1. Department of Livestock and Pasture Science, University of Fort Hare, King Williams Town, South Africa
2. Agricultural Research Council, Animal Production Institute, Pretoria, South Africa
3. Applied Behavioural Ecology and Ecosystem Research Unit (ABEERU), Department of Environmental Sciences, UNISA, Florida, South Africa
4. Department of Animal Sciences, Stellenbosch University, Matieland, South Africa
5. School of Life Sciences, University of KwaZulu-Natal, Scottsville, South Africa