Litter size and piglet BW is well documented to negatively correlate and generally attribute to nutrient restriction during foetus development. While supplementation with arginine has resulted in a greater number of live births, only few studies have shown positive effects on average BW or within-litter uniformity. Gestating gilts of high prolificacy may have higher dietary requirements to fulfill the growth demand and greater number of foetuses; therefore, they could be more sensible to a supplementation. The aim of this study was to evaluate the effects of dietary supplementation with arginine or a blend of other AA (lysine, methionine, threonine, and tryptophan) during different phases of gestation on piglet BW characteristics and placenta in hyper-prolific gilts. Pregnant gilts were divided into four treatment groups: Control (corn-soybean meal based diet from D25 to D112), Arginine (supplemented with 1% Arg from D25 to D80); Blend (20 g of blend from D81 to D112) and Argiblend (supplemented with 1% Arg from D25 to D80 and 20 g of blend from D81 to D112 of gestation).
The supplementation with Blend increased the weight of gilts at D112. The total number of piglets born, percentage of mummified fetuses, average BW, within-litter coefficient of variation in BW, percentage of low-birth-weight piglets (≤850 g or ≤1000 g), placental weight, placental efficiency and expression of vascular endothelial growth factor (VEGF) were not affected by the supplements. The supplementation with arginine decreased the number of born alive piglets and increased then percentage of stillborn piglets. The average placental weight was higher in Blend than in Control gilts. The effects of supplementation were also evaluated based on prolificacy of females categorized as either high (>14 total piglets born) and low (≤14 total piglets born). Within LowProlif group, gilts fed on the blend treatment had increased litter BW and average BW compared to control gilts. LowProlif gilts supplemented with arginine also had higher average BW than Control gilts. The LowProlif gilts fed on the arginine or blend diets had lower percentage of low BW piglets (≤850 g and ≤1000 g) than those fed on the control and argiblend diet.
Even though the supplement with arginine and/or an amino acid blend did not influence average piglet BW and the within-litter variation in BW, when all the litters were taken into account, the supplementation with arginine or blend increased the average BW and reduced the percentage of low-weight piglets at birth when the litter size was less than 14.
Dallanora, D., Marcon, J., Walter, M. P., Biondo, N., Bernardi, M. L., Wentz, I., and Bortolozzo, F. P. (2017). Effect of dietary amino acid supplementation during gestation on placental efficiency and litter birth weight in gestating gilts. Livestock Science, 197, 30-35. https://doi.org/10.1016/j.livsci.2017.01.005