PS3-13. Impact of Dietary Lactobacillus Probiotics During Mid- and Late Gestation on Farrowing Performance and Colostrum Immunoglobulins.

Abstract In the swine industry, improved farrowing performance, characterized by large litters of piglets with good viability, is vital to maximize farm profitability. The lack of intrauterine immune transfer during gestation leaves piglets reliant on their dam's colostrum for immunity. Immunoglobulin G (IgG) is the most prevalent antibody in colostrum and serves as the main humoral defense in piglet circulation, while Immunoglobulin A (IgA) provides tissue-specific immune protection. Recent research suggests feeding Lactobacillus-based probiotics during gestation improves swine health and farrowing performance. The objective of this study was to evaluate dietary Lactobacillus-based probiotics fed beginning in mid-gestation on farrowing performance and colostrum immunoglobulins. Crossbred gilts provided 2.3 kg per day of a standard gestation diet were assigned by body weight beginning on day 60 of gestation to receive 5 g probiotics per day until farrowing (PRO; 180.7±9.5 kg; n = 10) or Control (CON; 182.1±9.9 kg; n = 10). Gilts farrowed in two replicates (n = 5 CON and n = 5 PRO per replicate), and the farrowing room was supervised continuously by trained staff beginning on day 113 of gestation. Farrowing performance was evaluated as gestation length (GestLength), total number of piglets born (TNB), number of piglets born alive (NBA), percentage of TNB stillborn (%NSB), percentage of TNB mummified (%NMF), farrowing duration (FarrowDur), and both average pre-suckle piglet birthweight of the litter (AvgBWT) and total pre-suckle piglet birthweight of the litter (SumBWT). Colostrum was collected from multiple teats during farrowing, and IgG and IgA levels were analyzed using Pig ELISA kits according to manufacturer's instructions (Bethyl Laboratories; Montgomery, TX). Data were normally distributed and analyzed by the GLM procedure of SAS 9.4 (Cary, NC) with treatment and replicate as fixed effects and TNB as a covariate for AvgBWT. No significant differences were found between CON and PRO gilts in the following farrowing performance parameters: TNB (14.8±0.7 vs. 15.5±0.7; P = 0.52), NBA (14.1±0.7 vs. 14.8±0.7; P = 0.50), %NSB (3.2±1.2% vs. 2.5±1.2%; P = 0.67), %NMF (1.4±1.0% vs. 1.9±1.0%; P = 0.72), FarrowDurr (170.0±25.3 minutes vs. 187.8±25.3 minutes; P = 0.62), or AvgBWT (1.24±0.05 kg vs. 1.36±0.05 kg; P = 0.12). Additionally, there were no differences between CON and PRO gilts in IgG (96.6±12.3 mg/mL vs. 87.9±12.3 mg/mL; P = 0.64) or IgA (9.6±1.6 mg/mL vs. 10.8±1.6 mg/mL; P = 0.63) colostrum levels. However, probiotic supplementation tended to reduce GestLength (116.1±0.4 days vs. 117.1±0.4 days; P = 0.07) and increase SumBWT (20.1±0.9 kg vs. 17.8±0.9 kg; P = 0.09). Feeding a Lactobacillus-based probiotic from day 60 of gestation to farrowing did not impact litter size or colostrum IgG or IgA levels; however, tendencies in reduced gestation length and greater total litter birth weight may suggest greater litter viability. Further investigation into piglet performance and immune profiles during lactation and after weaning are warranted and ongoing.