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 pariti es to determine any reproductive or growth performance effects of an a ctive dry yeast supplement added to corn-soybean meal diets. Sow repro ductive performance from d 93 of gestation through d 21 of lactation a nd sow milk composition were evaluated. Pig growth performance was mea sured 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 lac tation 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 cel ls 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 grou ps. Milk from sows fed active dry yeast contained higher amounts of to tal 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 dif ferences in litter size at birth, litter birth weight, or litter weigh t at d 21 after farrowing. Active dry yeast supplementation to the sow and pig diets resulted in improved postweaning pig daily gain (P < .0 5) 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 g estation, lactation, and before and after weaning does not alter litte r weight at birth or weaning but does increase gamma globulin content of sow's milk and improves postweaning rate and efficiency of weight g ain of pigs.