妊娠后期饲粮营养水平对母羊和胚胎发育的影响

Effects of Dietary Nutrient Levels on the Development of Late Pregnant Ewes and Fetal

本试验旨在研究妊娠后期饲粮营养水平对母羊及胚胎发育的影响。试验选用健康、怀双羔的初产湖羊,妊娠0~90d采用相同的TMR,自由采食。妊娠90d时母羊(平均体重(44.45±2.2)kg)分3个处理组饲喂,每组11个重复,每个重复2只,共计66只。试验采用相同的精料补充料和粗料,分别按照以干物质为基础,精∶粗为5∶5、4∶6、3∶7定量饲喂母羊至妊娠140d,每组选取3只进行屠宰试验。结果表明,随着营养水平降低:1)母羊体重有降低趋势(P<0.10),对母羊腹围无显著性影响(P>0.05),但可显著影响到母羊的体增重(P<0.05);2)母羊的妊娠产物总重、羊水重及胚胎重无显著变化(P>0.05),但胚胎重量有降低趋势(P<0.10);3)除心重外(P<0.05),胚胎的体尺及内脏器官的发育无显著变化(P>0.05),但随营养水平降低,胚胎体高、体斜长、肝、肺、胃、小肠重量有降低趋势(P<0.10)。通过精∶粗调控妊娠后期母羊饲粮营养水平可显著影响到母羊的体增重;但在没超出母体的耐受范围的情况下,母羊以降低自身的体增重最大限度维持母羊的妊娠产物、胚胎的体尺、组织器官的发育,但仍会影响胚胎的正常发育。

This research aimed to study the effect of dietary nutrient levels on the development of late pregnancy ewes and embryos.Sixty-six primiparous and healthy Hu ewes with double lambs were provided with TMR diets ad libitum for the first 90 days of pregnancy,and the ewes（（44.45±2.2）kg body weight）were randomly divided into 3groups with 11 replicates for each group and 2ewes per pen.Each group was offered the dietary with the same concentrate supplement and forage but the different ratio of concentrate/forage for 5∶5,4∶6and 3∶7（DM basis）,respectively from 90 th days of pregnancy.Three ewes from each group were slaughtered on the140 th days of gestation for the slaughter experiment.The results showed as follows：1）With the nutrient levels decreasing,the body weight of ewes had decreased trend（P〈0.10）.No significant changes were found in abdominal circumference during late pregnancy of ewes（P〉0.05）,but the ewes＇ body weight gain were significantly affected（P〈0.05）.2）The dietary nutrient levels had no significant effect on the weight of pregnancy appendages,amniotic fluid and fetal in late pregnancy of ewes（P〉0.05）,but the fetal weight had the decreased trend（P〈0.10）with the nutrient levels decreased.3）Body size and organs weight of fetal in late pregnancy were notaffected by the different nutrient levels（P〉0.05）,except the heart weight（P〈0.05）,and the body height,body length and the weight of liver,lung,stomach,small intestine had the decreased trend（P〈0.10）.The late pregnancy dietary nutrient levels resulting from concentrate supplement/forage could affect the ewes＇ body weight gain,and the ewes would reduce their body weight gain to maintain the development of ewe pregnancy appendages,embryo body size,tissues and organs when it did not exceed the tolerance range of maternal,but which still impeded the normal development of embryo.