Nutrient composition of feeds
In planning a supplementary feeding program and choosing feeds or combinations of feeds it is important to know the nutrient composition of those feeds so that nutritional requirements for target animals can be met.
Energy requirements are expressed as megajoules (MJ) of metabolizable energy (ME). If a shortfall in daily requirements is known then from the table below it can be determined how much feed is required to correct the energy shortfall. For more information see Nutrient requirements of beef cattle.
Protein, calcium (Ca) and phosphorus (P) requirements are expressed as grams per day. From the table below it can be determined how much protein a feed is supplying. For example, 100g of cottonseed meal (37% CP) supplies 37g of crude protein (CP).
Nutrient composition of feeds used as supplements (as fed basis)
|Product||Dry matter %||ME (MJ ME/kg)||CP %||Bypass protein %||Ca %||P %|
The protein percentage is calculated by multiplying the nitrogen (N) per cent by 6.25. Urea has 287% crude protein: 46% nitrogen multiplied by 6.25 which equals 287% protein. Gran-Am® contains 20% nitrogen or 126% protein.
You can find more information on the nutritional composition of feeds and calculate and compare protein, energy and other components for different mixes of livestock feeds using the Feed cost calculator | NSW Department of Primary Industries.