Dealing with inbreeding in livestock
Posted Wednesday, October 23 2013 at 00:00
As the animals in the farm increase, one of the most important factors that farmers have to look out for is inbreeding among them.
For farmers with many animals, inbreeding could be one of those things that they need to pay attention to, as it is one of the main causes of low productivity.
Inbreeding could be termed to as reproduction through the mating of parents who are closely related genetically.
Herbert Kintu, the coordinator Wakiso District Farmer’s Association, says inbreeding results in an increased state of having two identical alleles in the same gene and that this in the long run can lead to the likelihood of the offspring being affected by recessive or harmful traits.
Inbreeding generally leads to decreased fitness of the animal population and this is usually referred to as inbreeding depression.
“Livestock breeders often practice controlled breeding to eliminate harmful characteristics within a population. Here, a farmer may decide to have a limited number of animals to ensure that he or she has enough space for their animals,” says Kintu. “This is also coupled with a mass of what is considered as unfit offspring, especially when trying to establish a new and desirable quality in the stock.”
Inbreeding may also occur because a small population of a particular type of animals has been isolated for a long period of time. This means that these animals will be forced to mate with each other and, in the process, with others that are genetically related.
Inbreeding however could also occur when large populations of animals that are closely related genetically are staying in a particular area.
Kintu says, as a result of inbreeding, the first-generation inbred animals are more likely to show physical and health defects.
This may also largely include a reduction in the fertility and sperm viability, thereby reducing reproduction in general.
There are also increased risks of genetic disorders, which are passed on through mating between related animals.
If related animals have a particular disorder, for example, genetically related birds that peck their eggs, they are most likely to pass on the habit to the offsprings.
“The reduced genetic diversity that results may also mean that the offspring will not be able to adapt to changes in environmental conditions due to their weak immunity. Each inbred will have a similar immune system because they are genetically based on the same parents,” explains Kintu.
Other side effects include a decrease in the rate at which the animals reproduce, a fluctuation in facial asymmetry, and reduction in growth rates whereby some animals are small in size and others tend to be stunted.
In this case, breeders who practice breeding for commercial purposes are bound to make less profit, because of the small size or the delayed growth of the animals.
He, however, notes that this will not change even when the animals are given medication to boost their growth, since these characteristics are genetically inherited. Therefore, he advises farmers to separate the housing.