Effect of enriched-chromium yeast on growth performance, carcass characteristics and fatty acid profile in finishing Rambouillet lambs

Abstract

• Supplementation of enriched-Cr yeast increased 12th rib back fat thickness by 23.3 %. • Intramuscular fat was decreased by 15.5 % in lambs supplemented with enriched-Cr yeast. • Enriched-Cr yeast marginally increased palmitic fatty acid in the meat. The objective of the present study was to evaluate the effect of enriched-chromium yeast (YCr) on growth performance, carcass characteristics and Longissimus dorsi muscle (LM) composition of finishing lambs. Fourteen Rambouillet lambs (23.3 ± 2.9 kg BW) were assigned to two treatments in a completely randomized design with 7 lambs per treatment: (i) Basal diet (control), (ii) YCr (Basal diet+0.3 mg of Cr/kg DM). The Cr was supplied as enriched-Cr yeast during the 74 days of the feeding period. The basal diet (13.9 % CP and 7.83 MJ NEm/kg DM) contained 85 % concentrate (ground corn, canola meal, soybean meal, wheat bran, mineral and vitamin premix and sodium bicarbonate) and 15 % ground corn stover. Lambs were weighed on day 1, 42 and 74 of the feedlot experiment. Enriched YCr supplementation had no effect ( P > 0. 05) on animal performance and carcass characteristics of lambs. YCr tended to increase 12th rib back fat thickness ( P < 0.10), increased ( P < 0.05) LM pH 45 min postmortem and tended to increase LM pH 24 h postmortem ( P < 0.10). Meat chemical composition and shear force was not affected ( P > 0.05) but meat intramuscular fat tended to decrease ( P < 0.10) in response to YCr supplementation. For meat fatty acids profile, no effect was noted with YCr supplementation.