The present study was done to investigate whether dietary guar gum (GG), which is known to delay the food passage from the crop, improves the performance of growing broiler chicks given diets containing phytase. Several combinations of dietary GG and partially hydrolysed GG at 40g per kg diets and two levels of phytase (0 or 500 units per kg diets) were prepared and the experimental diets were given for two weeks. Body weight gain was significantly improved by dietary phytase, but was decreased in a dose -dependent fashion as dietary GG increased. Weight and Ca content in the tibia were not influenced by dietary phytase, whereas significantly decreased by increasing dietary GG. Ash and P concentrations in the tibia were significantly improved by phytase treatment.
The results obtained here suggested that dietary phytase was available for the performance of growing broilers. However, dietary GG was not effective for the improvement of efficacy of dietary Phytase, because dietary GG suppressed the utilization of food in the chicken.