Had a calf with the end of the tail missing and the price was marked down, and they called the calf rat tail. Sometimes they just don't have a tail end switch.
"Rat-tail cattle" refers to cattle expressing a genetic condition called rat-tail syndrome, a form of congenital hypotrichosis characterized by short, curly, and often sparse hair, particularly lacking a normal tail switch. This syndrome results from specific genetic interactions, primarily between the
black color gene and another locus, and is seen in calves produced from crosses of certain Continental breeds, like Simmental or Charolais, with breeds carrying black color, such as Angus. Calves with the syndrome show slower winter growth rates, resulting in lighter weights at yearling and slaughter, though this doesn't affect birth or weaning weights.
Key Characteristics of Rat-Tail Syndrome
- Hair Abnormalities:
Calves have short, curly, malformed, and sometimes sparse hair on their bodies and a lack of a normal tail switch.
- Genetics:
The syndrome is inherited and results from the interaction of genes at two loci. Cattle must possess at least one dominant gene for black color and be heterozygous at the other locus.
- Breeding:
It often occurs when Continental breeds are crossed with black-colored breeds, such as Angus or Charolais.
Impact on Cattle Performance
- No Effect on Early Growth: The syndrome does not impact a calf's birth weight or weaning weight.
- Reduced Growth Rates: Rat-tail calves experience significantly lower rates of gain during the winter months (from weaning to yearling).
- Lighter Yearling and Slaughter Weights: This slower growth leads to a lower yearling weight and, consequently, lighter steers at slaughter compared to non-rat-tail calves.
Other Associated Symptoms
- Tongue Lesions: Some rat-tail calves may also develop rough, raised, and hyperkeratotic tongue lesions, which are sometimes observed in feedlot cattle with the syndrome.
