|dc.description.abstract||Small ruminants found in pastoral dryland systems face many challenges regarding constant
environmental and climate changes. These variable environments are home to many
pastoralists who use the natural resources to sustain their livestock. Due to the prevailing
environmental changes, these pastoralists require various adaptation strategies for the
survival of their small ruminants. Adaptation is vital for all pastoralists globally, especially
those living in semi-arid to arid regions as these areas are badly impacted by climate change.
Farming with small ruminants that are able to constantly adapt to variable environments are a
long-term and low cost resource strategy for farmers in these areas.
Drought is a recurring challenge that farmers in dryland systems have to cope with and small
ruminants are forced to adapt to food and water available to them as drought affects their
survival, reproduction and production. This is because drought affects the environment
directly as rainfall has an impact on all forage and water resources found in drylands. Thus
available forage and the utilisation of this resource by small ruminants is essential for sheep
and goat farmers who depend on these animals for their livelihoods.
This thesis sets out to establish sheep and goat breeds found in a dryland pastoral system in
South Africa focussing on their genetic differences and their diet selection during a drought
period. The study was carried out in the 582 634 ha Steinkopf communal area located in the
semi-arid to arid region of Namaqualand in South Africa. The dominant land use in this area
is livestock farming where farmers utilise two biomes for grazing.
Using mitochondrial DNA, genetic differences were investigated in small ruminants found in
Steinkopf. The small ruminants that were studied were the Boer goats, Swakara sheep
(Karakul) and cross-bred sheep. These were the most commonly farmed small ruminants in
this area. Genetic differences and diversity found within the small ruminants in this area
supports their ability to adapt to drought and changing environments. Diet selection of these small ruminants were assessed using direct forage observation during this drought period in
both the Succulent and Nama Karoo biomes.
Findings of the study indicate that small ruminants during a drought period will largely forage
on what is available to them. Boer goats changed their diets from browser to grazers in the
different biomes while sheep remained grazers in both biomes. This suggests that these
animals are well adapted to changing forage availability and will adjust their feeding
behaviours accordingly. Succulent plant species were utilised by all small ruminants and this
can be regarded as new knowledge for small ruminants in dryland systems. Succulent species
play a role in the diets of small ruminants in the Steinkopf rangeland and these animals have
adapted traits that allow them to eat plants that contain high levels of phenolics and tannins,
which show their high adaptability to this area. This study also revealed that indigenous and
locally bred sheep in this area are crucial resources for livestock farming in this area. Swakara
sheep in this area showed a low level of genetic variation while cross-bred sheep and the Boer
goat had significant variation. With a long tradition of breeding small ruminants in the
Steinkopf communal area that suit changing conditions, livestock keepers have accumulated
detailed knowledge of their animals.
Recommendations from this study were to do further studies regarding genetic variation
within the cross-bred sheep as this information will be useful for breeding programs in
dryland areas and it will add to the small ruminant genetics in South Africa. Because this
study was conducted in a drought period, I recommend that diet selection should be observed
during a regular wet and dry period as this would indicate how these animals adapt to what
forage is available to them. These studies can act as management strategies for herders as it
can provide information on how to use the natural resources sustainably.||en_US