Looks like swahili tribes put holes into their cows to harvest their blood then mix the extracted blood with the animal's milk to sustain themselves because their beliefs forbid them from eating plants. As a result it weakens their herds and reduces their milk and meat yield. A similar process is used by vegans of the west as well. To be able to create meat-like sustenance they use unnatural processes that cause extra energy expenditure, create waste and introduce chemicals to food. Both Swahilians and westerners are inefficient omnivores by proxy. If they managed to put their false beliefs and morals aside they would benefit greatly from their newfound modus operandi. Following the same logic we can easily say that borders and definitions are arbitrary constructs built on false beliefs as well and I am actually having intercourse with a polish woman by proxy when I fuck my dog.