This was less for any immediate military effect - although by killing the livestock that might then instead have been eaten by the guerillas this would clearly have slowly led to a weakening of support for rural Africans, but as part of the Rhodesians' increasingly desperate efforts to change the psychological balance in the war, to turn rural African supporters of the struggle against combatants, by blaming the guerillas for the spread of disease. Indirect proof of the Rhodesian forces' use of biological warfare was that the diseases - anthrax and cholera - occurred only in the TTLs, and in none of the adjacent while-owned farms. People in Zimbabwe continue to die from the effect of the anthrax spores.

Initially, the Selous Scouts were responsible for the first CBW actions, but it seems that other units may also have become involved. 

Following this link will take you to more information on the Rhodesian/ South African CBW programme. 

December 2008 
Cholera has once again broken out in Zimbabwe - the almost complete disintegration of medical facilities, running water, and practically any state-run sanitation programmes doing nothing to eradicate the disease, or prevent it spreading throughout the country, and across the neighbouring borders. In The Herald, 13/12/08, the Zimbabwean Minister of Information and Publicity, Sikhanyiso Ndlovu described the epidemic "as a calculated attack on Zimbabwe ... a serious biological chemical war force ... a genocidal onslaught on the people of Zimbabwe...by the unrepentant former colonial power which has enlisted support from its American and Western allies so that they invade the country".