Active yeast (Saccharomyces cerevisiae) supplementation improves digestibility of lamb diet1

The aim of the study was to evaluate the supplementation of active yeast (Saccharomyces cerevisiae) on diets of lambs fed with two different concentrate proportion on DM intake, apparent digestibility of nutrients, in vitro digestibility of dry matter and rumen fermentation parameters. Twenty non-castrated male lambs, averaging 120 days-old, housed in metabolism cages, with collector and separator of feces and urine fed with diets comprising grass hay and concentrate rations in two different proportion (80% or 60%, on DM basis), supplemented or not with active yeast (5 g/day) were used. Supplementation with active yeast increased (p<0.05) apparent digestibility coefficient of DM, OM, CP, NDF, non-fibrous CHO and HEM, as well as, TDN values, with no significant effect (P>0.05) on DM intake, independently of concentrate proportion. The rumen parameters were not changed by the active yeast supplementation since the rumen pH and ammonia nitrogen were similar between diets with or without active yeast. Values of in vitro digestibility of DM were higher for active yeast supplemented diets. Supplementation of diets of lambs with active yeast improves digestibility of DM and fiber, regardless of concentrate proportion, without changing DM intake.