Assessment of fodder quality and methane production potential of north-eastern Himalayan forest tree leaves

Abstract

Nutritional evaluation as tree fodder as well as a rumen manipulator of six multipurpose Himalayan forest tree leaves, viz. Kadam (Anthocephalus cadamba), Kaew (Costus speciosus), Karoi (Albizia procera), Bakful (Sasbania grandiflora), Gamar (Gmelina arborea), and Barhar (Artocarpus lakoocha), were evaluated by in vitro gas production test. The mean content of OM, CP, EE, T-CHO, NDF, ADF, cellulose and lignin of these tested tree leaves were 91.4, 14.6, 3.9, 72.8, 42.7, 31.2, 19.8, and 11.1% on DM basis, respectively. The gas production per g digested dry matter varied from 111.1 ml/g DDM/24h in Bakful (Sasbania grandiflora) to 612.3 ml/g DDM/24h in Barhar (Artocarpus lakoocha) tree leaves while methane production per gram digested dry matter varied from 14.7 ml/g DDM/24h in Kadam (Anthocephalus cadamba) to 102.2 ml/g DDM/24h in Bahar (Artocarpus lakoocha) tree leaves. TVFA and propionate production were higher due to inclusion of Karoi (Albizia procera) tree leaves in the incubation media. However, lowest NH3-N concentration and rumen protozoal population were observed due to incubation of Kadam (Anthocephalus cadamba) tree leave. Similarly, activity of polysaccharide degrading enzyme like carboxymethyl cellulase, xylanase and β-glucoidase enzymes were lower due to incubation of Kadam (Anthocephalus cadamba) in comparison to other tested tree leaves. However, activity of amylase enzyme was similar among all the tested tree leaves. Highest IVTDMD (52.3%) was observed for the Karoi (Albizia procera) tree leaves followed by Kaew (Costus speciosus) (47.9%) and Kadam (Anthocephalus cadamba) (43.8%) tree leaves. Similarly, TDN and ME content were also highest for Karoi (Albizia procera) tree leaves. The results indicated that among the tested tree leaves, Karoi (Albizia procera) was best tree fodder for feeding to the animals and Kadam (Anthocephalus cadamba) can be used as rumen manipulator to reduce ruminal methanogenesis and protozoal population for improving animal productivity.