Dexter Cattle - Knowing what you can't see
Dexter Cattle Breed Selection Backed by Science
After many years of breeding we have had time to establish a direction for our stud. More importantly we have learned the value of genetic testing to provide us with the right information to make the choices which are right for us and the future of the Dexter breed. Like most Dexter breeders we have limited acres so it is important to make breeding decisions that are backed by science. At this point our herd is very much how we like them, ‘Beefy little milkers’, with a good range of Dexter colours and mostly polled.
Having got the herd just the way we like them it is often a problem when deciding which to sell and which to keep when comparing two animals that to the eye are much the same. This is where we are now investigating what we can’t see to make those decisions.
Dexter cattle are traditionally horned, though the majority of cattle these days have their horn buds removed when they are very young. Polling was introduced to the Australian Herd by a polled Dexter bull Kalinda Angus. Polling was also introduced through the grading up process where naturally polled breeds such as Angus and Murray Grey cattle were used as foundation cows.
While polled animals are becoming more common in herds across Australia you cannot know by looking at an animal if it is carrying one polled (heterozygous) or two polled genes (homozygous) which is often referred to as double polled. So the only real way to know is by genetic testing. There has been some work done in Australia to develop a test for this but so far a reliable test is not available here. At this point in time tail hairs are sent to America where a test is available.
Dexter cattle are always a solid colour which can be black, red or dun. All three colours are equally acceptable for registration, breeding and showing but, like us, some people have a preference and some like variety. Knowing what colour your calves may be is also all about genetics.
If your cow is red or dun you know its genetic status for colour is homozygous or put simply it has two genes for that particular colour. But, if she is black you can’t see if she carries red or dun. If one of her parents was coloured she will carry one copy of the gene for that colour. A black cow may also carry genes for colour that could not be seen through several generations of black cows. Once again genetic testing from tail hairs is available. In Australia you can test for red. An American test is available for red and dun genes which is also tested from a sample of tail hairs.
There are two more genetic tests helpful in clarifying what we can’t see or be sure of by looking and those are the tests for PHA and Chondrodysplasia.(ref:P26) These are very useful tools for making breeding decisions, have been fully embraced by the DCAI and are readily available by tail hair testing in Australia.
Lastly, Dexters are reputed to produce meat that is low in saturated fat especially when grass fattened which is not hard to do with this breed. With low back fat and moderate marbling in most cuts the meat is flavoursome and not overly fatty. These are traits we can not see by just looking at a live cow and as yet, we have not identified any genetic tests for them.
However it would be nice if we could test for ‘low cholesterol’ meat. We all know it tastes good and can see the health benefits ourselves and perhaps in the future we will also be able to back up the anecdotal information about Dexter beef with the same level of science.
Editorial By: Gillian Vernon. Damolock Dexters.
Dexter Cattle Australia Inc. Member Western Australia