Influência do índice de Temperatura e Umidade sobre a qualidade do sêmen do reprodutor suíno.

Abstract

The quality of boar semen can be affected by many factors, such as nutrition, management and climate, so factors that alter the metabolic condition of the boar can affect the quality of the ejaculate. It is also known that heat waves in gilts and primiparous sows impair reproductive performance, but there is still a lack of information on this influence on male reproductive performance. In this way, this study sought to analyze the interference of temperature and humidity acting together as measured by the temperature and humidity index (ITU) on semen quality in boar. Meteorological and reproductive data were collected from a commercial farm located in the Triângulo Mineiro region of Minas Gerais. The temperature and humidity data were analyzed by calculating a single variable, the maximum daily temperature and humidity index (ITUmax), assessing the seminal quality parameters: sperm concentration, volume and motility within the following ITU ranges: less than or equal to 74, from 75 to 78, from 79 to 82, and greater than 82, with ITU < 74 being considered normal; 75 to 78 critical; 79 to 83 dangerous, and greater than or equal to 84 emergency. The animals were divided into six age categories: 1 (9-13 months), 2 (14- 17 months), 3 (18-21 months), 4 (22-25 months), 5 (26-29 months) and 6 (30-33 months). January to May and August to December represented the months without thermal comfort (ITU>74). In the evaluation of seminal parameters, sperm concentration and ejaculate volume showed significant differences between the treatments, so that heat-stressed animals had their semen production affected. Motility was less influenced by temperature and humidity. In a tropical environment, temperature and humidity can negatively affect the semen quality of boars, and the intensity of these effects varies according to the age of the animal.