This study evaluated the effects of increasing phytase levels on serum biochemical parameters and renal and hepatic changes in Japanese quails (Coturnix japonica) under different temperature conditions. A total of 720 quails were distributed in a 5 × 3 factorial design with five phytase levels (0, 500, 1000, 1500, and 3000 FTU/kg) and three temperature ranges (24, 30, and 36 °C), totaling 15 treatments with six replicates of eight birds each. Data were collected in cycles 2 and 4. The parameters measured included eggshell thickness (ST), total egg production (TEP), liver weight (LW), gamma-glutamyl transferase (GGT), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (FA), phosphorus (P), calcium (Ca), urea (URE), creatine kinase (CK), and uric acid (UA). PRO was higher at 30 °C compared to 24 °C and 36 °C. EC showed a significant interaction between phytase levels and temperature, with phytase improving EC, especially at 1500 FTU and 36 °C. PF was not affected in the second cycle but had a quadratic effect in the fourth cycle. Phytase supplementation improved shell thickness and regulated biochemical parameters, especially at high temperatures. Based on these results, a phytase level of 1500 FTU/kg is recommended to optimize performance and mitigate the negative effects of high temperatures on quail health.
Maia et al. (Mon,) studied this question.