Location: Genetics and Animal BreedingTitle: Uterine and vaginal bacterial community diversity prior to artificial insemination between pregnant and nonpregnant postpartum cows
|AULT, TAYLOR - University Of Tennessee|
|CLEMMONS, BROOKE - University Of Tennessee|
|REESE, SYDNEY - Texas A&M University|
|DANTAS, FLEIPE - University Of Tennessee|
|FRANCO, GESSICA - Texas A&M University|
|Smith, Timothy - Tim|
|EDWARDS, J - University Of Tennessee|
|MYER, PHILLIP - Tennessee University|
|POHLER, KY - Texas A&M University|
Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/26/2019
Publication Date: 6/28/2019
Citation: Ault, T.B., Clemmons, B.A., Reese, S.T., Dantas, F.G., Franco, G.A., Smith, T.P.L., Edwards, J.L., Myer, P.R., Pohler, K.G. 2019. Uterine and vaginal bacterial community diversity prior to artificial insemination between pregnant and nonpregnant postpartum cows. Journal of Animal Science. 97(10):4298-4304. https://doi.org/10.1093/jas/skz210.
Interpretive Summary: A substantial impact of microbial populations on a variety of phenotypes has been recently recognized in biomedical research, including pregnancy-associated traits. The present study reports investigation of the diversity of microbial populations present in beef cows during a breeding cycle, starting at the postpartum end of one breeding cycle and tracking through to ovulation and artificial insemination. The diversity of microbial populations in uterine and vaginal flushes for a group of 68 beef cows were estimated based on a gene shared across bacterial species, called the 16S rRNA gene, which supports identification of genera and species present. The diversity of the microbial populations were observed to change through the course of the reproductive cycle examined. Nonpregnant cows had a very narrow range of variation in diversity, while pregnant cows had a much broader range of diversity, suggesting that there is no single microbiome that encourages fertility, but that there may be specific microbial populations associated with, and potentially causing, infertility. Characterization of the common microbiome of nonpregnant animals may allow identification of animals at risk for pregnancy failure.
Technical Abstract: The present study evaluated the bovine vaginal and uterine bacterial community diversity and its relationship to fertility. Postpartum beef cows (n = 68) were synchronized beginning on day -21 and ending with timed arti_cial insemination (TAI) on day 0.Pregnancy was diagnosed 30 d after TAI. Uterine and vaginal ushes were collected on day -21, -9, and -2 for bacterial DNA extraction to sequence the V1 to V3 hypervariable regions of the 16S rRNA gene. Results indicated a decrease in the number of bacterial species over time in the uterus of resulting pregnant and nonpregnant beef cows (P < 0.0001). Principal coordinate analyses (PCoA) depicted clustering of samples, indicating closely related bacterial communities, by day in the uterus and vagina (P < 0.0001). At day -2, uterine samples from nonpregnant and pregnant animals clustered separately (P < 0.0001), with nonpregnant animal samples clustering tightly together. Overall, the current study suggests the shift in the reproductive bacterial communities’ diversity and phylogenetic relationship leading up to the time of breeding may contribute to successful pregnancy establishment.