Rumen methane amelioration in sheep using two selected tanniferous phyto-leaves

A study was conducted in eighteen sheep divided into three groups of six animals each and fed on a diet comprising finger millet (Eleusine coracana) straw and concentrate in 50:50. Animals in the control group (T0) received diet without tanniferous tree leaves, while in T1 and T2 groups, animals received diets with Syzygium cumini (source of HT) and Machilus bombycina (source of CT), respectively. Enteric methane emission from the animals was measured. Hydrolyzable and condensed tannin intake in the T1 and T2 groups was 14.08 and 4.29 g/kg dry matter, respectively. Results from the study did not reveal any adverse impact of hydrolyzable and condensed tannin-containing leaves on the dry matter (g/100 kg BW) or digestible dry matter intake. The study confirmed a significant reduction in enteric methane emission (g/d) due to the supplementation. The methanogen numbers in test groups T1 and T2 were lower than those in the control; however, the rumen protozoal population (× 105/mL) was adversely affected by Syzygium cumini. Supplementation of selected leaves would help in conserving additional energy for the animal's use and also to curtail the contribution of livestock to GHG emissions. Long-term studies are warranted with selected sources to confirm the persistency of methane reduction.