The effect of dietary active dry yeast supplement on performance of sows during gestation-lactation and their pigs.

Thirty crossbred sows and their pigs were evaluated through two parities to determine any reproductive or growth performance effects of an active dry yeast supplement added to corn-soybean meal diets. Sow reproductive performance from d 93 of gestation through d 21 of lactation and sow milk composition were evaluated. Pig growth performance was measured from birth to 28 d after weaning. Active dry yeast was added at 0, 1, or .2% of the sow gestation diet, 0, .15, or .3% of the sow lactation diet, 0, .2, or .4% of the pig prestarter diet, 1 wk before and 1 wk after weaning, and 0, .125, or .25% during the last 3 wk in the nursery. The yeast source consisted of a concentrate of live yeast cells of the Saccharomyces cerevisiae strain containing more than 15 x 10(9) live cells/g. Sow body weight at d 93 of gestation, at farrowing, and at d 21 of lactation did not differ (P > .10) among treatment groups. Milk from sows fed active dry yeast contained higher amounts of total solids (P < .05), crude protein (P < .10), and gamma globulin (P < .06) than milk from sows fed the control diet. Sow feed intake during lactation was not affected (P > .10) by treatment, nor were there differences in litter size at birth, litter birth weight, or litter weight at d 21 after farrowing. Active dry yeast supplementation to the sow and pig diets resulted in improved postweaning pig daily gain (P < .05) and gain-to-feed ratio (P < .05) but did not affect (P > .10) feed intake. Based on these data, active dry yeast supplement during late gestation, lactation, and before and after weaning does not alter litter weight at birth or weaning but does increase gamma globulin content of sow's milk and improves postweaning rate and efficiency of weight gain of pigs.