秸秆颗粒替代部分玉米青贮对肉牛育肥效果的影响

Effects of replacement of whole corn silage with straw pellets on finishing steers

为研究秸秆颗粒替代玉米(Zea mays)青贮饲喂肉牛的育肥效果,本研究以玉米秸秆+苜蓿(Medicago sativa)干草颗粒(在风干基础上玉米秸秆和苜蓿干草按照1∶1比例混合制粒)为试验材料,研究替代20%、50%和80%玉米青贮对肉牛干物质采食量(dry matter intake,DMI)、平均日增重(average daily gain,ADG)、料重比(feed conversion ratio,FCR)、养分表观消化率、血液生化指标、胴体性状、肉质性状的影响。试验选取20头体重基本一致[(410.56±19.27)kg]的西门塔尔杂交公牛,采用随机区组试验设计,分为4组(每组5头),分别饲喂100%玉米青贮+精料补充料(对照组)、20%秸秆颗粒+80%玉米青贮+精料补充料(试验1组)、50%秸秆颗粒+50%玉米青贮+精料补充料(试验2组)、80%秸秆颗粒+20%玉米青贮+精料补充料(试验3组)。结果表明:1)与对照组相比,试验3组的DMI显著提高(P<0.05),干物质表观消化率(apparent digestibility of dry matter)、有机物表观消化率(apparent digestibility of organic matter)和中性洗涤纤维表观消化率(apparent digestibility of neutral detergent fiber)显著降低(P<0.05),而试验1组和试验2组无显著差异(P>0.05);2)试验1组、2组和3组的ADG、FCR、血液生化指标、胴体性状、肉质性状相对于对照组均无显著差异(P>0.05)。综上所述,秸秆颗粒可替代部分玉米青贮饲喂育肥期西门塔尔杂交肉牛,替代比例为20%~80%时,对肉牛育肥效果无不良影响。

The objective of this study was to investigate the effects of 20%,50%,and 80%replacement of whole corn silage with straw pellets(on an air dried basis;corn straw and alfalfa hay were mixed and granulated in a 1∶1 ratio)on finishing steers.Twenty healthy Simmental crossbreed beef cattle with similar body weight[(410.56±19.27)kg]were randomly divided into four groups using a randomized block design and were fed 100%whole corn silage+concentrate supplementary feed(control group),20%straw pellet feed+80%whole corn silage+concentrate supplementary feed(group 1),50%straw pellet feed+50%whole corn silage+concentrate supplementary feed(group 2),and 80%straw pellet feed+20%whole corn silage+concentrate supplementary feed(group 3).The dry matter intake(DMI),average daily gain(ADG),feed conversion ratio(FCR),nutrient apparent digestibility,blood biochemical indexes,carcass traits,and meat quality were measured.The results showed that:1)Group 1 had significant improvement in DMI(P<0.05)and reduction in apparent digestibility of dry matter(DM),organic matter(OM)and neutral detergent fiber(NDF)(P<0.05),whereas group 1 and 2 had no significant effects.2)Group 1,2,and 3 had no significant effect on ADG,FCR,blood biological indicators,carcass traits,and meat quality traits(P>0.05).In conclusion,straw pellets can replace part of whole corn silage for feeding Simmental western hybrid finishing steers.When the replacement ratio is 20%~80%,it has no adverse effect on the finishing steers.