Breeding goals & design

Different Goals, Common Ground: A Global Perspective on Dairy Breeding Objectives

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Abstract

A global comparison of dairy cow breeding objectives provides valuable insight into areas of convergence and divergence, helping identify populations with compatible breeding goals for sourcing germplasm to strengthen domestic genetic improvement programs. The objective here was primarily to compare the rankings of Holstein-Friesian artificial insemination sires across countries. The study also examined how different countries present estimates of genetic merit and how frequently they update their base populations. Additionally, cross-country trends in the future direction of breeding objectives were also investigated. The partial correlation among indexes was calculated for Holstein(-Friesian) sires born post-2000 with a reliability >70%, adjusting for genetic trends through the inclusion of year of birth as a fixed effect. The correlations among the indexes varied from 0.34 (Ireland and Poland) to 0.87 (Net Merit Index in the US with Lifetime Profit Index in Canada). Notably, indexes designed for indoor production systems had weaker correlations with grazing-focused indexes from Ireland and New Zealand (~0.35) compared to stronger correlations (0.60 to 0.80) among the confinement-based indexes. Countries differ in their approach to trait weighting: some countries (e.g., Ireland, UK, Germany RZEuro, New Zealand, USA NM, Canada Pro$) rely solely on economic values, some (e.g., Italy, Japan, South Africa, Slovenia, Hungary) use desired genetic gains, while the others (e.g., Canada LPI) apply a hybrid approach - using economic values for milk production traits and otherwise desired gains or start with economic weights which may then be modified to achieve a desired gain (e.g., Nordic). Where economic values were applied, the economic value per kg ranged from -€0.109 (Ireland) to +€0.15 (Spain) for milk yield, from €0.47 (Spain grazing index) to €9.47 (US Net merit index) for fat yield, and from €0.74 (Spain grazing index) to €6.83 (Ireland) for protein yield. The US, Nordic countries, Belgium, New Zealand and Ireland all have negative weights on milk yield while Spain and Poland have a positive weight on milk yield; Germany, Hungary, and Italy do not consider milk yield but Italy includes fat and protein concentration. Expression of genetic evaluations also varies: while most countries publish milk production traits on the unit of measurement, the scale differs - some use predicted transmitting ability (e.g., USA, Ireland), others use estimated breeding value (e.g., Germany, Nordic, Italy, Switzerland, Spain, Japan). Base population updates occur at different intervals: several times a year (e.g., Nordic countries, Germany), annually (e.g., Canada, Italy, Switzerland, Spain, Poland), every five years (e.g., USA, Hungary, Japan, Belgium, South Africa) or periodically (e.g., Ireland, Slovenia). Health traits are increasingly being considered for inclusion in future breeding objectives. The findings underscore how economic, biological, and policy factors shape national breeding objectives, helping to interpret international differences in genetic trends and performance outcomes.

Keywords: 2026

How to Cite:

Amer, P., Axford, M., barenco, a., Berry, D., Byskov, K., Cole, J., de Jong, G., Finocchiaro, R., Gengler, N., González-Recio, O., Graham, J., Jiménez-Montero, J., Kasarda, R., Kelleher, M., László, B., Maelle, R., Miglior, F., Mostert, B., Neuenschwander' <, T., Osawa, T., Potočnik, K., Rzewuska, K., Schmidtmann, C., Splittorff, H., Wijnrocx, K. & Winters, M., (2026) “Different Goals, Common Ground: A Global Perspective on Dairy Breeding Objectives”, World Congress on Genetics Applied to Livestock Production Digital Archive 2026(1): 2286354. doi: https://doi.org/10.31274/wcgalp.23950

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