Genetic Diseases in Cattle
Cattle are susceptible to a wide range of genetic diseases. According to Arcangelo Gentile and Stefania Testoni from the University of Bologna, many of these diseases can be attributed to selective inbreeding. Most cattle lines are derived from only a few select bulls.
This has increased the possibility that both of a calf's parents will carry dangerous recessive genes that create birth defects and genetic diseases in their offspring.
Hydrocephalus, or water on the brain, is a common genetic brain defect in beef cattle. According to the Library 4 Farming website, calves with hydrocephalus have too much fluid in their brain cavities. Newborn calves are unable to stand or nurse, and most of them die either at birth or shortly afterward. They sometimes have domed heads and eye defects as well. The disease is prevented by keeping carrier bulls from breeding with carrier females.
Weaver syndrome is also known as bovine progressive degenerative myeloencephalopathy. It is most commonly seen in brown Swiss cattle. Cattle experience weakness and a lack of coordination in all four limbs. The disorder is called "Weaver Syndrome" because the animals have an odd weaving gait when they try to walk, according to the Merck Veterinary Manual. Library 4 Farming adds that the disease affects cattle when they are around six months of age. The disease becomes progressively worse until the animal either dies or is killed. There is no cure or treatment for the disease.
Spinal dysmielination is a disease that affects brown or American brown Swiss cattle. The disease is apparent as soon as the calf is born. According to Gentile and Testoni, the calf is unable to rise after birth. Its head is usually thrown backward and the back is arched, and the body lies rigid with the back legs outstretched. Despite its inability to move, the calf's reflexes are normal and it can suckle, defecate and urinate without difficulty. The condition is caused by deterioration of the white matter inside the spinal cord. The calves usually die or are humanely killed before they are a week old.
Cattle are prone to a number of different skeletal deformities. Arachnomelia, for example, is a disorder found among brown and Simmenthal calves. The animal is born in a hunched, spidery position with evident deformities in the hind legs, as well as withered muscles and a malformed heart. Their brittle legs are prone to fracture during delivery. This can be dangerous to the mother, according to Gentile and Testoni. Another bone disorder is called short spine lethal. This condition is evidenced by an abnormally short vertebral column. The neck is disproportionately short and the head looks fused to the chest. Calves with this disorder also have a low body weight. Autopsies reveal that the animals sometimes have too few vertebrae and that the vertebrae are misaligned or fused together.