Effects of diet and A spergillus oryzae extract or saccharomyces cervisiae on growth and carcass characteristics of lambs and steers fed to meet requirements of natural markets

Two studies were conducted to determinethe effects of diet and feed additive on growth andcarcass characteristics of lambs and cattle destined forall natural markets. In Exp. 1, 48 Dorset × Hampshirelambs (initial BW 29.4 ± 0.1 kg) were used in a randomizedcomplete block experiment to determine theeffects of Aspergillus oryzae extract, Amaferm (AMF)supplementation (1 g/d) in an 85% concentrate dieton growth and carcass characteristics. Lambs were allottedto 12 pens (4 lambs per pen), and blocked bysex and BW. Lambs were fed until the average BW ofeach pen reached a target BW (55.4 kg for wethers and50.0 kg for ewes), at which time the entire pen of lambswas slaughtered. Amaferm resulted in a greater (P =0.07) G:F. In Exp. 2, 168 crossbred steers (initial BW300 ± 0.7 kg) were used in a trial with a 3 × 2 factorialarrangement of treatments to examine the effectsof 0.5 g/d of Saccaromyces cervisiae boulardii CNCM1079-Levucell SB (LEV), or 3 g/d of AMF with 2 cornsources, dry whole-shelled corn or high moisture corn,on growth and carcass characteristics. Neither LEV norAMF improved (P > 0.10) carcass characteristics comparedwith control or non-feed-supplemented steers.Addition of LEV to high-concentrate, corn-based dietsdid not improve (P > 0.10) growth performanceof feedlot steers. However, addition of AMF to a dietcomposed of dry whole-shelled corn resulted in an improvement(P < 0.05) in G:F (0.208 vs. 0.194). Resultsindicate that at the amounts fed, AMF may improveG:F for lambs and steers fed dry corn-based finishingdiets.