Small Beef Cattle Farm


DNA Primer Related To Parentage Confirmation in Beef Cattle

      The beef cattle industry has for many years utilized parentage confirmation in their registered cattle. Experinces with this practice throughout the years has proven that parentage confirmation when in combination with a well run breeding program ensures more accurate pedigrees. More accurate pedigrees add value to the herd.

       DNA samples are all subjected to an identical process. Each sample is assigned a unique ID to allow lab personnel to trackthe  physical location and identify the DNA profile to be used in the parentage analysis. Many different sample types may be utilized for routine testing. Some of those are; blood, hair, semen, buccal swabs and blood FTA cards. Non-routine sample types include bone, teeth, saliva, dried blood, urine and feces.

     DNA is extracted from the samples and microsatellite marker analysis begins with the PCR procedure. When a DNA profile, which provides alleles sizes for all microsatellite markers is obtained the parentage analysis is performed. In this process a computer program compares the DNA profile of the offspring to those of the presumed parents. A parentage analyst reviews the results and, if no problems exist, a report is finalized. If a listed parent or parents are excluded, additional analysis is performed including retest of samples and the possible use of additional DNA markers to confirm the exclusion.
     The typical animal parentage case, species, includes a dam, offspring and one or more sires. Generally the identity of the dam is fairly certain. Parentage testing identifies individuals that, due to a specific combination of marker alleles, could qualify as a parent for a particular offspring. Accurate parentage testing requires breeders to identify possible parents since if considering a randomly selected large group of individuals there could be more than one that qualifies as a parent. A good application for animal parentage testing is verification that the dam is correct and which of the sires on a particular farm are the actual sire.

     Finally, it is important to remember that while parentage exclusions are 100% accurate, parentage qualifications are not. The accuracy of most animal parentage tests is greater than 99% when both parents are included in the analysis and drops to around 95% when only one parent is included in the analysis. However, this accuracy will decrease when the potential parents are part of a large group of closely related animals. Again this is due to the fact that an animal closely related to an actual parent could possess marker alleles that would make it appear that animal is the correct parent. To prevent erroneous parentage qualifications breeders may submit samples from all possible parents when first requesting parentage verification. If more than one sire and one dam qualify as parents of an offspring the laboratory can then test with additional DNA markers to sort out the actual parents.




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