P.PSH.0799 - P.PSH.0799 - Improving Fertility in Northern cattle through host and pathogen molecular diagnosis

Summary

Reproductive performance of the northern beef herd has been described as below expectation. By exploring the genome of the microbiome in the bull’s prepuce and the cow’s vagina, this project will aim to identify factors, which make cows more susceptible/resistance to infectious agents, and genetic markers, which could be used to select for resistance.

Objectives

The objectives of the project are as follows:
a. Sample at least 1,000 cattle (heifers, cows and bulls) from healthy and diseased northern beef herds for genotyping and microbiome analysis.
b. Define the microbiomes of the reproductive tracts in healthy and diseased cattle.
c. Investigate the host genomics associated with reproductive disease susceptibility/resistance.
d. Develop a validated specific molecular diagnostic test for BGC.
e. Determine whether the genital microbiome is associated with increased susceptibility to BGC.
f. Determine whether BGC immune biomarkers (post infection or vaccination) can be identified for assay development.
g. Pilot the development of genomic markers that can be used in breeding programs to select for resistant genotypes.

Key findings

Through undertaking vaccination challenge trials in heifers and bulls, and through sampling field herds, this project has developed a ‘tool kit’ for managing BGC. The trials demonstrated that C. fetus venerealis can be detected in vaccinated and unvaccinated animals and that qPCR positivity is transient.

Benefits to industry

This project will define the microbiomes of the reproductive tracts in healthy and diseased tropical cattle and also investigate the host genetics associated with reproductive disease susceptibility/resistance (within the same cattle). This will lead to the development of specific diagnostic tests for Bovine Genital Campylobacteriosis (BGC), determine whether the microbiome is associated with increased susceptibility to BGC and by understanding genetic variations between cattle will also pilot the development of genetic markers that can be used in breeding programs to select for resistant genotypes.

Serum biomarkers were identified which can confirm BGC infection and/or vaccination status. If an entity could be identified to deliver the genomic sequencing screening as a service, the tools developed here will ultimately enable red meat producers to manage vibriosis/BGC and other reproductive diseases.

MLA action

The final report will be published on the MLA R&D website.

Future research

For immediate adoption, the qPCR assay could be used however biomarker ELISA assays require further evaluations. For the long term, a service provider who can apply novel long read sequencing diagnostic data would be ideal for the industry.