Dry season: A guide to urea supplementation

Urea is needed during the dry season to help animals digest dry forage materials effectively.

However, it is very important to feed the correct amount of urea to animals, to provide or mix urea-containing lick supplements according to instructions, and to consult animal nutritionists or livestock experts.

Technical advisor for livestock and rangeland for Agribank, Erastus Ngaruka, stressed that the use or role of urea is not widely understood, apart from being labelled as a risk to livestock.

He explained that urea is a non-protein-nitrogen compound that is used in animal feeding to improve rumen function.



Effective breakdown

According to him, the digestive system of a ruminant animal is comprised of four stomach compartments: the rumen, abomasum, omasum and reticulum.

"Each of these compartments has a specialised function in the process of digestion of the ingested feed. This process involves breaking feed particles into smaller particles, absorption of nutrients and water, and up to the parting of excrete from the feed."

Ngaruka said that the rumen is the principal compartment for the fermentation of ingested feed. This fermentation or breakdown of food is performed by the microorganisms (bacteria and fungi) living in the rumen, referred to as "rumen microbes".

"The efficiency of fermentation in the rumen depends on the efficiency of these rumen microbes, and the efficiency of the microbes depends on the levels of nitrogen, sulphur, and energy in the diet."



Food for growth

Ngaruka added that the effective use of urea depends, among other things, on the population of rumen microbes and the energy content of the feed.

He explained that when urea enters the rumen, the microbes break it down to release ammonia gas, which they then convert into a protein known as microbial protein, which the microbes use as their food to grow and multiply, therefore enhancing their performance in terms of digestion and improving rumen function.

Much of the urea in licks and feed is utilised by the microbes rather than by the animal body itself.

According to Ngaruka, urea becomes a problem when the ammonia released by urea is in excess and cannot all be converted into protein by the microbes.

"This ammonia is transported to the liver for detoxification and excretion (removal) from the body via urine."



Dangers and remedies

When this ammonia is too much for the liver, toxicity occurs.

Urea is also a problem when not carefully handled at the farm.

"When urea is not thoroughly mixed, or has formed lumps, the animal is at risk of ingesting too much in an instant. A tablespoon of urea can be potent enough for the animal."

Ngaruka warned that urea dissolves easily in water, and if an animal drinks this water, it will be poisoned.

It is therefore advisable to avoid giving urea supplements when it is raining and not to expose the lick trough to moist conditions or water accumulation.



Take extra care

The symptoms of urea poisoning include muscle twitching, frothy salivation, incoordination, spasms, bloating, abdominal pain, rapid breathing, and weakness, among others. The onset of symptoms, depending on the amount, can happen after 30 minutes to three hours.

The most basic and readily available remedies for treating urea poisoning are water and vinegar. For cattle, a mixture of 750 ml of vinegar and one litre of water; for sheep and goats, half a bottle of vinegar and half a litre of water given orally.

Lastly, Ngaruka advised that farmers should provide the right supplements at the right time to the right animal in the right amount.

"Supervise the mixing and provision of lick supplements, and always observe the behaviour and conditions of animals, especially at feeding. Provide urea supplements during the dry season and mineral supplements during the rainy season."