Herd Prefix Explained

Every breeder in the PDCA registry has their own unique Herd Prefix. Every animal in the registry has the Herd Prefix of its breeder included in its name. A Herd Prefix is typically short, and might include your last name, initials, farm name or an abbreviation of that name. The Herd Prefix can go before or after the individual name of the animal. Little Farm Lucy Ace of Clovebrook Your Herd Prefix should be included in the name of all offspring that you are the breeder of. If your desired Herd Prefix is already in use; the registrar will contact you with available options. If you do not list a Herd Prefix when you first join PDCA, the registrar will assign one.

About Tattoos

Year/Letter 2018 - F 2019 - G 2020 - H 2021 - J Ear tags are a great way to easily identify an animal out in the field, but they tend to fade after several years or get lost, so should be considered only part of your animal identification system. For permanent identification ear tattooing, hot-iron and freeze branding are the choices. What do the Letters/Numbers mean? The series of digits used can mean whatever you want. There is no hard set rule, so select a system that suits your needs. A common way of identification consists of 3-4 digits. One digit represents your herd/farm name One or two digits represents the animal itself One digit represents the year of birth Example: A2E A = Amazing Acres
2 = animal (could be the second calf born that year)
E = 2017

Parent Verification Explained

Knowing some of the basics of parentage testing and how it works can help a breeder understand the benefits of testing to make important breeding/management decisions. The Concept The concept behind using genetic markers for parentage testing is based on the fact that each animal receives one copy of each gene, called an allele, from each parent. We can genotype an animal to determine what markers they have and compare that to potential parents to determine if those markers are consistent with that individual being a parent of the offspring in question. Common Misconception One common misconception of parentage testing is that the test confirms parentage absolutely based on matching DNA of offspring to their parents. Rather, parentage testing is about excluding animals that cannot be the parents of a particular offspring, rather than proving that an animal is the parent. In the simplest terms, we use the genetic markers to exclude animals as a possible parent, leaving those remaining (hopefully only one) as the most likely parent for that offspring. Ways to improve accuracy 1. Make sure your marker panels are consistent All of the animals being compared need to be genotyped with the same type of marker panel. Older animals that might have been genotyped on a microsatellite panel might need to be re-genotyped on a SNP panel if the genotypes are needed for a parentage test on a younger animal. Also, the quantity of different markers shown on a panel can vary, so the higher the quantity of markers being compared the greater chance for accuracy. SNP parentage panels include a large number of markers. 2. It is essential to genotype all possible parents If an individual that could have been a parent is not included in the comparison, it is possible that parentage may be incorrectly assigned. Ideally collect DNA from all herd sires BEFORE they go out with the cows for the breeding season. 3. Don’t include any animals that couldn’t possibly be the sire or dam of the individual in question due to their location or other factors Because parentage testing is about excluding animals that could not possibly have been the sire or dam of the individual in question, you risk an inconclusive result if two or more individuals cannot be excluded. This is more likely to occur if the animals are close relatives. Even if you have run parentage panels on all of your herd sires, do not include all of them just because you possess the information. 4. It is harder to resolve parentage when using related sires/animals Because related animals tend to share the same chromosomes, and thus have the same genotype at genetic marker loci, it is harder to resolve parentage when potential sires are related. This may be especially important to remember when using related sires in a multi-sire pasture if your intention is to parent-verify the calves. Because their genotypes are often similar, it becomes more difficult to exclude close relatives as potential sires, especially in the absence of dam genotypes. References: International Society for Animal Genetics. (2012). Guidelines for cattle parentage verification based on SNP markers. http://www.isag.us/Docs/Guideline-for-cattle-SNP-use-for-parentage-2012.pdf. Accessed 12/16/2016.

About Lethal Genes

Lethal genes exist in every breed of cattle: Neurophathic Hydrocephalus and Arthrogryposis Multiplex are lethal genetic defect that affects Angus and Angus-influenced cattle, Tibial Hemimelia is found in Shorthorns and Maine-Anjous. Beta (ß)-Mannosidosis in Salers, Contracture in Holstiens, Hypotrichosis congenita (Hairless) in Holsteins, Fresians and Jerseys and the list goes on. Chondro and PHA are the two biggies in the Dexter breed. Lethal genes typically cause birth defects which results in the death of the fetus or newborn calf but in some cases the resulting deformaties can mean death for the dam as well. But nowadays a lethal outcome is entirely preventable by using genetic testing to identify a carrier, having a clear understanding of inheritability and using both to make wise breed pairings. Learn more

Where to Test

There are three commonly used laboratories for genetic testing for cattle. UC Davis is the most commonly used laboratory by PDCA members and has a solid reputation for its accuracy. UCDavis Texas A&M University Igenity

What is Genotyping

The mapping of genetic markers within an animal's DNA to establish a unique identification like a fingerprint. Genetic material (DNA) is obtained from hair folical samples. Cost to geneotype at UCDavis - $ 25

How to Test

Cattle DNA tests are carried out using 20-30 hairs with roots, easily pulled from the switch (tip) of the tail then sent to a genetics laboratory for analysis. Detailed Instructions from UCDavis Veterinary Genetics Laboratory


Frequently Asked Questions