Farmers urged to adopt stover treatment to boost livestock nutrition 

By Ndumiso Tshuma

Agricultural experts in Zimbabwe have urged farmers to adopt innovative methods such as urea treatment of stover and silage production to improve livestock nutrition, particularly during dry seasons when grazing pastures are scarce.

Stover — the stalks and leaves left over after harvesting crops like maize — is often abundant at the end of the growing season but has limited nutritional value for animals in its raw state.

Nqobani Manyabi, an animal science specialist at EL Ganado Consultancy, said treating stover with urea could significantly improve its quality as livestock feed.

“Crop residues like maize stover have low protein content and high fibre, which makes them difficult for animals to digest,” said Manyabi. “Treating the stover with urea increases its nitrogen content, improves palatability and makes it easier for livestock to digest.”

Manyabi explained that farmers need about 1,000kg of dry stover, 50kg of urea and 200 litres of water to carry out the process.

The stover is stacked in layers of 100kg in a pit lined with black plastic sheeting. Each layer is then sprayed with 20 litres of water mixed with urea and compacted to remove air, which aids fermentation and reduces mould.

The pit is sealed with plastic and covered with soil. The treatment process takes between 21 and 35 days, depending on weather conditions. Once ready, the treated stover is aired in a shaded area for a week before being fed to animals.

“The poorer the initial quality of the stover, the greater the improvement after treatment,” said Manyabi. “Research shows that animals fed on untreated stover may lose 50 to 100 grams of weight per day, but with treated stover, they can gain a similar amount daily. Milk yields can also increase by up to a litre.”

Manyabi said various crop residues could be treated, including wheat and rice straws in addition to maize stover. He emphasised that using treated stover offers a sustainable and cost-effective way to boost livestock productivity while reducing waste.

“This method provides farmers with an opportunity to maximise the use of available resources, contributing to both economic and environmental sustainability,” he said.

In addition to urea-treated stover, Manyabi highlighted the role of silage — fermented green forage crops — in providing animals with high-quality feed during dry periods.

Silage is made by harvesting forage crops at the right stage of growth, chopping them into small pieces, and compacting them in airtight storage to promote fermentation by natural lactic acid bacteria.

“Proper compaction and sealing are critical to exclude oxygen and create an environment where beneficial bacteria can thrive,” said Manyabi. “This process preserves nutrients and ensures a steady supply of nutritious feed for animals.”

Manyabi added that successful silage-making could help farmers reduce feed shortages, maintain milk production and support livestock health even during challenging seasons.