不同组合青草对于关中奶山羊采食量、产奶量、乳品质及瘤胃参数的影响

Effects of different combinations of fresh grass on feed intake,milk yield,milk quality and rumen parameters of Guanzhong dairy goats

为了探究苜蓿青草与燕麦青草混合饲喂对关中奶山羊采食量、产奶量、乳品质及瘤胃发酵参数的影响,试验将240只体重相近、分娩胎次在2~3胎、24~48月龄的健康关中奶山羊随机分为4组,每组3个重复,每个重复20只,对照组饲喂含50%青贮玉米的试验日粮,试验1组饲喂20%青贮玉米+10%苜蓿青草+20%燕麦青草的试验日粮,试验2组饲喂20%青贮玉米+15%苜蓿青草+15%燕麦青草的试验日粮,试验3组饲喂20%青贮玉米+20%苜蓿青草+10%燕麦青草的试验日粮,预试期15 d,正试期75 d,测定各组试验羊只的日均干物质采食量、日均采奶量、乳品质指标(乳蛋白、乳脂肪、乳糖和全乳固体含量)、瘤胃液发酵参数(pH值、氨态氮和各挥发性脂肪酸含量)。结果表明:试验2组日均干物质采食量、日均产奶量、乳脂肪和乳糖含量显著高于其他三组(P<0.05),乳蛋白含量显著高于对照组和试验1组(P<0.05)。4组瘤胃液pH值差异不显著(P>0.05),试验2,3组氨态氮含量显著高于试验1组和对照组(P<0.05)。说明在关中奶山羊日粮中添加15%苜蓿青草和15%燕麦青草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。

In order to explore the combined effect of fresh alfalfa grass and fresh oat grass on feed intake,milk yield,milk quality and rumen fermentation parameters,in this experiment,240 Guanzhong dairy goats with similar body conditions and fetal childbirth times(two to three parities)from 24 to 48 months were randomly divided into four groups,with three replicates per group,20 sheep per replicate.Sheep in the control group were fed the experimental diet with 50%silagecorn,those in the test 1 group were fed the experimental diet with 20%silage+10%alfalfa grass+20%oat grass,those in the test 2 group were fed the experimental diet with 20%silage+15%alfalfa grass+15%oat grass,and those in the test 3 group were fed the experimental diet with 20%silage+20%alfalfa grass+10%oat grass.The preliminary trial period was 15 days and the trial period was 75 days.The average daily dry matter itake,average daily milk yield,milk quality indexes(the contents of milk protein,milk fat,lactose and total milk solids),and rumen fluid fermentation parameters(pH value,ammonia nitrogen and volatile fatty acid contents)of sheep in each group were determined.The results showed that the average daily dry matter intake,average daily milk yield,milk fat and lactose in the test 2 group were significantly higher than those in the other three groups(P<0.05),and the content of milk protein was significantly higher than that in the control group and and test 1 group(P<0.05).There was no significant difference in pH values of rumen fluid among the four groups(P>0.05).The ammonia nitrogen content in the test 3 group and the test 2 group was significantly higher than that in the test 1 group and the control group(P<0.05).The contents of propionic acid and valeric acid in the test 2 group were not significantly different from those in the other three groups(P>0.05).The results indicated that adding 15%alfalfa grass and 15%oat grass to the diet of Guanzhong dairy goats could significantly improve the digestive performance and production performance,and improve the milk quality of Guanzhong dairy goats.