The dairy industry is becoming more and more interested in breeding for a healthier, longer living cow. For many years already the individual traits contributing to this have been part of the national breeding goal, but up until now this may not have been very visible.
With the April 2021 release, we will publish a separate HealthyCow index containing the following traits;
HealthyCow is a sub-index of £PLI and is intended to be used as a secondary filter. By applying a minimum criteria for HealthyCow to the bulls remaining in your list after first applying your £PLI filter, you are ensuring that these bulls have profitable daughters due to improved genetics for health instead of just production or efficiency driving these bulls to the top of the list.
The differences between relative gains from selection on either the £PLI or the HealthyCow sub-index are illustrated in the graph.
The overall correlations between £PLI and HealthyCow index is around 0.66.
To further illustrate the daughter performance of top ranking HealthyCow index bulls (Q1) vs their lower ranking counterparts (Q4), we analysed the performance of progeny in their 1st, 2nd, 3rd, 4th and 5th+ lactations for Mastitis, Lameness, Calving Interval and overall Lifespan measured in lactations.
This clearly shows that progeny from the top ranking HealthyCow index, do indeed show a higher health status throughout their longer lifetime as expected.
£PLI will remain the primary breeding goal, containing all of the important traits for farm profitability.
The availability of the stand-alone HealthyCow index however, will enable farmers to find bulls that will breed even more fertile, healthier cows that have the ability to stay in the herd for longer.