Dietary overlap between Boer goats and indigenous browsers in a South African savanna
AbstractThe winter diet of free ranging Boer goats in Valley Bushveld, KwaZulu-Natal, was determined by direct observations and compared with the diet of indigenous browsers (kudu, eland, giraffe, black rhinoceros) in order to determine which browsers are most compatible with goats for ensuring more efficient use of savanna vegetation. Goats were predominantly browsers during winter, spending 73% of their time eating woody plant forage. Principal woody plant species in the diet included Rhus pentheri, Acacia nilotica, Acacia karroo, Euclea crispa and Ziziphus mucronata. Succulents (Aloe ferox and Aloe maculata) were also readily eaten. Highly preferred species were Capparis sepiaria, Phyllanthus verrucosus and Scolopia zeyheri, while Rhoicissus tridentata, Calpurnia aurea, Acacia ataxacantha, Euclea natalensis, Clerodendrum glabrum, Zanthoxylum capense and Hippobromus paucifolia were strongly avoided. Goats fed between ground level and 1m, with an average feeding height of 0.67m. The diet and feeding height of kudu and goats and of black rhinoceros and goats overlapped to a large extent suggesting that they are potential competitors for food resources. Similarly, overlap in diet between giraffe and goats was extensive, but overlap in feeding height was small. The potential for competition appeared to be the least between goats and eland because, despite feeding at similar heights, they generally consumed different species. A mixed farming system which includes goats, eland and giraffe is proposed as a useful management tool for using savanna vegetation more efficiently.
Keywords: animal production; bush encroachment; competition
African Journal of Range & Forage Science 2002, 19(1): 13-20