The words urea (English), “ureum” (Afrikaans), “oiriuma” (Otjiherero) are common to many farmers when it comes to livestock lick supplementation. However, the use or role of urea is widely not well understood, apart from it being labelled as a risk to livestock.
In livestock nutrition explanations, urea is a non-protein nitrogen compound that is converted into protein in the rumen of a ruminant animal (cattle, sheep, goats). These animals’ digestive system is comprised of four stomach compartments, the rumen, abomasum, omasum, and the reticulum.
The rumen is the principal compartment for fermentation of ingested feed. This fermentation or breakdown of food is performed by the microorganisms (bacteria) living in the rumen called “rumen microbes” or simply rumen bacteria. The efficiency of fermentation in the rumen depends on the efficiency of the microbes, and the efficiency of the microbes depend on the availability of urea, and the effective use of urea depend on the population of microbes and the energy content of the feed amongst others.
When urea enters the rumen, the microbes break it down to release ammonia (a gas) which they then convert into protein, known as “microbial protein” which the microbes use as their food to grow and multiply, thus enhancing their performance in terms of digestion. This is why urea is needed during the dry season to help animals digest the dry forage materials effectively. Much of the urea in licks/feed is utilized by the microbes than by the animal’s body itself.
Why and when is urea a risk?
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 detoxing and excretion (removed) from the body via urine.
When this ammonia is too much for the liver, then toxicity takes place. This happens when there is insufficient fermentable energy in the feed to help the breakdown of urea or when the feed contains a significantly high crude protein already. Therefore it is very important to feed the correct amount of urea to animals and to provide or mix urea-containing lick supplements according to instructions, and also to consult animal nutritionist or livestock experts. Most of the winter lick supplements contain urea, e.g. dryveld concentrate, cattle lick 40, cattle mix 415, and bush improver, amongst others.
On the other hand, urea is also a problem when not carefully handled at farm. When urea is not thoroughly mixed, has formed lumps, the animal is at risk of ingesting too much at an instant. A tablespoon of urea can be potent enough for the animal. Urea dissolves easily in water, thus, if the animal drinks such 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 water accumulation.
Signs of urea poisoning and remedial actions
The onset of symptoms after ingestion of urea can be from 30 minutes to three hours depending on the amount ingested amongst others. The symptoms of urea poisoning include muscle twitching, frothy salivation, incoordination, spasms, bloat, abdominal pain, rapid breathing and weakness amongst others. The most basic and available remedies for treating urea poisoning is water and vinegar. For cattle, a mixture of vinegar (750ml) and one litre of water, and for sheep and goats a half bottle of vinegar and half a litre of water given orally.
Lastly, provide the right supplements at the right time to the right animal in the right amount. Supervise the mixing of licks at the farm, and always observe animals around the lick and water troughs. Have a first aid tool box at the farm, and report any abnormalities immediately.
* Erastus Ngaruka is Technical Officer within Agribank’s Agri Advisory Services Division.
New Era Reporter
2018-10-26 10:11:10 8 months ago