author(s)
Vandana Kumari Leitanthem, R Bhar, A Kannan, M Wanta Khuman, Anchal Keshri, Digvijay Singh and Vikas Kumar

abstract
The present study was conducted to evaluate the effect of replacement of oat fodder (OF) with oak leaves (OL) on rumen fermentation and methane production in in vitro studies. Four different substrates (diets) were prepared with different combination of oat fodder and oak leaves. In Group I, 100% oat fodder was there, 5%, 10% and 20% of group I (100% oat fodder) was replaced by oak leaves in Group II, Group III and Group IV respectively. Different combination of diets was evaluated through Hohenheim IVGPT with 200 mg substrate and 30 ml of buffered rumen liquor. After 24hr incubation of syringe in buffered rumen liquor of cattle at 39 °C, total gas production was recorded and the remaining contents were used to analyzed in vitro methane production, protozoa no, ammonia-N, true dry matter and organic matter digestibility. As the level of oak leaves increases in the diet there was decreased (<0.05) in total gas production, methane, dry matter digestibility, organic matter (OM) digestibility, and metabolizable energy (ME) values. There was no effect in protozoal count. The study was concluded that replacement oat fodder with oak leaves decreases total gas production, methane production, dry matter, organic matter (OM) digestibility and ammonia-N. It is needed to explore in in vivo studies for the safe inclusion level of oak leaves in the ruminants diet.