CSRIO scientist Brad Hine’s research into beef cattle’s “immune competence” and resilience could have big impacts on the Australian industry.
Dr Hine is developing methods to assess immune competence, which he describes as the strength of an animal’s immune system and its ability to respond to a variety of pathogens that cause disease.
He said this immune competence was an important component of resilience, or an animal’s ability to deal with challenges in production systems that could include climatic conditions, animal husbandry practices and social stressors, such as when animals are introduced to one another.
Dr Hine said by understanding immune competence and its relationship with other resilience traits, the industry could improve animal health and welfare, reduce use of antibiotics and ultimately improve productivity and consumer confidence.
In a large MLA/CSIRO co-funded project aimed at developing methods to assess immune competence in beef cattle, Dr Hine worked with Angus Australia to immune competence test calves from the Angus Sire Benchmarking Program on co-operator herd farms, in cohorts two and three.
He said this helped ensure his research was industry relevant, and there was already extensive phenotypic, hereditary and genomic information about the animals.
From four cooperating commercial herds and some Angus Performance Recorded cattle at a CSIRO facility at Armidale NSW, they immune competence tested 1149 cattle at weaning, of which 859 were followed through to the feedlot.
Dr Hine found cell and antibody mediated immune responses were moderately heritable, which was supported by similar findings in dairy cattle in previous research.
He said people knew that focusing on production traits could see immune competence lowered – such as the incidence of mastitis generally increasing with milk production in dairy cows.
So, Dr Hine researched whether there was a production cost of animals having enhanced immune systems, particularly in feedlots.
“The benefits of selecting for immune competence far outweigh the costs to productivity,” Dr Hine said.
This is because although these animals might use more nutrients in immune responses, and not production, they were more likely to live and had lower disease treatment costs.
He also found a very strong correlation with fat cover; that is animals with more fat had better immune responses.
Angus Australia has contracted Dr Hine and team to do immune competence studies for cohort six animals. They’ve also submitted a proposal to the MLA National Livestock Genetics Consortium to do the next phase of this work, which he describes as validating these findings in higher risk environment.
He said dairy was “a long way ahead” in this field of research, for example Semex is selling immunity response tested bulls – which showed some of the possibilities for the beef industry including having EBVs or genomic tests for immune competence or resilience.