Possibilities for a specific breeding program for organic dairy production

Breeding programs for organic and conventional dairy production are the same in most countries, despite differences between the two production systems. Breeding goals (BG) might be different for the two production systems and
genotype by environment interaction may exist between organic and conventional dairy production, both of which have an effect on genetic gain in different breeding strategies. Other aspects also need to be considered, such as the application of multiple ovulation and embryo transfer (MOET), which is not allowed in organic dairy production. The aim of this research was to assess different environment-specific breeding strategies for organic dairy production.
An organic and conventional breeding program were simulated in five different scenarios. Scenario ‘Current’ had a conventional BG and both MOET and the selection of conventional bulls as breeding bulls in the organic breeding
program were allowed. The other four scenarios differed in these two aspects, but all had a specific organic BG in the organic breeding program. Implementation of a specific BG in the organic breeding program with BG weights that were adjusted to the organic production system increased genetic gain (ΔG) in the aggregate genotype slightly. The highest ΔG in the aggregate genotype was achieved in the scenarios where MOET was applied and conventional bulls could be selected for in the organic breeding program. This is therefore a recommendable breeding strategy. Not allowing for MOET or the selection of conventional bulls as breeding bulls in the organic breeding program decreased ΔG by as much as 24% and is not recommendable. ΔG on trait levels showed that a significant increase in functional traits was possible without a decrease in ΔG in the aggregate genotype. Thus, a specific breeding program for organic dairy production gives possibilities to breed in the desirable direction without losing on ΔG in the aggregate genotype.