发酵杂粕替代豆粕对肉牛生长性能、养分表观消化率及血清生化指标的影响

Effects of Fermented Mixed Meal Replacing Soybean Meal in Diets onGrowth Performance,Nutrient Apparent Digestibility andSerum Biochemical Indices of Beef Cattle

【目的】试验研究饲粮中不同比例发酵杂粕替代豆粕对肉牛生长性能、养分表观消化率及血清生化指标的影响,旨在为发酵杂粕在肉牛生产中的应用提供参考数据。【方法】选取35头体重为(480.71±45.65)kg、健康状况良好的西门塔尔杂交肉牛,随机分为5组,分别饲喂用发酵杂粕替代0(Ⅰ组)、25%(Ⅱ组)、50%(Ⅲ组)、75%(Ⅳ组)和100%(Ⅴ组)豆粕的全混合饲粮(total mixed ration,TMR)。预试期14 d,正试期60 d。试验结束时测定生长性能等指标;试验结束前第3天,采集饲粮和粪样测定养分表观消化率;试验结束当天,各组选取5头牛静脉采血20 mL,采用兽用全自动生化分析仪测定血清生化指标。【结果】①随着发酵杂粕替代豆粕比例的升高,平均日增重(ADG)呈先升高后降低的二次曲线变化趋势(P=0.096),Ⅲ和Ⅳ组料重比(F/G)显著低于Ⅱ组(P<0.05),Ⅳ组有最高的ADG和最低的F/G;②随着发酵杂粕替代豆粕比例的升高,饲粮粗蛋白质(CP)、中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)表观消化率呈先升高后降低的二次曲线变化(P<0.05),与Ⅰ~Ⅳ组相比,Ⅴ组有机物(OM)表观消化率显著低于其他4组(P<0.05),发酵杂粕替代豆粕对钙(Ca)和磷(P)表观消化率无显著影响(P>0.05);③随着发酵杂粕替代豆粕比例的升高,血清尿素氮(UN)含量和碱性磷酸酶(ALP)活性线性降低(P<0.05),血清总胆固醇(TC)含量有线性降低的趋势(P=0.098);④Ⅰ~Ⅴ组饲料单价分别为1.85、1.84、1.82、1.81和1.80元,肉牛每千克增重成本分别为17.09、17.88、15.32、14.86和16.13元,整个试验期间每头牛的毛利润分别为702.07、623.42、954.21、1011.48和778.89元。【结论】在本试验条件下,发酵杂粕完全替代饲粮中的豆粕对肉牛的生长性能和养分消化率无显著负面影响,发酵杂粕替代饲粮中75%的豆粕对肉牛生产性能和经济效益提升效果最显著。

【Objective】This experiment was conducted to investigate the effects of different proportion of fermented mixed meal replacing soybean meal in diets on growth performance,nutrient apparent digestibility,serum biochemical indexes of beef cattle,in order to provide a reference data for applying fermented mixed meal in beef cattle production.【Method】35 healthy Simmental crossbred cattle with an initial body weight of(480.71±45.65)kg were randomly divided into 5 groups,and were fed total mixed rations(TMR)which used fermented mixed meal replacing 0(groupⅠ),25%(groupⅡ),50%(groupⅢ),75%(groupⅣ),and 100%(groupⅤ)soybean meal,respectively.The experiment lasted for 74 days,the first 14 days were the adaptation period,and the last 60 days were the trial period.Growth performance was detected at the end of experiment.Diet and fecal samples were collected for nutrient apparent digestibility determination at last 3 days of the experiment.20 mL blood samples were collected from the vein of five beef cattle in each group at the end of experiment,and the serum biochemical indices were tested by veterinary automatic biochemical analyzer.【Result】①With the increase of the ratio of fermented mixed meal replacing soybean meal,the ADG first increased and then decreased(P=0.096),the F/G of groupⅢandⅣwas significantly higher than that of groupⅡ(P<0.05),and groupⅣhad the highest ADG and the lowest F/G.②As the replacement ratio of fermented mixed meal increasing,crude protein(CP),neutral detergent fiber(NDF),and acid detergent fiber(ADF)digestibility showed quadratic variation(P<0.05).Compared with groupⅠ-Ⅳ,the organic matter(OM)digestibility in groupⅤwas significantly decreased(P<0.05),and there was no significant difference in phosphorus(P)and calcium(Ca)digestibility among the five groups(P>0.05).③The contents of urea nitrogen(UN)and the activity of alkaline phosphatase(ALP)in serum decreased linearly with the increase of the ratio of fermented mixed meal replacing soybean meal(P<0.05),and the content of total cholesterol(TC)showed a tendency decreased linearly(P=0.098).④The unit price of feed in groupⅠ-Ⅴwere 1.85,1.84,1.82,1.81 and 1.80 yuan,respectively.The weight gain cost per kilogram of beef cattle was 7.09,17.88,15.32,14.86 and 16.13 yuan,respectively.the gross profit per beef cattle in the whole experiment period was 702.07,623.42,954.21,1011.48 and 778.89 yuan,respectively.【Conclusion】Under the conditions of this experiment,fermented mixed meal could completely replace soybean meal in diets and had no significant negative impact on growth performance and nutrient apparent digestibility of beef cattle,and 75%substitution in diets had the best effect on growth performance and economic benefits of beef cattle.