Comparison of dried whey permeate and a carbohydrate product in diets for nursery pigs.

Three experiments were conducted to compare dried whey permeate (DWP; 80% lactose) and a carbohydrate product (CHO; 40% lactose, 30% sucrose, and 10% glucose) for nursery pigs. Pigs were fed in a 3-phase feeding program, and diets contained 1.6, 1.4, and 1.2% total Lys for phases 1 (d 0 to 7), 2 (d 7 to 21), and 3 (21 to 28). Dietary treatments included 1) control (no lactose), 2) low level of DWP, 3) high level of DWP, 4) low level of CHO, and 5) high level of CHO. In Exp. 1 (4 reps of 4 pigs per pen; initial BW = 7 kg and 23 d of age), the low and high levels used for each source in each phase were phase 1 (12.5 and 25%), phase 2 (10 and 20%), and phase 3 (6 and 12%). In Exp. 2 (6 reps of 5 pigs per pen; initial BW = 8 kg and 26 d of age) and 3 (4 reps of 4 pigs per pen; initial BW = 6 kg and 21 d of age), the inclusion levels were phase 1 (6 and 12%), phase 2 (3 and 6%), and phase 3 (common diet with no lactose). In Exp. 1, pigs fed diets with DWP or CHO had increased ADG (P = 0.02 and P = 0.01) and ADFI (P = 0.01) compared with pigs fed the control diet during phase 1. Gain:feed was reduced (P = 0.08) for pigs fed diets with CHO. During phases 2, 3, and overall, ADG, ADFI, and G:F were not affected (P > 0.10) by diet. In Exp. 2, pigs fed diets with CHO had increased ADG (P = 0.08 and P = 0.07) and ADFI (P = 0.04 and P = 0.01) compared with pigs fed the control diet during phases 1 and 2. Pigs fed diets with CHO had increased ADFI (P = 0.08 and P = 0.07) in phases 1 and 2 and increased ADG (P = 0.02) in phase 2 compared with pigs fed diets with DWP. Overall, pigs fed diets with DWP and CHO had increased ADFI (P = 0.06 and P = 0.01) compared with pigs fed the control diet, but ADG was increased (P = 0.07) for pigs fed diets with CHO. In Exp. 3, ADG, ADFI, and G:F were not affected (P > 0.10) by DWP or CHO during phase 1. Daily BW gain was increased (P = 0.02 and P = 0.07) for pigs fed diets with DWP or CHO during phase 2 compared with pigs fed the control diet. Overall, ADG was increased (P = 0.05) for pigs fed diets with DWP, but ADFI and G:F were not affected. Results from the combined data of Exp. 2 and 3, indicated that overall ADG (P = 0.05 and P = 0.04) and ADFI (P = 0.04) were increased in pigs fed diets with DWP or CHO compared with pigs fed the control diet. These data suggest that DWP or CHO improve growth performance of weanling pigs.