Seasonal and circadian variation of the sexual behavior of Morada Nova rams in tropical environment

Abstract

-The objective of this study was to evaluate the seasonal and daily variation in sexual behavior of Morada Nova breeders raised in the Brazilian semi-arid region. The data were collected from four rams and 114 ewes of the Morada Nova breed -55 females in the dry season and another 59 in the rainy season. Observations were performed in the dry and rainy seasons, divided into four times of the day: morning (05:01 h to 11.00 h), afternoon (11.01 h to 17.00 h), evening (17.01 h to 23:00 h), and dawn (23:01 h to 05.00 h). Sexual behavior was assessed for a period of 24 h/day, in a breeding season. One ram was used each three days. The behavioral patterns of the rams in view of females were observed during the recognition (sniffing the female urine, bouts of anogenital sniffing, and flehmen reaction), preparatory (exposure of tongue and penis, leg-kicking, and low-pitched bleats), and copulatory (number of mounts, number of ejaculations, and refractory period) phases. The rams were more active during daytime. The animals in the rainy season showed more efficient sexual behaviors by the lower frequency of mounts per ejaculation and greater number of ejaculations in a shorter time. In contrast, courting behaviors such as exposure of tongue, number of mounts, low-pitched bleats, and leg-kicking were more frequent in the dry season. In the semi-arid region with latitudes close to 7°N, Morada Nova rams have a higher intensity of precopulatory behaviors and lower frequency of ejaculations in the dry season.

Sexual behavior of 'morada nova' breeding sheep under semi-intensive rearing during the mating season in the brazilian semiarid

“…According to Santos et al (2015), the sexual behavior rams is divided into three distinct phases: recognition, preparation, and copulation. The same authors studied 'Morada Nova' male sheep behavior and classified into sniffing the perineal region, courting, and horning as recognition.…”

“…The clustering of animals during the afternoon shifts facilitated the sexual stimulation of males as a function of the gathering of females and secretion of pheromones (VITALIANO et al, 2012). When assessing the sexual behavior of 'Morada Nova' sheep, Santos et al (2015) elucidated that during reproduction in the rainy season, males express more eminently investigative sex behaviors, manifested at similar frequencies among shifts.…”

“…Sheep belonging to the 'Morada Nova' breed are small and highly adaptable to the semi-arid conditions of the northeastern Brazil (SANTOS et al, 2015). Hence, knowing the behavior of these animals allows the adaptation of proper herd management practices to increase productive and reproductive indexes.…”

“…Heat stress has several unfavorable aspects of animal production such as physiological changes (BATISTA et al, 2014), estrus duration, estradiol and progesterone plasma concentrations (SEJIAN et al, 2012), plasma testosterone alterations (MAURYA et al, 2016), feed intake and milk production reductions (NASCIMENTO et al, 2014), besides behavioral changes (SILVA et al, 2016;SANTOS et al, 2015). Therefore, the evaluation of reproductive behavior in the face of adversities can be used as a crucial parameter for selection of sires and dams.…”

“…In this way, sexual behaviors can be influenced by several factors such as breed, age, breeding seasonality (ROSA et al, 2000), seasonal variation (SANTOS et al, 2015), previous sexual experience, hormonal and social factors (STELLFLUG;LEWIS, 2007), sanity, management and others SILVA, 2007).…”