发酵甘蔗渣对肉牛生长性能、养分表观消化率、瘤胃发酵特性和瘤胃菌群的影响

Effects of Fermented Sugarcane Bagasse on Growth Performance,Nutrient Apparent Digestibility,Rumen Fermentation Characteristics and Rumen Microflora of Beef Cattle

本试验旨在研究用发酵甘蔗渣替代甘蔗渣对肉牛生长性能、养分表观消化率、瘤胃发酵特性和瘤胃菌群的影响。选用14头体况良好、体重[(363.84±9.11)kg]相近的西门塔尔杂交公牛,随机分成2组,每组7个重复,每个重复1头牛。对照组(CON组)饲喂含20%甘蔗渣的基础饲粮,发酵甘蔗渣组(FSB组)饲喂用20%发酵甘蔗渣替代甘蔗渣的饲粮。试验期为87 d,其中预试期7 d,正试期80 d。结果表明:2组肉牛的终末体重和干物质采食量均无显著差异(P>0.05),但FSB组肉牛平均日增重显著高于CON组(P<0.05),料重比显著低于CON组(P<0.05)。FSB组肉牛干物质、有机物、粗蛋白质和中性洗涤纤维的表观消化率均显著高于CON组(P<0.05)。FSB组肉牛瘤胃液中氨态氮、菌体蛋白、丙酸、异丁酸、丁酸和总挥发性脂肪酸含量均显著高于CON组(P<0.05)。FSB组菌群中理研菌科_RC9_肠道群(Rikenellaceae_RC9_gut_group)和普雷沃氏菌科_UCG⁃003(Prevotellaceae_UCG⁃003)相对丰度显著低于CON组(P<0.05),但解琥珀酸菌属(Succiniclasticum)相对丰度显著高于CON组(P<0.05)。Tax4Fun基因功能预测表明,FSB组氨基酸代谢途径、核苷酸代谢途径和外源生物降解与代谢途径相对丰度显著高于CON组(P<0.05)。综上所述,添加20%发酵甘蔗渣替代甘蔗渣可改变瘤胃菌群结构,可通过提高瘤胃液中挥发性脂肪酸、菌体蛋白的含量和肉牛养分表观消化率,进而提高肉牛生长性能。

The experiment was conducted to explore the effects of replacing sugarcane bagasse with fermented sugarcane bagasse on growth performance,nutrient apparent digestibility,rumen fermentation characteristics and rumen microflora of beef cattle.A total of 14 healthy Simmental crossbred cattle with similar body weight of(363.84±9.11)kg were randomly divided into two groups with 7 replicates per group and 1 cattle per replicate.Beef cattle in control group(CON group)was fed a basal diet containing 20%sugarcane bagasse,and those in fermented sugarcane bagasse group(FSB group)was fed a diet with 20%fermented sugarcane bagasse replacing sugarcane bagasse.Test period was 87 d,the preliminary trial period was 7 d,and the experiment lasted for 80 days.The results showed as follows:there was no significant difference in final body weight and dry matter intake between the two groups(P>0.05),but the average daily gain(ADG)of cattle in the FSB group was significantly higher than that in the CON group(P<0.05),and ratio of feed to gain was significantly lower than that in the CON group(P<0.05).The apparent digestibility of dry matter,organic matter,crude protein and neutral detergent fiber in the FSB group was significantly higher than that in the CON group(P<0.05).The contents of ammonia nitrogen,microbial protein,propionic acid,isobutyric acid,butyric acid and total volatile fatty acid in the rumen of cattle in the FSB group were significantly higher than those in the CON group(P<0.05).The relative abundance of the Rikenellaceae_RC9_gut_group and Prevotellaceae_UCG003 in the FSB group was significantly lower than that in the CON group(P<0.05),but the relative abundance of Succiniclasticum in the FSB group was significantly higher than that in the CON group(P<0.05).Tax4Fun gene function prediction showed that the relative abundance of amino acid metabolism,nucleotide metabolism,and exogenous biodegradation and metabolic pathways in the FSB group was significantly higher than that in the CON group(P<0.05).In conclusion,adding 20%fermented sugarcane bagasse which is fermented by bacteria and enzyme can change the rumen microflora structure,and can improve the growth performance of beef cattle by increasing the contents of the rumen volatile fatty acid and microbial protein and the apparent digestibility of nutrients.