Effects of Inclusion Levels of Dietary Vitamins and Trace Minerals on Growth Performance and Nutrient Digestibility in Growing Pigs

Two feeding trials were conducted to evaluate the effects of inclusion levels of dietary vitamin and trace mineral (VTM) premixes on growth and nutrient digestibility in growing pigs. A total of 112 pigs ($24.82{\pm}3.22kg$) were employed for 49 days (exp. 1), and 168 pigs ($21.64{\pm}1.41kg$) for 40 days (exp. 2) in completely randomized block designs. Treatments were: 1) 100%, 2) 150%, 3) 200% and 4) 250% NRC (1998) requirement of VTM in exp. 1, and the ratio of vitamins to trace minerals at 1) 100:100%, 2) 100:150%, 3) 150:100% and 4) 150:150% of NRC (1998) requirement in exp. 2. Basal diets for feeding trials were formulated to contain 3,310 kcal ME/kg and 18% crude protein, and contained 0.25% chromic oxide as an indigestible marker for digestibility trials. Increasing dietary VTM premix in growing pigs had linear and quadratic effects (p<0.05) on ADG, and feed conversion ratio was also improved (p<0.05) as VTM premix was increased by 150-250% of NRC (1998) requirements in exp. 1. Adding vitamin to trace mineral premixes at 150% NRC (1998) over the control improved (p<0.05) ADG and feed efficiency in growing pigs, but performances were not improved by vitamin nor by trace mineral premixes alone (p>0.15) (exp. 2). There were no differences (p>0.05) in the digestibilities of energy, crude protein and fat among dietary treatments. However, increasing dietary VTM premix in growing pigs had a linear effect (p<0.05) on the digestibilities of calcium and phosphorus. The 200 or 250% fed group showed improved (p<0.05) calcium digestibility, and 250% fed group also showed improved (p<0.05) phosphorus digestibility as compared to 100% or 150% fed group (exp. 1). The digestibilities of Ca and P were higher (p<0.05) in 150% addition of vitamins than in 150% addition of trace minerals in the diet (exp. 2).