BY, Bovine Brachyspina Syndrome

Breed: Holstein-Friesian

BY (Bovine Brachyspina Syndrome). The name of the defect comes from Latin and refers to the fact that the calf is born with a very short spine. The foetuses are often aborted around day 40. A few calves are born after a prolonged gestation of 2-4 weeks, and they only live for a few days. The full-born calves have a very low weight of about 10 kgs, the body and neck are short, a hump can be spotted between the shoulder blades, and often the lower jaw is deformed. The legs seem long compared to the body, and autopsies show deformed internal organs. The calves look a little like moose calves.

The defect is inherited recessively, i.e. a sick calf must inherit the defect from both parents. Carriers of BY are healthy, but can be identified by a DNA analysis. Bovine Brachyspina Syndrome is only seen in Holstein-Friesian cattle.

BY is a relatively new defect and was first described in Denmark in 2006. Most likely it prevails in Holstein-Friesian cattle worldwide. The ancestor was found to be Sweet Haven Tradition (US 1682485), but also his much used son Bis-May Tradition Cleitus (US 1879085) is a carrier of the defect.

For further information about BY

Results for BY test

• TY (the animal has not inherited the defect from its parents) 
• BY (the animal is a carrier and has inherited the defect from one of its parents).

Information about multiple birth