.75, 3.67 g/kgW0.75, 0.722 MJ/kgW0.75, 5.55g/kgW0.75, 2.37g/kgW0.75, 0.710MJ/kgW0.75, 8.79 g/kgW0.75, 4.45 g/kgW0.75.