TMR制粒与补饲干草组合处理对育肥羊生长性能和瘤胃发酵的影响

Effects of TMR pelletizing and supplementary feeding hay combination treatment on growth performance and rumen fermentation of fattening sheep

试验旨在研究全混合日粮(total mixed ration,TMR)不同物理形态(A1颗粒、A2粉料)及饲喂模式(B1不补饲苜蓿、B2补饲苜蓿)组合下,对育肥羊生长性能和瘤胃发酵的影响,以期为育肥羊TMR的生产和应用提供参考数据。选取4只安装永久性瘤胃瘘管的哈萨克育肥公羊作为试验动物,采用2×2二因子析因试验设计,4×4拉丁方饲喂方式,连续进行4期动物试验。结果表明:①各TMR间平均日采食量接近,A1B2组较其他TMR组平均日增重达到极显著水平(P<0.01),A1B2组料重比较A1B1、A2B1组达到显著水平(P<0.05);②日粮更换后,瘤胃pH值呈先下降后上升趋势,在第4 d达到最低值,其中A1组降低幅度达到了极显著水平(P<0.01),A2组瘤胃pH值波动较小,采食后12 h内,各组育肥羊瘤胃pH值在5.31~6.39之间变动,均在食后4 h达到最低,B2组各时间点瘤胃pH值略高于B1组(P>0.05),A1B1组瘤胃pH值在食后2~8 h降低到5.5以下,处于亚急性酸中毒(subacute rumen acidosis,SARA)状态;③瘤胃液氨氮浓度在更换日粮后呈先下降后上升趋势,在第3 d达到最低值,恢复稳定后,A1组较更换前有所提高(P>0.05),A2组接近日粮更换前水平,采食后12 h内,A1组瘤胃液氨氮浓度显著高于A2组(P<0.05)。综上所述,颗粒全混合日粮(pelleted total mixed ration,PTMR)与苜蓿干草组合,对羊育肥效果最佳,并且不会对育肥羊瘤胃发酵产生不利影响。

The purpose of the experiment was to study the effects of different physical forms(A1 pellets,A2 meal)of total mixed diet(TMR)and feeding patterns(B1 without alfalfa and B2 supplementation)on growth performance and rumen fermentation of fattening sheep,in order to provide reference data for the production and application of TMR in fattening sheep.Four Kazakh fattening rams with permanent rumen fistula were selected as experimental animals,four consecutive animal experiments were carried out by using 2×2 two-factor factorial design and 4×4 Latin square feeding method.The results showed that:①The average daily feed intake of each TMR was similar,the average daily gain of A1B2 group was significantly higher than that of other TMR groups(P<0.01),and the feed gain of A1B2 group was significantly higher than that of A1B1 and A2B1 groups(P<0.05);②After diet replacement,the rumen pH decreased at first and then increased,and reached the lowest value on the fourth day,in which A1 group decreased significantly(P<0.01),the rumen pH of A2 group fluctuated slightly,and the rumen pH value of each group varied from 5.31 to 6.39 within 12 hours after feeding,and reached the lowest at 4 hours after feeding,the rumen pH value of B2 group was slightly higher than that of B1 group at each time point(P>0.05),the rumen pH value of A1B1 group decreased to less than 5.5 from 2 to 8 hours after feeding,which was in the state of subacute rumen acidosis(SARA);③The concentration of ammonia nitrogen in rumen fluid decreased at first and then increased after diet replacement,and reached the lowest value on the third day,after it was stable,the concentration of rumen ammonia nitrogen in group A1 was higher than that before replacement(P>0.05),and that in group A2 was close to the level before dietary change,within 12 hours after feeding,the concentration of ammonia nitrogen in rumen fluid of A1 group was significantly higher than that of A2 group(P<0.05).In conclusion,the combination of pelleted total mixed ration(PTMR)and alfalfa hay has the best fattening effect on sheep,and will not adversely affect the rumen fermentation of fattening sheep.