Energy Feeds

[Kvet Forum]

Energy is the fuel that keeps all body functions working. Milk production requires a lot of energy. If energy in the ration is not enough, the animal will lose body condition and for milking cows, milk yield will drop, pregnant cows become ill after calving and the calf will usually be small in size. If there is excess energy in the ration, the animals becomes too fat. Cows that are too fat at calving usually have difficult births, often have problems with retained placenta, displaced abomasums and may suffer from milk fever and ketosis. Sources of energy are roughages and concentrate supplements fed to your animals.

Roughages form the main bulk of the dairy cow ration.
Roughages are bulky feeds that have a low energy content per unit volume (i.e. hay, straw). They can have a high moisture content (grass). Generally feedstuffs with more than 18% crude fibre and low digestibility are considered as roughages. Ruminating animals (cattle, goats, sheep) need a certain amount of crude fibre to keep a healthy stomach system. On the other hand high yielding animals may not have enough capacity to consume the amount of roughage required to meet the energy requirement due to limitation of stomach size. For this reason, supplementing roughage diets with feeds high in readily available energy is often recommended. Examples of energy sources (forages and fodders, agricultural by-products and concentrates) are shown in Tables 2 and 3. In the tables the average values of feedstuffs are given. Local conditions can cause differences in chemical composition of the same feedstuff. The values in the table can be used as guidelines when no information is available from the farmers own feeds. .

The currently recognized energy feed nutrients include:

• Simple Carbohydrates such as Glucose, Fructose, Galactose, Sucrose, Maltose and Lactose, all different types of sugar
• Complex (Carbohydrates) Polysaccharides such as
  • Starch, found in roots and tubers as well as in grain,
  • Hemicellulose (somewhere between sugar and cellulose chemically speaking),
  • Cellulose, the principal constituent of cell walls of plants. Most abundant in more fibrous feeds, generally low in digestibility. Cattle, goats, sheep (as ruminants) and horses (with a large colon-caecum) digest cellulose fairly easily. Pigs and chicken (as mono gastric animals) do not digest cellulose very easily.
  • Lignin which essentially is not digestible to animals. Found in over mature hays, straws and hulls. High lignin content in feed may reduce the digestibility of cellulose and other nutrients.
• Fats and oils. Found in seeds, grains, avocados etc. Fats contain 2.25 times as much energy per kg compared to carbohydrates, but are usually expensive to produce.