While many communal livestock farmers are well versed in the need to regularly replace sires or male breeding animals, I have visited former homeland regions where there exists clear signs of excessive inbreeding.
This is not usually intentional and can be due to a lack of effective farming infrastructure like fenced camps, a lack of marking or identifying male animals and their offspring (record-keeping), or the occurrence of wandering male animals of unknown origin.
Inbreeding is generally the mating of closely related animals, like fathers to daughters, or brothers to sisters.
While some experts have in the past undertaken specific inbreeding programmes to ‘fix’ good genetic traits into offspring, inbreeding can be risky and can result in the breeding of animals with ‘recessive’ or bad genes.
Signs of abnormalities
Signs of inbreeding abnormalities can range from physical deformities such as testicular abnormalities, poor body conformation or shape, misshapen limbs, crooked backs, and undershot jaws.
More subtle problems may include compromised immune systems, reduced milk production (and thus offspring feeding ability), and increased exposure to the effects of parasite infestation.
Other breeding programmes include line breeding – the use of related but not closely related animals – and outcrossing, which generally involves the use of unrelated animals.
Generally, ‘hybrid vigour’, or the breeding of superior, robust, and fast-growing offspring can be achieved in outcrossing programmes, but I’ve noticed that while valuable genetic diversity (reducing the chance of recessive genes) can be achieved through such breeding, the offspring may not always go on to be valuable future breeding animals.
This risk in outcrossing is generally seen when totally different breeds are used, for example when crossing British beef breeds and Nguni cows. The offspring may grow well and quickly and may show larger frames (indicating hybrid vigour) but may lose some of the innate traits of the Nguni, such as parasite and disease resistance.
If the same breeds are being used, but are unrelated, such as putting Dohne Merino rams to Dohne ewes, the good traits will generally be retained. Offspring will be ‘true to type’ (look like a Dohne sheep should look), providing you are using good genetic material.
Control in breeding
First and foremost, record-keeping is essential in any successful livestock breeding programme. Without doing this, you cannot maintain or gain control of what male animals or sires are being used on what female animals from breeding season to season.
This is difficult, however, in farming regions where numerous different farmers are using different sires in communal herds and flocks. Some form of uniformity should thus be considered or discussed by the farming collective, and record-keeping should involve all stakeholders.
Essentially, animals with very poor genetic traits or deformities can have dire impacts on the entire collective flock or herd.
Good record-keeping involves the following:
- Ear-tag sires being used in a specific breeding season with colour-coded tags, or by placing dates onto tags and ensuring that offspring have the same colour tags or corresponding date and sire information on their ear tags;
- Try to create different regional herds or flocks and rotate bulls and rams accordingly. Communities should consider pooling resources in order to pay trained herders;
- Even if wanting to maintain the use of specific breeds as sires, try to use sires or bulls and rams that are not closely related to increase genetic diversity;
- As a community, try to purchase good genetic material as a collective and obtain such animals from different reputable breeders who will know the genetic make-up of such animals;
- Try to avoid retaining offspring you have bred yourself as sires, especially if you’re unaware of their genetic make-up.
It is due to this challenge that many commercial farmers would rather purchase sires from dedicated stud breeders, rather than taking a chance by retaining self-bred animals.
The difference in monetary value between well and poorly bred animals can be substantial, while the input costs of maintaining weaker or inferior offspring can be way higher.
Shane Brody is involved in an outreach programme aimed at transferring skills to communal farmers.
