基于CNCPS体系与体外发酵技术的5种常见树叶类饲料营养价值评价OA

This study aimed to systematically evaluate the nutritional value and fermentation characteristics of five common unconventional tree leaf roughages from the Qinghai-Tibet Plateau.A comparative analysis of poplar leaves,locust leaves,willow leaves,elm leaves,and pine needles was conducted by combining conventional nutrient composition analysis,the Cornell Net Carbohy-drate and Protein System(CNCPS),and in vitro rumen fermentation techniques.The results showed that:①significant differences in nutrient composition were observed among different tree leaves(P<0.05).Locust leaves had significantly higher crude protein(CP),calcium(Ca),phosphorus(P)and other mineral element contents than other tree leaves(P<0.05).Elm leaves had significantly higher ether extract(EE)and crude ash(Ash)contents than poplar leaves,willow leaves,locust leaves and pine needles(P<0.05).For fiber-related indexes,poplar leaves had significantly higher neutral detergent fiber(NDF)content than locust leaves,elm leaves and pine needles(P<0.05);willow leaves had significantly higher acid detergent fiber(ADF)content than the other four tree leaves(P<0.05);poplar leaves had significantly higher acid detergent lignin(ADL)content than the other four tree leaves(P<0.05).② CNCPS protein fraction analysis indicated that elm leaves had a higher true protein content than the other groups.There were significant differences in acid detergent lignin(ADL)and non-protein nitrogen(NPN)contents among all tree leaves(P<0.05).③ In vitro fermentation results showed that elm leaves had significantly higher 72 h cumulative gas production,total volatile fatty acid(TVFA)and propionic acid yields than the other four tree leaves(P<0.05),indicating stronger rumen degradation capacity.Comprehensive analysis demonstrated that all five kinds of tree leaves possessed good feeding potential,and elm leaves had the optimal comprehensive nutritional value and rumen fermentation characteristics.