Finding the future now – health, genomics, and calves

Abstract Text:  The rearing of replacement heifers and breeding of cattle has become much more complicated due to the increase in knowledge about the longer term impacts of calf care in the first 90 days on lifetime productivity and the ability to genomically predict genetic production potential. The health of heifers under 90 days of age has been shown to have long-term impacts on their future productivity.  This has resulted in increased  focus on prevention of calfhood illness.  However, the question of what to do with animals that have become ill is still unclear.

      The guidelines on calf nutrition have also been altered and appear to have long-term impact on the productivity of these calves as adults. There have been several studies which have shown that improved growth due to feeding biologically appropriate milk levels in the first 60 days are beneficial to the calf’s future milk production.  Ollivett and colleagues (2012) found a positive impact of increasing energy allotments to calves on the duration of clinical signs of diarrhea.  However, the mechanism of this change is still unknown. Further research is needed to determine how genetics and epigenetics interact with health status and increased nutritional planes.

Genomicsis changing the dairy industry and future implications are unknown.  One potential role of genetics is management and selection of future generations of breeding animals.  Genomics allows for improved knowledge of the animal genetics at an earlier age.  Questions on reliability of the results and the impact of other calf factors, such as health and phenotype, are still being expressed by producers and have anecdotally led to reluctance of producers to use this information.   For genomics to be fully integrated into the decision making at the farm level more research is needed on the economic concerns of testing animals genomically, the reliability of to find the best cows and the worst cows, and a decision model that includes not only genetic factors but also phenotypic factors that increase the reliability of not just future generations of animals but also those in the current herd and increased education of the strengths and weaknesses of these tools. 

Knowledge of genetics and calf health has evolved and will continue to do so. Understanding of the commercial applications and scientific principles that underline these changes and how they interact will be essential for producers and scientists in the future. 

Keywords: genomics, management, health