PSIV-2 Impact of Vitamins C and E on Sow Mortality and Stillborn Rate

Abstract

Abstract The objective of the study was to evaluate late gestation supplementation of vitamins C and E on sow mortality and percentage of stillborn piglets. Sows (n = 466), housed in stalls at a commercial sow farm in eastern North Carolina, were randomly allocated to either receive 35g of a top-dress containing vitamins C and E or no top-dress (Control). The 35g top-dress contained 1.05g of vitamin C (from STAY-C 35), 500 IU of vitamin E (from ROVIMIX E50) and ground corn as a carrier. Vitamins C and E were top-dressed twice per week, from day 87 of gestation until farrowing. At the start of vitamin supplementation, sow body condition was measured using a Knauer sow body condition caliper (Knauer scale: < 12 = “thin”, 12 to 15 = “ideal”, >15 = “fat”). The gestation and lactation diets on the farm were formulated to contain no vitamin C and 66 IU/kg of vitamin E. Sow mortality was evaluated from day 95 of gestation through day 30 post-farrow. Mortality codes recorded by farm technicians included sudden death, lameness, prolapse and farrowing difficulty. Sow mortality traits were analyzed using a Chi-square analysis and percentage of stillborn piglets [stillborns ÷ (number born alive + stillborns)] was analyzed using linear regression. Of the 466 sows, 29 (6.2%) died or were euthanized between day 95 of gestation and 30 days post-farrow. Sows that died had less (P < 0.01) body condition (15.3 vs. 16.4 sow caliper score) and were greater (P < 0.01) parity (2.8 vs. 1.9) than sows that survived. Sows supplemented with vitamins C and E tended (P = 0.11) to die less from sudden death and prolapse when compared with Control sows (6.0 vs. 3.0%). Vitamin C and E supplementation tended (P = 0.08) to reduce the number of sows that died at or before farrowing. There was no difference (P=0.33) in percentage of stillborn piglets between sows supplemented with vitamins C and E when compared with Control sows (6.4 vs. 5.5%, respectively). Yet there was an interaction (P < 0.01) between sow body condition caliper score and vitamin supplementation in relation to percentage of stillborn piglets. Thin and ideal sows supplemented with vitamins C and E, thin and ideal Control sows, fat sows supplemented with vitamins C and E, and fat Control sows had stillborn rates of 8.3, 4.8, 4.4 and 6.1%, respectively. For each additional piglet born, percentage of stillborn piglets increased (P < 0.01) by 0.38%. Results suggest supplementation of vitamins C and E in late gestation may be a strategy to enhance sow livability.