Using Automated Activity Monitors Modify Reproductive Programs

摘要

The actual display of estrous behaviour and the intensity of it seem to have a profound effect on fertility (Madureira et al., 2015, Burnett et al., 2017; Silper et al., 2017; Madureira et al., 2018). Most of the data available in dairy cows on the effect of proestrus and estradiol pertains to the manipulation of the timing of luteolysis and ovulation induction, therefore modifying the proestrus. Studies that modified follicular dominance length (Cerri et al., 2009), concentrations of progesterone during diestrus (Cerri et al., 2011; Bisinotto et al., 2015), proestrus length and estradiol exposure (Mussard et al., 2003; Bridges et al., 2005) and production parameters (e.g., lactation and age; Sartori et al., 2002) have described these effects on fertilization, embryo quality and uterine environment, and reduction in pregnancy losses during the late embryonic development (Ribeiro et al., 2012). However, in spite of marked effects related with the aforementioned modifications of the estrous cycle, not much emphasis was previously placed on the sole or additive effect of expression of estrus on reproductive tissues. The effect of estrus on fertility will be extensively discussed in this manuscript, but it is clear that estrus has an important positive impact on fertility. Moreover, this effect also seems to be associated with the intensity of estrus, which collectively leads us to questions regarding the physiological mechanisms associated with this improvement in fertility.