They contain about two and a half times as much energy as carbohydrates. Proteins Proteins are composed of amino acids which contain carbohydrates, nitrogen and sometimes sulphur. Ten amino acids are essential to monogastrics, whereas ruminants only need a source of nitrogen, or a poor quality protein, from which the microbes in the rumen can then construct the essential amino acids. Protein is absolutely essential for growth, reproduction and maintenance in monogastrics and ruminants. Mature animals require less protein on the basis of percentage of the feed offered than young ones.
Excess protein is utilised as an energy source.
The major minerals in cattle nutrition are calcium, phosphorus, sodium, chlorine, magnesium, and potassium. They are required at comparatively high levels described as percent of diet or grams per day. An essential mineral performs specific functions in the body and must be supplied in the diet, but too much of any may be harmful or even dangerous. They are also the ones most often added to ruminant diets. Both are found in the teeth and bones, but calcium is also found in milk and eggs.