Effects of high dietary zinc supplementation timing on the biological responses of gestating sows and their piglets

High dietary zinc (Zn) fed to gestating sows may have utility as a fetal imprinting strategy to decrease pre-weaning mortality of piglets. However, the biological action that Zn may work through is unknown. High Zn may modulate the microbiome of the sow and the microbial seeding of the offspring’s gut microbiome. Additonally, high dietary Zn and piglet birth weight may alter gene expression in piglet whole blood. Sows (n = 267) were fed 1 of 3 dietary treatments: 1) Control: a corn-soybean meal-based diet containing 125 ppm total supplemental zinc, 2) Breed-to-Farrow: as Control + 141 ppm supplemental Zn as ZnSO4 fed from 5 days post-breeding to farrowing; and 3) Day 110-to-Farrow: as Control + 2,715 ppm supplemental Zn as ZnSO4 starting on day 110 of gestation until farrowing. A subset of third parity sows (n = 30) were selected to assess the microbiome of colostrum, milk, and rectal and vaginal surfaces of sows. At farrowing, 4 pigs per litter (n = 120) were selected based on birthwei...