Selection is critical to optimal livestock performance
By Erastus Ngaruka
Technical Officer within Agribank’s Agri Advisory Services Division.
Every livestock farmer should strive for optimal productivity while keeping the costs of production in check
The production efficiency on any livestock enterprise is directly linked to the efficiency of livestock selection. In order to maximise productivity, a livestock farmer should establish breeding objectives and goals, and implement a selection process that will meet his/her objectives. The purpose of livestock selection is to improve herd or flock productivity, meet market demands and increase farm income.
There are several factors that hinder livestock improvement, which amongst others include:
1) Costs of breeding materials: expensive breeding bulls, rams, cows, ewes, etc.
2) Uncontrolled breeding practices: no selection, in-breeding, delayed castrations and no breeding camps.
3) Absence of records: with no records, it is difficult to trace or monitor livestock performance. Important information to track includes: birth weight, pregnancy, weaning weight, market weight, calving intervals, etc.
4) Skills/knowledge and information gap: some farmers do not adopt contemporary livestock management practices. Some also do not have the right information and skills to make a success of their farming enterprises.
5) Climatic/environmental conditions: harsh conditions such as droughts, floods, and extreme temperatures negatively affect livestock performance physiologically and physically.
Selection is critical to optimal livestock performance, and the objective is to retain and maintain superior breeding animals that will pass the most desired traits onto future generations. To achieve that, three common approaches can be used in order to help the farmer make desired and well-informed decisions.
a) Visual assessment (phenotypic): this type of selection is based on descriptive standards set to identify an ideal animal based on its physical soundness, e.g. body conformation, posture (e.g. legs, neck, back, and head), udder and testicle size and placement, etc. For example, if an animal is observed to have weak legs (unstable) or sickle hocks, then it is not selected for breeding but culled or removed from the herd.
b) Genetic assessment (genotypic): This assessment is based on known inherited characteristics which are influenced by an animal’s genotype. This is done by genetic evaluation methods such as Estimated Breeding Value (EBV) or Expected Progeny Difference (EPD) amongst others. The use of these methods is based on statistical formulas to predict if an animal is able to pass on the most economically important traits such as growth rate, carcass quality, reproductive efficiency, parasite resistance etc. The difference between the two is that EBV estimate individual animal breeding value whereas EPD estimate the Individual animal’s progeny (offspring) breeding value. Farmers can always obtain such estimates from livestock stud breeders associations (https://www.nsba.iway.na).
c). Classing and culling (visual and history): this is visual assessment of the animal, and the use of its performance history (e.g. calving intervals, abortions, complications at birth, etc.). For example, a cow on average should have a calf every year (365 days and less), but if it starts delaying and have longer intervals between every calf, then it can be selected and classed as a low or non-producer, thus, culled for market.
For any animal type or breed, a farmer should take into account the environmental conditions and his/her management ability. On that, what is expected is a productive and adaptive animal, and the management should be able to meet the animal requirements in terms of health and nutrition, and general animal welfare practices.