by Jeff Pastoor, M. Ag.
Urea or NPN (non-protein nitrogen) has been used in cattle rations for nearly 100 years as a cost-effective protein source. While the use of NPN in the ration will often reduce cost, there are nutritional advantages to the ration as well.
An optimum population of rumen microbes is essential for proper and efficient rumen function. Rumen microbes need an energy source (typically from starch or fiber) and a nitrogen source (rumen ammonia) to reproduce themselves. This is why the rumen has a requirement for Rumen Degradable Protein; if the ration is lacking in rumen ammonia, we will starve those rumen microbes and the result will be lower dry matter intakes.
When NPN is fed to cattle, the conversion from urea to rumen ammonia is very quick and efficient. In comparison, when natural protein sources such as hay, grains, and grain by-products are fed, the metabolism to break these down to rumen ammonia is more complex & less efficient. Some feeds, such as distillers grains, are naturally high in by-pass protein which the rumen microbes cannot use.
Some grains, such as wheat, barley, and high moisture corn, are highly soluble sources of starch and because they degrade so quickly they require greater levels of Rumen Degradable Protein for efficient rumen fermentation. NPN is an excellent addition to rations that contain these highly soluble grains.
In addition to breaking down feedstuffs in the rumen, these rumen microbes are also very important as a protein source to the true stomach (the abomasum). So, supplying the right amount of Rumen Degradable Protein is not only important for proper rumen function, but also for supplying the proper flow of microbial protein to the abomasum.
To illustrate of the importance of NPN, QLF has summarized the results of 9 different University Trials which show the addition of NPN to cattle rations can improve performance, using a variety of grains and other supplemental protein sources.
| Average Response of 9 University Trials on the Addition of Urea in Cattle Rations: | ||
| Dry Matter Intake | Average Daily Gain | Feed Efficiency |
| +2% | +6% | +4% |
With some ethanol plants shutting down or running at reduced levels the supply of corn by-products has gotten tighter and the price has often risen. This means that in addition to improving nutrition and performance the use of NPN can also save you money. In recent projections, when comparing rations with low NPN levels to rations with higher NPN levels, the expected cost of gain was similar (assuming the same performance) but there was a $20-30/head savings in out of pocket expenses (the cost of the by-products + the cost of the balancer). By using more NPN, less by-products need to be purchased and more home-grown feeds can be utilized in the rations. This reduction in by-product purchases improves the feedlot cashflow.
Quality Liquid Feeds are the best way to bring NPN into your cattle rations and we can help you make the most of your home-grown feeds.