碎米替代木薯粉对肉牛生长性能、瘤胃发酵及胴体性状的影响

Effects of broken rice replacing cassava on growth performance,rumen fermentation and carcass traits of beef cattle

文章旨在探讨日粮添加不同水平碎米替代木薯对肉牛生长性能、养分消化、瘤胃发酵及胴体性状的影响。试验将平均体重接近的144头肉牛随机分为3组,每组6个重复,每个重复8头。3组肉牛在为期26周的饲养试验中分别饲喂碎米替代木薯水平为0、50%和100%的全混合日粮。结果:碎米替代木薯水平对肉牛的体重、采食量及大部分养分消化无显著影响(P>0.05),碎米完全替代木薯可以显著提高肉牛日增重和粗蛋白质表观消化率(P<0.05),显著降低肉牛料重比(P<0.05)。100%碎米组肉牛瘤胃挥发性脂肪酸总量、丙酸和戊酸浓度均显著高于木薯组(P<0.05),但乙酸浓度及乙酸与丙酸比值均显著低于木薯组和50%碎米组(P<0.05)。木薯组肉牛瘤胃异丁酸浓度显著高于50%和100%碎米组(P<0.05)。100%碎米组肉牛背膘厚度显著高于50%碎米组(P<0.05),同时50%碎米组肉牛大理石花纹评分显著低于木薯组和100%碎米组(P<0.05)。结论:全混合日粮用碎米完全替代木薯可以改善粗蛋白质表观消化率,提高瘤胃挥发性脂肪酸和丙酸浓度,进而改善肉牛生长性能。

This experiment was conducted to investigate the effects of different levels of broken rice supplementation instead of cassava on growth performance,nutrient digestion,rumen fermentation and carcass traits of beef cattle.A total of 144 beef cattle with similar average body weight were randomly divided into 3 groups with 6 replicates per group and 8 cattle per replicate.Three groups of beef cattle were fed a total mixed diet with 0,50%and 100%broken rice replacement cassava,respectively,during a 26-week feeding trial.Results:The replacement of cassava with broken rice had no significant effects on the body weight,feed intake and most nutrients digestion of beef cattle(P>0.05).The complete replacement of cassava with broken rice could significantly improve the daily gain and crude protein apparent digestibility of beef cattle(P<0.05),and significantly reduce the feed to gain ratio of beef cattle(P<0.05).The total volatile fatty acid,propionic acid and valenic acid concentrations in rumen of beef cattle in 00%broken rice group were significantly higher than those in 100%cassava group(P<0.05),but the acetic acid concentration and the ratio of acetic acid to propionic acid were significantly lower than those in 100%cassava group and 50%broken rice group(P<0.05).The rumen isobutyric acid concentration in cassava group was significantly higher than that in 50%and 100%broken rice groups(P<0.05).The backfat thickness of beef cattle in 100%broken rice group was significantly higher than that in 50%broken rice group(P<0.05),and the marbling score of beef cattle in 50%broken rice group was significantly lower than that in cassava group and 100%broken rice group(P<0.05).Conclusion:Complete replacement of cassava with broken rice in total mixed diet can improve the apparent digestibility of crude protein,increase the concentration of volatile fatty acid and propionic acid in the rumen,and then improve the growth performance of beef cattle.