不同干草比对关中奶山羊瘤胃参数和产奶量及乳成分的影响

Effects of different hay ratios on rumen parameters,milk yield and milk composition of Guanzhong dairy goats

【目的】探究苜蓿干草与燕麦干草的组合效应对关中奶山羊采食量、瘤胃发酵参数、产奶量、乳品质的影响,为合理利用苜蓿干草和燕麦干草资源提高关中奶山羊的生产性能提供支持。【方法】选取体况相近的泌乳中期关中奶山羊240只,随机分为对照组及T1、T2和T3组,每组3个重复,每个重复20只羊。对照组饲喂50%配方精料+50%苜蓿干草,T1组饲喂50%配方精料+25%苜蓿干草+25%燕麦干草(m(苜蓿)∶m(燕麦)=1∶1),T2组饲喂50%配方精料+30%苜蓿干草+20%燕麦干草(m(苜蓿)∶m(燕麦)=3∶2),T3组饲喂50%配方精料+37.5%苜蓿干草+12.5%燕麦干草(m(苜蓿)∶m(燕麦)=3∶1),进行75 d的饲喂试验。期间进行采食量、产奶量、瘤胃发酵参数(pH,NH_(3)-N、乙酸、丙酸、异丁酸、丁酸、异戊酸、戊酸、总挥发性脂肪酸含量及乙酸/丙酸)、乳成分(乳蛋白、乳脂肪、乳糖、全乳固体含量及脂蛋比)数据的采集及测定。【结果】与对照组相比,T3组奶山羊的日干物质采食量和产奶量显著提高(P<0.05)。4个处理组奶山羊瘤胃液的pH差异不显著,T1和T3组奶山羊瘤胃液的NH_(3)-N显著高于对照组和T2组(P<0.05)。T1、T2和T3组奶山羊瘤胃液的乙酸、丙酸、戊酸、乙酸/丙酸和总挥发性脂肪酸含量显著高于对照组(P<0.05);T3组的乳脂肪、全乳固体含量和脂蛋比显著高于其他3组(P<0.05)。T3组和对照组乳蛋白含量显著高于T1和T2组(P<0.05),4组奶山羊瘤胃液乳糖含量差异不显著(P>0.05)。【结论】苜蓿干草与燕麦干草以质量比3∶1比例组合,可以提高关中奶山羊的消化性能和生产性能,改善奶山羊乳品质。

【Objective】This study explored the combined effect of alfalfa hay and oat hay on feed intake,rumen fermentation parameters,milk yield and milk quality of Guanzhong dairy goats to provide basis for improving production performance.【Method】A total of 240 Guanzhong dairy goats in middle lactation with similar body conditions were randomly divided into control group and treatment groups of T1,T2 and T3,with 3 repetitions in each group and 20 sheep in each repetition.The control group was fed with 50%formula concentrate+50%alfalfa hay,the T1 group was fed with 50%formula concentrate+25%alfalfa hay+25%oat hay(m(alfalfa):m(oat)=1∶1),the T2 group was fed with 50%formula concentrate+30%alfalfa hay+20%oat hay(m(alfalfa):m(oat)=3∶2),and the T3 group was fed with 50%formula concentrate+37.5%alfalfa hay+12.5%oat hay(m(alfalfa):m(oat)=3∶1)for 75 days.Feed intake,milk yield and rumen fermentation parameters(pH,NH_(3)-N,acetic acid,propionic acid,isobutyric acid,butyric acid,isovaleric acid,valeric acid,total volatile fatty acid content and acetic acid/propionic acid)were determined.Milk was also collected and composition(milk protein,milk fat,lactose,whole milk solid content and fat-protein ratio)was determined.【Result】Compared with the control,dry matter intake and milk yield of T3 group were significantly increased(P<0.05).There was no significant difference in pH among the four groups.NH_(3)-N in T1 and T3 groups was significantly higher than that in control group and T1 group(P<0.05).Contents of acetic acid,propionic acid,valeric acid,acetic acid/propionic acid and total volatile fatty acids in T1,T2 and T3 group were significantly higher than those in control group(P<0.05).Contents of milk fat,whole milk solid and fat egg ratio in T3 group were significantly higher than those in the other three groups(P<0.05).The milk protein content in T3 group and control group was significantly higher than that in T1 and T2 groups(P<0.05),and there was no significant difference in lactose content among the four groups(P>0.05).【Conclusion】The combination of alfalfa hay and oat hay with mass ratio of 3∶1 could improve digestive performance,production performance and milk quality of Guanzhong dairy goats.