Composite analysis of pharmacological ZnO and superdoses of phytase on piglet fecal scores from d 1 to 10 post-weaning

Abstract Text: Pharmacological zinc oxide (ZnO) may reduce the incidence of scours in newly weaned piglets. However, the level of ZnO required to reduce scours may vary depending on the piglet age at weaning and length of ZnO supplementation. Data from 4 piglet trials were combined and an analysis was conducted to evaluate the influence of pharmacological ZnO dose and superdoses of phytase (1250 to 3750FTU/kg; Quantum Blue) on fecal scores from d 1 to 10 post-weaning. The experiments were conducted between 2011 and 2013 in the US or UK according to the dietary and husbandry conditions typical for each location. In each trial, 2 fecal scores were recorded/pen/day and an average score was calculated from d 1 to 10. Scores were based on a 4 point scale (Wellock et al., 2006) with scores of 1 = firm; 2 = soft, spreads slightly; 3 = very soft, spreads readily; and 4 = watery liquid consistency. Scores are presented in 4 phases: d 1 to 3 as phase 1, d 4 to 6 as phase 2, d 7 to 10 as phase 3 and d 1 to 10 as phase 4. Data were analysed in JMP v. 10.0 and the model included phase, phytase (none or superdose), dietary ZnO supplementation (0, 1750 or 3500 ppm Zn) and the 2 and 3-way interactions. Significant means were separated using linear and quadratic contrasts. To account for differences in the husbandry and diet from each trial, research site was included in the model as a covariate. There were a total of 128 fecal scores in the composite analysis with a minimum score of 1.16, a maximum score of 2.50, and a mean score of 1.53. There was a main effect (P<0.0001) of phase on fecal scores, with the lowest scores recorded in phase 1 (1.47) and the highest scores recorded in phase 2 (1.79) compared to phase 3 or 4 (quadratic P<0.0001). There was a main effect (P<0.004) of phytase on fecal scores, whereas phytase reduced fecal scores from 1.66 to 1.56. Pigs fed ZnO at 1750 ppm had the highest scores (1.65) compared with pigs fed 3500 ppm Zn (1.56), but these were not different than fecal scores at 0 ppm Zn from ZnO (1.62). In conclusion, fecal scores were highest between d 4 and 6 post-weaning and superdoses of phytase reduced the incidence of scours in piglets.

Keywords: phytase, piglet, scours