Things I've Learned About Feeding Straw
CANADA - In Western Canada cow calf producers have an excellent opportunity to lower their winter feeding costs by using straw in their wintering rations.
10 November 2006
4 minute read
Over the years many studies have been done at Agriculture and Agri-Food Canada at Melfort and Swift Current, SK and Lacombe, AB; the University of Saskatchewan; the University of Alberta; and the Saskatchewan Research Council on using cereal crop residues for wintering beef cattle. This research has been recently summarized for the Canadian Journal of Animal Science and Canadian Cattlemen magazine. Here are some of the overall findings.
Feed quality is determined by a combination of intake and digestibility. Straw and chaff are lower quality due to lower intake and digestibility, with neither feed being able to meet the nutrient requirements of cattle without supplementation. This does not mean that straw and chaff are of no value!
These materials can represent approximately one-half of the ration fed to wintering beef cows with appropriate supplementation coming from grain or higher quality forages. This represents a substantial economic savings compared to other wintering rations if straw and chaff are available in your area.
Straw quality is determined by the amount of leaves fed to the cow. A cereal plant consists of approximately 40% grain, 17% chaff, 18% leaves, and 25% stems on a dry matter basis. Leaves contain about 5 - 6% crude protein while the stems have about 2.5%. Chaff can have a crude protein content as high as 8%.
Cows can be successfully wintered on chaff piles in a grain field. Salt and mineral will need to be provided.
Cows can be wintered on free choice straw supplemented with some grain, alfalfa hay, or grain silage. In our studies at Melfort, SK and Lacombe, AB an average size cross bred cow will eat about 12 to 15 pounds of straw free choice. We fed them 14 pounds of rolled barley or 14 pounds of alfalfa hay on alternate days. By going to every other day feeding of the grain or hay supplement, we were able to reduce labour costs. Salt and mineral were also provided free choice.
When harvesting straw it is important to bale it as soon as possible after combining. By delaying the baling, the fibre levels in the straw can increase due to weathering resulting in a lower nutritional value than baling behind the combine.
There is still enough residue left in the roots and stubble to prevent soil erosion after chaff and straw have been collected.
Research has shown that 2-row barley straw has a 5 to 10% higher dry matter degradability than six-row barley straw. There is a significant difference in nutritional quality between cereal cultivars. Year to year variation, due to the weather during the growing seasons, also has an effect on nutritional quality. When given a choice, cows prefer the finer stemmed straws such as 2-row barley straw. If this is not available cows can still winter on other types of straw and supplemented with limited amounts of grain, hay or silage.
Desiccant treatment of a cereal crop to speed drying time and control weeds may improve the quality of the straw and chaff by allowing an earlier harvest but leaf loss may be high if harvesting and baling of the straw is delayed.
Cutting the cereal crop with a high stubble height can increase the overall crude protein content and digestibility of the straw as less stems are harvested. However, greater stubble height decreases total straw yield.
Next spring, if you have excess straw and you wish to carry it over until next winter, it is essential that you rearrange your straw piles so that there is an air space around each bale - especially at the butt ends. Studies at Lacombe, AB have shown a 25% spoilage loss from summer rains when the butt ends of the bales touched.
In Western Canada there is a lot of cereal grain production. In these areas, cow calf producers would be economically better off harvesting and feeding high proportions of straw in their wintering cow rations rather than feeding the more expensive hay. These hay lands could be better used for late fall and early winter grazing rather than baling and hauling the hay to the cows.
The current review of straw and chaff used as a cattle feed has identified several issues requiring further research effort including a need for more accurate predictions of energy values and especially voluntary intake. This information will better allow cattle producers to realize all of the value represented by straw and chaff feeds.
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