Consider the following before cross breeding
I have a ranch in Mpeketoni where I keep cows and wish to cross breed them so that I can increase their number and possibly milk production. Advise on how I can go about this.
Cross breeding is an advantageous reproduction practice when done correctly. For cross breeding to yield these advantages it has to be planned and done well. Most farmers consider cross breeding a trial-and-error affair often hoping for some miracle in terms of superior traits.
However, hybrid vigour or heterosis is the main advantage of crossbreeding as it brings out the favourable genes from both parents in the offspring. These good traits include high productivity of meat and milk, fertility, ease of calving, calf survival and a long productive life otherwise summarised as production, reproduction and survival traits.
Cross breeding also directly helps reduce negative effects of inbreeding. If you want to appreciate the negative effect of inbreeding look at the ever reducing size and milk production of our Zebus back in the village.
Long term not short term venture
A planned crossing breeding program must be long term and the full realisation of the benefits can take generations. If we take an example of a cross bred female that has just reached maturity the farmer must be aware of what sire it will be mated to and to potentiate what desirable characteristics; this will require the services of a veterinary doctor with experience in breeding. Good record keeping is therefore a pre-requisite to a good breeding program.
Many farmers base their cross breeding decisions on what they have heard from fellow farmers. I am not in any way discouraging horizontal discussions among farmers, I am also alive to the fact that sometimes myths have been transmitted through those interpersonal sessions.
A farmer may, for instance, get Friesian semen because Friesians are known to be high milk producers. However, crossing a big bull with a small cow can be fatal. Mating of disproportional parents will result in difficult birth requiring caesarian section which is expensive and subsequently if not well done can result in the death of the calf, the mother or both. So as you select the sire look at the size of the dam and find out if they are a match.
There are breeds of animals which are resistant to certain diseases, like the Fleckvieh’s thick skin is said to make it resistant to tick borne diseases. This trait can be passed on when such animals are cross bred with other breeds that have other advantages like the Zebus which are well adapted to hot tropical climates.
The man-made component
The phenotype - what is seen in terms of performance of the offspring - is a factor of the genetic make-up and the environmental factors. Therefore, you cannot have high milk yielding cows if you don’t feed the cows.
Dr. Othieno was the winner of Vet of the Year Award 2016 and works with the Kenya Tsetse and Trypanosomiasis Eradication Council (KENTTEC)