Bernard Nyamushamba, Godfrey, B. Tavirimirwa, and N.Y. D. Banana. 2013. “Non-Genetic Factors Affecting Milk Yield and Composition of Holstein-Friesian Cows Nested Within Natural Ecological Regions of Zimbabwe”. Scientific Journal of Animal Science 2 (5):102-8. http://sjournals.com/index.php/sjas/article/view/1081.