Efficacy of live yeast in lactating dairy cattle1

A 12-wk continuous lactation trial with 60 primiparous and multiparous Jersey cows was conducted to evaluate the efficacy of Yea-Sacc TS (Alltech Inc., Nicholasville, KY). Cows were given fresh feed in a TMR twice daily, and at each feeding cows were individually provided top-dresses (50 g/animal) of either a ground corn control or ground corn mixed with Yea-Sacc TS (total of 100 g/animal daily). Cows received 1.94 × 1010 to 4.35 × 1010 cfu of Saccharomyces cerevisiae per animal per day for the Yea-Sacc TS treatment. Cows consuming Yea-Sacc TS increased (P = 0.01) DMI by 0.7 kg/d, which increased (P < 0.05) milk fat, milk protein, and energy-corrected milk yields by 0.067, 0.037, and 1.0 kg/d, respectively. Under our conditions, Yea-Sacc TS demonstrated efficacy for lactating cows fed moderately high starch diets primarily through increased DMI.