Sustainable production systems need long-term and equitable solutions emphasize resource efficiency, profitability, productivity, product quality, environmental soundness, biodiversity, social viability and ethical aspects. Therefore long-term biologically, ecologically, and sociologically sound breeding goals is emphasized.
Improving milk yield in dairy cattle has a favourable impact on greenhouse gas emissions as fewer cows and followers are required to meet the same production level at a farm. Improving the average lifespan of dairy cows with one year has a large favourable impact on greenhouse gas emissions. The expected annual response in milk yield per cow increased when selection index weights were increased from current economic weights to environmental weights.
3.10.1 Defining breeding goals at different levels
Breeding goal traits can be considered at different levels: 1) at individual animal level: what is the effect of the improvement of a trait on the profitability of an animal, 2) at (cross)breeding system level: what is the effect of selection in the grandparents on the profitability of the crossbred grandchild in producing the final product and 3) at farm level: what is the effect on income per farm and 4) at production chain level: what is the effect on production and processing level? On these different levels different effects might be generated. When a beef producer has a contract with a slaughter house to deliver annually a fixed amount of carcass, selection on daily gain will result in heavier carcasses and less carcasses sold by the producer per year. When subsequently he keeps less animals he might be confronted with a surplus of roughage at his farm that he cannot transfer into saleable carcasses. Then the profit from a higher daily gain is lower at farm level. When in a breeding program of dairy cattle selection for milk protein variants is practised, it may lead to a higher cheese yield of milk. If a milk producer is not paid for the protein variants in the milk, the full profit of the selection for milk variants goes to the cheese factory.