不同营养水平对滩×寒杂种母羊繁殖性能的影响

Effect of nutrition level on reproductive performance of Tan×Small Tail Han crossbred ewes

为研究妊娠后期(97～150d)、泌乳期(30d)、催情期(断奶至第2个情期)0.8×NRC(Ⅰ)、0.9×NRC(Ⅱ)和1.0×NRC(Ⅲ)代谢能(metabolic energy,ME)与粗蛋白(crude protein,CP)水平对母羊繁殖性能的影响。将30只1～2胎的滩×寒杂种妊娠母羊随机分成3组(统计的母羊数依次为6,5和7只),单栏饲养。结果表明,1)Ⅰ组母羊产后体重(43.50±7.50kg)低于Ⅱ(47.20±2.12kg,P>0.05)、Ⅲ组(54.79±6.72kg,P<0.05),Ⅱ组呈低于Ⅲ的趋势;Ⅲ组母羊自身日增重(137.4±59.8g)极显著高于Ⅰ、Ⅱ组(-57.7±39.9,34.2±56.2,P<0.01),Ⅱ也显著高于Ⅰ组(P<0.05)。各组羔羊初生重(3.82±0.76,3.86±0.58和4.10±0.77kg)相近(P>0.05);Ⅲ组的羔羊初生窝重(7.69±2.24kg)高于(P=0.086)Ⅰ、Ⅱ组(5.73±1.34,5.40±1.65kg),与其多羔率高有关。2)在泌乳期,母羊泌乳量(27.08±4.52,40.34±11.90,55.48±14.29kg)、羔羊断奶窝重(13.49±3.82,14.62±3.64,19.32±4.45kg)、窝增重(7.17±2.71,9.22±2.17,12.28±3.15kg)、羔羊断奶均重(7.71±2.26,10.45±1.72,11.19±2.51kg)和增重(4.10±1.60,6.59±1.38,7.08±2.09kg)均随母羊营养水平而提高(P<0.05或P>0.05)。Ⅰ组母羊泌乳期增重,Ⅱ、Ⅲ组均减重(相应为+0.94±2.05,-0.35±2.74和-1.86±3.89kg),但组间差异不显著(P>0.05)。3)3组母羊授乳末体重分别为(46.31±7.61),(46.85±2.58)和(52.93±4.20)kg(P=0.067),断奶后第1次发情分别是在(18.60±12.86),(13.25±6.70)和(10.71±4.07)d,第2情期结束时的空怀率为16.67%,20.00%和14.29%。母羊2次产羔间隔相应为201.8,183.5和187.7d。

The effects of（Ⅰ） 0.8×NRC,（Ⅱ） 0.9×NRC and（Ⅲ） 1.0×NRC levels of metabolic energy（ME） and crude protein（CP） on reproductive performance of ewes during the late period of pregnancy（97-150 d）,lactation period（30 d） and flush period（from weaning of lambs to end of the second estrus cycle） were studied.Thirty Tan×Small Tail Han crossbred ewes in lamb at the first or second conceiving stage were randomly divided into three groups（6,5 and 7 ewes in groups Ⅰ,Ⅱ and Ⅲ respectively were used for statistical analysis）.All the ewes were individually housed in pens with lamb creep.1） During the late period of pregnancy,the postpartum weight of ewes for group Ⅰ（43.50±7.50 kg） was lower than those of groups Ⅱ and Ⅲ（47.20±2.12 and 54.79±6.72 kg）.The average daily gain（ADG） of ewes-selves for group Ⅲ（137.4±59.8 g） was greater than those of groups Ⅰ and Ⅱ（-57.7±39.9 and 34.2±56.2 g）.Differences in birth weight of lambs（3.82±0.76,3.86±0.58 and 4.10±0.77 kg respectively） among the three groups were not significant,but litter weight was greater for group Ⅲ（7.69±2.24 kg） than for groups Ⅰ and Ⅱ（5.73±1.34 and 5.40±1.65 kg）.2） During the period of lactation,milk yield of ewes（27.08±4.52,40.34±11.90 and 55.48±14.29 kg）,body-weight（BW）（13.49±3.82,14.62±3.64 and 19.32±4.45 kg） and body-weight gain（BWG） of litters（7.17±2.71,9.22±2.17 and 12.28±3.15 kg）,BW at weaning（7.71±2.26,10.45±1.72 and 11.19±2.51 kg） and BWG of lambs（4.10±1.60,6.59±1.38 and 7.08±2.09 kg） increased with the nutritive levels of ewes.BW of group Ⅰ ewes increased（＋0.94±2.053 kg） but for groups Ⅱ and Ⅲ,it decreased（-0.35±2.74 and-1.86±3.89 kg）,although there were no significant differences in BWG among all groups.3） For group Ⅰ,Ⅱ and Ⅲ ewes,BWs at the end of nursing were 46.31±7.61,46.85±2.58 and 52.93±4.20 kg respectively.The first estrous cycle occurred at 18.60±12.86,13.25±6.70 and 10.71±4.07 d after cessation of nursing.The ratios of barren ewes at the end of the second estrous cycle were 16.67%,20.00% and 14.29%,and the lambing intervals were 201.8,183.5 and 187.7 d.