Effects of Feeding Increased Levels of Vitamin B12 to Weanling Pigs

Increasing concentrations of vitamin B 12 were fed to 144 weanling pigs (weaned 13-14 days) in two, five-week trials.­ Pigs were fed one of six diets: NC, negative control, basal diet without supplemented vitamin B 12 ; or the basal diet with the inclusion of 100% (1X, 7.­94 μg/lb), 200% (2X, 15.­87 μg/lb), 400% (4X, 1.­75 μg/lb), 800% (8X, 6.­49 μg/lb), or 1,600% (16X, 126.­98 μg/lb) of NRC requirements for the 11-to 22-lb pig.­ Each trial was divided into two phases: phase 1, day 0-day 14 and phase 2, day 14-day 5.­ Throughout phase 1, there were no differences among treatments, although ADG (average daily gain) and ADFI (average daily feed intake) increased linearly (P< 0.­1).­ During phase 2, the inclusion of B 12 resulted in a linear increase (P< 0.­05) in ADG with pigs receiving the 16X treatment (126.­98 μg/lb) having the greatest gains (ADG = 1.­24 lb) in contrast with pigs receiving the control diet (ADG = 1.­08 lb).­ Average daily feed intake increased linearly (P< 0.­05) with pigs receiving the control diet consuming less (P< 0.­1) than the 2X, 4X, 8X, and 16X treatments during phase 2.­ Overall (phase 1 and phase 2), ADG increased (P< 0.­01) as much as 0.­1 lb (16X treatment, 126.­98 μg/lb) over the negative control with the inclusion of vitamin B 12 .­ Increased concentrations of B 12 resulted in a linear increase (P< 0.­05) in ADG and ADFI overall.­ This study suggests that feeding levels of vitamin B 12 above the NRC recommendation may improve weight gain and feed intakes of weanling pigs.­