饲粮添加木薯渣对羔羊生长性能、血清指标及瘤胃发酵指标的影响

本试验旨在研究饲粮中添加不同比例木薯渣对羔羊生长性能、营养物质表观消化率、血清指标及瘤胃发酵指标的影响。试验选取3~4月龄、体重相近、健康状况良好的断奶湖羊羔羊96只,采用单因素随机分组设计方法,随机分为4组,每组6个重复,每个重复4只,分别在饲粮中添加0(对照)、5%、10%、20%的木薯渣,配制成等能等氮的4种饲粮。预试期10 d,正试期45 d。结果表明:1)饲粮添加不同比例木薯渣对羔羊的终末体重、平均日采食量及营养物质表观消化率均无显著性影响(P0.05),但随着木薯渣添加比例的升高,平均日增重、料重比呈一次线性升高和降低(P0.05)。2)随木薯渣添加比例的升高,血清总抗氧化能力(T-AOC)呈先降低再升高的二次曲线变化(P=0.007),对照组最高;血清谷胱甘肽还原酶(GSH)含量呈先升高后降低的二次曲线变化(P=0.001),10%组显著高于其他各组(P0.05);血清丙二醛(MDA)含量变化不显著(P0.05);血清超氧化物歧化酶(SOD)活性呈一次线性降低(P=0.010)。4)随着饲粮中木薯渣添加比例的提高,血清总蛋白(TP)和白蛋白(Alb)含量均呈一次线性和二次曲线变化(P0.05);血清白球比(A/G)、门冬氨酸氨基转移酶(AST)活性、甘油三酯(TG)和球蛋白(Glb)含量呈二次曲线变化(P0.05);血清尿酸(UA)和肌酐(Crea)含量呈一次线性变化(P0.05);各组之间血清丙氨酸氨基转移酶(ALT)活性和葡萄糖(GLU)含量差异不显著(P0.05)。5)饲粮木薯渣添加比例对生长羔羊瘤胃液的p H,乙酸、丙酸、丁酸、异戊酸、戊酸浓度及乙酸/丙酸无显著性影响(P0.05)。综合得出,饲粮中添加木薯渣提高了羔羊生长性能,但高添加比例的木薯渣会对羔羊抗氧化能力和肾脏造成损害,建议木薯渣添加比例低于20%为宜。

Effects of Dietary Cassava Residue Supplementation on Growth Performance,Serum Indexes and Rumen Fermentation Indexes of Growing Lambs

This experiment was conducted to investigate the effects of dietary cassava residues ( CR) supple?mentation at different proportions on growth performance, nutrient apparent digestibility, serum indices and ru?men fermentation indexes of growing lambs. Ninety?six healthy Hu lambs of 3 to 4 months of age with similar body weight were randomly allocated into 4 groups with 6 replicates in each group and 4 lambs in each repli?cate. Lambs were fed with diets contained 0 ( control) , 5%, 10%, and 20% CR, respectively. The adjustment period lasted for 10 days and the experimental period lasted for 45 days. The results showed as follows:1) fi?nal body weight, average daily feed intake and apparent digestibility were not significantly different among groups ( P>0.05) . Average daily gain and ratio of feed to gain were linearly increased and decreased, respec?tively, with the increase of CR supplementation proportion ( P<0.05) . 2) With the increase of CR supplemen?tation proportion, serum total antioxidant capacity ( T?AOC) showed a quadratic change of firstly decreased and then increased ( P=0.007) , and control group was the highest; serum glutathione reductase ( GSH) con?tent showed a quadratic change of firstly increased and then decreased ( P=0.001) , and 10% group was signif?icantly higher than the other groups (P<0.05); serum superoxide dismutase (SOD) was linearly decreased ( P=0.010) . 3) With the increase of CR supplemental proportion, serum contents of total protein ( TP) and albumin ( Alb) changed linearly and quadratically ( P<0.05);serum albumin/globulin ( A/G) , aspartate ami?notransferase (AST) activity, and contents of globulin (Glb) and triglyceride (TG) changed quadratically (P<0.05); serumuric acid (UA) and creatinine (Crea) contents changed linearly(P<0.05); serum alanine aminotransferase ( ALT) activity and glucose content were not significantly different among groups ( P<0.05) . 4) Rumen fluid pH, concentrations of acetic acid, propionic acid, butyric acid, isovaleric acid and valeric acid, and acetic acid/propionic acid were not significantly different among groups( P>0.05) . Therefore, dieta?ry supplementation of CR can improve growth performance of growing lambs. But it may damage antioxidant capacity and kidney function with the high supplemental proportion of CR. It is suggested that the supplemental proportion of CR in diet of lambs should be less than 20%.