Dr Nozipho Phila Gamedze

Setting out to resolve
feed problems

Dr Gamedze's findings have the potential to:

• Lower the cost of animal feed production, especially for small-scale and emerging farmers;
• Promote the cultivation and use of Mucuna pruriens utilis, an underutilised yet valuable local crop;
• Encourage the use of green nanotechnology in agriculture and veterinary science;
• Contribute to environmental sustainability by reducing reliance on synthetic feed additives and imported protein sources.

As she looks to the future, Dr Gamedze plans to continue her research and commercialise elements of her work in collaboration with agricultural stakeholders.

"We have the science, the resources and the indigenous knowledge to solve our own problems. This research is a step toward food sovereignty and scientific excellence driven from within the continent," she says.

The seeds of this legume have high levels of energy, protein (amino acids), minerals and essential fatty acids, among other nutritional qualities. However, their usage as animal feed is limited because they have a high fibre content and contain toxic substances, primarily a noxious amino acid called 3,4-dihydroxy-L-phenylalanine (L-DOPA). Consumption of this amino acid reduces appetite and growth.

Impact and future directions

Seeking to resolve the problems of high fibre content and toxic substances, Dr Gamedze undertook nanoparticle pre-treatment of the seeds so that they could be used as beef cattle feed.

She developed the green-synthesized ZnO nanoparticles at the NWU's subject group Chemistry, using the aqueous extract of Mucuna seeds.

In a pioneering cross-disciplinary study involving in vitro and in vivo techniques, Dr Gamedze tested the nutritional utility of these green nanomaterials in improving the diets of beef cattle.

She found that the plant-based ZnO nanoparticles could enhance feed efficiency and animal health when combined with Mucuna seed meal-based feed as a cost-effective alternative to conventional protein sources such as soybean meal, cottonseed cake and sunflower seed cake.

Double-checking the findings

An important quality of her research was that she used both in vitro and in vivo methods. This turned out to be critical.

In the in vitro system, both the green and conventional nanomaterials increased the digestibility of Mucuna seed meal. However, in an in vivo experiment with Bonsmara steers fed a high dietary level of the seed meal, the phytogenic nanomaterials deteriorated the detrimental effects of the legume on growth, carcass traits, and some haematological responses while the conventional nanomaterials abrogated the harmful effects.

These findings highlighted the danger of solely relying on research outcomes achieved using in vitro systems without further validation using in vivo systems.

"This research shows how indigenous knowledge and advanced science can come together to solve real-world problems," says Dr Gamedze. "We're not only reducing feed costs for farmers, but also using safe, sustainable technologies that protect the environment and improve animal nutrition."

Bringing diverse perspectives to her work, Dr Gamedze's PhD was supervised by a dynamic team of experts including Dr Doctor MN Mthiyane as lead supervisor and Prof Sydney Mavengahama, expert in agronomy and legume utilisation, and Prof Damian C Onwudiwe, an expert in nanobiotechnology and inorganic chemistry.

Their collective mentorship enabled Dr Gamedze to bridge the gap between chemistry, agriculture and biological systems, making her work a true reflection of the NWU's commitment to transdisciplinary research for sustainable development.