Assessment of Biostimulation Methods based on Chemical Communication in Female Doe Reproduction

Abstract

Biostimulation is an animal management practice that helps improve reproductive parameters by modulating animal sensory systems. Chemical signals, mostly known as pheromones, have a great potential in this regard. This study was conducted to determine the influence of short-term female rabbit exposure to different conditions, mainly pheromone-mediated, on reproductive parameters of inseminated does. Groups of 60 females/each were exposed to 1) female urine, 2) male urine, 3) seminal plasma and 4) female-female interaction, just before artificial insemination, and compared to isolated females controls (female-female separated). The following reproductive parameters were analyzed for each group: receptivity (vulvar color), fertility (calving rate), prolificacy and number of born alive and dead kits ⁄ litter. Our results showed that the biostimulation methods employed in this experiment did not significantly improve any of the analyzed parameters. However, female doe exposure to urine, especially to male urine, slightly increased fertility levels when compared to the rest of the experimental conditions. Female-female interaction before artificial insemination, which is a common practice in rabbit farms, did not have any effect, which suggests its removal to avoid unnecessary animal management and time cost. On the other hand, fertility ranges were lower for animals with pale vulvar color whereas no differences were noticed among the other three colours which measure receptivity (pink, red, purple), thus suggesting that these three colours could be grouped together. Additionally, equine chorionic gonadotropin injection could be replaced with various biostimulation methods, therefore reducing or replacing current hormonal treatments, and contributing to animal welfare and to a natural image of animal production.

Biostimulation methods based on chemical communication improve semen quality in male breeder rabbits

“…Additionally, dry swabs were introduced in the vaginal region of multiparous, non-lactating and no-white vulvar colour females (females with white vulvar colour show lower receptivity levels [14]) for 15 seconds. A maximum of two swabs were taken from each female to ensure impregnation of vaginal fluid.…”

“…In this way, an increase in semen quality would have potential benefits also in female reproduction. Further studies should evaluate reproductive parameters, such as fertility and prolificacy rates (following the protocol described in [14]) of female rabbits when they are inseminated with semen of males exposed to female urine, vaginal secretion or 2phenoxyethanol. Little increases in fertility and/or prolificacy would be highly beneficial for the farm management and the competitiveness of the sector.…”

“…Biostimulation constitutes a natural animal husbandry practice targeting the optimization of reproductive parameters by modulating animal sensory systems. Specifically, chemical communication, often referred to as pheromone-mediated communication, has been postulated to exert a pivotal role in biostimulation owing to its impact on sexual behaviour and reproductive physiology [14]. Most mammals use pheromones to convey information among themselves [15], and these intraspecific cues are essential for individuals and species survival.…”