Nutrient composition of feeds
When planning a supplementary feeding program and choosing feeds it is important to know the nutrient composition of those feeds so that nutritional requirements for target animals can calculated and met.
Energy content | Protein content | Hay | Cost
Energy content
Energy requirements are expressed as megajoules (MJ) of metabolisable energy (ME). The available energy in the fodder depends chiefly on the dry matter content and the digestibility of the fodder. For more information see Nutrient requirements of beef cattle.
If a shortfall in daily energy requirements is known, then Table 1 can be used to determine how much feed is required to correct the energy shortfall.
Protein content
While energy is a critical nutrient for productivity the total supplement must have adequate protein and minerals for the most efficient use of the energy.
Pregnant, lactating and growing cattle will require a higher level of protein than other classes of cattle for tissue and milk production. For more information see Nutrient requirements of beef cattle.
Grains and good quality hay generally have sufficient protein for survival feeding, whereas molasses will need to be fortified with urea and/or vegetable protein meal to lift the protein content.
Bypass protein % is the percentage of crude protein which is not degraded in the rumen, and capable of passing through to the abomasum of cattle.
The crude protein percentage (CP%) is calculated by:
Nitrogen (N) % x 6.25
This is because on average protein contains around 16% Nitrogen (1/0.16 = 6.25).
Urea has 287% crude protein:
46% nitrogen x 6.25 = 287% protein.
Gran-Am® contains 20% nitrogen or 126% crude protein.
For more information on different types of protein see protein and urea supplementation.
Protein, calcium (Ca) and phosphorus (P) requirements are expressed as grams per day. Table 1 can be used to determine how much protein a feed is supplying. For example, 100 g of cottonseed meal (37% CP) supplies 37 g of crude protein (CP).
The nutrient composition values in the table below are on an as fed basis. If values of feeds are given on a dry matter (DM) basis, multiply the dry matter value of the feed (as a fraction) by the corresponding measurement. For example, if a feed is 90% DM and has a value of 10 MJ ME/kg DM, then 0.9 x 10 = 9 MJ ME as fed, i.e. in every kilogram of the feed fed out in the paddock, it contains 9 MJ of metabolisable energy.
Table 1. Nutrient composition of feeds used as supplements
| Product | Dry matter % | As fed basis |
||||
| ME (MJ ME/kg) | CP % | Bypass protein % | Ca % | P % | ||
| Soybean meal | 90 | 11 | 45 | 35 | 0.24 | 0.84 |
| Sunflower meal | 89 | 8 | 32 | 26 | 0.38 | 0.93 |
| Barley | 89 | 11.3 | 12 | 27 | 0.07 | 0.34 |
| Corn | 88 | 10.8 | 8 | 52 | 0.18 | 0.28 |
| Oats | 89 | 9.1 | 9 | 20 | 0.13 | 0.32 |
| Sorghum | 88 | 10.6 | 10 | 57 | 0.04 | 0.32 |
| Wheat | 89 | 10.7 | 12 | 22 | 0.09 | 0.27 |
| Copra Meal | 90 | 10.8 | 21 | 56 | 0 | 0.45 |
| Peanut Meal | 90 | 10.8 | 41 | 16 | 0.11 | 0.65 |
| Whole cottonseed | 91 | 13.1 | 21 | 30 | 0.15 | 0.67 |
| Lupins | 91 | 10.1 | 30 | 35 | 0.18 | 0.27 |
| Chick peas | 91 | 10 | 20 | 22 | 0.05 | 0.04 |
| Mung beans | 90 | 11.4 | 25 | 23 | 0.09 | 0.22 |
| Faba beans | 89 | 10.7 | 24 | 20 | 0.1 | 0.5 |
| Cotton hulls | 91 | 5.2 | 4 | 30 | 0.1 | 0.1 |
| Sunflower hulls | 90 | 4.5 | 4 | 30 | 0.3 | 0.14 |
| Molasses | 75 | 8.7 | 4.3 | Nil | 0.89 | 0.05 |
| Urea | 100 | Nil | 287 | Nil | Nil | Nil |
Table 2 shows the comparative protein content and energy values of some common fodders on a dry matter basis, and on a ‘fresh’ (as-fed) basis together with the calcium and phosphorus content. The fresh basis figures will vary slightly as moisture content varies. However, the figures are adequate to compare feeds and their cost.
