Opportunity lot feeding of beef cattle, Chapter 7: Suitability of feedstuffs
Date: 06 Jul 2006
Warning: Chemical residues
Some sources of fodder have been linked with an increased risk of chemical residues in slaughter animals. While most problems have been linked to persistent chemicals such as the organochlorines (OCs), any chemical contaminant in feed can cause unacceptable residues in livestock products if present in sufficient concentration. Residues can persist for a variable time after feeding of contaminated material ceases. The time taken for residues to clear varies greatly depending on factors such as the chemical involved, the level in the feed, the duration of feeding and changes in the animal’s body weight and condition.
It is vital to maintain the ‘clean’ reputation of our animal products in both domestic and export markets.
You should be particularly cautious when sourcing materials not commonly used as animal feeds. Unless the materials have been tested for residues of all the chemicals to which they may have been exposed during their production, harvesting, storage, processing and transport, it should be assumed that chemical residues may be present.
In past droughts, chemical residues in livestock have been traced to feeding materials such as sugar cane tops harvested from OC-treated land, waste fruit and vegetables, cotton gin trash and a variety of other unusual feeds. Problems have also been associated with the feeding of pickled seed grain and grain stored in OC-contaminated silos.
Producers should check with suppliers as to what chemicals the feed has been or may have been exposed to during its production, harvest, storage, processing and transport. If the feed has been raked and baled in the field or if it may contain soil, additional assurances should be sought that it was harvested from land which had no previous applications of persistent OCs.
Fodder samples can be tested for specific chemical residues. It is the submitter’s responsibility to specify the particular tests required on any sample sent for analysis. The request should be based on information as to the chemicals to which the feed may have been exposed during its production, harvesting, processing, storage and transport. A general screen test for organochlorine and organophosphate chemicals costs less than $100 per sample. However, this screening test will not detect residues of chemicals other than those organochlorines and organophosphates covered by the screening test.
Producers should seek professional advice if uncertain as to the interpretation or significance of any residue test results.
Be warned that if chemical residues are detected, the animals or their carcases may be condemned at your expense (no compensation will be paid). In addition, the property from which the animals were sold may be targeted for more intensive residue monitoring.
When purchasing any feed, producers are advised to:
- inform the seller what they are purchasing the feed for;
- inquire whether the feed is suitable for that purpose;
- inquire if any chemicals have been applied to the feed, or if there are any chemical residues in the feed, or if the feed is ‘free of unacceptable residues’;
- request a National Commodity Vendor Declaration be supplied (see: Commodity vendor declarations for stockfeeds).
It is desirable that all feed is purchased with a statement that it is ‘free of known unacceptable chemical residues and is suitable for the intended purpose — i.e. to feed cattle’. However, when adverse seasonal conditions reduce the availability of feed, it may be necessary to buy feed without such a disclaimer. In such circumstances, you need to test not only for energy and protein values, but also for residues. (See: Management of organochlorine and related residues and Dangers in feeding waste material to livestock.)
For further information on residue testing, contact:
Chemical Residue Laboratories
Norco Lane
South Lismore NSW 2480
(PO Box 285, Lismore NSW 2480)
Phone (02) 6621 2632; Fax (02) 6621 4319
Warning: Endosulfan
Findings of excessive endosulfan levels in crops and crop stubbles used as stock feeds has reinforced the need for caution in the use of this chemical. Unacceptable residues in any agricultural product can lead to market closures and multimillion dollar costs to primary producers and agribusiness.
Key messages
- Do not slaughter stock within 42 days of their last feeding or grazing on vegetative material, including silage, originating from endosulfan-treated crops or vegetation exposed to spray drift.
- Pastures and fodder crops which may be contaminated with endosulfan spray drift should not be fed to stock within 42 days of slaughter. Any detectable level of endosulfan may breach fodder supply contracts and result in rejection of the fodder.
- Determine the chemical treatment history of all stockfeed prior to purchase and/or use. Be particularly cautious about any material not originally produced or intended for stockfeed use.
- Talk to neighbours about chemical use on adjoining land. Ensure crop, chemical and stock management are compatible.
- Where any doubts exist as to the residue status of stock, fodder, pasture or land, residue tests should be used to clarify the situation and allow informed, responsible decisions.
ALWAYS READ THE LABEL
Users of agricultural (or veterinary) chemical products must always read the label and any Permit before using the product, and strictly comply with the directions on the label and the conditions of any Permit. Users are not absolved from compliance with the directions on the label or the conditions of the Permit by reason of any statement made or not made in this publication.
