Microbiota in Goat Buck Ejaculates Differs Between Breeding and Non-breeding Seasons

Abstract

Changes in semen microbiota are associated with alterations to sperm quality and fertility. However, the microbiota from most livestock species has not yet been studied. Goats are seasonal breeders, but semen microbiota has never been described in this species, and it is unknown how seasonality affects it. Our study objective is 2-fold: to describe the microbiota in goat buck ejaculates and to determine if it differs between breeding and non-breeding seasons. Semen from six males of the Murciano-Granadina breed was collected during both seasons. Two replicates were performed per male and season on different days. The microbiota was characterized by genomic sequencing technology. Sperm quality was also evaluated. Repetition was not significant for the studied variables. Sperm velocities were higher for the breeding than for the non-breeding season. The ejaculates from both seasons also differed in the proportion of apoptotic spermatozoa. The five dominant phyla were Firmicutes, Proteobacteria, Fusobacteria, Actinobacteria, and Bacteroidetes during the breeding season and Firmicutes, Proteobacteria, Actinobacteria, Bacteroidetes, and Cyanobacteria during the non-breeding season. The dominant genus during both seasons was Ureaplasma. Differences in microbial community structure (the beta diversity) were found. A decrease in the relative abundance of the genus Faecalibacterium and an increase in the genera Sphingomonas and Halomonas were observed in the ejaculates collected during the breeding season. Sphingomonas and Faecalibacterium abundance favorably and unfavorably correlated with sperm quality, respectively. In conclusion, the semen microbiota from goat bucks varies between breeding and non-breeding seasons, and the microbiota remains stable for 7 days within a season. In addition, the genera Sphingomonas and Faecalibacterium could be possible biomarkers of semen quality in goat bucks. These results contribute to an in-depth understanding of the effects of reproductive seasonality on goat buck ejaculates.

Description of the vaginal microbiota in nulliparous ewes during natural mating and pregnancy: preliminary signs of the male preputial microbiota modulation

“…One possible explanation for this rise could be the transmission from rams through mating, as one of the males showed the presence of Ureaplasma USP128 in its preputial microbiota. Furthermore, Ureaplasma was the most abundant genus identified in goat buck semen present in a sperm donor center ( Mocé et al, 2022 ) and among the ten most abundant genera in rams ( Serrano et al, 2020 ). Ureaplasma spp.…”

“…Not only sponge devices and antibiotics are factors that can affect the vaginal microbiota, but the male preputial microbiota could also have effects on the vaginal microbiota and vice-versa during mating. Preputial and semen microbiota in domestic ruminants have been described in bulls ( Wickware et al, 2020 ; Cojkic et al, 2021 ) and bucks ( Mocé et al, 2022 ). Moreover, the presence of Actinobacillus seminis and Histophilus somni , known to be related to infertility, has been observed in the preputial microbiota of service rams from a herd with low artificial insemination success ( Serrano et al, 2020 ).…”

Mammals’ sperm microbiome: current knowledge, challenges, and perspectives on metagenomics of seminal samples

“…Therefore, there is a variation in the microbiota within the seasons in goats, where the microbiota remains stable for 7 days within a season. Finally, the authors postulate that the genera Sphingomonas and Faecalibacterium could be possible biomarkers of semen quality in male goats ( Mocé et al, 2022 ).…”

Identification of bull semen microbiota and possible alternatives for antibiotics in semen extenders

“…This study is the first to perform a metagenomic analysis of the microbiota in commercial bull semen samples, assessing seasonal variations in sperm quality and its association with bacterial composition. Other studies have assessed the seminal microbiome in other species in different seasons; in a study of goat semen microbiota (Moce et al 2022), slight differences between the breeding and non-breeding seasons were observed.…”