Abstract
In wean-to-finish systems, nursery diets are commonly blended with leftover finishing feed from the previous group. A total of 1,260 pigs (initially 10.6 kg) were used in a 28-d study to determine the effects of feeding increasing amounts of finishing feed to nursery pig on growth performance and economics. At weaning, pigs were placed into pens (21 pigs/pen) and fed commercial nursery diets in a 5-phase program with phases 1 and 2 fed before the start of the experiment. Phase changes were based on feed budgets of 2.5, 3.7, 3.7, 9.5, and 9.5 kg/pig in phases 1 to 5, respectively. At the beginning of phase 3, pens of pigs were blocked by weight and room and allotted randomly to 1 of 4 treatments (15 replications/treatment). Treatments consisted of a dose-titration of blending increasing amounts (0, 1.25, 2.50, and 3.75 kg/pig) of a late finisher feed (0.74% SID Lys) into phase 3 nursery diet. Data were analyzed using the GLIMMIX procedure of SAS with the fixed effect of dietary treatment and random effects of weight block and room. Contrasts were used to determine the linear and quadratic effects of increasing finisher feed amount. Overall, increasing the amount of late finisher feed blended into the phase 3 nursery diet decreased ADG (linear, P = 0.050) and tended to decrease (linear, P < 0.07) ADFI and final BW, but did not affect G:F (Table 1). Feed cost, gain value, and feed cost/kg gain decreased (linear, P < 0.05) as finishing feed budget increased from 0 to 3.75 kg/pig. However, income-over-feed-cost was not different among treatments. In conclusion, feeding increasing amounts of late finisher feed to 11-kg nursery pigs decreased overall ADG and ADFI, but did not affect income-over-feed-cost.