Published online by Cambridge University Press: 27 March 2009
1. Africander and Mashona steers, fitted with rumen cannulae, were used to study pH values and concentrations of volatile fatty acids in the rumen of cattle grazing on natural subtropical pasture through the year. Some steers received concentrated, foods in winter. During the summer, rainy season, two Africander and two Mashona steers were studied while in winter a further four steers, two of each breed, were added to the trial. The eight steers in winter were divided into four similar groups, one group received a carbohydrate-rich concentrate, another group received a protein-rich concentrate, a third group was given both concentrates, while the fourth group received no additional food.