Effects of Sugarcane-Derived Polyphenol Supplementation on Methane Production and Rumen Microbial Diversity of Second-Cross Lambs.

The objective of this study was to evaluate the effects of feeding sugarcane-derived polyphenolic supplement (Polygain, The Product Makers Australia, Keysborough, VIC, Australia) on enteric methane (CH 4 ) emission, rumen microbiota, and performance of second-cross lambs. For this purpose, 24 Poll Dorset × (Border Leicester × Merino) lambs were allocated to 3 different treatments: Control (C), 0.25% Polygain (0.25 PG), and 1% Polygain (1 PG) diets with a uniform basal feed (25% cracked wheat grain, 25% cracked barley grain, 25% oaten chaff, 25% lucerne chaff). Both doses of Polygain reduced the total CH 4 production (g/day; p = 0.006), CH 4 yield (CH 4 , g/kg of dry matter intake; p = 0.003) and CH 4 intensity (CH 4 , g/kg of BW; p = 0.003). Dry matter intake tended to be greater ( p = 0.08) in sheep fed 1 PG compared to the C group, with the 0.25 PG group being intermediate. The average daily gain of the lambs was improved ( p = 0.03) with 1% Polygain supplementation. The relative abundance of genera Methanobrevibacter_ unidentified, Methanomethylophilaceae_ uncultured, Methanogenic archaeon mixed culture ISO4-G1, Methanosphaera uncultured rumen methanogen, Methanogenic archaeon ISO4-H5, and Methanobrevibacter boviskoreani JH1 were reduced with Polygain supplementation. In conclusion, feeding Polygain reduced lambs' enteric CH 4 emissions, altered the rumen microbiome, and improved the growth performance of lambs.