Effects of dietary vitamin E on sow reproductive performance over a five-parity period

A study involving 360 farrowings over a five-parity period evaluated the effects of dietary vitamin E on sow reproductive performance and the subsequent effects on serum, colostrum, and milk tocopherol contents. The 2 x 3 split-split-plot experiment was conducted at two locations that differed in the type of facility (indoor gestation pens/farrowing crates [IP/FC] or outside gestation lots/indoor farrowing pens [OL/FP]) and three dietary levels of dl-alpha-tocopheryl acetate (22, 44, or 66 IU/kg of diet), with five parities nested within sow in a repeated measure design. Sow serum alpha-tocopherol, Se, and glutathione peroxidase (GSH-Px) activity were measured at 30 and 90 d postcoitum and at 21 d postpartum (weaning) during each parity. Colostrum and 7-, 14-, and 21-d milk samples were analyzed for alpha- and gamma-tocopherol and Se concentrations. Three pigs per litter were bled at weaning and their serum was analyzed for alpha-tocopherol and Se concentrations and GSH-Px activity. The results indicated that sow weights and daily lactation feed intakes or litter birth and weaning weights were not affected by dietary vitamin E levels provided to the sow. There was an increased number of pigs born (total, P < .01; live, P < .10) when dietary vitamin E was increased. The incidence of mastitis, metritis, and agalactia decreased (P < .05) as dietary vitamin E was increased. The incidence of mastitis, metritis, and agalactia decreased (P < .05) as dietary vitamin E increased was higher (P < .05) with first- and second-litter sows, and was higher (P < .01) at the location that had the OL/FP facility. Colostrum and milk alpha-tocopherol increased (P < .01) as dietary vitamin E increased. Milk alpha-tocopherol declined linearly (P < .01) from 7 to 21 d postpartum in a parallel manner between dietary vitamin E levels. At weaning, pig serum alpha-tocopherol increased (P < .01) as sow dietary vitamin E level increased. These results support a higher dietary level of vitamin E than currently recommended by NRC (1988) for both gestating and lactating sows.