CNCPS及体外产气法评价青海地区6种常用粗饲料的营养价值

Evaluation of nutritional value of six common forages by using cornell net carbohydrate and protein system and in vitro gas production method in Qinghai

本研究以豌豆秸秆、蚕豆秸秆、苜蓿干草、小麦秸秆、燕麦青干草、青贮玉米秸秆为研究对象,先采用概略养分法和康奈尔净碳水化合物—蛋白质体系(CNCPS)进行6种粗饲料养分含量的化学分析,再利用体外产气法进一步评价6种粗饲料在牦牛瘤胃内的发酵产气参数,为以上粗饲料在牦牛养殖中的应用提供重要基础数据。结果表明:苜蓿干草CP、CNSC含量最高,NDF含量最低,具有良好的营养价值,是优质粗饲料;小麦秸秆CP、CNSC含量最低,NDF含量最高,营养价值较差;青贮玉米秸秆和燕麦青干草CC和PC含量较低,营养价值优于豌豆秸秆、小麦秸秆、蚕豆秸秆;6种粗饲料48h积累产气量和有机物消化率由大到小依次为青贮玉米秸秆>燕麦青干草>苜蓿干草>豌豆秸秆>小麦秸秆>蚕豆秸秆,代谢能由大到小依次为青贮玉米秸秆>苜蓿干草>燕麦青干草>豌豆秸秆>小麦秸秆>蚕豆秸秆,苜蓿干草和燕麦青干草ME没有显著差异; CNCPS测定指标较多,可在一定程度上反映动物对饲料利用情况,对饲料营养价值的评价更精确;青贮玉米秸秆有益于反刍动物瘤胃微生物的发酵和利用。

This study selected pea straw,broad bean straw,alfalfa hay,wheat straw,oat hay and silage corn straw as objective,firstly the nutrients content of six kinds forage were analyzed using general nutrients method and Cornell net carbohydrate and protein system ( CNCPS) method ,and then using in Vitro Gas Production method further evaluated rumen fermentation parameters of six kinds forage in yak for providing important basic data for the application of theses roughage in yak feeding . The results showed that the content of CP and CNSC in alfalfa hay was the highest and the content of NDF was the lowest. It had good nutritional value and was high quality roughage. CP and CNSC contents of wheat straw were the lowest,NDF content was the highest and nutritional value was poor. The contents of CC and PC in silage maize straw and oat hay were lower,and their nutritional value was better than that of pea straw,wheat straw and broad bean straw. The accumulative gas production and organic matter digestibility of six kinds of roughage in 48 hours were silage corn straw > oat green hay > alfalfa hay > pea straw > wheat straw > broad bean straw. The order of metabolic energy was silage maize straw > alfalfa hay > oat green hay > pea straw > wheat straw > broad bean straw . There was no significant difference in ME between alfalfa hay and oat green hay. CNCPS has many indexes, which can reflect animal’s utilization of feed to a certain extent and evaluate the nutritional value of feed more accurately. Silage corn straw is beneficial to ruminant rumen microbial fermentation and utilization.