Worldwide, the invasiveness of Opuntia spp. and its impact on various ecosystem services has been recognised especially in semi-arid areas where rainfall is erratic. The semi-arid environments are the habitats of plants which have adapted to be able to grow in severe hot and dry regions. Opuntia spp. normally thrives in conditions of high temperatures, low rainfall, saline soils and it can also adapt and survive in severely degraded soils which have a limited nutrients supply. Its positive impact includes its recognised value as livestock fodder. Opuntia’s adaptability to harsh conditions, high dry matter yield, palatability and significant levels of energy, as well as its availability at a low cost during the dry season, decreases the use of expensive supplements and conventional diets in many areas. There is a need to understand the importance of this invasive Opuntia species when incorporated in animal diets. As a part of its control measures, the use of livestock in controlling the spread of Opuntia may assist in reducing its abundance and invasiveness while at the same time providing a consistent supply of forage during the dry season. Information on its nutritive value, incorporating the species in animal diets and the means to control it must be well understood to recognise the species’ contribution to an ecosystem.

Among the possible impacts of plant invaders on South African biodiversity, water supplies, and rangeland production, Lantana camara is ranked the highest in terms of its environmental impact. Globally, L. camara is regarded as one of the most ecologically and economically destructive invasive alien plants. The spread of L. camara affects the environment and threatens livestock productivity due to its toxicity to animals (especial cattle and sheep) in most semi-arid areas of South Africa. Lantana camara is known to have high concentrations of nutrients that are beneficial to livestock, but most previous research has concentrated on its toxicity. To enrich our knowledge on its nutritive value, further research has to evaluate its dietary impact on the growth and health of different ruminant livestock species, particularly goats. This review evaluates L. camara as a potential browse species for goats in southern Africa, and its adverse effects on goats and other ruminant livestock are also presented. The review describes L. camara and its distribution globally, its poisonous effect to livestock, and potential use as an alternative forage to browsing animals such as goats, which have proved resistant to its harmful traits. The high crude protein content, low fibre and adequate macro-minerals for small ruminants makes L. camara a good ruminant protein supplement in semi-arid areas. In addition to other biological control strategies, the prospects of using goats as a biological management tool is discussed. The research will contribute to the understanding of the control measures of L. camara while improving the productivity of small stock, especially goats. This means that a balanced understanding of its nutritional value as a source of protein and its negative impact on the environment should be considered in developing mitigation strategies to arrest its spread. We, therefore, recommend the use of goats in the control of L. camara; however, further studies are needed to limit its toxic effects, and thus improve its value.

Globally, there have been differing views on whether the proliferation of invasive species will be of benefit as a livestock feed source or it will have detrimental effects on the ecosystem. The infestation of invasive plants such as Prosopis species does not only affect the groundwater levels but also threatens the grazing capacity and species richness of most of the semi-arid areas around South Africa. Though Prosopis is invasive, it is however of good nutritive value and can serve as an alternative source of protein and minerals for livestock during the dry season. Bush encroachment by browsable invasive species can be controlled through biological methods by using organisms such as livestock. The utilisation of Prosopis through browse benefits livestock production and at the same time reduces its spread, thereby preventing possible environmental harm that may arise. Although several studies have been carried out globally on the assessment of the Prosopis species’ nutritive value and also on the threat of this invasive species to the environment, there is a need to update the state of knowledge on this species, particularly in the context of the semi-arid areas of South Africa where the dry season is characterised by less herbage of poor quality. It is therefore critical to understand whether Prosopis is a beneficial invader, or a detriment that needs to be eradicated. This review will contribute knowledge towards finding practical solutions to controlling Prosopis species and whether utilising Prosopis as a feed source will limit its spread and result in a vegetation structure where Prosopis becomes part of the ecosystem with limited detrimental impact. This means that the several components of the species such as nutritive value and the negative impact associated with this plant species along with the means to control its spreading must be well understood to recognise the plant species’ vital contribution to the ecosystem.

Cropland abandonment has been happening in different parts of the world and is being driven by socio-economic, ecological, edaphic, and environmental factors. Most of the research focusing on drivers of cropland abandonment, succession trajectories, and responses to active restoration initiatives has been conducted in the republic of Nepal and regions such as Europe and America. In South Africa, the impact of cropland abandonment on household livelihoods, changes in vegetation and soil properties, and soil seed bank statuses have been conducted mainly in the Eastern Cape Province. The drivers of cropland abandonment in South Africa are like those observed in other countries, except for a few, which are country-specific such as poor support of communal farmers compared to their counterparts in the highly mechanised commercial farming sector. There is also a shift from low input cropping in the distant fields to high input cultivation in homestead gardens. Research results elsewhere suggest a woody growth suppressive effect of grazing, particularly average grazing intensities, being crucial in suppressing woody proliferation while high grazing intensities are detrimental to herbaceous species’ richness and promote woody species’ encroachment. A combination of fire and grazing alters the natural succession trajectory by promoting fire-tolerant species and arresting woody species. Similar to other countries, cropland abandonment is associated with colonisation by alien invasive species which are favoured by cropping legacies, such as altered soil levels of pH, Nitrogen, and phosphorus. Furthermore, limited moisture in semi-arid areas promotes the encroachment of indigenous woody species. Secondary succession in abandoned croplands can be manipulated for the benefit of livestock production in communal areas by introducing management strategies that will discourage encroachment by both invasive and indigenous woody species which lowers the grazing capacity. Furthermore, active restorative practices, such as reseeding with indigenous mid succession perennial grasses and legumes, will improve forage quality in abandoned croplands. Our understanding of succession trajectories under various unique disturbance regimes experienced in South Africa, such as communal grazing of abandoned croplands, compared to situations in other parts of the world is limited. Furthermore, the influence of other factors such as fire, soil fertility, and moisture needs to be understood.

A cost-effective, alternative protein and mineral source such as the Viscum species can be key to livestock production. Viscum spp. are used as feed in many semi-arid and arid regions globally, particularly during feed shortages. The species’ feeding value, and their pharmaceutical attributes, have been recognized worldwide, albeit with variation in nutritive value from one host to another. The antinutritional factors found in Viscum spp. may benefit livestock when consumed in moderation due to their immunomodulatory, proapoptotic, and antimicrobial properties. The Vachellia species are known to be the common hosts for Viscum spp. Further, even though Viscum spp. inhibit host tree development by reducing carbon absorption and the host tree’s carbohydrates, the efforts to regulate their infestation should not result in the plant’s total eradication due to the benefits to livestock (as well as in fodder and medicine). This review will help to improve understanding of Viscum species control measures, while also increasing the productivity of ruminants.

This paper assessed the factors influencing farmers’ choice to participate in selling goats and the extent of goat commercialization in Zululand district of Kwa-Zulu Natal Province in South Africa. Data were collected through questionnaires administered to 175 selected goat farmers in five local municipalities within Zululand district. A Probit model was used to estimate the factors affecting farmers’ choice to commercialize while Tobit regression model was used to analyze the factors affecting the extent of commercialization. The Probit results show that the factors that positively and significantly affect farmers’ choice to commercialize are gender, education level, quantity of goats, and type of marketing channel. The Tobit results revealed that factors that have a positive significant effect on commercialization are gender, level of education, experience in goat farming, and time of the year. The paper recommends that government support programs should be promoted to achieve high goat production and establishment of formal marketing goat sector to promote commercialization. Furthermore, information about goat nutritional attributes must be effectively shared with the society to change the negative stigma towards goats thus increasing the demand for goat and goat products, thus increasing farmers’ market participation and promoting commercialization.