by
Thierry Aubert, and Elisabeth Rohrer, Delacon, Austria
Ruminants such as dairy cows accomplish true wonders, as they can transform inedible, low‐quality protein in roughage and concentrates into the high‐quality protein found in milk and meat. But which role does nitrogen (N) play here and, in fact, how does urea get into milk? And how do natural, plant-based feed additives make a substantial contribution in this context?
Like proteins, the rumen ecosystem is very complex in its structure and
function. Proteins are made up of 50 amino acids and more, delivering the
material for the building and renewal of cells and tissues. This function
cannot be performed by any other food. Cows require specific amounts of amino
acids to maintain the body, including muscles and bones, the unfolding of a
calf, and the milk production. There are two main sources that contribute to
the amino acid pool available at the ruminants’ duodenum:
First, the microbial protein, synthesised in the rumen by microbes and with 50-75 percent representing the most important amount of cows’ total protein supply. With the energy supply through carbohydrates, the microbes build up their own precious body protein out of nitrogen and amino acids, before they are being washed down to the cow’s duodenum where they are digested.
Though the microbial protein production is only ensured by simultaneous availability of ammonia, produced by hydrolysis of degradable protein (or N) sources and carbon skeletons from fermentable carbohydrates.
In case of energy deficiency and protein surplus, the microbes use protein for energy production, resulting in a waste of N. A waste that will be excreted in the cow´s urine and that will be reflected in higher levels of urea nitrogen in blood and milk as well.
Second, the undegradable protein (UDP), the part of feed protein that withstands the processes in the rumen, hence being available for the cow directly at the small intestine.
Regarding the UDP, it is important to make sure that the amino acid balancing of the raw materials of the ration is adjusted to the cows’ requirement. Though high yielding cows require more UDP to meet the cows needs of protein, it is always the microbial protein that remains the most important protein source.
Read more HERE.
Ruminants such as dairy cows accomplish true wonders, as they can transform inedible, low‐quality protein in roughage and concentrates into the high‐quality protein found in milk and meat. But which role does nitrogen (N) play here and, in fact, how does urea get into milk? And how do natural, plant-based feed additives make a substantial contribution in this context?
First, the microbial protein, synthesised in the rumen by microbes and with 50-75 percent representing the most important amount of cows’ total protein supply. With the energy supply through carbohydrates, the microbes build up their own precious body protein out of nitrogen and amino acids, before they are being washed down to the cow’s duodenum where they are digested.
Though the microbial protein production is only ensured by simultaneous availability of ammonia, produced by hydrolysis of degradable protein (or N) sources and carbon skeletons from fermentable carbohydrates.
In case of energy deficiency and protein surplus, the microbes use protein for energy production, resulting in a waste of N. A waste that will be excreted in the cow´s urine and that will be reflected in higher levels of urea nitrogen in blood and milk as well.
Second, the undegradable protein (UDP), the part of feed protein that withstands the processes in the rumen, hence being available for the cow directly at the small intestine.
Regarding the UDP, it is important to make sure that the amino acid balancing of the raw materials of the ration is adjusted to the cows’ requirement. Though high yielding cows require more UDP to meet the cows needs of protein, it is always the microbial protein that remains the most important protein source.
Read more HERE.
The Global Miller
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which is published by Perendale Publishers Limited.
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