Influence of pharmacological zinc oxide, phytase and phosphorus on weaned piglet growthperformance and apparent faecal phosphorus digestibility

摘要

Implications Pharmacological ZnO reduced phosphorus digestibility and average daily gain when fed at 3500 mg/kg. Thiseffect was mitigated with supplemental phytase or excess digestible P, especially when ZnO was reduced to 1750 mg/kg.Introduction Pharmacological doses of zinc oxide (ZnO) are commonly fed to piglets to reduce post-weaning scour(Carlson et al., 1999) and in some cases improve growth performance. However, previous authors have reported areduction in average daily gain (ADG) and feed conversion ratio (FCR) as ZnO supplementation increased above 2000mg/kg (Hill et al., 2001; Walk et al., 2013). Walk et al. (2013) suggested this may be associated with a reduction inphosphorus (P) digestibility. Furthermore, phytase has been found to improve P and Zn digestibility in weanling pigs (Revyet al., 2004; Kies et al., 2006). The aim of this study was to evaluate the interaction between pharmacological ZnO, phytaseand excess dietary P on piglet growth performance and apparent faecal P digestibility.