LAUSR

This study evaluated the effects of high levels of dietary vitamins to gilts and sows during two consecutive reproductive cycles on dams’ reproductive performance, piglets growth performance and immunoglobulins concentrations in dams and piglets. From mating, 18 gilts and 23 sows were randomly assigned to the experimental treatments: CTR - gestation diet with NRC (2012) levels of vitamins; or HiVit - gestation diet exceeding the North American industry standards (Flohr et al., 2016) for vitamins. No supplementation was done during lactation. A commercial vaccine was given to dams. In both cycles, blood samples were collected from dams prior to the beginning of treatments and at days 100 and 110 of gestation, as well as colostrum (day 1) and piglets blood at days 2 and 21 for the detection of immunoglobulins. In both cycles, dams reproductive performance and piglets growth performance were recorded. Performance and metabolic parameters were statistically analyzed according to a 2x2 (treatment x cycle) and a 2x2x3 (treatment x cycle x time) factorial design. There was no difference on sows reproductive performance. In cycle 2, gilts bodyweight at mating tended to be higher for CTR (P = 0.10) but HiVit gilts had greater bodyweight gain (P = 0.04). Although not statistically different between treatments, total born (P = 0.12) and total born alive (P = 0.14) were reduced by 3.2 and 2.7 for CTR gilts between cycles and by 0.5 and 0.3 for HiVit. There was no difference for the number of weaned piglets (P ≥ 0.16). In cycle 2, average litter weight at 24 hours was higher for HiVit litters (P = 0.04) but at weaning the average piglets bodyweight tended to be higher for CTR (P = 0.06). Although in CTR sows had higher total IgG quantities in cycle 1 (P = 0.03), these values decrease by half in cycle 2 (P < 0.01), whereas HiVit sows had similar quantities between cycles (P = 0.86). For vaccine-specific IgG, a tendency for overall higher titers were detected in HiVit gilts serum (P = 0.09) but not on colostrum or piglets serum. Sows colostrum vaccine-specific IgG titers tended (P = 0.06) to be higher for CTR group in cycle 1 and for HiVit groups in cycle 2. Compared to cycle 1, piglets serum vaccine-specific IgG titers increased for CTR groups at day 21 of cycle 2 (P < 0.01) but not for HiVit (P = 0.37). In conclusion, supplementing gilts with high levels of vitamins during more than one reproductive cycle may improve piglets performance during the early suckling period but withdrawing HiVit maternal supplementation during lactation may have been detrimental to piglets performance at weaning. Immune response to vaccine was inconsistent between reproductive cycles in both treatments.