7 strategies to minimise urea poisoning

As the season progresses and pasture quality declines, supplementing the breeder herd with adequate amounts of urea regularly, will reduce the rate of weight loss typically observed during the final quarter of the year.

Why feed urea and not a protein meal?

Well you can feed a protein meal, for sure! But if you aren’t close to a processing plant, or grain growing region, the cost of freight may be prohibitive.

When you feed urea, you aren’t directly feeding the bovine (cattle), instead you are feeding the gut microbes inside the bovine.

As the pasture quality declines and gets physically tougher, microbes in the rumen find it harder to digest. As a result, their productivity declines and less grass is digested. In turn, the whole bovine digestive system slows down, preventing the cow from eating as much grass as she needs to maintain condition.

However, when fed with urea containing about 10 Nitrogen to 1 Sulphur, urea will substantially increase microbe activity and growth, speeding up the passage through the digestive system, allowing the cow to consume more grass, and reducing the rate of weight loss.

With more feed coming in and a productive rumen microbe population more microbes get caught up in the feedstuff as it is washed further through the digestive system, becoming a source of protein themselves for their host cow as they are digested.

Not all poop and parties – proceed with caution

While feeding urea will help the cattle’s digestive system function better, there are a few things to be aware of to prevent your efforts from proving fatal to the cow.

When urea is digested by the microbes it turns into ammonia and carbon dioxide. If that ammonia isn’t either digested again by the microbes, or processed quickly by the liver, ammonia poisoning can occur, which can be fatal.

Strategies to minimise the risk of urea poisoning

While extreme toxicity of this type is almost always fatal, there are several strategies that can greatly reduce the risk to your herd.

Keep feed stations under cover (watch our Lick Sheds of Queensland reel).
Increase the amount of urea in the supplement over a period of weeks to allow the microbe population in the rumen to grow accordingly.
Avoid letting your cattle go for more than 2–3 days without urea supplement as the microbe population will decline again, meaning toxicity may occur when supply resumes.
If lick blocks have developed wells, turn them onto their side to allow moisture to drain away, as the urea concentration can build up in the water. It is critical to do this as soon as possible after rain or heavy dew.
For loose licks, add products that are known to control intake, such as salt and dicalcium phosphate.
Loose licks should always be fed in open ended troughs or troughs with large slits to allow water drainage.
Feed hungry cattle to reduce appetite before allowing them access to urea supplements. Hungry cattle are likely to gorge the lick while having insufficient microbes to process the ammonia.

Final thoughts

Keep in mind that urea, whether fed in a lick block, dry lick, or molasses format, is not a stand-alone feed product, and is therefore not suitable as a forage substitute. In fact, providing urea to stock will increase their appetite by 20–30%, so stocking rates will need to be adjusted to reflect this.

Additionally, urea supplementation will only help to minimise weight loss when supplied in the last quarter of the year, weight gain should not be expected.

It is also recommended to distribute lick blocks or supplement stations away from water sources to encourage stock to utilise the pasture and not attempt to subsist on lick and water alone (which can result in fatalities).

Despite these considerations, urea remains one of the most cost-effective strategies to increase protein in the diet, allowing the cows to consume more pasture and therefore energy.

FutureBeef has several resources detailing the ins and outs of supplementation.

Here’s the factsheet: Protein and urea supplementation

Here’s the podcast: How to make your stock thrive in the dry season

Here’s the webinar series: Sensible supplementation considerations, planning and actions