2种营养水平饲粮对2种牛生长性能、养分表观消化率、血清生化指标和粪便微生物区系的影响

Effects of Two Nutrient Level Diets on Growth Performance,Nutrient Apparent Digestibility,Serum Biochemical Indices and Fecal Microflora of Two Breeds of Cattle

本试验旨在研究2种营养水平饲粮对2种生长牛生长性能、养分表观消化率、血清生化指标和粪便微生物区系的影响。采用2×2双因素随机试验设计,选取月龄(6月龄左右)、体重[(204.63±23.65) kg]相近的安格斯(♂)×黑西门塔尔(♀)杂交牛(安黑杂交牛)和西门塔尔牛各12头(公母各占1/2),分别随机分为2组,分别饲喂低营养水平[试验前期,综合净能(NE_(mf))为5.42 MJ/kg,粗蛋白质(CP)含量为9.66%;试验后期,NE_(mf)为5.57 MJ/kg,CP含量为9.05%]和高营养水平(试验前期,NE_(mf)为5.77 MJ/kg,CP含量为12.47%;试验后期,NE_(mf)为6.00 MJ/kg,CP含量为10.44%)饲粮。预试期12 d,正试期62 d,分为试验前期(第1~31天)和试验后期(第32~62天)2个阶段,最后8 d进行消化试验。结果表明:与西门塔尔牛相比,安黑杂交牛试验前期平均日增重(ADG)(P=0.076)、对有机物(P=0.051)和CP(P=0.087)的表观消化率、血清尿素氮(UN)含量(P=0.077)和谷草转氨酶活性(P=0.070)有提高的趋势,对中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)的表观消化率显著提高(P<0.05)。与低营养水平组相比,高营养水平组试验前期干物质采食量(DMI)、试验后期ADG、DMI和饲料转化率(FCR)以及试验全期ADG和DMI显著提高(P<0.05),试验全期FCR(P=0.085)和血清总胆固醇(P=0.077)含量有提高趋势;低营养水平组NDF和ADF表观消化率显著高于高营养水平组(P<0.05)。品种和营养水平对血清UN含量有显著交互作用(P<0.05)。2种牛粪便微生物在门水平上的优势菌群为厚壁菌门(Firmicutes)和拟杆菌门(Bacteroidetes),各组间相对丰度无显著差异(P>0.05);在属水平上,高营养水平组粪便苏黎世杆菌属(Turicibacter)相对丰度显著高于低营养水平组(P<0.05)。综上所述,安黑杂交牛的ADG和对CP、OM、NDF和ADF的表观消化率优于西门塔尔牛;高营养水平饲粮更有利于肠道有益菌相对丰度的提高,促进生长牛的快速生长。

This experiment was conducted to investigate the effects of two nutrient levels on growth perform⁃ance,nutrient apparent digestibility,serum biochemical indices and fecal microflora of two breeds of growing cattle.In a 2×2 two⁃factor randomized experiment design,12 Angus()×Black Simmental(♀)crossbred cattle(Anhei crossbred cattle)and 12 Simmental cattle(half male and half female)with similar age(about 6 months)and body weight[(204.63±23.65)kg]were randomly divided into 2 groups each and fed diets with low nutrient level[the comprehensive net energy(NEmf)was 5.42 MJ/kg and the crude protein(CP)content was 9.66%in the early stage,and NEmf was 5.57 MJ/kg and CP content was 9.05%in the late stage]and high nutrient level(NEmf was 5.77 MJ/kg and CP content was 12.47%in the early stage,and NEmf was 6.00 MJ/kg and CP content was 10.44%in the late stage),respectively.The pre⁃trial period lasted for 12 days and the trial period lasted for 62 days,which were divided into two stages as the early stage(days 1 to 31)and the late stage(days 32 to 62),and the digestion experiment was conducted on the last 8 days.The re⁃sults show that:compared with Simmental cattle,the average daily gain(ADG)(P=0.076),apparent di⁃gestibilities of organic matter(P=0.051)and CP(P=0.087),serum urea nitrogen(UN)content(P=0.077)and glutamic oxalacetic transaminase activity(P=0.070)of Anhei crossbred cattle had a tendency to be increased,the apparent digestibilities of neutral detergent fiber(NDF)and acid detergent fiber(ADF)were significantly increased(P<0.05).Compared with low nutrient level group,the dry matter intake(DMI)in the early stage,the ADG,DMI,feed conversion rate(FCR)in the late stage and the ADG and DMI during the whole trial period in high nutrient level group were significantly increased(P<0.05),and the FCR(P=0.085)and serum total cholesterol content(P=0.077)during the whole trial period were tended to be in⁃creased;the apparent digestibilities of NDF and ADF in low nutrient level group was significantly higher than that in high nutrient level group(P<0.05).There was significant interaction between breed and nutrient level on serum UN content(P<0.05).At the phylum level,Firmicutes and Bacteroidetes were the dominant bacteri⁃al community in fecal microflora of the two breeds of cattle,and there was no significant difference in relative abundance among all groups(P>0.05).At the genus level,the fecal Turicibacter relative abundance in high nutrient level group was significantly higher than that in low nutrient level group(P<0.05).In conclusion,the ADG and apparent digestibilities of CP,OM,NDF and ADF of Anhei crossbred cattle are better than Simmen⁃tal cattle;the high nutrient level diet is more conducive to the relative abundance of intestinal beneficial bacteria and can promote the rapid growth of growing cattle.[Chinese Journal of Animal Nutrition,2024,36(5):3082⁃3093]