PSA Nutrition: Phytase

Both 1,25-dihidroxyvitamin D3 and phytase are known to improve phosphorus utilization in broilers(Biehl and Baker,J Nutr 1997). Solanum glaucophyllum(Sg) is a plant containing high amounts of 1,25dihydroxyvitamin D bound to a glycoside. It may be an economical source of 1,25-dihydroxyvitamin D for animal feeds. We examined the effect of Sg, with and without phytase, on phosphorus utilization in broilers fed corn-soybean meal diets. The basal diet was 0.6% Ca, 0.45% total P(0.15% available P) with adequate vitamin D3(3000IU/kg). The six treatments included basal diet,basal with 7.5 g Sg/kg, basal with 10 g Sg/kg, basal with 1200FTU phytase/kg,basal with phytase (1200FTU/kg) and Sg (7.5g/kg), and ”normal” diet (0.7% total phosphorus, 1% calcium). Each treatment was given to six pens of 8 chicks. When compared with the basal diet, addition of 7.5 gSg/kg or phytase improved growth and bone mineralization. Increasing Sg to 10 g/kg diet did not significantly improve weight gain or bone density over the 7.5 g Sg/kg dose. Phytase and Sg supplementation increased plasma and bone Ca and P concentration similarly, however the greatest weight gain and tibiae ash was observed in the phytase (1200FTU/kg) group. Adding 7.5 g Sg to the phytase supplementation did not significantly improve P utilization over phytase alone.