杂交狼尾草饲粮中添加过瘤胃蛋氨酸对福清山羊生长性能及消化代谢的影响

Effects of Hybrid Pennisetum Forage Supplemented with Rumen-protected Methionine on Growth and Nutrient Digestion of Fuqing Goats

【目的】研究杂交狼尾草饲粮中添加过瘤胃蛋氨酸(RPMet)对福清山羊生长性能及营养物质消化代谢的影响,为杂交狼尾草在肉羊育肥中的高效利用提供参考。【方法】选择经同一批次同期发情处理生产的体况良好、体重相近的4月龄福清山羊羯羊30只[(11.88±1.48)kg]作为试验羊,采用单因素试验设计,随机分成5组,每组6只。分为饲养试验和消化代谢试验,对照组饲喂基础饲粮,试验Ⅰ、Ⅱ、Ⅲ和Ⅳ组在基础饲粮基础上每只羊添加RPMet 2.5、5.0、7.5和10 g·d^(−1)。饲养试验预试期15 d,正式期60 d,测定试验羊的生产性能;饲养试验中期各组随机选择3只试验羊进行消化代谢试验,测定试验羊对饲粮中养分表观消化率和氮代谢指标。【结果】1)各组间DMI、IBW和FBW差异均不显著(P>0.05);试验Ⅰ、Ⅱ组的总增重及ADG显著高于对照组(P<0.05),而与试验Ⅲ、Ⅳ组差异不显著(P>0.05)。2)试验Ⅱ组试验羊对饲粮中干物质、有机物等6种营养物质的表观消化率均为最高,其中对GE、CP和ADF的表观消化率显著高于其他组(P<0.05),对干物质和有机物的表观消化率显著高于试验Ⅲ、Ⅳ组和对照组(P<0.05),对NDF的表观消化率显著高于试验Ⅲ、Ⅳ组(P<0.05)。3)对照组进食氮显著低于4个试验组(P<0.05);试验Ⅰ组和试验Ⅱ组的尿氮和粪氮分别最低,均显著高于其他试验组(P<0.05),而与对照组差异不显著(P>0.05);试验Ⅰ和Ⅱ组的沉积氮和氮沉积率均显著高于其他组(P<0.05);试验Ⅰ组的氮生物学价值最高,显著高于试验Ⅲ、Ⅳ组和对照组(P<0.05),试验Ⅳ组氮生物学价值显著低于对照组(P<0.05)。【结论】杂交狼尾草饲粮中每只羊添加2.5~5.0 g·d^(−1) RPMet,有利于福清山羊对饲粮中各营养物质的消化利用,提高氮的利用效率,进而促进福清山羊育肥期生长。

【Objective】Effects of feeding hybrid pennisetum forage supplemented with rumen-protected methionine(RPMet)on the growth and nutrient digestion and metabolism of Fuqing goat were studied.【Method】Thirty 4-month-old,11.88±1.48 kg Fuqing goats from a same batch of estrus synchronization were randomly divided into 5 groups of 6 goats in each group.The feeding experiment including basic diet(CK)and an addition of RPMet at 2.5 g·d^(−1)(GroupⅠ),5.0 g·d^(−1)(GroupⅡ),7.5 g·d^(−1)(GroupⅢ),or 10 g·d^(−1)(GroupⅣ)started after a pre-testing period of 15 d to last for 60 d.In the middle of the feeding period,3 goats were randomly selected from each group to determine the apparent nutrient digestion and nitrogen metabolism of the animals.【Result】(1)No significant differences in DMI,IBW,and FBW were found among all groups(P>0.05).The total weight gain and ADG of GroupⅠand GroupⅡwere significantly higher than those of control(P<0.05),but not on those of GroupⅢand GroupⅣ(P>0.05).(2)The apparent digestions of DM,OM,GE,NDF,ADF,and CP by the goats in GroupⅡwere the highest.Those of GE,CP,and ADF were significantly higher in GroupⅡthan in other groups(P<0.05),those of DM and OM significantly higher than in GroupⅢand GroupⅣor control(P<0.05),and that of NDF significantly higher than in GroupⅢand GroupⅣ(P<0.05).(3)The nitrogen intake of the goats in the control group was significantly lower than that of the treatment groups(P<0.05).The urine and fecal nitrogen in goats of GroupⅠand GroupⅡwere not significantly different from those of control(P>0.05),but significantly higher than those of other test groups(P<0.05).GroupⅠand GroupⅡanimals also had significantly higher nitrogen deposition and deposition rate than those of other groups(P<0.05).The biological value of nitrogen of the goats in GroupⅠwas the highest and significantly higher than that in GroupⅢ,GroupⅣ,and control(P<0.05),while GroupⅣwas significantly lower than control(P<0.05).【Conclusion】The supplementation of RPMet at a rate of 2.5~5.0 g·d^(−1) in the hybrid pennisetum forage benefited nutrient digestion and utilization of the Fuqing goats which promoted fattening before slaughtering.