190. Effects of High Dietary Inorganic and Organic Selenium Supplementation in Gestating and Lactating Sows on Selenium Status and Piglet Performance.

Abstract This study evaluated the effects of supplementing sows with different sources and levels of selenium (Se) on sows and piglets Se status as well as piglets’ performance. Sixty-four sows were initially assigned to treatments consisting of two sources [sodium selenite (Inorg) or hydroxy-selenomethionine (Org)] and levels (0.3 or 1.0 ppm) of dietary Se. The experiment comprised two consecutive reproductive cycles (G1-L1 and G2-L2). Selenium supplementation started at d60 of G1 and continued up to the end of L2. Growth performance was evaluated at weaning (d21) and during the early nursery period (d25) only in cycle 2 using a sub-group of 32 sows (8 sows per treatment; two mean BW piglets per litter selected for euthanasia; data not shown). Between d21-25, all piglets were fed Inorg0.3. Data were analyzed as a 2 x 2 factorial design with repeated measures over time when appropriate. No difference was detected between treatments at d60 of G1 (P ≥ 0.492). At the weaning-to-estrus interval and d30, 60, 90 and 110 of G2, when increasing Se levels (0.3 vs 1.0 ppm) sows blood Se concentrations increased by 3-14% in Inorg and by 43-58% in Org (sources x levels interaction; P ≤ 0.001). Colostrum Se concentrations increased by 14% in Inorg1.0 compared to Inorg0.3, whereas they increased by 107% in Org1.0 compared to Org0.3 (sources x levels interaction; P ≤ 0.001). Piglets’ Se concentrations were not affected by supplementation level in Inorg (3%), whereas they increased by 67% in Org1.0 compared with Org0.3 (source × level interaction; P ≤ 0.001). In the group of piglets euthanized at d21, no treatment effect was detected on BW at birth (P ≥ 0.432). However, when increasing Se levels (0.3 vs 1.0 ppm), BW at weaning and ADG d0-21 slightly increased (8 and 4%, respectively) in Org and tended to be reduced (-16 and -13%, respectively) in Inorg (sources x levels interaction; P ≤ 0.075). In the group of piglets euthanized at d25, no treatment effect was detected on BW at birth and at weaning (P ≥ 0.148). However, the ADG from birth to weaning was increased (13%; P = 0.047) by maternal Se supplementation with 1.0 ppm compared to 0.3 ppm. At d25, BW tended to be higher (8%; P = 0.095) and ADG was higher (12%; P = 0.050) in piglets from sows supplemented with 1.0 ppm compared to 0.3 ppm. However, the ADG d21-25 was lower (-34%) in Org compared to Inorg (P = 0.004). In conclusion, supplementing sows with Org1.0 was the most effective strategy to increase Se concentrations in sows and piglets. High maternal Se supplementation tended to enhance piglet ADG during the suckling and early post-weaning periods. However, these effects were inconsistent between Se sources.