A tree long overlooked as goat feed could help farmers in the North West Province boost meat production and cut feed costs, new research from the North-West University (NWU) has found.

NWU researchers from the subject group Animal Sciences at the Mahikeng Campus, led by primary author Onke Hawu, say the Searsia lancea tree, commonly known as the Karee tree, has untapped potential as livestock feed. It is a hardy, evergreen and drought-resistant tree with a graceful, weeping form common in semi-arid parts of southern Africa. While its leaves are rich in protein, they also contain tannins, compounds that make them harder for goats to digest and less appealing to eat.

By treating the leaves with polyethylene glycol (PEG), a substance that neutralises tannins, the team found that goats ate more, digested more nutrients and grew faster.

“We wanted to see if treating Searsia lancea with incremental levels of PEG would improve intake, digestion and growth without harming the goats,” Onke said. “Our results show that it can be done.”

The study determined that 15,4 grams of PEG per kilogram of dried leaves offered the best balance between weight gain and feed conversion. Blood tests confirmed there were no negative health effects and, in some cases, nutrient levels in the blood improved.

This could be a game changer for farmers during the dry season when poor-quality grazing limits animal growth. Searsia lancea is abundant in the region, but tannins have historically restricted its use as feed.

The research provides evidence that simple, affordable treatments can increase the value of locally available forage, offering small-scale and commercial farmers a way to rely less on purchased feed.

“By using what we already have in the environment, we can address feed shortages and support farmers without increasing production costs,” Onke concluded.

Onke Hawu