Analysis of feed composition
NSW DPI's Feed Quality Service at Wagga Wagga provides testing of a range of feeds for farmers and producers. NSW DPI extension staff can also assist in the interpretation of results and offer an advisory service backup to translate feed analyses into appropriate responses.
The following information and form will help with your feed sample submission:
- Collecting feed samples (PDF file)
- Interpreting the feed analysis report (PDF file)
- Feed sample submission form (PDF file)
The contact phone number for the Feed Quality Service is (02) 6938 1957.
Roughages
Almost any type of roughage can be fed in a feedlot, but palatability of some may be a limiting factor.
Roughage is essential to make grain feeding safe and to aid digestion of grain. Digestibility will be improved by milling, but finely milled roughage may cause upsets.
See 'Screen size is critical' in the section on Feed, for screen sizes for roughages.
See Table 8 below for the dry matter, metabolisable energy, and protein content of feeds.
Crop stubbles
Crop stubbles are low in protein and ME but are useful as a cheap filler in the ration. They are light in relation to their bulk and cause problems in milling. They are useful for blending with lucerne hay to reduce bloat incidence. Stubble should be crisp and fresh. Soft, lightweight, powdery straw is unsuitable. Beware of mouldy stubble. It could lead to mycotoxin poisoning, or be so unpalatable that cattle will refuse to eat it. See the chemical residues warning and the endosulfan warning.
Hays
Hays have higher ME levels than does stubble and are excellent roughages for feedlotting. Lucerne hay is high in protein and is suitable for young stock, but it can cause bloating if fed by itself as roughage, particularly in mixes with wheat and barley. Feed lucerne hay at levels less than 40% of the roughage portion to avoid bloat.
Good quality cereal hay has a similar value to lucerne hay and is safer and easier to feed. Powdery, lightweight cereal hay should not be used.
Good quality hays can be fed at higher rates (30–40% of the total ration) if they are cheaper than grain on an ME basis, but weight gains will not be as good. See the section Buying feed on a feed value basis for calculations of feed values.
Hulls
Cottonseed hulls are generally low in feed value, but are palatable and easy to mix, with no processing required. Oat, barley and sunflower seed hulls can be abrasive when fed in high quantities and can cause digestive problems. Therefore, they are generally not used, except in extreme circumstances, when other roughage sources are expended. It is best to mix them with other roughages during the build-up stages. Hulls are very light, making transport costs high.
Silage and green chop
Silage and green chop can be used as part or all of the roughage component of the ration. They should be substituted for hay at the rate of 3–5 kg of silage or green chop per kilogram of hay, depending on moisture content of the silage. Silage quality can vary considerably.
High-quality silage can be substituted for some of the grain portion of the ration. For more information see Silage for Beef (1997), the silage manual from NSW DPI.
High-quality silage (ME 9.5 or better) may lead to liveweight gains of 0.8 to 1.0 kg/day in yearling-age cattle when fed as chopped silage.
Energy feeds
See the chemical residues warning and the endosulfan warning.
All the coarse grains except oats are similar in feed value, and any grain or mixture of grains can be used.
Be aware that water or drought stress of cereal crops during the grain filling stage will result in less starch, hence lower energy value. The protein content of the grain remains the same, but because pinched grain is lighter, the crude protein percentage will be higher than in a normal sample. Testing of grains, especially for energy, may indicate that suggested prices for pinched samples are not competitive with alternative sources.
See Table 8 below for the dry matter, metabolisable energy, and protein content of feeds.
Wheat
While protein content of hard wheats can be high enough to supply the protein requirements of the ration when fed at 75–80% of the ration, the higher risk of digestive upsets limits its use in a feedlot. It should be coarsely cracked or rolled but must not be crushed to a fine powder. It is safer when mixed with another grain, such as barley or oats, and the addition of an appropriate additive, such as 2% sodium bentonite, will reduce the risk of grain poisoning, particularly in the build-up phase. If precautions are taken, especially during the build-up of grain levels of the ration, wheat can be a most satisfactory feedlot grain.
Barley
Barley is an excellent feedlot grain, but can cause bloat when fed with lucerne hay. You can overcome this problem by replacing the lucerne hay with cereal hay or mixing the barley with sorghum, maize or oats. Barley needs to be coarsely cracked or rolled. Stock can lose their taste for barley, but mixing it 50:50 with sorghum or another grain generally overcomes the problem.
