Effects of vitamin supplementation on growth performance and carcass characteristics in pigs

Three experiments involving a total of 405 crossbred pigs were performed to evaluate the effects of increasing vitamin supplementation on growth performance and carcass characteristics. A common vitamin premix (VP) that provided adequate amounts of vitamins (4 fat-soluble and 7 B vitamins), was added at varied levels in Exp. 1 and 2. Experiment 1 used 125 weanling pigs with initial body weight (BW) of 7.5 ± 0.2 kg. Dietary treatments were basal diet with 0.00%, 0.05%, 0.10%, 0.25%, and 0.50% added VP. The experimental diets were fed for 28 d in a single phase. The results demonstrated that average daily gain (ADG) and average daily feed intake (ADFI) linearly increased (P < 0.005) with increasing VP levels during d 14–21, d 21–28, and the overall 28-d period. Experiment 2 used 100 crossbred pigs with initial BW of 49.4 ± 1.0 kg. Dietary treatments were basal diet with 0.05%, 0.10%, and 0.15% added VP. The experimental diets were fed for 67 d in a single phase. The results showed that the increasing VP levels did not affect growth performance or carcass characteristics of grower to finisher pigs. Experiment 3 was designed to evaluate the effects of increasing dietary supplementation of 5 B vitamins (niacin, riboflavin, folacin, pantothenic acid, and vitamin B₁₂) on growth performance and carcass characteristics of nursery-finisher pigs. A total of 180 weanling pigs were provided a common diet without supplementation of the test B vitamins until they reached an average BW of 10 kg. Then, 155 pigs were selected for allotment. The experimental diets were fed in 3 phases corresponding to 10–20 kg, 20–50 kg, and 50–105 kg of BW, respectively; the 5 B vitamins were provided to be equivalent to 70%, 170%, 270%, 470%, and 870% of the NRC (1988) requirement estimates on a bioavailable basis for each BW phase. The results demonstrated that overall ADG and gain to feed ratio (G:F) increased quadratically (P < 0.05), while overall ADFI tended to increase linearly (P = 0.10) as dietary B vitamins increased. The loin depth, loin eye area, and lean gain improved with increasing B vitamin levels (quadratic, P < 0.05). In summary, increasing supplementation of VP beyond NRC (1988) requirement estimates improved ADG and ADFI of nursery pigs while supplementing a subset of 5 B vitamins improved growth performance and carcass characteristics of grower to finisher pigs.