Influência da sazonalidade climática amazônica sobre parâmetros termorregulatórios, comportamentais a pasto e características seminais de ovinos Santa Inês.

Abstract

The aim of this study was to evaluate the seasonality influence of thermoregulatory parameters, behavior grazing and seminal characteristics of Santa Inês ovine created in Brazil Northern. Nine Santa Inês male sheep, black coat colored with an average weight range of 32.5 ± 3.5 kg and an average of one year of age was selected. At the experimental period the animals have not received natural or artificial shadows inside the paddocks in order to be directly exposed to the weather conditions of the region. The experimental design was completely randomized (CRD) with two treatments (rainy and dry season), nine repetitions with an animal in each experimental unit. The first period was from March to April 2015 (rainy season) and the second from August to September 2015 (dry season). Climate variations as temperature, relative humidity, wind speed, dew-point temperature, rainfall and black globe temperature were recorded. The data of thermoregulatory parameters such as respiratory rate (RR), heart rate (HR), rectal temperature (RT), skin temperature (ST) and sweat rate (SR) were recorded. The behavioral parameters observed were feed intake (FI), standing idle (SDI), lying idle (LI) and ruminating (R). In addition, the water volume consumed by the animals was recorded in both periods. Seminal characteristics analyzed in terms of physical aspects were volume, aspect, turbulence, motility, vigor, concentration and live sperm percentage and about the morphological aspects of semen were major and minor defects. Semen was collected using standard technique of artificial vagina and and analyzes were performed in the CPCOP Semen Technology Laboratory (UFRA). Data were subjected to normality test and Analysis of Variance (ANOVA) and, when they were significant, compared using Student's Tukey at the level of 5% probability. Correlations of submitted data with the treatments were analyzed using the Pearson correlation. All statistical procedures were performed using the SAS statistical package (2001). The results indicated that the thermoregulatory parameters were influenced by the rainy and dry seasons and that average values were higher in the dry season in almost all parameters, except RT. Moreover, 11am and 2pm had the highest average in the dry season, excepted by RR and RT that were higher during the rainy season at 11am. The behavior of animals was not significantly different for the periods however there was influence between the hours, because the animals have consumed more feed at 8 and 11 am (morning shift), had presented idleness at 2pm, and ruminated more at 11am. The animals consumed more water during the dry season, in the afternoon. In relation to the semen characteristics, the physical aspects were not statistically different. On the other hand, the morphological aspects were affected by period, showing higher values in the rainy season. We can conclude that the Amazon seasonality affect the studied parameters, however animals can use the thermoregulatory mechanisms adjusting their behavior to the Amazon climate adversity.