189. Feeding Gestating and Lactating Sows with High Dietary Selenium Levels to Improve Reproductive Performance and Piglets Survivability and Performance.

Abstract

This study evaluated the effects of high levels of selenium (Se) supplementation using different sources on sows’ reproductive performance and piglets survival and performance. Seventy-two multiparous sows (220 ± 15 kg BW; parity 4.36 ± 0.5) initially selected and assigned to one of four experimental diets using body weight (BW) and blood Se concentrations as blocking factors. Treatments included low and high levels (0.3 or 1.0 ppm) of dietary Se in the form of sodium selenite or hydroxy-selenomethionine. The experiment comprised two consecutive reproductive cycles (G1–L1 and G2–L2). Selenium supplementation started at day 60 of G1 and continued up to the end of L2. Piglets performance during the suckling and nursery period (21–45 days) was evaluated only in cycle 2. During the nursery phase, piglets received experimental diets with the same Se source and level as their dams and were evaluated for BW and average daily gain (ADG). Data were analyzed using one-way ANOVA followed by Tukey post-hoc comparisons. In G1, no treatment effect was observed for presence of mummies and stillbirths, total number of piglets born, number of weaned piglets, BW at birth, BW at 24h, BW at weaning, or litter ADG (P ≥ 0.14). There were treatment effects for the number of piglets born alive and piglets alive at 24h (P ≤ 0.04). For the number of piglets born alive, however, the post-hoc comparisons did not detect differences between treatments. For piglets alive at 24h, sows supplemented with 0.3 ppm inorganic Se showed higher values than those receiving 1.0 ppm organic Se, whereas the other treatments were intermediate. In G2, no treatment effects were observed for the number of piglets born alive, piglets alive at 24h, weaned piglets, BW at birth, BW at 24h, BW at weaning, or litter ADG (P ≥ 0.13). A tendency was detected for total piglets born, presence of mummies, and presence of stillbirths (P ≤ 0.10). For total piglets born, the post-hoc comparison did not detect differences between treatments but the 1.0 ppm organic Se treatment showed lower odds of mummies and stillbirths than the inorganic Se treatments at both 1.0 and 0.3 ppm. No differences between treatments were observed for BW or ADG during the nursery phase (21–45 days). In conclusion, high supplementation levels of dietary Se, independently of source, had limited effects on reproductive performance and piglet growth. Although the number of piglets alive at 24 h was reduced in multiparous sows supplemented with 1.0 ppm of organic Se from mid-gestation (G1), the number of weaned piglets was not affected, suggesting a potential lower mortality during lactation (L2). After long-term supplementation (G2), 1.0 ppm organic Se reduced the odds of mummies and stillbirths.