The effects of an active live yeast product on the growth performance of finishing lambs

Abstract

A study was conducted to evaluate the effects of a rumen-specific, active live yeast (Saccharomyces cerevisiae; SC CNCM I-1077), alone or in combination with an ionophore (lasalocid-Na) in standard feedlot diets, on production performance and carcass quality of lambs. Sixty South African (S.A.) Mutton Merino lambs, weighing 25.7 ± 2.2 kg, were randomly allocated to four treatments (15 lambs per treatment) and further subdivided into five replicates per treatment (three lambs per replicate). The four dietary treatments consisted of an iso-nitrogenous and iso-energetic basal diet (177 g crude protein (CP)/kg dry matter (DM) and 276 g neutral detergent fibre (NDF)/kg DM) differing only in the additive included, i.e. (i) the control (C) diet (no additive), (ii) live yeast (SC) (220 g/ton), (iii) ionophore (G) (120 g/ton) and (iv) both live yeast with ionophore (SCG) at the same mentioned levels. After adaptation (8 days), the experimental diets were fed for 47 days in a finishing period. Feed intake and body weights were recorded weekly. At completion all animals were slaughtered (44.5 ± 3.8 kg) and the cold (2 °C) carcass weight and carcass characteristics recorded. Dietary treatment had no effect on feed intake, daily live weight gain, feed conversion ratio, carcass weight and carcass characteristics. Carcasses were leaner on the ionophore treatment (G) in comparison to the control diet (C). The results suggested that this rumen-specific live yeast included alone or in combination with an ionophore in finishing diets, containing less than 28% NDF/kg DM, did not affect performance and carcass traits of S.A. Mutton Merino lambs.

Keywords: Feedlot lambs, ionophore, live yeast