While the European Union (EU) totally banned the use of antibiotic growth promoters (AGPs) in broiler chicken production in 2006, South Africa and some developing countries continue to use AGPs as in-feed additives in poultry diets.
“The late 1990s saw many consumers in the EU up-in-arms about harmful concentrations of drug residues, linked to the development of antibiotic-resistant pathogenic bacteria, in the chicken meat they were being sold,” said Dr Thobela Nkukwana from the Poultry Nutrition Division of the Agricultural Research Council (ARC).
This led to certain EU countries restricting the use of antibiotics to therapeutic use, and then by prescription only. That was in 2000. Six years later, a total ban on AGPs was instituted.
Since the early 1950s, the inclusion of AGP’s as additives in poultry feeds, during the early stages of growth, has been practiced widely. The objective was to improve gut functionality and health, thereby maximising nutrient utilisation and growth performance.
The reason for the madness
“With advances in poultry breeding, a broiler chicken fed on a balanced AGP-enhanced diet, reared in a bio-secure environment grows to 2 kg in just 35 days,” said Thobela, who sits on a sub-committee of the Animal Feed Manufacturers Association (AFMA). The sub-committee deliberates on whether South Africa should continue with the in-feed inclusion of AGPs in broiler chicken production.
AGP-enhanced feed enables large chicken flocks to be reared under intensive systems with minimal mortality and pathogenic infestation. Large poultry producers in South Africa try to mitigate the effect of AGPs by feeding an AGP-free “withdrawal” diet five to seven days before the chickens are slaughtered.
This facilitates the withdrawal of AGP residues from the chicken system. This process is regulated by ACT 36 of 1947. However, due to high feed costs, some of the low capital farmers in informal markets, are sometimes not able to buy the withdrawal diet. Sometimes they don’t do this because of a lack of knowledge.
In South Africa chronic diseases such as tuberculosis and HIV/ AIDS are prevalent. Selling AGP contaminated poultry to people infected with these diseases is tantamount to putting them at a higher risk of succumbing to opportunistic diseases like the common cold.
Finding an alternative
Since 2013, the FDA in the US has been pushing for restricted use of antibiotics to therapeutic use only, while companies across the globe are looking for alternatives.
So too is Thobela. Her PhD revolved around investigating whether or not certain endemic plants were suitable as replacements for AGPs.
By chance she heard about Moringa oleifera from a University of Fort Hare student who used it to feed goats. The Moringa oleifera reportedly has nutritional properties that holds health benefits. The goats were purportedly extremely healthy and the student put it down to the tropical plant’s anthelmintic and antioxidant properties.
“He told me that he bought the plant in Limpopo and that the locals drank it as a tea in warm water and sprinkled the ground leaves into their porridge. I went to see for myself and was amazed. I asked some village women to harvest some for me and took that back to Stellenbosch University.”
“My thesis was premised on the idea that if you raised your chickens in a clean environment and fed them on a natural diet containing high levels of the leaf they should grow with good gut health and therefore reach the market healthy and safe enough to be consumed.”
Her supervisor at the time, Professor Voster Muchenje, says Thobela will be a top researcher because she believes in top-quality science and is not comfortable publishing something that is sub-standard. “She strives for quality,” he says.
It was also by chance that Thobela ended up doing a PhD in animal science. After school she wanted to study pharmacy, but the University of the North in Pietersburg rejected her application because she did not meet the entry requirements.
Instead she enrolled in a medical sciences course but when the curriculum was revised, Thobela did not know what to do next. She spoke to fellow students who were studying animal science. “I went to see their lecturer, Prof Lindelani Ndlovu. He explained the curriculum to me and got me interested. But I told him my first love was medicine.”
“If you relate that to the health sciences you are still helping people. Agriculture is about food security and producing food for humans,” he told me.
Thobela took the course but it wasn’t until her fourth year that it gelled with her. Her Honours focused on the reproductive physiology of chickens and by the end of the year she was hooked. Her Professor at the time mentioned that there was a world-renowned Professor at the University of KwaZulu-Natal, Professor Rob Gous, who specialised in the study of poultry. He recommended that she contact him.
She didn’t have a cellphone so she emailed him immediately from her professor’s office. The email introduced her and requested him to be her Masters supervisor. Unfortunately, Rob replied that he did not have the funds available but would keep her in mind if things changed.
“I took up a position at Jet at the East Rand Mall at the beginning of the following year. I was over the moon when my father contacted me towards the end of that year to say that he had received an email from Rob. He had received funds and asked if i was still interested?”
With Rob’s encouragement Thobela finally settled on researching the “effect of dietary protein and energy on feed intake and performance of laying hens”. Rob often reminded her that she was not there to write a thesis but rather to receive an education. She submitted her thesis in 2003 and while waiting for her results Rob offered her a post as a research assistant.
After receiving her MSc, Rob recommended her for a position at Nutec SA (Pty) Ltd, where she worked for two years as a monogastric nutritionist before taking up a post as a lecturer at Fort Hare University.
“At first I did not enjoy lecturing but I soon realised the value in what I was doing and that changed my perspective. I also realised that an academic was only really recognised if you had a PhD.”
Thobela was interested in antibiotic growth promoters and drafted a proposal for a PhD. It was not long before she received her doctorate. In 2014, she left Fort Hare to take up a post as a researcher in the poultry nutrition division of the ARC.
Her motivation to switch back to the research field was prompted in part by patriotism.
“Poultry research in South Africa was dwindling, and there was no interest in researching on alternatives to AGPs. I thought how can a country that consumes so much poultry not be conducting research necessary to find an alternative?” she said.
She also views poultry production as a tool to combat food insecurity, especially in developing countries like South Africa.
“Stability in a society is crucial in my view, and I believe an educated nation with sustainable agricultural production systems is the foundation for the development of quality livelihoods.”
Thobela has also been involved in many upliftment projects as a role model.
“My message to school learners has always been and will always be that mathematics and science are key subjects to studying agriculture or getting into any science field.”
Thobela tries to convey to learners that agricultural studies are imperative for ensuring food security and the well-being of households, particularly in rural areas. Not just from a quantitative perspective but also from a qualitative and safety perspective.
“I convey a similar message to farmers, who, at the end of the day, are one of the most important cogs in this wheel.”