本试验旨在研究妊娠后期饲粮代谢能水平对绒山羊母羊增重、血浆生殖激素浓度、初乳产量、初乳乳成分及羔羊初乳期生长的影响。选用18只体重（39.75±2.86）kg、年龄3~4岁，处于妊娠91 d的内蒙古白绒山羊，随机分为3组，每组6只。根据NRC制订基础饲粮，各组饲粮代谢能分别为7.70（基础饲粮的70%）、11.00（基础饲粮，对照组）、14.30 MJ/kg（基础饲粮的130%）。预试期为妊娠91~100 d，正试期为妊娠第110天至产后第5天。结果表明：1）14.30 MJ/kg饲粮代谢能可显著提高妊娠后期血浆雌二醇（E2）浓度平均值、妊娠后期母羊体增重、产后第1~4天初乳乳蛋白含量及初乳期羔羊平均日增重（P<0.05）；母羊饲粮代谢能水平对母羊血浆孕酮（P4）及催乳素（PRL）浓度、初乳乳脂含量（产后第4天除外）、羔羊初生重影响不显著（P>0.05）。2）7.70 MJ/kg饲粮代谢能可降低妊娠后期母羊血浆E2、P4及PRL浓度平均值，妊娠后期母羊体增重，羔羊初生重，初乳产量（产后第5天除外），初乳乳蛋白含量（产后第1、3天除外），初乳期羔羊平均日增重，但影响不显著（P>0.05），显著降低初乳乳脂含量（产后第3天除外）（P<0.05）。因此，饲粮代谢能为14.30 MJ/kg更适合妊娠后期母羊，为应对饲草料不足可以以代谢能为7.70 MJ/kg的饲粮限饲。

This study researched the effects of dietary metabolic energy level during later pregnancy on body weight gain, plasma reproductive hormone concentrations, yield and milk composition of colostrum of ewes, and growth of their lambs during colostrum period. Eighteen Inner Mongolia white cashmere goats in later pregnancy (91 d), weighing (39.75±2.86) kg and aged between 3 and 4 years, were randomly divided into 3 groups with six goats in each group. A basal diet was made according to NRC. metabolic energy level in different groups was 7.70 (70% of the basal diet), 11.00 (the basal diet, control group) and 14.30 MJ/kg (130% of the basal diet). The pre-experimental period was from 91 to 100 d of pregnancy, and the experimental period was from 101 d of pregnancy to day 5 after delivery. The results showed as follows:1) dietary metabolic energy of 14.30 MJ/kg could significantly increase average vale of estradiol (E2) concentration in plasma and ewes' body weight gain during later pregnancy, milk protein content on day 1 to 4 of post pregnancy and lambs' average daily gain of colostrum period (P<0.05), while had no significant impacts on progesterone (P4) and prolactin (PRL) concentrations in plasma, milk fat percentage of colostrum (except day 4 after delivery) and lambs' birth weight (P>0.05). 2) Dietary metabolic energy of 7.70 MJ/kg could decrease average values of E2, P4 and PRL concentrations in plasma, ewes' body weight gain during later pregnancy, lambs' birth weight, colostrum yield (except day 5 after delivery), milk protein content of colostrum (except day 1 and 3 after delivery), lambs' average daily gain during colostrum period, but the effects were not significant(P>0.05), and could significantly decrease milk fat content of colostrum (except day 3 after delivery) (P<0.05). Thus, dietary metabolic energy if 14.3 MJ/kg is more suitable for ewes in later pregnancy; in order to deal with lack of forage, it is viable that restricted feeding using diet with 7.70 MJ/kg metabolic energy.