Abstract
Gilts [n = 50; initial body weight (BW) 190.7 ± 4.2 kg] were used to determine the optional inclusion level of postbiotic Saccharomyces cerevisiae in late gestation and lactation diets to improve immunoglobulin transfer and piglet growth performance during the suckling period. Gilts were assigned to one of five (n = 10) diets: standard gestation and lactation diets (Y0) or diets with postbiotic yeast included at either 0.25% (Y0.25), 0.5% (Y0.5), 1.0% (Y1), or 1.2% (Y1.2). Diets were fed from d 85 of gestation until weaning (d 21 after farrowing). During gestation gilts were fed 2.6kg/d and feed was offered ad libitum during lactation. Gilt BW was recorded on d 85 and 110 of gestation, and gilt and piglet BW were recorded on d 1 and 21 of lactation. Twenty-four hours after farrowing, plasma was collected from each gilt and two median BW piglets per litter via orbital sinus. Additionally, 50 mL of colostrum was collected in equal parts from all functional teats on the right side. On d 21, plasma samples were collected from each gilt and two median BW piglets per litter. Concentrations of immunoglobulin (Ig) A, G, and M were quantified in plasma and colostrum. Data were analyzed in SAS with treatment as the main effect. Linear, quadratic, and yeast vs. no yeast contrast statements were used to assess responses to dietary inclusion of yeast. Time (minutes) between farrowing (defined as birth of the first piglet, confirmed by video recording) and sampling was used as a covariate for d 1 Ig concentrations. There were no differences in number of piglets born alive (12.5 ± 0.9), birth weight (1.40 ± 0.45kg), or gilt BW change during lactation (-7.98 ± 6.68kg). Lactation average daily feed intake tended to be 14.6% greater for gilts provided yeast versus no yeast (5.11 vs. 4.46 ± 0.31kg, respectively; P = 0.069). At weaning, offspring from Y0.25 fed gilts had greater BW than piglets from Y0- or Y1.2-fed gilts (6.48 vs. 5.66 and 5.82 kg ± 0.16, respectively; P < 0.001), with all other treatments intermediate. On d 1, colostrum and gilt plasma Ig concentrations were unaffected by diets. However, yeast increased piglet plasma concentrations of IgM (linear; P = 0.034) and tended to increase IgA (linear; P=0.093), and total Ig (linear; P = 0.074). On d 21, gilts fed yeast-containing diets tended to have greater plasma IgA (yeast vs. no yeast and quadratic; P = 0.063 and P = 0.076, respectively), but IgM was greater for gilts fed Y0 (yeast vs. no yeast; P < 0.05). On d 21, piglet plasma IgA tended to be greater when gilts were provided yeast-containing diets (yeast vs. no yeast; P = 0.069). Therefore, postbiotic Saccharomyces cerevisiae was effective in improving maternal transfer, with piglet IgA and IgM concentrations increasing linearly with increasing yeast inclusion, while Y0.25 also improved piglet growth performance during the suckling phase.