Influência do índice de temperatura e umidade no consumo de matéria seca em touros da raça Senepol

Abstract

The livestock activity of beef cattle in Brazil stands out very positively in the country's economy, however it can be influenced by the environment, making it necessary to understand the relationship between this environment and the animal's physiological processes. Given this, the Senepol breed, due to its resistance to climatic adversities and ability to adapt, attracted the interest of many producers as an option for feedlots. Thus, the objective was to evaluate the effect of the temperature and humidity index (THI) on the feeding behaviour and consumption of Senepol bulls in a tropical environment. The data used, was obtained in the Brazilian Cerrado region during summer. A total of 31 Senepol bulls, with an initial average age of 15.1 months and average body mass of 396.5 kg, were confined in paddocks with an automatic GrowSafe®️ feeding system. Dry matter intake (DMI) expressed in grams, dry matter intake in relation to body weight (DMI%BW), total number of visits to the trough (NV) and feeding time (FT) were obtained from the database. Air temperature and humidity were measured every thirty minutes and THI was calculated. The eating behaviour variables were determined by THI class. The data did not answer the assumptions of normality and homoscedasticity, and then the Kruskal-Wallis test was used with a significance of 5% and the completely randomized experimental outline (CRO). DMI and DMI%BW were not influenced by THI, but NV and FT were reduced under THI ≥ 74. It is concluded that Senepol bulls in a tropical environment, during summer, under heat, have reduced NV and FT, however DMI and DMI%BW are not influenced.