Like the American, Batswana believe in big things (the big vans, big SUV and the bigger cows). However, when it comes to which cow is sustainable for rearing in Botswana, big is not the answer. Science of animal nutrition will tell you that when ruminants (cows) eat fibrous diets, such as commonly found in Botswana, they produce heat in their body. In cold environments this heat is useful to keep the animal warm.
However, in hot countries like Botswana this heat is a challenge to animals because the animal has to get rid of this heat. Nature has made local Tswana cattle to be smart in getting rid of this heat. Tswana cattle are able to get rid of this heat through sweating, having a shorter hair and not wool and more sweat glands and blood vessels nearer to the skin. And because of their small body weight in relation to their volume they have a higher surface area which helps in evaporative cooling. Other tropical cattle like the Brahman have excess skin to increase the area for riddance of this heat of metabolism. Local cattle are more efficient in digestion of fibrous diets because of high rumen volume relative to their body mass. These attributes are lacking in big exotic cattle like Holstein/Friesian. In addition, the Friesian eats a lot to satisfy its huge maintenance requirement. This further increases its need to get rid of heat of metabolism, especially if the diets are fibrous. So the logical thing for a Friesian cow to do in order to reduce this heat is to reduce eating. But we all know that reducing eating will result in reduced milk production and fertility. So if we were to allow ourselves to be informed by science, we would be cautious in advocating for the use of a Friesian as an animal of choice in Botswana. If we were to use the Friesian cow, we would need to put strategies to help it get rid of the heat alluded above. This means building cooler houses for them to rest during the high heat from the surroundings.
