CORRELAÇÃO ENTRE VARIÁVEIS CLIMÁTICA E TAXAS DE RECUPERAÇÃO DE OÓCITOS DE DOADORAS BOVINAS

Abstract

With the constant evolution of national cattle ranching, become necessary the development and refinement of various biotechnologies linked to animal reproduction, as main aim of achieve improvements in herd reproductive efficiency. The objective of the present study is evaluate the influence of climatic variables beneath the recovery rates of oocytes after ultrasonically guided follicular aspiration. A data collection of follicular aspirations was performed between the months of april unto december of 2020. The data was referent 84 aspirations performed in distint breeds. Climatologyc datas from National Institute of Meteorology (INMET) and IF Goiano site was collected in the dates and schedules of procedures. For the statistics analysis, descriptive analysis was used to climatic variables (temperature, humidityand temperaturehumidity index – THI), rectal temperature and recovery rates of oocytes (quantity of total oocytes, viable, non-viable, grades I, II and III), calculation of Pearson correlation and, with finality of verify the difference between the groups, the ermal Kruskal-Wallis was used at 5% of significance. The means of climatic variables was hereunder the cited by literacture as references of ermal stress (temperature IF Goiano 23,14±3,8ºC; temperature INMET 17,37± 2,87º C; THI IF Goiano 69,63±3,64 e THI INMET 64±3,83). The rectal temperature was one more variable submited within the animal termic confort zone (38,37±4,21º C). Analysing correlations between the climatic variables and recovery rates of oocytes, was found void and low correlation, as the animals was not in thermal stress situation. Therefore, not reflect influency against the quantity of recovered oocytes in procedure, except between THI IF Goiano and atresic oocytes (0,22). Weak correlation between the age of donors and quantity of grades II and III oocytes (-0,26 e -0,26) and moderate inverse correlation between age and atresic oocytes (-0,30); total (-0,35), viable (-0,32) and non-viable (-0,38). Upon months relation, was found weak correlation, nevertheless significative with the quantity of grade I oocytes (0,23) and degenerated (0,21), thus the months that has largest means for quantity of oocytes level I was november, october, december, july and august, and degenerated oocytes, november, august and may. The climatic variables did not affected the recovery rates of oocytes, except the temperature-humidity index calculated from datas obtaneid from IF Goiano site, the rectal temperature of the donors likewise not affected the technique results.