Evaluating the effects of supplemental B vitamins in practical swine diets during the starter and grower-finisher periods -- A regional study

¹ North Central Coordinating Committee on Swine Nutrition (NCCC-42)

^* To whom correspondence should be addressed. E-mail: mahan.3{at}osu.edu.

	Abstract

Two experiments were conducted to evaluate dietary fortification levels of a B vitamin premix for starter and grower-finisher pigs on subsequent performance responses. The objective was to determine if the modern pig required higher dietary levels of B vitamins than estimated by NRC (1998). Both experiments added fat soluble vitamins at the requirement levels (NRC, 1998) in all diets, whereas the B vitamins were added at 0, 100, 200 or 400% of the total NRC (1998) requirement levels for the starter and grower pig. Indigenous vitamin contributions from the feed grains were not included in the estimates. Each station used the same vitamin premixes but incorporated their own grain sources in the diets. The first experiment was conducted across 7 stations (IN, OH, OK, MI, MO, NE, TX) involving 660 pigs, in a randomized complete block (RCB) design in 30 replicates. Complex nursery diets were fed in 2 phases. The first phase (0 to 14 d postweaning) and second phase (15 to 35 d postweaning) diets were formulated to Lys (total) levels of 1.50 and 1.30%, respectively. The results demonstrated no performance response to B vitamin additions from 0 to 14 d postweaning, but performances quadratically increased (P < 0.01) to the 100% NRC level from 14 to 35 d postweaning and for the overall 35 d period. The second experiment, conducted across 3 stations (OH, NE, and SD), involved 216 pigs in a RCB design in 10 replicates. Corn-soybean meal mixtures were fed in 3 phases formulated to total Lys levels of 1.30% (23 to 55 kg BW), 1.00% (55 to 85 kg BW), and 0.78% (85 to 120 kg BW). Pig performances increased (P < 0.01) to the 100% B vitamin level from 23 to 85 kg BW, but there was no response to any level from 85 to 120 kg BW. Carcass measurements demonstrated a greater LM area (P < 0.01) and a lower backfat depth (P < 0.01) to the 100% B vitamin level. One station evaluated an additional treatment (3 replicates) where each replicate was fed a fifth diet containing the 100% dietary level of B vitamins from 23 to 85 kg BW, but the B vitamins were removed from 85 to 120 kg BW. This removal did not reduce pig performance responses for the final or for the overall period. The results demonstrated that supplementation of B vitamins at the 100% total NRC levels for starter and grower pigs was sufficient to meet their needs, and there was no further improvement or deleterious effect to greater dietary levels.

Key Words: B vitamins, grow-finish, nursery, pigs