117 Evaluation of the Effects of Dried Live Yeast on Rumen pH and in Situ Digestibility of Dry Matter in growing cattle

• Published in: Journal of animal science 2018-03, Vol.96 (suppl_1), p.62-63
• Main Authors: Cagle, C M, Tedeschi, L O, Runyan, C A, Callaway, T R, Cravey, M D
• Format: Article
• Language: English
• ISSN: 0021-8812; 1525-3163
• DOI: 10.1093/jas/sky027.117

Abstract Live yeast (LY) supplementation to ruminants has been shown to increase nutrient digestibility and improve the rumen environment by increasing its pH in dairy cows. Few studies have determined the impact of LY in the rumen of growing cattle receiving high-concentrate diets. This study was designed to evaluate the effects of LY-(Saccharomyces cerevisiae) Actisaf (Phileo Lesaffre Animal Care) on rumen pH and dry matter digestibility during three feeding phases [grower (GRW), transition (TRANS), and finisher (FIN)]. Eight ruminally cannulated cattle (n=4 steers and n=4 heifers) were blocked by sex into two pens containing Calan gate feeders and received a standard diet (13.7% CP, 42.4% NDF, 88% DM) without LY for 10 d (d -10 to d -1). On d 0, each animal was randomly assigned to one treatment [control (CON), LY1 (2.5 g/d per head), LY2 (5 g/d per head), or LY3 (10 g/d per head)], and fed every morning (0800) for 55 d. Each of the three diets (GRW, TRANS, and FIN) were fed sequentially as follows: GRW for 27 d, TRANS for 14 d, and FIN for 14 d. There were nine collection days (d -1 and every 7 after) in which ruminal pH was determined and nylon bags containing 5 g of diet substrates (GRW, TRANS, and FIN) were incubated in the rumen at 1200 for 48 h to determine the DM digestibility (DMD) of the three diets. Data was analyzed as a RCBD with day as a repeated measure. For the GRW diet, TRT was not different (P=0.12) for pH, but for the TRANS diet, TRT was different (P=0.02) and had a quadratic pattern (P=0.01) in which LY1 and LY3 had the greatest pH (P