Breeding boasts the advantage of being a proven technology that has clearly been demonstrated over decades to be able to deliver changes in performance.
The benefits from breeding cumulate over time and can be permanent. While an advantage, this can also be a disadvantage in that a lapse in concentration or interest in breeding leading to the wrong choice of bulls for any given year can cause repercussions which could take years to purge out of a herd. In this article, Donagh Berry, Director of VistaMilk SFI Research Centre, detailed more on breeding policies and future improvements to the Economic Breeding Index (EBI), which he discussed during Teagasc Breeding Week (video below).
Because cows have to produce a calf to milk, the technology of breeding has a 100% adoption rate. Additionally, it requires no change in farm management as the cow has to establish pregnancy, so it is as easy to use a good bull as use a bad bull. As the cost differential between a good bull and bad bull is often very low, good breeding practices do not incur an additional cost. Moreover, the benefits of breeding are complementary with non-breeding techniques, with the benefits of both stacking to further accelerate the rate of change in performance.
The Irish national breeding index, the Economic Breeding Index (EBI), is comprised of eight sub-indexes related to: milk production; fertility and survival; calving performance; beef performance; carbon output; cow maintenance (i.e., size); health; and management. The impact of each sub-index on profit is simply summed together to generate a single expected profit figure per animal – this figure is the EBI. Each sub-index has a series of underpinning traits, each weighted by their calculated effect on farm profit. While EBI is the unit of currency of individual bulls and cows, it is advised to also examine the sub-indexes of the candidate parents of the next generation and choose those most suited to the farming system where they will be used. Given that breeding contributes half the gains in performance observed across the world, irrespective of species, it is crucial that effort and time is put into properly selecting the best sires and dams for future generations.
Improvements in the EBI will come through changes in the trait definition or how the genetic evaluations are undertaken (i.e., data quality control and statistical modelling), but also the suite of traits included in the index. For a trait to be included in an index it must 1) be important, 2) exhibit genetic variation, and 3) be measureable on individual animals or correlated with a trait that is measurable.
Traits poorly represented in the EBI include: 1) more granular measures of product quality which are important given our reliance on the export market and the intensifying interest and demand of consumers for safe, nutritious, healthy and tasty products; 2) efficiency of production representing both feed and environmental efficiencies; and 3) animal health and disease. The latter is particularly important with the improving reproductive performance of the national herd contributing to an aging cow population. Genetic variation exists in product quality, efficiency of production, and animal health and disease signifying that breeding programs will be fruitful.
Source: EMM/ Dgriculture and food industry