Dunmire, K M, Wickersham, T A, Frenzel, L L, Sprayberry, S R, Joiner, L C, Hernandez, L P, Cassens, A M, Dominguez, B, and Paulk, C B
Two experiments evaluated the effects of liquid lactose (SweetLac63) and molasses in swine diets on pellet quality and pig performance. A total of 194 nursery pigs (DNA 241 × 600, initially 6.7 kg) from 2 groups were used in a 33-d experiment. Pigs were weaned at 27 d and randomly assigned to pens balanced by BW, sex, and within group with 4 to 7 pigs per pen. A total of 32 pens were used to provide 8 pens per treatment. Pens were allotted to 1 of 4 dietary treatments consisting of a control diet containing 19.1% total sugars from whey powder and permeate and experimental diets with a percentage of whey permeate replaced by either 5 (5LL) or 10% liquid lactose (10LL) or 9.4% cane molasses (9.4M). All diets were balanced for SID Lys and total sugars and fed in pelleted form. Treatments were fed from d 0 to 21, and a common pelleted diet fed from d 21 to 33. Hot pellet temperature and production rate decreased (P<0.05) from the control to 9.4M with 5LL and 10LL having intermediate effects. Pellet durability index (PDI) increased (P<0.05) from control to 5LL, 10LL and 9.4M, respectively. From d 0 to 21, there were no treatment effects on ADG or G:F. In pigs fed the control diet, ADFI decreased (P<0.05) compared to those fed 10LL with 5LL and 9.4M being intermediate. From d 0 to 33, ADFI increased (P<0.05) in pigs fed 10LL compared those fed other diets. There were no treatment effects on ADG or G:F. For Experiment 2, a total of 289 finishing pigs (initially 53.5 kg) from 3 groups were used in a 53-d experiment. Pens were randomly assigned to 1 of 4 dietary treatments within location block and group. There were 6 pens per treatment with 8 to 14 pigs per pen, with number of pigs and gender balanced across treatment. Dietary treatments were a control pelleted diet with 0, 2.5, 5, and 7.5% liquid lactose. Pellet durability index improved (linear, P<0.01) with increased levels of liquid lactose. There were no differences in ADG, ADFI, final BW or carcass characteristics. Pigs fed diets with increasing liquid lactose had marginally significant increased (quadratic, P=0.070) G:F. Overall, liquid lactose and molasses improved PDI, without negatively influencing growth performance in nursery pigs and marginally improving G:F in finishing pigs. [ABSTRACT FROM AUTHOR]