Abstract:
The north-western part of South Africa, in particular, is well known for mineral imbalances.
Aphosphorosis, resulting in rickets and osteomalacia, received a lot of attention at the turn of
the nineteenth century (1882–1912). This was followed in 1997 by research on Vryburg
hepatosis, another area-specific mineral imbalance–related disease in young calves reared on
manganese-rich soil derived from the weathering of dolomitic (carbonate) rock formations. In
1982, a totally new syndrome (osteochondrosis) manifested in, amongst others, areas in South
Africa where aphosphorosis was rife. Osteochondrosis was also identified in the south-western
parts of Namibia as well as southern Botswana and other areas in South Africa. Osteochondrosis
has a multifactorial aetiology and this study focused on the role of minerals, particularly
phosphorus, in the development of the disease. A significant improvement in the clinical signs
in experimental animals and a reduction of osteochondrosis occurred on farms where animals
received bioavailable trace minerals and phosphorus as part of a balanced lick. An increase in
the occurrence of the disease on farms during severe drought conditions in 2012–2013
prompted researchers to investigate the possible role of chronic metabolic acidosis in the
pathogenesis of the disease.
