花生藤替代颗粒型全混合日粮中苜蓿对湖北黑头羊生长性能、瘤胃发酵及血清生化指标的影响

Effects of Peanut Vine Instead of Alfalfa in Granulated Total Mixed Ration on Growth Performance,Rumen Fermentation and Serum Biochemical Indexes of Hubei Black-Head Goats

本试验旨在研究花生藤替代颗粒型全混合日粮中苜蓿对湖北黑头羊生长性能、瘤胃发酵和血清生化指标的影响,从而为黑头羊育肥过程中合理使用粗饲料提供依据。选取30只体重[(20.46±3.23) kg]接近、体况良好的8月龄湖北黑头山羊羯羊,随机分为3组,每组10只,分别饲喂以花生藤(Ⅰ组)、苜蓿(Ⅱ组)和苜蓿+花生藤(Ⅲ组)为粗饲料来源的颗粒型全混合日粮,试验期60 d,其中预试期10 d,正试期50 d。试验结束后称重,并采集瘤胃液和血液样品,分别测定瘤胃液挥发性脂肪酸、氨态氮浓度以及血清总蛋白(TP)、白蛋白(ALB)、尿素氮(UN)、葡萄糖(GLU)含量等指标。结果显示:1)与Ⅰ组相比,Ⅱ组和Ⅲ组黑头羊的平均日增重(ADG)极显著增加(P<0.01),料重比(F/G)极显著降低(P<0.01);2)各组黑头羊的干物质(DM)、粗蛋白质(CP)、中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)表观消化率无显著差异(P>0.05),但Ⅱ组和Ⅲ组在数值上均较Ⅰ组有不同程度的提高;3)Ⅱ组和Ⅲ组黑头羊瘤胃液乙酸、总挥发性脂肪酸浓度显著高于Ⅰ组(P<0.05);4)Ⅱ组和Ⅲ组黑头羊血清ALB含量和白球比(A/G)分别极显著(P<0.01)和显著(P<0.05)高于Ⅰ组,Ⅲ组血清UN、高密度脂蛋白胆固醇(HDL-C)含量以及肌酸激酶(CK)活性显著高于Ⅱ组(P<0.05),其他血清生化指标各组之间无显著差异(P>0.05)。由此得出,在能量和蛋白质水平相当的条件下,单纯以花生藤作为颗粒型全混合日粮的粗饲料来源会降低湖北黑头羊的ADG,提高F/G,降低瘤胃液总挥发性脂肪酸和乙酸浓度;以花生藤和苜蓿组合作为颗粒型全混合日粮的粗饲料来源,则湖北黑头羊可获得与以苜蓿为粗饲料来源时相当的养殖效果。

This experiment was conducted to study the effects of peanut vine instead of alfalfa in granulated total mixed ration(TMR) on growth performance,rumen fermentation and serum biochemical indexes of Hubei black-head goats,in order to provide some basis for the reasonable roughage feeding during black-head goat fattening.Thirty 8-month-old Hubei black-head goats(wethers) with similar body weight [(20.46±3.23) kg]and those in good physical condition were randomly divided into 3 groups with 10 goats per group.The animals were fed granulated TMR,in which the roughage was derived from peanut vine(group Ⅰ),alfalfa(groupⅡ) or alfalfa+peanut vine(group Ⅲ).The experimental period was 60 days,including a 10-day pre-experimental period and a 50-day formal trial period.The animals were weighed after the experiment.Rumen fluid and blood samples were collected to assess rumen fluid volatile fatty acids(VFA) and ammoniacal nitrogen(NH3-N) concentrations and serum total albumen(TP),albumin(ALB),urea nitrogen(UN),glucose(GLU) contents,etc.The results showed as follows:1) groups Ⅱ and Ⅲ had a significantly higher average daily gain(ADG) with a significantly decreased feed/gain(F/G) relative to group Ⅰ(P<0.01).2) There was no significant difference in the apparent digestibility of dry matter(DM),crude protein(CP),neutral detergent fiber(NDF) and acid detergent fiber(ADF) of blackheads among groups(P>0.05),but groupsⅡand Ⅲ,in terms of numerical values,had different degrees of improvement than group Ⅰ.3) Acetate and total volatile fatty acid concentrations in rumen fluid of groups Ⅱ and Ⅲ were significantly higher than those of group Ⅰ(P<0.05).4) Serum albumin content(P<0.01) and albumin/globulin(P<0.05) of groups Ⅱ andⅢ were significantly higher than those of group Ⅰ(P<0.05);serum UN and high density lipoprotein cholesterol(HDL-C) contents and creatine kinase(CK) activity of group Ⅲ were significantly lower than those of group Ⅱ(P<0.05);there were no significant differences in the other serum biochemical indexes among groups(P>0.05).These results indicate that under the similar energy and protein level conditions,TMR only using peanut vine as the roughage source may decrease ADG,increase F/G,and decrease acetate and total volatile fatty acid concentrations in rumen fluid of Hubei blackhead goats;TMR using the combination of peanut vine and alfalfa as the roughage source can obtain similar feeding effect as alfalfa.