For most areas of the world, access to dairy cattle genetics is only what the imagination holds. Except in the cases of disease transmission, semen, embryos, and even live animals can cross borders – with opportunity to catch entire populations up on the progress made in production and other traits (less management skills).

For nearly 250 years, the island that gave us the now fast-growing Jersey breed was banned from importing genetics. From 1763 to 2008, genetics could leave the island, officially known as the Bailiwick of Jersey, but no genetics could enter. Jersey is a nine mile by five mile area with a population of 100,000 off the coast of Normandy, France. Together with the Bailiwick of Guersney, the pair is often called the “Channel Islands” and are under the British Crown.

In 2010, the island had 5,200 cattle, nearly all Jerseys. But only 2,970 were milking. That was down significantly from 3,570 milking animals in 2007.  In 1763, the ban went into place to protect trade, and created a niche for exports from the original herd. But finding bulls with new genetics on the island proved difficult over time.

In 2008, the island’s Jerseys lagged 22% behind the UK’s stock in milk production. Feed efficiency is especially important on Jersey, since much of it comes across the English Channel.

Today, all but two of the island’s 24 herds have expanded their genetic base outside of the island stock. Farmers Weekly interviews two contrasting herds, one importing that has increased production 2,200 pounds (1000 liters) and the other using only island genetics and focusing on type.

Read the interesting interviews here: “Jersey dairy cow six years after genetics ban,” Farmers Weekly

Other sources: States of Jersey Statistics Unit, 2011