Table 2. Nutrient composition of feeds used as supplements
| Product | |||||
|---|---|---|---|---|---|
| Dry matter basis (MJ per kg) | Fresh basis (MJ per kg) | CP % | Ca % | P % | |
| Roughages | |||||
| Good quality lucerne hay | 9.5 | 8.6 | 18 | 0.91 | 0.33 |
| Oaten hay | 9.5 | 8.6 | 9.0 | 0.34 | 0.24 |
| Oaten straw | 7.5 | 6.8 | 4.0 | 0.24 | 0.06 |
| Wheat straw | 5.6 | 5.6 | 2.7 | 0.15 | 0.04 |
| Sileage (Sorghum) | 8.0 | 8.0 | 8.0 | 0.20 | 0.19 |
| Sileage (Maize) | 9.0 | 9.0 | 8.0 | 0.27 | 0.20 |
| Buffel grass | 7.5 | 7.5 | 9.2 | 0.28 | 0.10 |
| Grain | |||||
| Barley | 12.5 | 11.3 | 12.0 | 0.05 | 0.38 |
| Maize | 13.2 | 11.9 | 10.0 | 0.07 | 0.27 |
| Meals | |||||
| Palm Kernel | 11.5 | 10.3 | 18.0 | 0.21 | 0.15 |
| Miscellaneous | |||||
| Sugarcane | 9.5 | 3.0 | 3.0 | 1.3 | 0.08 |
| Mulga leaves | 5.9 | 3.7 | 11.5 | 1.04 | 0.08 |
| Wilga leaves | 8.0 | 4.8 | 13.8 | 2.07 | 0.14 |
| Pumpkins | 12.3 | 1.2 | 10.0 | 0.24 | 0.43 |
Hay
The information in Table 3 is a guide to the feed value of most common hays.
Table 3. Feeding value of hay sources
| Type | Palatibility | Digestible protein % | Need more protein? |
| Good lucerne | good | 18 | no |
| Grassy lucerne | good | 8 | no |
| Peanut hay | |||
| -with nuts | very good | 10 | no |
| - leafy | good | 6 | no |
| - stalky | fair | 5 | yes |
| Soybean, some seed | good | 10 | no |
| Soybean straw | fair | 2-4 | yes |
| Navy bean straw | poor | 1-3 | yes |
| Forage sorghum | |||
| - cut at flower | good | 10 | no |
| - cut when mature | fair | 2-5 | yes |
| Sorghum stubble | poor | 3-5 | yes |
| Winter cereal stubble | fair | 2-4 | yes |
| Winter cereal hay | good | 7-9 | no |
| Native pasture (mature) | poor | 2-4 | yes |
Medium to high protein hays (6%+) can be fed at the rate of 1 to 2 kg/head/day when there is plenty of paddock feed available.
When paddock feed becomes scarce, feeding rates for maintenance are as shown in Table 4.
Table 4. Feeding rate in kg / head / day for different cattle classes.
| Feed | Weaners | Pregnant breeders | Dry cattle |
| Early | Late | over 18 mths | |
| Treated stubbles (sorghum, wheat or barley) | 2.0 | 3.5 | 3.0-6.0 |
| Legume hay | 1.5 | 3.0 | 2.5-5.0 |
Raising protein content of hay
The protein intake of cattle fed poor quality hay can be lifted by:
- feeding a protein supplement to the animal
- treating the hay 12-24 hours before feeding with the following mixture. Do not feed this mixture direct to any livestock.
- 9 kg urea
- 45 L water
- 18 kg (13 L) molasses.
One litre of this mixture contains 150 g urea, which is sufficient to treat a 20 kg bale.
To treat a bale, stand it on its side with cut ends upwards, cut the top string and pour the mixture evenly over the surface. Round bales can be treated by pumping the mixture into the bale with a spear.
Cost
Additionally, knowing the nutrient composition of feed is important when comparing the cost of different feed sources. For example, if you are comparing two feed sources for supplying additional phosphorus (P), they should be compared based on price per tonne of P, rather than price per tonne of product.
You can use the following tool to compare the costs of different feeds and they’re nutrient composition: Feed cost calculator | NSW Department of Primary Industries