Location: Genetics and Animal BreedingTitle: Bacterial taxonomic composition of the postpartum cow uterus and vagina prior to artificial insemination
|AULT, TAYLOR - University Of Tennessee|
|CLEMMONS, BROOKE - University Of Tennessee|
|REESE, SYDNEY - University Of Tennessee|
|DANTAS, FLEIPE - University Of Tennessee|
|FRANCO, GESSICA - Texas A&M University|
|Smith, Timothy - Tim|
|EDWARDS, J - University Of Tennessee|
|MYER, PHILLIP - University Of Tennessee|
|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. Bacterial taxonomic composition of the postpartum cow uterus and vagina prior to artificial insemination. Journal of Animal Science. 97(10):4305-4313. https://doi.org/10.1093/jas/skz212.
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 species composition 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 species composition 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 composition of the microbial populations were observed to change through the course of the reproductive cycle examined, with some species becoming more numerous through the cycle and others less numerous, and the relative abundance of bacterial species were documented. Some bacteria were found to be lower in abundance specifically in pregnant cows, consistent with the hypothesis that microbiome composition could affect fertility.
Technical Abstract: The current study characterized the taxonomic composition of the uterine and vaginal bacterial communities during estrous synchronization up to timed artificial insemination (TAI). Postpartum beef cows (n = 68) were subjected to presynchronization step 21 d prior to TAI (day -21), followed by an industry standard 7 Day Co-Synch on day -9 and TAI on day 0. Uterine and vaginal flushes were collected on days -21, -9, and -2 of the protocol and pH was immediately recorded. Pregnancy was determined by transrectal ultrasound on day 30. Bacterial DNA was extracted and sequenced targeting the V1 to V3 hypervariable regions of the 16S rRNA bacterial gene. Results indicated 34 different phyla including 792 different genera present between the uterus and vagina. Many differences in the relative abundance of bacterial phyla and genera occurred between resulting pregnancy statuses and among protocol days (P < 0.05). At day -2, multiple genera were present in >1% abundance of nonpregnant cows but <1% abundance in pregnant cows (P < 0.05). Uterine pH increased in nonpregnant cows but decreased in pregnant cows (P > 0.05). Overall, our study indicates bacterial phyla and genera abundances shift over time and may potentially affect fertility by altering the reproductive tract environment.