Cattle DNA Testing
Checking parentage in cattle with DNA
Scientists have long understood that each individual (with the exception of identical twins) is genetically unique. This applies to cattle as much as to people, dogs, horses and any other animal. Once DNA had been identified as the molecular basis of genes, this variability between individuals could be analysed in detail. Although the variation within genes is small between two individuals of the same species, DNA markers lying between the genes show much higher degrees of variability.
Any two individuals will differ in many of these DNA markers and by analysing a set of the most variable markers we can build up a unique profile for an individual animal. The technology used for cattle is identical to that used for establishing human paternity, the only difference being that the DNA markers used are derived from cattle, rather than human DNA.
How to submit samples
DNA profiling or parentage analysis in cattle uses samples of hair. Hairs must be plucked not cut, and should be submitted in a labelled bag obtainable free of charge by contacting us using the details below.
Because samples usually only contain very limited quantities of DNA, all the laboratory manipulations are carried out on a minute scale - the DNA from samples we routinely work with will typically be contained in a volume of 1/100,000 of a litre!
Quantities of DNA present in samples are far too small to measure successfully themselves, so we amplify up the DNA to a detectable level using the polymerase chain reaction - a technique that has revolutionised genetics since its development in the late nineteen eighties. This amplification specifically targets those segments of DNA which will give us a profile; coloured fluorescent dye is added to each fragment of amplified DNA at this stage so we can detect the DNA.
After amplification the DNA is run on a Genetic Analyser which separates out the DNA fragments. In practice, a number of DNA markers are amplified at the same time and identified from the Genetic Analyser by the length of the fragments and by the colour of the fluorescent dye on each one.
Detailed statistical analysis has demonstrated that a set of 13 different DNA markers is required for DNA profiling. This set has been standardised through the International Society for Animal Genetics. After conversion to this standard, DNA profiles can be exchanged between laboratories across the world.
For parentage testing, the DNA profile of the calf is compared with the profile of possible sires or dams. Each calf has two copies of each DNA marker, one inherited from the sire and one from the dam. For each of the thirteen DNA markers one of the copies in the calf must match a copy in the sire and the other copy in the calf match one in the dam. Any mis-matches will exclude the sire or dam (or both) from being the true parents.
Telephone: +44 (0) 1638 555621
Fax: +44 (0) 1638 555666
Address: Genetic Services, Animal Health trust, Lanwades Park, Kentford, Newmarket, Suffolk CB8 7UU