Feeding canola to livestock - what do I need to know?
By Eve Hall
District Veterinarian, Holbrook
Canola hay and silage is in abundance this season, with many farmers deciding to cut and bale failed crops due to moisture stress, frost damage or other limiting factors.
Canola forage can be a very useful source of feed for cattle and sheep. It generally has good protein and energy levels, averaging around 18-21 per cent crude protein and 9-10 megajoules per kilogram of dry matter. However, these values are showing to be highly variable depending on many factors, including the stage at which it was cut and the hay or silage-making process used. Feed testing is the only way to ascertain the nutritional quality of individual cuts of canola. All fodder should be tested prior to purchase or feeding in order to decide whether it is appropriate for the class of stock being fed.
A feed test will also measure the level of nitrates, which can be dangerously high in canola, especially if there is a history of recent nitrogen fertiliser application, moisture stress, or frost damage. High levels of nitrates can cause poisoning in sheep and cattle, resulting in respiratory distress, nervous signs and sudden deaths. Generally, hay or silage with less than 5000 parts per million (ppm) nitrate on a dry matter basis is safe; 5000 to 10,000ppm is potentially toxic when provided as the only feed. Forage above 10,000ppm nitrate is considered dangerous but can often be fed safely if diluted with other feedstuffs and supplemented with energy.
Top tips for feeding canola to livestock:
- Get a feed test done. Core-sampling devices may be borrowed from Landcare or other local agribusinesses. Alternatively, grab-samples can be used. Results can be expected within a week.
- Introduce canola to the diet slowly over a number of days. This helps the animals’ rumens to adapt to the new feed source and develop a tolerance to some of the nitrates. Try to offer a mixture of fodder options, especially in the early stages.
- Avoid using canola as the sole ration. Try to limit it to no more than 60 per cent of the ration, making up the remainder with an alternate fodder source.
- Request a stockfeed commodity vendor declaration when purchasing feed. This will include details about any recent chemical applications and potentially harmful chemical residues.
For further advice on canola forage, feed testing, supplementary feeding, and livestock health, contact your nearest Murray Local Land Services veterinarian or livestock officer in Albury 02 6051 2200, Holbrook 0439 078 989 or Deniliquin 03 5881 9900.