Date of this Version
An experiment was conducted to assess the responsiveness of weanling pigs to increased dietary concentrations of niacin and vitamin B12. The purpose of the experiment was to determine if the niacin and vitamin B12 requirements of nursery pigs are greater than the NRC (1998) recommendations for 11 to 22 lb pigs. Pigs (initial weight 9.4 lb) were fed one of four diets for a total of 35 days: 1) Negative control, common nursery diet with no added niacin or vitamin B12; 2) Niacin, common nursery diet with 22.7 µg/lb added niacin; 3) B12, common nursery diet with 36.3 µg/lb added vitamin B12; and 4) Positive control, common nursery diet with 22.7 µg/lb added niacin and 36.3 µg/lb added vitamin B12. Pigs and feeders were weighed weekly to determine average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency (ADG/ADFI). Pigs were visually scored to assess any potential niacin and vitamin B12 deficiencies on days 14, 21, 28, and 35. No niacin x vitamin B12 interactions were observed. During Phase I, pigs fed supplemental niacin had a greater ADFI (P < 0.01) than pigs fed supplemental vitamin B12. During Phase II, pigs fed supplemental vitamin B12 had the greatest ADG (P < 0.001) and ADFI (P < 0.01). Overall, the pigs fed supplemental vitamin B12 had greater ADG (P < 0.001), ADFI (P < 0.01), and ADG/ADFI (P < 0.05) than pigs fed supplemental niacin. There were no differences among groups for visual assessment of B vitamin deficiencies. Based on these results, the niacin requirement of 10 to 40 lb pigs is not greater than 4.5 µg/lb of diet and the vitamin B12 requirement is greater than 3.1 µg/lb.