Phytase and amino acids for broilers from 36 to 42 days of age

Abstract

The effects of the nutritional reduction of diets supplemented with phytase and amino acids provided to broilers from 36 to 42 days of age were evaluated. Five diets were evaluated in six replicates, totaling 750 and 90 birds in the assays of performance and metabolism, respectively. Control diet, without phytase, contained 18% of crude protein (CP), 0.386% of available phosphorus (aP) and 0.764% of calcium (Ca). The remaining diets (0.236% of aP and 0.464% of Ca) were supplemented with phytase and amino acids, with the CP reduced from 18 to 15%. The performance, yield and nutrient retention by the birds, besides of the energetic value (AMEn) and metabolizability of the diets were evaluated. There was no difference in the performance, yields of carcass and cuts, and in the AMEn. 16 and 15% of CP in the diet increased their metabolizability. The protein reduction improved N retention, but increased abdominal fat. Phytase increased the use of P. With the phytase and amino acids supplementation, the levels of CP, aP and Ca can be reduced to 15, 0.236 and 0.464%, respectively, without compromising on performance, yields of carcass and cuts and AMEn, besides improve the diet metabolizability and utilization of nitrogen and phosphorus.