Bioclimatic interference in fertility in cows in the Amazon biome

The objective was to evaluate the correlation between environmental temperature-humidity index (THI), rectal temperature (RT), plasma cortisol concentration and pregnancy rate in embryo recipient cows Amazon biome. Embryo recipients (n=235) underwent estrus synchronization via simplification of P36 protocol for Fixed-Time Transfer (TETF). On days zero (D0), eight (D8) day 16 (D16), measured, as well ambient relative humidity. 16th after start each received an transferred being diagnosed with a corpus luteum (CL) one ovaries by ultrasonography (US) and, from them, blood sample collected venipuncture coccygeal vein, tubes ethylenediaminetetraacetic acid (EDTA) anticoagulant obtain plasma, where measured radioimmunoassay (RIA) solid phase, using commercial kits. It found that group pregnant cows, mean values parameters RT, THI (P < 0.05) were lower than those presented non-pregnant cows. Moreover, two groups there positive significant correlations RT 0.05), relation 0.05). is concluded it possible validate use auxiliary tool estimating concentrations.