Native legume species from the Northern Cape province of South Africa and their potential use as forage crops.

Philosophiae Doctor - PhDThe lack of bioclimatically suitable forage species for livestock production in the water-limited agro-ecological areas of South Africa has resulted in significant feed shortages within these areas during the ongoing drought experienced within the country. This, in turn, has resulted in significant livestock mortalities leading to financial difficulties for the farmers and farming communities within these areas. Thus, many of the water-limited agro-ecological areas in South Africa have been declared disaster areas. These cyclic long-term droughts, as well as more common short-term droughts are expected to increase in frequency, duration and intensity under the predicted future bioclimatic conditions. Although there has been significant investment into the development of improved, better-adapted forage crops for these bioclimatically marginal agro-ecosystems, these efforts, to date, have largely been unsuccessful. Therefore, in this study, we propose to identify and evaluate species that are native to the water-limited South African agro-ecosystems and that can potentially be implemented in alternative fodder flow programs within these water-limited agro-ecological areas

Nutritional quality of Calobota sericea fodders. A preliminary assessment

This study aimed to provide preliminary information regarding the nutritional quality of Calobota sericea, a preferred perennial legume forage species from the water-limited rangelands of South Africa. Calobota sericea plant samples were collected from the Namaqualand rangelands in the wet and dry season and analysed for secondary compounds, fibre, protein and mineral nutrient content. The results from the fibre analyses were used to determine the digestibility and energy content of fodders. Preliminary results indicate that C. sericea fodders are of better nutritional quality in the wet season and that protein content, digestibility and energy content is sufficient for maintenance of lambs and dry ewes. The energy content, however, was not sufficient for maintenance of pregnant and lactating ewes. Furthermore, certain mineral nutrients (Na, P and K) were not found in sufficient concentrations in this species, and it was thus suggested that further investigation is needed into whether fertilisation could potentially improve the protein, digestibility and mineral nutrient content of C. sericea fodders

Nutritional quality of Calobota sericea fodders: A preliminary assessment

This study aimed to provide preliminary information regarding the nutritional quality of Calobota sericea, a preferred perennial legume forage species from the water-limited rangelands of South Africa. Calobota sericea plant samples were collected from the Namaqualand rangelands in the wet and dry season and analysed for secondary compounds, fibre, protein and mineral nutrient content. The results from the fibre analyses were used to determine the digestibility and energy content of fodders. Preliminary results indicate that C. sericea fodders are of better nutritional quality in the wet season and that protein content, digestibility and energy content is sufficient for maintenance of lambs and dry ewes. The energy content, however, was not sufficient for maintenance of pregnant and lactating ewes. Furthermore, certain mineral nutrients (Na, P and K) were not found in sufficient concentrations in this species, and it was thus suggested that further investigation is needed into whether fertilisation could potentially improve the protein, digestibility and mineral nutrient content of C. sericea fodders

The Potential for Endozoochorous Dispersal of <i>Vachellia nilotica</i> Seeds by Goats: Implications for Bush Encroachment

Seed dispersal has become an important component in understanding plant–animal interaction. Recently, there have been concerns about the role of ruminants, particularly browsers, in the dispersal of woody plant seeds. This study aimed to determine whether including Vachellia nilotica seeds in livestock, diets could reduce the spread of viable seeds in the rangelands and control bush encroachment. The shoots and seed pods of Vachellia nilotica were harvested and analyzed for fiber, protein, and mineral nutrients at different seed pods inclusion rates, with or without a feed additive. Six diets were selected for feeding 24 goats and quantifying seed recovery and germination after ingestion. Results indicated that including seed pods and feed additives to Vachellia nilotica shoots significantly improved the quality of the fodder. Chipping the seed pods prior to including them in the diet resulted in 13% intact seed recovery, and approximately 2% of these seeds were recovered after ingestion. These recovered seeds were mostly still viable but were still dormant as seed coats were not sufficiently damaged after ingestion. Therefore, viable seeds may still be dispersed in the rangeland, leading to further bush encroachment

The impacts of season and livestock management strategy on the quality of diets selected by goats and sheep in the semi-arid rangelands of Namaqualand, South Africa

Access to good-quality forages is one of the major limitations to livestock production in semi-arid pastoral systems. This study aimed to determine whether there are differences in the nutritional quality of diets selected by herded and free-ranging goat and sheep flocks utilising Namaqualand Granite Renosterveld vegetation during the wet and dry seasons. Plant samples collected along the grazing routes of livestock were dried and analysed for their fibre, condensed tannin, total phenolic and mineral nutrient contents. The study showed that a large variety of forages were on offer and livestock groups selected different diets of which some were different to the total diet on offer. In general, significant deficiencies in phosphate, protein and energy in the diets selected by herded and free-ranging goats and sheep were observed in both wet and dry season. The quality of the diets selected by herded and free-ranging livestock was also found to be different from each other, with herded livestock generally selecting more nutrient-dense diets. Herding, therefore, allows livestock to access better-quality forage in the Namaqualand Granite Renosterveld rangeland, where it is generally poor.Keywords: herding, Namaqualand Granite Renosterveld, pastoral livestock, protein deficiencies, small stock nutritio