青饲油菜对母牛表观消化率的影响

Effects of green rape on apparent digestibility of cows

为研究青饲油菜对母牛消化率的影响,试验选择30头西门塔尔牛,随机分成3组,基础饲粮由青贮玉米、稻草和混合精料混合而成,对照组(CK组)饲喂基础饲粮,试验Ⅰ组用青饲油菜替代30%的青贮玉米,试验Ⅱ组用青饲油菜替代15%的青贮玉米,青饲油菜分初花期和终花期两个阶段,采用指示剂(酸不溶灰分)法测定养分表观消化率或利用率。试验结果表明:(1)初花期青饲油菜粗蛋白质(CP)、钙(Ca)、总磷(TP)和粗脂肪(EE)含量分别高于终花期20.4%、6.9%、94.7%和26.3%,终花期中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)含量较初花期分别低18.1%和22.6%。(2)初花期青饲油菜中,Ⅰ组CP、ADF、EE、干物质(DM)、总能(GE)及Ca的消化(利用)率较CK组分别提高了16.9%、6.5%、9.4%、5.1%、3.8%和39.6%(P<0.01),总磷(TP)的利用率提高了17.8%(P<0.05),CP和Ca的消化(利用)率较Ⅱ组分别提高了7.4%和11.9%(P<0.01),DM的消化率提高了2.7%(P<0.05);Ⅱ组CP和Ca的消化(利用)率较CK组分别提高了8.9%和24.7%(P<0.01),ADF和DM的消化率分别提高了3.1%和2.3%(P<0.05)。(3)终花期青饲油菜中,Ⅰ组CP、Ca、DM和GE的消化(利用)率较CK组分别提高了19.8%、96.4%、6.5%和5.3%(P<0.01),EE的消化率较CK组提高了13.5%(P<0.05),CP、Ca、NDF、EE、DM和GE的消化(利用)率较Ⅱ组分别提高了12.0%、28.5%、4.3%、20.5%、6.9%和6.1%(P<0.01);Ⅱ组CP和Ca的消化(利用)率较CK组分别提高了7.0%和52.9%(P<0.01),NDF的消化率较CK组降低了3.0%(P<0.05)。综上所述,初花期青饲油菜营养价值高于终花期,用初花期青饲油菜替代30%或15%青贮玉米以及用终花期青饲油菜替代30%青贮玉米,均有利于提高母牛饲粮的表观消化率。

To study the effect of green rape on the digestibility of cows,30 Simmental cows were selected and randomly divided into 3 groups.Basic forage was made from silage maize,straw and mixed concentrates.The control group(CK group)fed basic forage,the groupⅠreplaced 30%silage maize with green rape,and the group II replaced 15%silage maize with green rape.Green rape was divided into the early bloom period and the final bloom period.The apparent digestibility or availability of nutrients was determined by the indicator(acid insoluble ash)method.The results showed that:(1)The crude protein(CP),Ca,total phosphorus(TP)and ether extract(EE)content at early bloom of green rape were 20.4%,6.9%,94.7%and26.3%higher than those of the final bloom period,neutral detergent fiber(NDF)and acid detergent fiber(ADF)were 15.9%and 15.3%lower.(2)In early bloom period,the digestibility or availability of CP,ADF,EE,DM,GE and Ca in groupⅠincreased by 16.9%,6.5%,9.4%,5.1%,3.8%and 39.6%respectively(P<0.01),TP increased by 17.8%(P<0.05)than those of CK group,and CP,Ca increased by 7.4%and 11.9%(P<0.01),DM increased by 2.7%(P<0.05)than those of group II;the digestibility or utilization of CP and Ca in groupⅡincreased by 8.9%and 24.7%(P<0.01),ADF and DM increased by 3.1%and 2.3%respectively(P<0.05)than those of CK group.(3)In the final bloom period,the digestibility or availability of CP,Ca,DM and GE in group I were 19.8%,96.4%,6.5%and 5.3%higher than those in group CK(P<0.01),EE was 13.5%higher than that in group CK(P<0.05),and CP,Ca,NDF,EE,DM and GE were12.0%,28.5%,4.3%,20.5%,6.9%and 6.1%higher than that in group II(P<0.01);The digestibility or utilization of CP and Ca in groupⅡwere 7.0%and 52.9%higher than that in group CK(P<0.01),and the digestibility of NDF was 3.0%lower than that in group CK(P<0.05).In conclusion,the nutritional value of the early bloom period of green rape was higher than the final bloom period.The replacement of 30%or 15%silage maize with early bloom period of green rape and the replacement of 30%silage maize with final bloom period of green rape all were conducive to improving the apparent digestibility of cows.