Abstract:
Microorganisms live in complex communities across various body sites in all animals. Advances in sequencing technology have allowed these communities to be fully characterised. Sequencing based studies have shown these communities to be more diverse than previously thought. This is because many bacteria are not easily cultured in laboratory conditions. The microbiomes of different body sites have been associated with a variety of inflammatory conditions. In some cases, transfer of microbes from healthy subjects into affected subjects can improve, cure, or prevent certain conditions. Dairy cows in New Zealand are susceptible to post-calving inflammatory conditions such as endometritis and mastitis. These conditions are costly to the farmer and the dairy industry as a whole. Treatment often involves antibiotics which are causing increasing concerns over antibiotic resistance. Illumina MiSeq paired-end sequencing was used to characterise the microbiomes of the uterus and milk of New Zealand dairy cows. The microbial communities at both sites were identified as being diverse. Differences in the composition of samples between day 14 and day 35 post-calving, in cows experiencing high or low inflammation, and cows that got pregnant within 6 weeks compared with those that did not, were identified in the microbiome of the uterus. Additionally, differences in diversity between milk samples on different days post-calving, and in cows identified to be Streptococcus uberis positive or negative, were identified. This study provides compelling evidence that the microbiome is associated with health and fertility and raises the possibility that modifying the microbiome at these sites may be a viable prevention or treatment option for improving the health and fertility of the New Zealand dairy cow.