Sorghum
Sorghum is a high-energy grain, but its protein content is variable and the crude protein needs to be tested. It is safer than wheat or barley, but should be coarsely cracked or rolled and needs careful processing to avoid powdering.
Sorghum is very palatable and useful for mixing with wheat and barley to improve their palatability.
Always include 1% urea when feeding sorghum grain, because the protein in sorghum can be highly protected, so that insufficient nitrogen is available.
Maize
Maize is a high-energy grain but its protein content is variable, so testing for crude protein is important. It is very palatable but, like sorghum, must be coarsely cracked or rolled.
Urea and true protein, in combination, are often required to balance dietary crude protein when sorghum or maize are used.
Oats
Oats have a lower energy content than other grains and, if fed alone, will give lower weight gains. Oats are safer to feed than wheat or barley. Due to the high fibre content, digestive upsets may occur at levels over 60% of the ration, but oats have been fed satisfactorily at higher levels. Oats mix well with wheat at ratios of 60:40 wheat to oats.
Testing oat crude protein levels can be important to ensure dietary crude protein requirements are satisfied.
Cottonseed
White (‘fuzzy’) cottonseed, or black (delinted) cottonseed can be used as an energy source, at no more than 15% of the ration. It is high in crude protein.
WARNING
White cottonseed (WCS) and de-linted cottonseed (black cottonseed) may contain residue of chemicals applied to the cotton crop during the growing season. The National Registration Authority (NRA) calculates maximum residue levels on the basis of a 30% maximum dry matter (DM) intake of cottonseed (WCS and black cottonseed) in the diet. This means that using WCS at levels above 30% of the total dry matter intake could result in excessive residues in cattle. This is particularly true for cattle destined for export markets, where the 30% limit set to comply with domestic MRLs may not apply. If you have fed WCS from crops treated with chemicals within 60 days of harvest (all cotton would be in this category) to cattle within 60 days of sending them for sale/slaughter, then you must disclose this at Question 7 of the National Vendor Declaration (Cattle). NSW Department of Primary Industries does not recommend the use of cottonseed at more than 30% of the total dry matter intake, even in severe droughts.
NSW Department of Primary Industries and the cattle and cotton industries recommend that cotton trash NOT be fed to livestock due to residue concerns.
Grain by-products
Grain by-products such as sunflower screenings and the various grain pollards can be higher in protein than grain and similar to oats in ME but their feed value can be variable. The risk of digestive upsets can be a problem because of the fine powdery nature of pollard.
Millrun (a pollard/grain mix) is a high-energy high-protein feed.
The high fat content of rice pollard may cause digestive upsets at high levels. Generally these products can be fed at up to 30% of the grain ration, but only if at least 20% of the whole ration is roughage.
Molasses
Molasses is a high-energy feed, but is very low in protein. It can be fed up to 10% of the ration to reduce costs. Small quantities diluted in water will increase the palatability of rations and reduce dust problems. Larger quantities of molasses can be fed, provided sufficient roughage is supplied. For more information see the Primefact Fortified molasses mixes for cattle and Agnote DAI-14 Handfeeding cattle in drought — molasses.
Molasses is also used as a carrier in some commercial liquid mineral supplements (see 'Proprietary mineral and vitamin premixes' in the section The feedlot ration).
Protein feeds — concentrates
Protein concentrates are produced from oilseed crops as by-products of oil extraction. They include soybean meal, cottonseed meal, linseed meal, canola meal, copra meal, peanut meal, safflower and sunflower meal. Lupins, vetches and similar plants may also be used as a protein concentrate. They are generally high in ME but are costly when compared with urea as a source of protein. They are usually necessary in rations for very young stock, and some of them can improve palatability during the first 2–3 weeks when cattle are being accustomed to a high-grain ration.
See Table 8 below for the dry matter, metabolisable energy, and protein content of feeds.
