非常规饲料对肉牛生长性能、养分消化率及血液生化指标的影响

Effects of un-conventional diets on growth performance,nutrient digestibility and blood biochemical indices of beef cattle

为探讨不同非常规饲料(棕榈粕、大豆皮、喷浆玉米皮、木薯渣)混合替代部分玉米精料对肉牛生长性能、养分消化率、瘤胃发酵及血液生化指标的影响,试验选取30头10月龄,体重相近[(289.77±10.05)kg],膘情相似、无病的荷斯坦公牛,随机分为3组,每组10头,拴系单栏饲养。饲粮精料及组成为干物质基础,替代I组(PRDⅠ组)为50%玉米+7.5%喷浆玉米皮+7.5%大豆皮+7.5%木薯渣+7.5%棕榈粕,替代Ⅱ组(PRDⅡ组)为40%玉米+10%喷浆玉米皮+10%大豆皮+10%木薯渣+10%棕榈粕,替代Ⅲ组(PRDⅢ组)为30%玉米+12.5%喷浆玉米皮+12.5%大豆皮+12.5%木薯渣+12.5%棕榈粕,预饲期5 d,正式期55 d。结果表明:(1)各替代组肉牛的干物质采食量(DMI)和平均日增重(ADG)差异不显著;PRDⅠ组的精料干物质采食量和粗料干物质采食量与其他两组相比差异极显著(P<0.01)。替代组干物质(DM)消化率存在显著差异(P<0.05),酸性洗涤纤维(ADF)、中性洗涤纤维(NDF)表观消化率差异不显著(P>0.05);(2)PRDⅠ组的谷丙转氨酶(ALT)含量与PRDⅡ组、PRDⅢ组相比差异极显著(P<0.01),PRDⅠ组<PRDⅡ组<PRDⅢ组;PRDⅠ组的谷草转氨酶/谷丙转氨酶(AST/ALT)显著高于PRDⅡ组、PRDⅢ组(P<0.05);PRDⅠ组的低密度脂蛋白(LDL)含量显著高于PRDⅡ组、PRDⅢ组(P<0.01)。研究表明,选用棕榈粕、大豆皮、喷浆玉米皮、木薯渣四种经济作物副产品部分替代玉米精料后提高了肉牛的生长性能且对肉牛健康无影响,其中,以30%玉米+12.5%喷浆玉米皮+12.5%大豆皮+12.5%木薯渣+12.5%棕榈粕的组合比例效果最好。

This experiment was conducted to investigate the effects of different un-conventional feeds(palm meal,soybean hulls,spray corn hulls and cassava residue)replacing part of corn concentrate on growth performance,nutrient digestibility,rumen fermentation and blood biochemical indices of beef cattle.Thirty 10-month-old Holstein bulls with similar body weight[(289.77±10.05)kg],similar fat condition and no disease were randomly divided into 3 groups with 10 bulls in each group and fed in a single pen.The concentrate and composition of the diet were dry matter basis,the replacement group I(PRDⅠgroup)was 50%corn+7.5%spraying corn husk+7.5%soybean husk+7.5%cassava residue+7.5%palm meal,and the replacement groupⅡ(PRDⅡgroup)was 40%corn+10%spraying corn husk+10%soybean husk+10%cassava residue+10%palm meal,the replacement groupⅢ(PRDⅢgroup)was 30%corn+12.5%shotcreted corn husk+12.5%soybean husk+12.5%cassava residue+12.5%palm meal,and the prefeeding period was 5 days and the formal period was 55 days.The results showed as follows:(1)There were no significant differences in dry matter intake(DMI)and average daily gain(ADG)among the replacement groups;The dry matter intake of concentrate and crude in PRDⅠgroup was significantly different from that in the other two groups(P<0.01).The dry matter(DM)digestibility of replacement group was significantly different(P<0.05),while the apparent digestibility of acid detergent fiber(ADF)and neutral detergent fiber(NDF)was not significantly different(P>0.05).(2)The content of alanine aminotransferase(ALT)in PRDⅠgroup was significantly different from that in PRDⅡgroup and PRDⅢgroup(P<0.01),PRDⅠgroup<PRDⅡgroup<PRDⅢgroup;The aspartate aminotransferase/alanine aminotransferase(AST/ALT)in PRDⅠgroup was significantly higher than that in PRDⅡgroup and PRDⅢgroup(P<0.05);The low density lipoprotein(LDL)content in PRDⅠgroup was significantly higher than that in PRDⅡand PRDⅢgroups(P<0.01).The study showed that the growth performance of beef cattle was improved and the health of beef cattle was not affected by the partial substitution of corn concentrate with palm meal,soybean husk,spray corn husk and cassava residue as the by-products of four cash crops.The combination ratio of 30%corn+12.5%spraying corn husk+12.5%soybean husk+12.5%cassava residue+12.5%palm meal had the best effect.