The big question to livestock and game farmers is: how do you reconcile a world in which the grasslands are declining, woody vegetation is expanding and the human population – which represents increased demand for food – is also increasing? Dr Ntuthuko Mkhize Agricultural Research Council says farmers cannot afford to leave the question for scientists alone to answer.
The ideas of range and forage scientist Dr Julius Tjelele recently got me curious about how vegetation has changed and is likely to change in the future.
He contributed an article titled “Bush encroachment: Making the best of a bad situation”, published by Food For Mzansi in August. In this article, he defines bush encroachment, gives a brief discussion on the potential causes and the negative effects of this phenomenon, especially on the grazing capacity and biodiversity status of the veld.
I also wondered about the implications of future vegetation change on the livestock and game industries that are heavily dependent on veld as an important resource.
My curiosity stemmed from the fact that about 70% of our country’s land is veld, largely used by livestock and game for forage. This article seeks to put together some predictions that may have serious future implications for livestock and game production off the veld, and to call for a critical evaluation of some herbivore and veld management options available to farmers.
It is my contention that farmers need to take cues from researchers proactively and adapt if they are to survive a future that will bring different challenges.
Encroachment a worldwide occurrence
Woody encroachment has increased in both farmed and conserved savannas all over the world in the last century. The highest increases have been in the arid and semi-arid ecosystems.
Scientific evidence predicts woody plant expansions to continue increasing with concomitant declines in the grassy vegetation in the future.
Concurrent with woody expansion is the increasing societal demand for animal protein and livestock products. The Food and Agriculture Organization (FAO) of the United Nations expects this demand to continue through to 2030. This demand will probably follow from the predicted increase in the global human population to around 9 billion by 2050.
In his article on 8 June 2021 on this platform, Dr Igshaan Samuels mentioned South Africa’s veld-dependent cattle to be roughly at 13 million, goats at 2 million, sheep at 20 million as well as more than 40 species of game.
It is worth mentioning that goats’ numbers, specifically in Africa, have been increasing over the past 30 years and it is predicted that by 2030 the numbers of cattle, buffaloes, sheep and goats in the developing world alone will exceed those of the rest of the world.
Remember, it is in the developing world where most of the woody expansion is increasing at the expense of the declining grassy vegetation.
If the numbers that I have put together here are anything to go by, then there is a serious challenge to feed the additional animals. To be a bit more specific, about 3.2 billion tons of additional animal forage per year will be required to ensure survival of these additional animals.
So the big question is: how do you reconcile a world in which the grasslands are declining, woody vegetation is expanding and human population – which represents increased demand for food – is also increasing?
This is problematic, partly because the majority of livestock species (cattle and sheep) and game species (African savanna buffalo, white rhino, roan and sable antelope, reedbuck, zebra and wildebeest) are predominantly grazers. Grazers’ diet is predominantly made up of grasses, herbaceous vegetation (forbs and sedges) and little to no woody vegetation.
From these numbers it is obvious that if farmers do not come up with some pro-active management strategies, the future is rather going to be bleak for these herbivorous species, as well as for extensive livestock and game enterprises.
If farmers fail to come up with adaptive systems, then it might not be possible to meet future demand for meat protein, meat products and ecotourism. These demands will be driven by increasing human population that will be accompanied by increasing animal numbers. The consequences of that failure are dire as they threaten to undermine any efforts of ensuring food security.
Farmers dare not sit back
Farmers cannot afford to falter. They also cannot afford to wait for botanists, plant or rangeland ecologists to come up with ways to stop or even reverse bush encroachment, because time is not on our side.
In his article, Dr Tjelele talks about making use of a bad situation by feeding the encroaching plants to the animals. He also indicates that some of these encroaching species have been proved to be a good source of the nutrients (energy, protein, minerals and vitamins) required by the livestock and game species for their survival and growth. After all, it is only by nourishing animals species that we can nurture ourselves.
While it is not a simple matter to train or force animals, that would ordinarily exclude browse or trees from their diets, to start ingesting what they consider unpalatable forages, there is an element of validity in Dr Tjelele’s call. Rather than spending millions of rand controlling these plants, I support the idea that we start investing our efforts towards embracing and using these encroaching species as forage for herbivores.
Hopefully we can spark a focused debate that will unpack the modalities of possible management strategies.
Dr Ntuthuko Mkhize is a rangeland ecologist at the Agricultural Research Council. He is based at Cedara in Pietermaritzburg, KwaZulu-Natal, where he heads the forage breeding and evaluation team. His research interest is broadly in plant-herbivore interactions, with special focus on the mechanisms that influence food selection and intake in large herbivores. He explores principles that underlie feeding behaviour with the aim to obtain reliable knowledge on the plant species, parts and chemicals that herbivores select while grazing, as well as why, how and when specific foods are ingested.
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