Effects of live yeast supplementation to gestation and lactation diets on reproductive performance, immunological parameters and milk composition in sows

A 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. A total of 47 F1 sows (Yorkshire×Landrace) were allotted to five dietary treatments and two different levels (106 or 107 CFU/g of diet) of live yeast (Saccharomyces cerevisiae Sc47) were supplemented during gestation, lactation or both. Treatments were (1) no yeast supplementation during gestation and lactation, (2) gestation-basal diet, lactation-106 CFU of yeast/g of diet, (3) gestation-basal diet, lactation-107 CFU of yeast/g of diet, (4) gestation-106 CFU of yeast/g of diet, lactation-106 CFU of yeast/g of diet, (5) gestation-107 CFU of yeast/g of diet, lactation-107 CFU of yeast/g of diet. Inclusion of live yeast in sow diets did not result in any significant difference in body weight or backfat thickness of sows at 110 d of gestation and 21 d postpartum. Additionally, reproductive performance of sows, i.e. litter size, total born alive, birth weight and weight gain of progeny, was not influenced by live yeast supplementation (P>0.13). Dietary treatment did not affect average daily feed intake of sows during lactation. Compared with the control, weaning to estrus interval (WEI) was shortened (P<0.01) and percentage of sows in estrus by day 7 after weaning was increased (P<0.01) when sows were fed live yeast contained diet during lactation, regardless of yeast supplementation during gestation. There was no significant difference in milk composition during overall lactation except that IgG concentration in colostrum tended to be higher in the groups receiving live yeast supplementation (P=0.10) compared with the control group, resulting in higher IgG concentration in plasma of piglets at 24 h postpartum (P<0.05). These results suggested that the reproductive performance of sows might be improved as shown by reduction of WEI when sows were fed diets supplemented with live yeast. Moreover, the supplementation of live yeast in sow diets could elevate IgG concentration in colostrum and subsequently plasma IgG of piglets.