Protein - which is best?

Protein can either be Rumen Degradable (RDP) or Bypass Protein (BP). Most “real foods”, for example grains, pasture, hay and protein meals will have a bit of both in them, whereas urea is entirely Rumen Degradable.

Rumen Degradable protein is handy, as it stimulates and feeds the rumen bugs so that they live, work and die, and are then washed down into the small intestine where they are absorbed as Microbial Protein.  On the other hand, Bypass Protein is the most closely aligned with lean muscle, otherwise known as (beef and lamb!) production.

Recently I’ve been doing some cattle and sheep drought rations where we are bumping up the protein content of the diet by using a feedlot concentrate which contains urea. Generally, if we add 1% urea to the diet, it increases the overall protein content of the ration by 3%.  It’s powerful stuff.  We can get a fairly good result out of this, in terms of weight gains, especially in mature animals.

So, if we can get by with just some urea, why would you bother with real food sources of protein?

The need for Bypass Protein will be higher in younger animals that are laying down muscle tissue. For example, early weaners or young growing stock will really benefit.  

Furthermore, the need for Bypass Protein will be determined by the efficiency of microbial protein production.  In other words, you need a well formulated ration that has good substrates for fermentation, the correct amount of oil, the presence of vitamin and mineral co-factors and the right rate of protein fermentation in order to generate good amounts of useful microbial protein.  This will reduce the reliance on Bypass Protein to some degree.  If you need help formulating your ration please get in touch!

Interestingly, I’ve also been doing the sums on these rations and sometimes it’s actually around the same price to use “real foods” rather than urea.  For example, a 75% barley, 25% oaten hay and 5% feedlot concentrate ration costs $464/tonne; whereas a 56% barley, 20% oaten hay, 4% vitamin/mineral mix and 20% lupin ration costs $449/tonne.  

The beauty of using a pulse grain, cotton seed or protein meal as the protein source also means that we can dial it up or down in the ration to suit the needs of the group of animals you are feeding.

So, it will be horses for courses but it’s worth getting some advice on what’s best in your situation. As always, protein is second in importance to energy in the ration!

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