桑叶黄酮对肉兔生长性能、肠道组织结构和消化酶活性、营养物质表观消化率及血清生化指标的影响

Effects of Mulberry Leaf Flavonoids on Growth Performance,Intestinal Tissue Structure,Digestive Enzyme Activities,Nutrient Apparent Digestibility and Serum Biochemical Indexes of Meat Rabbits

本试验旨在研究饲粮中添加不同水平桑叶黄酮对肉兔生长性能、肠道组织结构和消化酶活性、营养物质表观消化率及血清生化指标的影响。采用单因素试验设计,选取120只体重相近、体况良好的42日龄伊拉肉兔,随机分为4个组,每组5个重复,每个重复6只兔。对照组饲喂基础饲粮,试验组分别在基础饲粮中添加30、60和90 mg/kg的桑叶黄酮。预试期7 d,正试期35 d。结果表明:1)与对照组和30、60 mg/kg桑叶黄酮组相比,90 mg/kg桑叶黄酮组的终末体重和平均日增重显著提高(P<0.05),料重比显著降低(P<0.05);与对照组相比,30、60和90 mg/kg桑叶黄酮组的死亡率显著降低(P<0.05)。2)与对照组相比,30、60和90 mg/kg桑叶黄酮组的十二指肠绒毛高度和绒毛高度/隐窝深度显著提高(P<0.05);与对照组和30、60 mg/kg桑叶黄酮组相比,90 mg/kg桑叶黄酮组的十二指肠隐窝深度显著降低(P<0.05)。3)与对照组和30 mg/kg桑叶黄酮组相比,60和90 mg/kg桑叶黄酮组的空肠淀粉酶、脂肪酶活性显著提高(P<0.05),回肠淀粉酶、胰蛋白酶活性显著提高(P<0.05);与对照组和30、60 mg/kg桑叶黄酮组相比,90 mg/kg桑叶黄酮组的回肠脂肪酶活性显著提高(P<0.05)。4)与对照组和30、60 mg/kg桑叶黄酮组相比,90 mg/kg桑叶黄酮组的干物质和粗纤维表观消化率显著提高(P<0.05);与对照组相比,30、60和90 mg/kg桑叶黄酮组的总能、粗蛋白和粗脂肪表观消化率显著提高(P<0.05);与对照组和30 mg/kg桑叶黄酮组相比,60、90 mg/kg桑叶黄酮组的酸性洗涤纤维表观消化率显著提高(P<0.05)。5)与对照组和30和60 mg/kg桑叶黄酮组相比,90 mg/kg桑叶黄酮组的血清葡萄糖和尿素氮含量显著降低(P<0.05)。由此可见,饲粮中添加桑叶黄酮可提高肉兔肠道消化酶活性和营养物质表观消化率,改善肠道形态,从而提高生长性能。本试验条件下,肉兔饲粮中桑叶黄酮适宜添加水平为90 mg/kg。

This experiment was conducted to study the effects of dietary difference supplemental levels of mul-berry leaf flavonoids on growth performance,intestinal tissue structure,digestive enzyme activities,nutrient apparent digestibility and serum biochemical indexes of meat rabbits.The experiment adopted a single factor ex-perimental design,one hundred and twenty 42-day-old Ira rabbits with good physical condition and similar body weight were selected and randomly divided into 4 groups with 5 replicates in each group and 6 rabbits in each replicate.Rabbits in the control group were fed a basal diet,and others in experimental groups were fed the basal diets supplemented with 30,60 and 90 mg/kg mulberry leaf flavonoids,respectively.The pre-experi-mental period lasted for 7 days,and the experimental period lasted for 35 days.The results showed as follows:1)compared with control group and 30 and 60 mg/kg mulberry leaf flavonoids groups,the final body weight and average daily gain of 90 mg/kg mulberry leaf flavonoids group were significantly increased(P<0.05),and the feed to gain ratio was significantly decreased(P<0.05);compared with the control group,the mortali-ty rate of 30,60 and 90 mg/kg mulberry leaf flavonoids groups was significantly decreased(P<0.05).2)Compared with the control group,the duodenal villus height and villus height/crypt depth of 30,60 and 90 mg/kg mulberry leaf flavonoids groups were significantly increased(P<0.05);compared with control group and 30 and 60 mg/kg mulberry leaf flavonoids groups,the duodenal crypt depth of 90 mg/kg mulberry leaf flavonoids group was significantly decreased(P<0.05).3)Compared with control group and 30 mg/kg mulberry leaf flavonoids group,the activities of amylase and lipase in jejunum of 60 and 90 mg/kg mulberry leaf flavonoids groups were significantly increased(P<0.05),and the activities of amylase and trypsin in ile-um were significantly increased(P<0.05);compared with control group and 30 and 60 mg/kg mulberry leaf flavonoids groups,the ileal lipase activity of 90 mg/kg mulberry leaf flavonoids group was significantly in-creased(P<0.05).4)Compared with control group and 30 and 60 mg/kg mulberry leaf flavonoids groups,the apparent digestibility of dry matter and crude fiber of 90 mg/kg mulberry leaf flavonoids group was signifi-cantly increased(P<0.05);compared with the control group,the apparent digestibility of gross energy,crude protein and ether extract of 30,60 and 90 mg/kg mulberry leaf flavonoids groups was significantly increased(P<0.05);compared with control group and 30 mg/kg mulberry leaf flavonoids groups,the acid detergent fi-ber apparent digestibility of 60 and 90 mg/kg mulberry leaf flavonoids group was significantly increased(P<0.05).5)compared with control group and 30 and 60 mg/kg mulberry leaf flavonoids groups,the contents of glucose and urea nitrogen in serum of 90 mg/kg mulberry leaf flavonoids group were significantly decreased(P<0.05).In conclusion,dietary mulberry leaf flavonoids can improve the intestinal digestive enzyme activi-ties nutrient apparent digestibility and intestinal morphology of meat rabbits,then improve the growth perform-ance.Under the conditions of this experiment,the dietary appropriate supplemental level of mulberry leaf fla-vonoids for meat rabbits is 90 mg/kg.