PSI-15 - Evaluation of a feed sanitizer in sow diets

Abstract: Reduced microbial and pathogen content in feed is hypothesized to improve performance of sows and their nursing litters. The objectives of this study were to evaluate the effects of a formaldehyde, propionic acid, and terpene-based feed sanitizer (Termin-8) on performance, health, and gut microbiome of sows and their nursing piglets. Two contemporary cohort groups of sows (n=107 mixed parity Topigs Norsvin TN70 females) were allocated randomly within parity to 1 of 2 dietary treatments. The treatments were corn-soybean meal-based diets (Control; n=53) or the Control diet containing 0.55% feed sanitizer (Treatment; n=54). Treatments were imposed from day 80 of gestation and continued through lactation to weaning. Sows were moved to individual farrowing stalls at approximately day 109 of pregnancy. Sows received 2.72 kg daily of their assigned lactation diet from entry to farrowing accommodations until farrowing. After farrowing, sows had ad libitum access to feed and water until weaning on about day 19 ± 2 postpartum. Piglets were cross-fostered within dietary treatments within 24 hours of birth to equalize litter size. DNA for microbiome analyses was extracted from fecal swabs collected from sows before administration of diets and at weaning, and from piglets at weaning. Statistical analysis of performance data was conducted using the GLIMMIX procedure of SAS with treatment as a fixed effect, group as a random effect, and sow parity as a covariate. Qiime2 and various R packages were used to analyze 16S rRNA (V4 region) MiSeq microbiome sequence data. Treatment diets had no significant effects on sow body weight, backfat depth, average daily feed intake of sows, wean-to-estrus interval, litter size and weight at weaning, or incidence of diarrhea in piglets. We observed decreased weight of stillborn pigs for sows fed Treatment diets compared to sows fed Control diets (P = 0.010). Gut microbiome composition (beta diversity) of both sows fed Control and Treatment diets changed from gestation to weaning in a similar manner, except for some distinctions in the taxa driving these differences. At weaning, there were significant compositional differences in gut microbiomes between sows fed Control and Treatment diets (PERMANOVA, R² = 0.048, P= 0.006). Except for a few differentially abundant bacterial taxa, there were no significant compositional differences between the gut microbiome of piglets from sows fed either Control or Treatment diets. No differences in alpha diversity were observed in sows or piglets during the study period. In conclusion, supplementing a feed sanitizer to sow diets did not significantly impact overall sow and litter performance or piglet health; but did influence gut microbiome of sows. This finding warrants further investigation into potential effects of a feed sanitizer on sows’ microbiome as it might influence sow and piglet health.