Screening of phyto-sources from foothill of Himalayan mountain for livestock methane reduction

Abstract

The present study was undertaken to explore the methane reduction potential of phyto-sources from the foothills of Himalayan region. The qualitative screening of phyto-sources confirmed the presence of tannins in ~ 80% of the samples. Similarly, most of the phyto-samples were also possesses flavanoids (66%) and terpenoids (94%); however, none of the samples consist saponins or phlobatannins. The highest tannins concentration was reported in Terminalia chebula (245 g/kg DM), Zanthoxylum alatum (219 g/kg DM) and Punica granatum (207 g/kg DM). Phyto-sources such as Pittosporum eriocarpum, Prunusdomestica and Berberis lycium contain condensed and hydrolysable tannins in nearly equal proportions and comparatively produce lesser methane than non-tanniniferous phyto-sources sources or phyto-sources which possess either condensed or hydrolysable tannins. The study established that entodinomorphs were most vulnerable protozoa to tanniniferous phyto-sources. The attenuation of tannins impact through polyethylene glycol (PEG-6000) addition revealed a substantial increase in total volatile fatty acids (up to 23%) and ammonia nitrogen (up to 50%). It can be inferred from the study that Prunus domestica, Berberis lycium and Terminalia chebula due to their methane mitigation potential can be incorporated in animal feed for reducing methane emission. The present study unequivocally demonstrated that tannins-containing phyto-sources could be of great interest in the development of novel anti-methanogenic feed additives. However, the optimization of level of inclusion for the selected phyto-sources in animals diet should be studied.