LAUSR

This experiment evaluated the effect of dietary protease supplementation on pig’s growth performance and post-weaning diarrhea in a 43-d trial. A total of 936 weaned pigs [21 d of age, initial BW 5.87 ± 0.31 kg] were used in a 2 × 2 factorial design (2 nutritional levels × 2 protease levels). The nutritional levels corresponded to a standard feeding program and a reduced feeding program (15% lower SID Lys) and without or with protease supplementation (0.0125% inclusion). Piglets were distributed in 36 pens with 26 pigs per pen and 9 replicates per dietary treatment. Pigs received a common Phase 1 diet and experimental diets in Phase 2, 3, and 4, (0.91, 3.4, 4.5, and 24.0 kg/pig, respectively). Phytase was included at 2,500 U in Phase 2 – 4, all diets met energy and AA:Lys requirements for nursery pigs. Feed intake and body weight were determined every 2 weeks. A pen fecal score assessment was performed at d7, 10, and 14. Performance data were analyzed using the PROC MIXED procedure and fecal score data using the PROC FREQ procedure (SAS Inst., Inc., Cary, NC). No significant interactions (P > 0.05) were observed between dietary treatments. From d15 to 43 and during overall experimental period, pigs fed standard diets had greater BW, ADG, and G:F (P < 0.05) than pigs fed deficient diets (Table 1). On d7, pigs fed deficient diet had more (X2 < 0.05) soft and watery feces, and consequently less normal feces compared to pigs fed standard diets (Figure 1). On d7, 10, and 14, pigs fed diets with protease supplementation had more (X2 < 0.05) normal feces compared to control pigs. Overall, effects of dietary protease supplementation on growth performance were not expressive under the conditions of this study but protease addition benefited intestinal health of nursery pigs.