| Experiments were designed to evaluate the effects of vitamin and mineral supplementation (VM) in lactating sows and finishing pigs. For Exp. 1, 300 lactating sows were used to determine the effect of adding 0, 35, 70, and 105% of NRC recommendations for Cu, Fe, Mn, and Zn from inorganic or organic mineral sources. No effects were observed for sow weight loss (P = 0.16), daily feed intake (P = 0.10), litter weight gain (P = 0.08), or days to rebreeding (P = 0.13). For Exp. 2 and 3, 384 pigs were fed from 90 and 70 kg to market to determine the effects of crowding and maximum BW variation on the need for VM supplementation. No differences were observed for ADG, ADFI, gain/feed, variation in BW, or carcass measurements (P = 0.13). For Exp. 4 and 5, treatments were VM status (with vs without) and ractopamine (RAC) additions (none vs 20 ppm) applied at 70 and 90 kg to market. No interactions were observed among the VM and RAC treatments for ADG, ADFI, gain/feed, or carcass measurements (P = 0.06). Treatments with RAC increased ADG and gain/feed (P < 0.06) in both experiments. Deletion of VM premixes from 90 kg to market had no effect on growth performance (P = 0.34). However, deletion of VM premixes decreased ADG and HCW (P < 0.01) when those diets were fed from 70 kg to market. For Exp. 6, treatments from 32 to 123 kg were corn-soy based diets formulated to 70 or 130% of NRC recommendations for VM. From 96 kg to 123 kg, additional treatments of with or without VM additions and without or with RAC (5 mg/kg) were imposed. No differences were observed for the 70 and 130% treatments from 32 to 96 kg (P = 0.2). Also, from 96 to 123 kg no differences were observed for ADG or gain/feed among pigs fed the diets with or without VM premixes (P = 0.12). In conclusion, omitting vitamin and mineral premixes from diets for lactating sows and finishing pigs posed no negative effects of growth or reproductive performance. |
