Avaliação da sazonalidade climática sobre a performance reprodutiva de ovinos e caprinos criados no semiárido.

Abstract

The objective of this study was to evaluate the physiological and reproductive characteristics of sheep and goats in dry and rainy periods in the semi-arid region of Paraiba. This dissertation is composed of two chapters. The first is a study evaluating the physiological and reproductive characteristics of Dorper sheep in the dry and rainy periods of the Paraíba semi - arid region. The second is a study evaluating the physiological and reproductive characteristics of British Alpine goats in the dry and rainy periods of the semi-arid region of Paraíba. Twelve animals were used, six Dorper sheep and six British Alpine goats, aged between two and three years. All animals were submitted to a general clinical examination followed by andrological examination. The experiment was divided into two phases, the dry season (September to December) of the year 2016 and the rainy season (April to July) of the year 2017. During the experimental period, the climatological data were recorded through an HOBO type datalogger with external cable attached to the black globe. The datalogger was programmed, through its software, to record the environmental data every hour, for 24 hours, during the whole period of the experiment. The physiological variables were recorded biweekly with two daily measures: at 9h and 15h, respiratory rate (RF), real temperature (TR), body surface temperature (TS) and testicle surface temperature (TTS) were measured. Blood glucose levels were checked biweekly as well as spermogram and testicular biometry. The animals of the present study in the rainy season and in the morning shift are in an environment of thermal comfort and in the dry season and in the afternoon shift a situation of thermal discomfort. In both periods the averages are within the reference values for each species. The means of the physiological parameters in relation to the season, with higher averages in the dry season for FR, TR, Tsméd, TSmax. The sheep presented values of the scrotal perimeter (PE) within the means of the age group for the age of the species. Among the seminal parameters of the sheep, only the volume presented difference in relation to the dry and rainy season. The average of total defects in the dry season exceeded the desirable seminal patterns for the ovine species. PE values are within the mean age range for the age of the goat species. Among the seminal parameters of goats, only the swirling was below the recommended average for the goat species. The mean total defects of goats at times did not exceed the desirable standards for the species. Both Dorper sheep and British Alpine goats reared in the semi-arid region of Brazil have low levels of stress and good physiological adaptability to the climatic conditions of the region. different periods of the year (dry and rainy period), the reproductive parameters evaluated have negative influence exerted by the ambient temperature in the dry season, which interfered with the seminal parameters, presenting a higher percentage of spermatic pathologies.