Published online by Cambridge University Press: 20 November 2017
Recommended P concentrations in pig diets have been reduced recently (NRC, 1998) but few studies have evaluated these throughout both the growing and finishing stages (Harper et al., 1997). These new recommended P concentrations were based on feed intakes of 1.8 and 2.8 kg/d for growers and finishers respectively which are much higher than the feed intakes of 1.4 and 2.1 kg/d currently achieved in normal UK commercial practice. This suggests that dietary P concentrations should be increased from NRC (1998) estimates to approximately 6 g/kg to ensure adequate growth performance and structural soundness of UK pigs. Phytase enzyme has also been shown to improve the bioavailability of dietary P (Harper et al., 1997). This experiment was designed to examine the effects of grower/finisher diet P concentration and presence of phytase on growth performance and finisher bone thickness and strength.