Maternal age modulates the effects of early-pregnancy L-proline supplementation on the birth-weight of piglets.

Previous results obtained in gilts maintained under experimental conditions suggest that amino acid supplementation during pregnancy may be a promising strategy for diminishing the incidence of embryo losses and low birth-weight newborn. The current study evaluated the effects of a short-term supplementation with L-proline, around implantational stages, on litter size and birth-weight of piglets in sows of different parities maintained under commercial farm conditions. There were no significant effects in mature sows with three or more parities, but the supplementation improved the reproductive efficiency of the high-prolific first-parity sows and of all the sows at second-parity. There were numerically higher litter size (of around two more live piglets; n.s.) and higher birth-weights (P<0.05) in the supplemented animals. The results of this study indicate that the effects of L-proline supplementation on litter size and birth-weight are strongly modulated by the maternal characteristics; specifically by parity and prolificacy and that supplementation may be cost-efficient for the management of females with compromised energy balance; specifically, sows at second farrowing and highly-prolific primiparous gilts.