本试验旨在研究代乳品和开口料的饲喂对哺乳中后期羔羊生长性能、血清生化指标和营养物质表观消化率的影响。选择体重相近的30日龄羔羊75只，随机分成5组，每组3个重复，每个重复5只。各组分别饲喂代乳品1+开口料（A组）、代乳品1（B组）、代乳品2（C组）、母乳+开口料（D组）和母乳（E组）。分别在30、40、50、60、70日龄称重并对体尺进行测量，68~70日龄连续收集3 d粪样测定营养物质表观消化率，在70日龄颈静脉采血测定血清生化指标。结果表明：1）30、40、50、60、70日龄D组体重、体长、体高、胸围高于A、E组，E组高于B组，B组与C组间差异不显著（P>0.05）；但60~70日龄期间，A组平均日增重显著高于D组（P<0.05），B组显著高于E组（P<0.05）。2）血清尿素氮含量及谷丙转氨酶、谷氨酰转移酶、乳酸脱氢酶活性组间差异不显著（P>0.05）；血清总蛋白和甘油三酯含量D组显著高于A组（P<0.05），E组血清甘油三酯含量显著高于B、C组（P<0.05）；血清白蛋白和球蛋白含量A、D、E组之间差异不显著（P>0.05），但D组有增高趋势，E组显著高于B、C组（P<0.05）；血清葡萄糖含量A、D、E组显著高于B、C组（P<0.05）；A组血清碱性磷酸酶活性显著高于其他各组（P<0.05）；B、C组之间上述血清生化指标差异均不显著（P>0.05）。3）各营养物质采食量A组显著高于B、C组（P<0.05），B、C组之间差异不显著（P>0.05）；干物质、钙、磷表观消化率差异不显著（P>0.05）；粗蛋白质、总能、中性洗涤纤维和酸性洗涤纤维表观消化率A组显著高于B、C组（P<0.05），且B、C组差异不显著（P>0.05）。由此可见，代乳品和开口料的饲喂对羔羊生长性能、血清生化指标及营养物质表观消化率有不同程度的影响，羔羊代乳品加开口料的饲喂模式可实现羔羊的早期断奶，具有一定的推广价值。

This study was to research the effects of feeding milk replacer and starter on growth performance, serum biochemical indexes and nutrient apparent digestibility of lambs during mid-late lactation. Seventy five 30-day-old lambs with similar weight were selected and randomly divided into 5 groups with 3 replicates per group and five lambs per replicate. Lambs were fed milk replacer 1+ starter (group A), milk replacer 1 (group B), milk replacer 2 (group C), breast milk + starter (group D) and breast milk (group E), respectively. At 30, 40, 50, 60, 70 days of age, body weight and body size were measured. A total of 3 consecutive days of fecal sampling was carried out to determine nutrient apparent digestibility at 68 to 70 day of age. Jugular venous blood was collected at 70 days of age to determine serum biochemical indexes. The results showed as follows:1) at 30, 40, 50, 60, 70 days of age, body weight, body length, body height and heart girth of group D were higher than those of groups A and E, group E was higher than group B, and there were no significant differences between groups B and C (P>0.05); but during 60 to 70 days of age, average daily gain of group A was significantly higher than that of group D (P<0.05), group B was significantly higher than group E (P<0.05). 2) Serum urea nitrogen content and the activities of alanine aminotransferase, glutamyl transferase, lactate dehydrogenase were not significant different among groups (P>0.05); serum total protein and triglyceride contents of group D were significantly higher than those of group A (P<0.05), triglyceride content of group E was significantly higher than that of groups B and C (P<0.05); there were no significant differences of serum albumin and globulin contents among groups A, D and E (P>0.05), but group D has higher values, group E was significantly higher than groups B and C (P<0.05); serum glucose content of groups A, D and E was significantly higher than that of groups B and C (P<0.05); serum alkaline phosphatase activities of group A was significantly higher than that of other groups (P<0.05); all the above serum biochemical indexes of groups B and C were not significantly different (P>0.05). 3) Feed intakes of various nutrients of group A were significantly higher than those of groups B and C (P<0.05), and the differences were not significant between groups B and C (P>0.05); the apparent digestibility of dry matter, calcium and phosphorus had no significant difference among groups (P>0.05); the apparent digestibility of gross energy, crude protein, neutral detergent fiber and acid detergent fiber of group A was significantly higher than that of groups B and C (P>0.05), groups B and C had no significant difference (P>0.05). It is concluded that feeding milk replacer and starter has different effects on performance, serum biochemical indexes and apparent digestibility of nutrients of lambs, the feeding mode of milk replacer and starter can realize early weaning of lambs, which has certain value of popularization.