|
Foodstuff |
Dry matter (%)* |
ME (MJ/kg DM) | Crude protein % DM |
||
| Average* | Tested range | Average* | Tested range | ||
| Low protein dry roughages | |||||
| Oaten hay | 90 | 9.3 | (8.5–9.5) | 5.8 | |
| Wheaten hay | 90 | 8.0 | 6.0 | ||
| Pasture hay (mostly grass) | 85–90 | 8.3 | 6.0 | ||
| Oat, barley or wheat straw | 90 | 5.0 | (4.5–5.5) | 3.0 | |
| Sorghum stubble | 90 | 7.0 | (6.5–8.0) | 3.6 | |
| Cottonseed hulls | 90 | 5.15 | (2.9–6.3) | 7.7 | (4.0–11.5) |
| Rice hulls | 90 | 2.4 | 2.0–3.1 | ||
| Corn stubble | 90 | 5.5 | (4.5–6.5) | 4.8 | (2–7) |
| Soybean stubble | 90 | 5.5 | (4.0–6.5) | 5.5 | (4–6.5) |
| Peanut hulls | 90 | 3.6 | 3.3 | ||
| Oat hulls | 90 | 5.3 | (5.3–5.4) | 3.8 | |
| Sorghum (failed crop) | 90 | 9.0 | (8.5–9.5) | 7.4 | |
| Peanut hay | 90 | 8.5 | (8.0–9.0) | 9.3 | (7.6–10.7) |
| Soybean hay (mature) | 90 | 6.0 | (5.5–6.5) | 8.1 | |
| Wheat stubble | 90 | 5.1 | (4.8–8.2) | – | |
| Barley stubble | 90 | 5.5 | (5.1–6.2) | – | |
| Rice stubble | 90 | 5.7 | (5.3–6.6) | – | |
| Oat stubble | 90 | 4.6 | – | ||
| High-protein dry roughages | |||||
| Lucerne hay | 90 | 8.5 | (8–9.8) | 15–20 | |
| Clover hay | 85–90 | 9.0 | (8.3–10.9) | 13 | |
| Pasture hay (mostly clover) | 85–90 | 8.3 | 11 | ||
| Cowpea and field pea | 90 | 9.5 | 16 | ||
| Soybean hay (full pods) | 90 | 9.5 | (9–10) | 13–14 | |
| Soybean hay (75% pods) | 90 | 8.5 | (8–9) | 17 | |
| Low protein wet roughages | |||||
| Maize silage | 25–30 | 8.5 | (7.5–9.5) | 6.9–9.0 | |
| Sorghum silage | 25–30 | 8.0 | (8.0–8.5) | 6.9–7.5 | |
| Oat, wheat, barley or rye green fodder or silage (cut at flowering stage) |
25–30 | 8.5 | (8.3–8.7) | 6.0–8.0 | |
| High-protein wet roughages | |||||
| Lucerne green fodder | 25 | 8.3 | 16 | ||
| Lucerne silage | 25–30 | 8.4 | 15 | ||
| Pasture fodder (mixed grass & clover) | 25 | 10.3 | 17.5 | ||
| Pasture silage (mixed grass & clover) | 20 | 8.2 | 16 | ||
| Young oats, wheat, barley, rye, or millet grazing | 25 | 9.3 | 10 | ||
| Grains | |||||
| Maize | 90 | 13.5 | (13–14) | 9.5 | (9.0–10) |
| Grain sorghum | 90 | 13 | 9 | (5–11) | |
| Wheat | 90 | 13 | (12.5–13.5) | 12 | (11–13) |
| Barley | 90 | 13 | (12.5–13) | 11 | (10–12) |
| Oats | 90 | 10.5 | (5–12.5) | 10.5 | (10–11) |
| Lupins | 13 | 32 | |||
| Cereal grain by-products | |||||
| Wheat pollard | 90 | 11 | 15 | ||
| Wheat bran | 90 | 12 | 15 | ||
| Oat bran | 90 | 9 | 8.0 | ||
| Hominy | 90 | 12.6 | 11 | (10–12) | |
| Rice bran | 90 | 11 | 14 | ||
| Protein-rich concentrates | |||||
| Soybean meal | 90 | 12 | 50 | ||
| Safflower meal | 90 | 11 | 40–55 | ||
| Peanut meal | 90 | 11 | 42 | ||
| Cottonseed meal (decorticated) | 90 | 10.5 | 28–43 | ||
| Linseed meal | 90 | 11.5 | 30–35 | ||
| Sunflower meal | 90 | 10.5 | 40–45 | ||
| Coconut meal (6% fat) | 90 | 12.5 | 21 | ||
| Milk powder (cow’s whole) | 90 | 17 | 26.5 | ||
| Milk powder (cow’s skimmed) | 90 | 12.8 | (12.6–13) | 36 | |
| Urea (46% nitrogen) | 90 | – | Equivalent to about 280 | ||
| Miscellaneous | |||||
| Brewers grains (dry) | 90 | 9.5 | 20 | ||
| Molasses | 75 | 13 | 3.5 | ||
| Sheep and cattle nuts | 90 | 11 | (9–13) | 15 | |
* This is the suggested most likely value.
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