PSII-15 Effect of Low Protein Diets Fed to Weanling Pigs on Growth Performance, Fecal Score, and Carcass Characteristics

Abstract

Abstract Two experiments were conducted to test the hypothesis that feeding low protein diets to weanling pigs reduces diarrhea with no effects on growth performance from wean to finish or on carcass characteristics. In Exp. 1, 160 pigs (BW: 6.88 ± 0.36 kg) were allotted to 5 diets with 4 pigs/pen and 8 pens/diet. Five phase 1 diets were fed from d 1 to 14 and included the positive control (PC; CP = 23%) with an antibiotic growth promoter (AGP), the negative control (NC; CP = 23%) without the AGP, the NC containing 25% rolled oats (RO), and 2 diets containing 17% CP and 0 or 25% RO. Phase 2 diets were fed from d 14 to 35 and included the PC (CP =21 %) with an AGP, the NC (CP = 21%) without the AGP, the NC containing 20% RO, and 2 diets containing 19% CP and 0 or 25% RO. The statistical model included diet as fixed effect and replicate as random effect. Results from Exp. 1 indicated that pigs fed the 17% CP diet without RO had decreased (P < 0.05) diarrhea scores compared with the NC diet containing RO. Pigs fed the 17% CP diet containing RO had reduced (P < 0.05) G:F compared with the NC diet, but there was no difference among pigs fed the other 4 diets. In Exp. 2, 160 pigs (BW: 6.29 ± 1.00 kg) were allotted to 4 diets with 5 pigs/pen and 8 pens/diet in a wean to finish experiment with 6 phases. Phase 1 and 2 diets were fed for 14 d each, phase 3 was fed for 18 d, and phase 4, 5, and 6 diets were each fed for 35 d. In Phase 1, four diets included the PC diet (CP = 23%) with an AGP, the NC diet (CP = 23%) without the AGP, and 2 diets containing 19% CP or 17% CP and no AGP. In Phase 2, four diets included the PC diet (CP = 22%) with an AGP, the NC diet (CP = 22%) without the AGP, and 2 diets containing 20% CP or 19% CP and no AGP. All pigs were fed common conventional diets from Phase 3 to market. Data were analyzed as in Exp 1. Overall results from Exp. 2 indicated that there were no differences among treatments in the growth performance and carcass characteristics of pigs from wean to finish. In conclusion, feeding low protein diets to weanling pigs reduced post-weaning diarrhea and may replace antibiotic growth promoters without affecting growth performance or carcass characteristics at the time of marketing of pigs although slight reductions in growth performance in the nursery phase may be observed.