TH (TIBIAL HEMIMELIA):
As we continue to test our Shorthorns for TH, many members have been questioning what is TH? Why do we test for it? And how does it affect my herd? All very valid questions which we are happy to answer. Below are a number of questions and answers to help members understand TH in simple terms.
TH testing began in Ireland in 2009, and while there are some Tested TH Free herds in Ireland, we encourage breeders to continue to test their unverified animals. Note: it is not a requirement to test animals to receive a pedigree certificate, however, it is good practice when breeding Pedigree Shorthorn Cattle.
What is TH?
According to the American Shorthorn Association, Tibial Hemimelia (TH) is a lethal genetic condition inherited when affected animals inherit two copies of a recessive gene. Calves are born with severe deformities including twisted rear legs with fused joints, large abdominal hernias, and/or skull deformities. Should calves survive the birthing process, they cannot stand to nurse.
https://shorthorn.org/genetic-conditions/
Why do we test for TH?
As TH is a lethal genetic condition that is found in Shorthorn cattle, it is important that we make educated decisions when mating animals. It is important to remember that if two carriers are mated together, there is a 1 in 4 chance (25%) that you could have a calf born from this
mating with severe defects. It is imperative that we educate ourselves when mating animals and continue to test unverified animals.
How does it affect my herd?
While some herds were once ‘Tested TH Free’, many have since bought in new animals. This means your once free herd may have animals that need to be tested. If in doubt, please check with our secretary Shauna and she will help identify any animals that require testing. It is important to remember that the society does not gain financially from these tests, we simply work with breeders in order to make
sure animals have the correct TH stamp on their pedigree certificates.
The three stamps are:
Tested TH Free: Breeders must email/post a copy of TH results from Weatherbys Scientific to the society office.
Predicted TH Free by Inheritance: Sire & dam/grandparents/great-grandparents etc. were TESTED TH FREE. This means both sire & dam must have tested TH Free animals in their line i.e. parents/grandparents etc. Again, results must be provided.
TH Status Not Verified: Owner cannot provide a TH result from Weatherbys Scientific and/or chooses not to test animal.
Please note that it is not a rule that animals must be tested to receive a certificate. However, all certificates must have the correct stamp on them when leaving the society office.
Testing for the TH Genetic Defect: Step-by-step Guide
1. Collect Hair Samples: Collect a hair sample from each animal you wish to test.
2. Prepare the Samples: Place each sample in a separate zip-lock bag (freezer bag). Important: Do not use sample bags labelled with society branding. This is to avoid additional VAT costs billed to the society, which would increase expenses for the breeder. Breeders must pay Weatherbys directly for TH testing.
- Include a piece of paper inside each bag with the following details:
- Animal TAG Number
- Your Herd Number
- Your Name, Address, and Phone Number
- Test Required: TH Test for This Animal
Note: If desired, you can request that results be sent to both the breeder and directly to the society.
3. Packaging and Posting: Send the prepared samples to the address below:
TH Testing,
Weatherbys Scientific,
Unit F1 – M7 Business Park,
Newhall, Naas,
Co. Kildare.
4. Contact Information: If you have any questions or need assistance during the process, contact Weatherbys at: Phone: +353 (0)45 875521
5. Payment: Weatherbys will contact you directly to arrange payment for the testing service.