The University of Mpumalanga (UMP) hosted a Seminar titled: Ruminant Production for food security, environmental stewardship, and thin waistlines: A philosophical balancing act, which was delivered by NRF-rated researcher Professor Victor Mlambo from the Faculty of Agricultural and Natural Sciences.
Whereas the contribution of ruminants to human civilization remains unequivocal, there are concerns regarding the unintended negative consequences of rearing these animals for food. These concerns range from the ruminant’s contribution to greenhouse gas emissions to negative impacts of its products on the health of consumers. Rearing ruminants for food is thus seen as the root cause of ills such as climate change, species extinction, deforestation, food insecurity, cardiovascular disease, obesity, cancer and diabetes.
Professor Mlambo explained the balancing act required to ensure that ruminants continue to play a crucial role in meeting global protein demand thus contributing towards food and nutrition security.
“However, animal production also has profound implications for animal welfare, the environment and human health. As animal scientists these are the concerns we should take into consideration as we continue to produce animals for food. The question we want to answer is whether we can design ruminant production systems that can maximize food security, while minimizing negative impacts on human and environmental health.”
He further said there is a high demand for meat, which is driven by the growing economy, cultural affluence, human population and rapid urbanisation which makes meat more accessible.
“As animal scientists, we need to satisfy this growing demand even in the face of societal concerns regarding the wisdom of humanity’s reliance on animal agriculture. Indeed, we must answer questions such as: Are ruminants still a viable option to improve food and nutrition security? Is ruminant production an environmentally friendly pursuit? And does the consumption of ruminant products impact human health?”
Ruminants: Food and Nutrition Security Nexus
Professor Mlambo further said ruminant production has positives impacts on food and nutrition security because these animals convert cellulose into meat and milk for human consumption. Given that cellulose is one of the most abundant biomolecules on the planet and that humans are incapable of using it as a direct food source, ruminants are indispensable to the effort of provide high quality food to a growing human population. In addition, meat and milk are dense sources of essential macro- and micro-nutrients with high biological value.
“This means these products contain digestible nutrients in the same quantities and ratios that human beings require. The opposite will be a plant food source, where plant tissues provide nutrients to form animal tissues – given that the two tissues differ greatly in terms of their nutrient composition, there is a mismatch between nutrients required and nutrients supplied resulting in lower biological value of plant nutrients. However, if it’s an animal tissue providing nutrients to form another animal tissue, there is a close match and the biological value is considered to be high.
For example, for Vitamin B12, meat and milk are the only natural dietary source, which highlights the importance of meat and animal products. In certain dry areas, it may not be possible to grow plants, but animals might have the ability to survive. All these are the positive contributions of ruminant agriculture to food and nutrition security.”
Dr Bongiwe Mcata closed the seminar with words of appreciation.
During the seminar, Professor Mlambo touched upon the potential threats of ruminant production to food security, specifically raising the question of whether ruminants compete with humans for food.
“The answer I will give is that sometimes yes, other times no. Reared as nature intended, ruminants offer no completion to humans for food because they consume 6 billion tons of feed per annum and 90% of it is not human edible.
Second question is whether ruminants compete for land with crops? And the answer is yes, when considering cultivated pastures that use fertile lands. Indeed, more people could be supported from the same amount of land if vegetarian. However, ruminants can also use marginal lands, unsuitable for crops and can also use crop residues and by-products.
The third concern is that ruminants have a very low feed conversion efficiency and thus are costly to produce. While ruminants are, indeed, less efficient (10%) compared to other animals when it comes to converting feed to animal products, these animals use feed that is otherwise of no food value to humans. So, the fact that they convert the feed inefficiently has no negative implications on food and nutrition security. However, we should continue to enhance feed conversion efficiency in ruminants for meat production.”
Greenhouse Gas Emissions
In addition, Professor Mlambo highlighted that ruminants have a multitude of environmental impacts, with global warming emerging as the most significant concern among them. “You might start to think linking this climate crisis or this environmental problem with ruminants is probably tenuous. But it really is a straightforward link through greenhouse gas emissions from ruminants.
According to the IPCC (2008), agriculture contributes 14% of anthropogenic greenhouse gas emissions. Just in case you might think it’s only agriculture to blame, several other industries also contribute larger proportions of greenhouse gases. How do ruminants end up producing such dangerous gases?
“Ruminal microbial fermentation produces two major greenhouse gases, carbon dioxide and methane. In addition, carbon dioxide from feed production and deforestation and nitrous oxide from manure and slurry management are also sources of greenhouse gas anthropogenic emissions associated with ruminant production,” he said.
He added: "Now you will notice that when people talk about greenhouse gases from animals, they don't talk much about carbon dioxide but methane. There are two reasons for this; as far as carbon dioxide is concerned, we consider ruminants to be carbon neutral and methane has 30 times the global warming potential of carbon dioxide despite a shorter lifespan in the atmosphere, about nine to 12 years.
The reason why ruminants are considered to be carbon neutral is that they produce carbon dioxide from the fermentation of carbohydrates in plants. These carbohydrates are made when plants capture the carbon dioxide in the atmosphere through photosynthesis.”
Head of School of Agricultural Sciences, Professor Fonso Kutu welcomed and introduced the speaker.
Animal scientists and producers have responded to the enteric greenhouse gas emission challenge by identifying and evaluating strategies that mitigate enteric methane emissions. Methane emissions represent a major (about 4–10% of gross energy intake) energy loss from the diet offered. As such, it is not that difficult to convince ruminant farmers to do more to reduce these emissions because if they succeed, it will increase the efficiency of ruminant production while at the same time protecting the environment.
Animal Products and Human Health Nexus
Professor Mlambo said that “the increasing popularity of vegetarianism in developed countries reflects the concerns regarding the role that meat (particularly red meat) plays in the aetiology of chronic diseases such as colorectal cancer, coronary heart disease and type II diabetes. It is, however, important to state that the exact aetiology of these diseases remains largely unknown despite years of scientific research."
Given that the aetiology of these lifestyle diseases is multifactorial, attributing increasing incidence of these diseases to meat consumption is done with little evidence based on observational studies. Given that humans rarely use meat as a sole food item, it remains incredibly difficult to establish a cause–effect relationship between meat consumption and the incidence of these chronic diseases.
Professor Mlambo concluded by stating that, “Whatever is the scientific consensus, or lack of it, on the effects of meat consumption on human health, it is clear that reflections on many fronts are required. For animal scientists and meat producers, this is an opportunity to identify and evaluate strategies that could be used to make meat and meat products healthier.”
@ Story by Cleopatra Makhaga. Pictures @Chrisplphoto.