Comparison of yellow dent and NutriDense corn hybrids in swine diets

Two experiments were conducted to verify the feeding value of NutriDense (ND) and Nutri-Dense Low-Phytate (NDLP) corn (Exseed Genetics LLC, BASF Plant Science, Research Triangle Park, NC) relative to that of yellow dent (YD) corn in swine diets. NutriDense corn is a high-protein, high-oil variety, and NDLP is a high-protein, high-oil, low-phytate variety. In Exp. 1, 315 nursery pigs that initially weighed 15.2 kg were used in a 21-d growth assay. Dietary treatments were arranged in a 3 x 3 factorial; main effects were corn source (YD, ND, and NDLP) and added fat (0, 3, or 6%, as-fed basis). Diets were formulated to contain 3.83 g of lysine/Mcal using calculated nutrient values. There were no corn source x fat interactions observed. Pigs fed YD, ND, and NDLP had ADG of 750, 734, and 738 g/d and G:F of 0.64, 0.66, and 0.65, respectively. No differences (P > 0.10) in ADG were observed among the three corn sources; however, pigs fed diets containing either ND or NDLP corn had decreased ADFI (P < 0.02) and improved G:F (P < 0.05) compared with pigs fed diets containing YD corn. Increasing dietary fat increased ADG (727, 746, and 748 g/d; linear, P < 0.04) and G:F (0.62, 0.66, and 0.68; linear, P < 0.01) and decreased ADFI (linear, P < 0.01). Using the NRC (1998) value for ME in YD corn, we calculated the energy value for ND and NDLP based on G:F differences compared with pigs fed YD corn. These data indicated the ME values for ND and NDLP corn are 4.5 and 2.5% greater (3,575 and 3,505 Kcal/ kg), respectively, than for YD corn (3,420 Kcal/kg). In Exp. 2, 1,144 gilts (initial BW = 50.1 kg) were used in a commercial research facility to evaluate the effects of corn source (ND and YD) and added fat (0, 3, or 6%, as-fed basis) in a 2 x 3 factorial on pig performance and carcass traits. There was a corn source x fat interaction for ADFI and G:F. Increasing added fat resulted in greater changes in ADFI and G:F in pigs fed YD corn diets compared with those fed ND corn. Feeding ND corn increased ADG (main effect, P < 0.04), and greater percentages of added fat increased ADG (main effect; linear, P < 0.01). Results of Exp. 2 suggest that ND corn has 5.3% more ME than YD corn. The additional energy provided by ND corn improves G:F in both nursery and grow-finish pigs, and ND corn offers a means of formulating diets more concentrated in energy than YD corn.