Lactose, sucrose, and molasses in simple and complex diets for nursery pigs

Two experiments were conducted to determine the effects of lactose, sucrose , and molasses in simple and complex diets for nursery pigs. In Experiment 1, 210 weaned pigs (4.6 kg) were used in a 30-day growth assay. Treatments included complex diets with 100 g crystalline lactose/kg, and 50% or 100% o f the lactose replaced with sucrose or molasses. Overall, replacing lactose with sucrose or molasses did not affect weight gain, feed intake, or effic iency of feed utilization. Surprisingly, diets with molasses supported grea ter overall weight gain than diets with sucrose (P < 0.05), because of redu ced performance when lactose was totally replaced with sucrose (sucrose ver sus molasses at 50% versus 100% replacement of lactose, P < 0.01). In Exper iment 2, 180 weaned pigs (6.4 kg) were used in a 30-day growth assay. Treat ments were arranged in a 2 x 3 factorial design with diet complexity (simpl e or complex) and added sugar (none, lactose, or sucrose) as main effects. Complex diets supported greater performance (P < 0.05) during the first 10 days post-weaning compared with simple diets, but performance was equal dur ing the last part of the experiment. Apparent digestibilities of dry matter and nitrogen on day 10 were greater (P < 0.05) in pigs fed complex diets v ersus simple diets, but they were not affected by sugar additions. Furtherm ore, addition of either simple sugar improved feed utilization (P < 0.01) r egardless of diet complexity throughout the experimental period, whereas su crose tended to be as effective as lactose (P = 0.07). In conclusion, sucro se and molasses effectively replaced lactose, supporting comparable perform ance in nursery pigs. (C) 2001 Elsevier Science B.V All rights reserved.