本研究旨在探讨在蛋鸡饲粮中添加不同比例的苜蓿草粉和在高水平苜蓿草粉饲粮中添加纤维素酶对其脂质代谢、抗氧化能力及肠道菌群的影响。试验选用40周龄健康海兰褐蛋鸡210只,采用单因子完全随机设计,将其分为7个组,每组3个重复,每个重复10只鸡,分别在饲粮中添加不同比例的苜蓿草粉和纤维素酶,依次为:0苜蓿草粉(对照组)、3%苜蓿草粉(试验Ⅰ组)、5%苜蓿草粉(试验Ⅱ组)、7%苜蓿草粉(试验Ⅲ组)、7%苜蓿草粉+0.1%纤维素酶(试验Ⅳ组)、7%苜蓿草粉+0.2%纤维素酶(试验Ⅴ组)、7%苜蓿草粉+0.3%纤维素酶(试验Ⅵ组)。结果表明:1)蛋鸡血清中甘油三酯和总胆固醇含量随着苜蓿草粉和纤维素酶添加量的增加而递减,试验Ⅲ~Ⅵ组均显著低于对照组(P<0.05),且试验Ⅳ~Ⅵ组之间无显著差异(P>0.05)。2)试验组蛋鸡肝脏、肌肉和蛋黄中总胆固醇和甘油三酯含量下降,其中:在肝脏中,总胆固醇含量试验Ⅲ~Ⅴ组最低,甘油三酯含量试验Ⅵ组最低;肌肉中总胆固醇含量试验Ⅴ、Ⅵ组最低;蛋黄中总胆固醇和甘油三酯含量试验Ⅲ~Ⅵ组最低,均显著低于对照组(P<0.05),试验Ⅳ~Ⅵ组间总胆固醇和甘油三酯含量均差异不显著(P>0.05)。3)试验组蛋鸡血清、肝脏及肌肉中的超氧化物歧化酶活性均有所升高,其中血清、肝脏中以试验Ⅴ、Ⅵ组最高,蛋黄中以试验Ⅲ、Ⅵ组最高,均显著高于对照组(P<0.05)。4)各试验组蛋鸡血清、肝脏及蛋黄中的丙二醛(MDA)含量均有所下降,其中血清中以试验Ⅳ、Ⅵ组和肝脏中以试验Ⅴ、Ⅵ组最低,均显著低于对照组(P<0.05);各试验组蛋黄中MDA含量均显著低于对照组(P<0.05),各纤维素酶组均显著低于苜蓿草粉组(P<0.05),其中试验Ⅲ组显著低于试验Ⅰ、Ⅱ组(P<0.05),试验Ⅳ~Ⅵ组间均差异不显著(P>0.05)。5)在蛋鸡盲肠和回肠中,添加苜蓿草粉和纤维素酶后大肠杆菌数量下降,而乳酸杆菌数量上升,其中回肠大肠杆菌数量以试验Ⅵ组最低,盲肠大肠杆菌数量以试验Ⅴ、Ⅵ组最低,盲肠乳酸杆菌数量以试验Ⅳ~Ⅵ组最高,均显著高于对照组(P<0.05),但试验Ⅳ~Ⅵ组间均差异不显著(P>0.05)。综上所述,在蛋鸡饲粮中适量使用苜蓿草粉和纤维素酶可改善其脂质代谢和抗氧化能力,改善肠道微生物菌群。综合各方面考虑,以7%苜蓿草粉+0.2%纤维素酶添加效果较佳。

The objective of this study was to evaluate the effects of dietary alfalfa meal and cellulase on lipid metabolism, antioxidant capacity and intestinal flora of layers. A total of 210 Hyline brown layers aged 40 weeks were randomly divided into 7 groups and 3 replicates in each group and 10 layers in each replicate. The layers were fed a basal diet containing 0 (control group), 3% (group 1), 5% (group 2), 7% (group 3) alfalfa meal and 7% alfalfa meal plus 0.1% (group 4), 0.2% (group 5) and 0.3% (group 6) cellulase, respectively. The results showed as follows: 1) the contents of triglycerides (TG) and total cholesterol (TC) in serum of layers were decreased with the increasing of dietary alfalfa meal and cellulose levels, and above indexes in groups 3, 4, 5 and 6 were significantly lower than those in the control group (P<0.05), but there were no significant differences among groups 4, 5 and 6 (P>0.05). 2) The contents of TG and TC in liver, muscle and yolk of layers in experimental groups were decreased to some extent. In liver, TC content in groups 3, 4 and 5 and TG content in group 6 were the lowest among all groups; in muscle, TC content in groups 5 and 6 was the lowest; in yolk, the contents of TC and TG in groups 4, 5 and 6 were the lowest. All of the above were significantly lower than those in the control group (P<0.05), but there were no significant differences in the contents of TC and TG in groups 4, 5 and 6 (P>0.05). 3) SOD activity in serum, liver and muscle of layers in experimental groups was increased to some extent. SOD activity in serum and liver in groups 5 and 6 was the highest, whereas that in yolk in groups 3 and 6 was the highest, and all of the above were significantly higher than that in the control group (P<0.05). 4) MDA content in serum, liver and muscle in experimental groups was decreased to some extent, of which in serum in groups 4 and 6 and in liver in groups 5 and 6 was lower than that in the control group (P<0.05). In yolk, MDA content in experimental groups was significantly lower than that in the control group (P<0.05); there was a significant difference between groups 1, 2 and 3 and groups 4, 5 and 6 (P<0.05); MDA content in group 3 was lower than that in groups 1 and 2 (P<0.05); there were no significant differences among groups 4, 5 and 6 (P>0.05). 5) The number of E. coli was decreased, while that of Lactobacillus was increased in experimental groups. The number of E. coli in ileum in group 6 and in caecun in groups 5 and 6 was the lowest, and that of Lactobacillus in cerum in groups 4, 5 and 6 was the highest, and all of the above were better than that in the control groups (P<0.05), but there were no significant differences among groups 4, 5 and 6 (P>0.05). In conclusion, lipid metabolism, antioxidant capacity and and intestinal flora of layers are improved by adding alfalfa meal and cellulase in the diet, and 7% alfalfa meal+0.2% cellulase is recommended.