0
Two different experiments were conducted; a nursery trial involving a total of 660 in 30 replicates at 7 stations (Exp 1) and a grower-finishing trial with a total of 216 pigs in 10 replicates at 3 different stations (Exp 2). In Exp 1 dietary vitamin levels of 0, 100, 200 and 400% of NRC (1998) requirements levels; 5kg pigs were used. Complex nursery diets were fed in two phases (0 to 14 and 14 to 35 days post weaning) and in Exp 2 the same proportions of the requirements listed in NRC but for 20-kg pigs were used. The pigs in this experiment were fed similar nursery diets from weaning to approximately 23 kg of BW. Performance measurements (ADG, ADFI and G:F) were collected for each pen at the various measurement periods.
No performance response to addition of B vitamins from 0 to 14 post weaning, but performances increased quadratically (P<0.01) to the 100% NRC level from 14 to 35 d post weaning and for the overall 35d period. On the other hand, pig performance increased (P<0.01) to the 100% B vitamin level from 23 to 85 kg of BW, but there was no response to any level from 85 to 120 kg of BW. Carcass measurements showed higher longissimus muscle area (P<0.01) and lower backfat depth (P<0.01) to the 100% B vitamin level.
It was concluded the supplementation of B vitamins at 100% total NRC levels for starter and grower pigs was sufficient to meet their needs and no further improvement was obtained to higher dietary levels.
DC Mahan, SD Carter, TR Cline, GM Hills, SW Kim, PS Miller, JL Nelssen, HH Stein, TL Veum and the North Central Coordinating Committee on Swine Nutrition (2007), Journal of Animal Science, 85: 2190-2197.
