The Southern Cross breed is the result of crossbreeding and selection for performance in the New Zealand seasonal pasture-based sheep dairy farm system.

Coopworth ewes were initially bred to East Friesian and Awassi sires, but since 2017, an Artificial Insemination programme has been run annually using imported semen from progeny tested French Lacaune sires. The Lacaune breed is the mainstay of the French industry where 800,000 ewes are supported by the only large-scale, scientific breeding programme in the world for dairy sheep.

The Southern Cross breeding goal is efficient conversion of pasture into profit. Accordingly, key traits include, but are not limited to, milk production, high component percentage, udder conformation, low Somatic Cell Count, good feet and legs, and longevity. These traits closely match the French breeding goal, which is a another reason why the Lacaune is the main contributor of genes to the Southern Cross breed.

The nucleus herd is run on a commercial sheep dairy farm at lake Taupo. Frozen semen is inseminated laparoscopically, all progeny are electronically tagged at birth and DNA parentage tested. Ewes are performance tested at every milking with electronic milk meters recording milk volume, milkfat and protein.

A key role for the nucleus herd is to provide rams, and some ewes, to support the establishment and growth of the sheep dairy industry in New Zealand. This industry is expected to offer diversification in exports for New Zealand, profitability and stability in income for farmers, and environmental sustainability for all.