Effects of Microbial Phytase on Apparent Digestibility of Amino Acids and Crude Protein by Female Broiler Chickens

An experiment was carried out to evaluate the effects of microbial phytase on apparent digestibility of Amino Acids (AA) and crude protein in female broiler chickens. The 240 day-old female broiler chicks were wing banded, weighted and randomly allocated to six treatment groups with 4 replicates of 10 chicks in each battery cages appropriate for completely randomized design. The treatments included supplementation of 6 dietary levels of phytase (0, 250, 500, 750, 1,000 and 1,250 FTU kg(-1)) during 0-28 days of age. All chicks were fed a nutritionally adequate typical commercial broiler starter and grower ration (adequate in phosphorus and calcium). During days 21 to 24 excreta totally were collected for AA and CP analyzing. 250 and 500 FTU kg(-1) phytase significantly improved digestibility of amino acids (except than alanine, valine and threonine) and CP (p<0.05). Phytase had no significant effect on live body weight, feed intake and feed efficiency (p>0.05) of the broiler chicks up to 28 days of age.