Abstract
This study was carried out to evaluate the effect of heat stress and/or multi-enzyme supplementation on the productivity and physiological parameters of laying Japanese quail from 5 to 11 weeks of age. A total of 132 Japanese quail pullets were distributed in a completely - randomized design in the 2 x 2 factorial design, with two ambient temperatures (thermoneutral - TN and heat stress - HS) and two enzyme inclusion levels (0 and 0.01), totaling four treatments with 11 replicates. Productive performance, carcass traits, hemogram and blood biochemical profile were evaluated. The effect of the ambient temperature x enzyme interaction was significant for weight gain, feed conversion rate (P<0.04), red blood cell count and mean corpuscle value. I feat stress reduced (P<0.05) the laying rate and egg mass, the relative weight of feathers, the mean corpuscular hemoglobin and blood glucose level, while it increased (P<0.03) the time to lay the first egg and to reach 25% of egg production. Enzyme supplementation improved (P<0.01) the laying rate, egg mass and blood glucose levels, but reduced (N0.02) packed cell volume, mean corpuscular hemoglobin concentration and blood levels of alanine aminotransferase. Enzyme supplementation improved only the productive performance and blood parameters of quails reared in TN conditions, whereas heat stress impaired productive performance of the birds.