A number of management and nutritional strategies and dietary supplement approaches have been proposed for increasing the reproductive performance of sows. Yeast supplementation has been known to improve growth performance and immunological status of pigs. This study was conducted to determine the effect of live yeast supplementation of sow diets on reproductive performance, immune function, milk composition of sows and performance of their progeny.

In order to carry out the present study, five feeding programs were allocated and applied to a total of 47 sows of the F1 generation (Yorkshire X Landrance), which were given two different levels of yeast Saccharomyces cerevisiae during pregnancy and/or lactation. em>.

The addition of yeast to the diet of sows did not cause any significant change in the body weight or back subcutaneous fat density of the sows, as determined by measurements on day 110 of gestation and day 21 postpartum. In addition, the reproductive performance of sows, i.e. farrowing group size, total number of live piglets after farrowing, weight of piglets after farrowing and piglet weight gain rate, were not affected by the change in sow diet. The average daily feed consumption of the sows during the lactation period remained unaffected. Compared to the control group, the yeast-supplemented groups during lactation showed a reduction in weaning-to-estrus (WEI) and an increase in the percentage of sows in estrus by day 7 post-weaning. The aforementioned results occurred regardless of whether or not sows were supplemented during gestation.

No significant differences were found in the composition of sows' milk during lactation, with the exception of IgG immunoglobulin concentration, which tended to be slightly increased in the yeast-supplemented groups compared to the control group. This resulted in increased levels of IgG concentration in the blood serum of the piglets 24 hours after birth.

The results of this research indicate that the reproductive performance of sows can be improved if yeast is added to their diet during pregnancy and lactation.

Source: Live yeast supplementation to gestation and lactation diets on reproductive performance in sows, Y.D.Jang et al (2013). Livestock Science, 152, 2-3; 167-173