Abstract Two experiments were conducted to evaluate the effect of nursery phase feeding budgets on weanling pig growth performance and economics. In Exp. 1, a total of 630 pigs (initially 6.0 ± 0.09 kg) were sorted by body weight (BW) and then randomly assigned to treatments arranged in a 3 × 3 factorial under a generalized randomized block design. Main effects included nursery phase feeding budget (high, medium, or low) and BW category (light, medium, or heavy). There were five pigs per pen and 14 pens per interaction mean (42 pens per main effect). The feed budgets for high, medium, and low programs were 1.8, 0.9, and 0 kg/pig for phase 1, and 5.4, 3.6, and 1.8 kg/pig for phase 2, respectively. After the allotted feed budgets were finished, all pigs transitioned to a common diet until day 42. Diets were formulated to provide the same amino acid concentrations but using different ingredients to reduce diet complexity between phases. Phase 1 was formulated with specialty animal protein and lactose products and contained 18.0% lactose with 16.3% soybean meal. In phase 2, specialty protein sources and the lactose level were reduced, with diets containing 7.2% lactose and 22.5% soybean meal. Phase 3 was a common corn-soybean meal-based diet with no specialty protein or lactose sources. In Exp. 1, the response of the budget program was independent of initial BW. Overall, no differences were observed between budget programs for any performance criteria. To validate these results, an experiment was conducted in a commercial research facility. A total of 1,170 pigs (initially 5.7 ± 0.32 kg) were used in a 63-d experiment with 26 pigs per pen and 15 pens per treatment. Pigs were randomly assigned to one of three budget programs in a randomized complete block design. Feed budgets were identical to those used in Exp. 1. followed by common diets until d 63. Pigs fed the high-budget program tended (P .10) to have increased daily gain and feed intake during period 2 (d 14 to 33); however, by d 63, no differences between nursery budget programs were observed for any of the response criteria. In both experiments, feed cost and feed cost per kg of gain decreased (P .001) as feed budget was reduced and simpler diets were used. Income over feed cost was maximized (P ≤ .004) with the use of the low-budget program in both experiments. In conclusion, reducing phase 1 and 2 budgets improved economic outcomes without affecting overall growth performance.
Arroyave et al. (Fri,) studied this question.