Utilização de protease em dietas de codornas de corte

Abstract

The objective of this study was to evaluate the effects of supplementation of protease at different protein levels on the performance characteristics, carcass yield and chemical composition of meat of quails at 42 days of age. The experimental design was completely randomized with five treatments and eight replicates with 12 birds each. The birds were subjected to the following treatments: T1 - basal ration (22% CP); T2 - ration containing 20% CP + Protease; T3 - ration containing 20% CP; T4 - ration containing 18% CP + Protease; T5 - ration containing 18% CP, all treatments, keeping the amino acid profile. The performance variables evaluated were: weight gain (g / bird), feed intake (g / bird) and feed conversion. For carcass yield were evaluated: slaughter weight (g) and relative (%) of carcass, prime cuts (chest and legs) and edible offal (heart, liver and gizzard). Variables analyzed for chemical composition of the carcass were: dry matter (DM), mineral matter (MM), ether extract (EE) and crude protein (CP). The results for the period of one to 42 days to show that feed intake was no positive effect (P <0.05) protease on the level of 20% CP, and the treatment that showed a better feed intake. For weight gain and feed conversion treatments with 22% (T1) and 20% protein (T3). The results observed for carcass yield, cuts and edible offal of quail slaughtered at 14 days of age showed a significant difference (P <0.05) in the absolute weight of birds after fasting, housing, chest, legs and back of quails in the treatments with lower protein content showed lower results, regardless of the presence or absence of protease. The results observed at 28 days of age indicate a significant difference only for the parameters of absolute weight after fasting and chest of birds, and the treatment of lowest result was 18% CP without supplementation of protease (T5). The results observed for carcass yield, cut and edible offal of quails at 42 days of age indicate no significant differences (P> 0,05) among diets. There was no (P> 0,05) differences on the DM content in the meat of quail, among the treatments. About the content of MM and only basal diet with 20% CP + protease (T2) differ, and the higher T2. For the results of the PB and EE treatments with 24% and 18% CP differed and were superior to the 20% CP supplemented with protease. According to the results of the protease was not efficient in quail diets based on corn and soybean meal, however it was possible to reduce the crude protein level of 20% while keeping the profile of the main amino acids.