Species for extending the grazing season

Species for extending the grazing season
Courtesy ARECA-Year Round Grazing 365 Days - 6, 2008

Plan now for your winter feeding needs as there are several things to consider when it comes to winter forage.

Forages used for winter feeding should be tested using a wet chemistry test for feed value whether they are in a pit, standing or lying in the field. Pay close attention to the mineral requirements of animals, especially cows close to calving. Different species have different mineral profiles. For example, cereals tend to be low in calcium and magnesium, and higher in phosphorous and potassium. This combination can causes winter tetany. ALL species have losses in yield, crude protein and energy over the course of time; especially those left to the elements. Do not assume that what you tested in September is what the cattle are eating in February.

With regard to annual cereals: Traditionally grown cereal crops are low risk compared to some of the newer species entering the market place. They are low cost to grow and will produce good yields in almost any kind of weather. Barley and oats are most commonly used.

Producers and researchers have found that high yielding grain varieties generally produce higher forage yields. That is because the head makes up a significant portion of the dry matter yield in a plant. Barley has higher feed value than oats. Forage quality of barley is 11-12% crude protein (CP) and the total digestible nutrients (TDN) are 62-64% while oats is 10-11% CP and 60-61% TDN.

Oats can tend to have higher feed wastage due to the coarseness of the stem.

If using barley for swath grazing, smooth-awned varieties are preferred as rough barley awns may lodge in a cow's mouth causing lump jaw. Triticale or wheat can also be used for swath grazing, however they are less commonly used and have limitations. Triticale will have similar yields and quality as oats and barley. Seeding mid-June reduces yields by about 40% when compared with mid-May seeding. Forge quality at the time of swathing can be enhanced by selecting late maturing forage type varieties. Crops that are in the soft dough stage, green and leafy at the time of cutting will provide the best forage quality for swath grazing. Cereals should be swathed in the soft to mid-dough stage.

Normal fertilizer rates used for grain crops are adequate for a swath grazing program, however, increasing the fertilizer rates by 25% has been advocated by some. The rationale behind this thought is to extend the growing season and increase potential for growth. Nitrate accumulation can be a concern with swath grazing. If normal fertility rates are used the incidence of nitrate problems is very low. Nitrate accumulation might be a concern in fields with a history of high soil test nitrogen. Regular soil samples and feed analysis are the best ways to manage the winter feed your cows depend upon. A feed nutritionist will consult and advise on feed elements you may not have considered.

Fall/winter crops
Fall rye, winter wheat, winter triticale and annual rye grass are the fall/winter crops commonly grown in Alberta.

These crops provide late fall and early spring grazing when perennial pastures may not be able to be grazed. Fall rye is the most winter hardy followed by winter triticale and winter wheat, which more often shows signs of winterkill. Winter triticale, fall rye and annual ryegrass are more productive during the fall than winter wheat. These crops are capable of withstanding frosts and still maintain their green color and quality. Optimal seeding dates for winter crops vary slightly across the province. However, if the crop is intended for fall grazing, it should be seeded by the middle of August.

If the crop is intended for spring grazing as well, the goal is for the crop to reach the three to five leaf stage before freeze up. The plant mustn't be grazed too heavily in the fall to ensure good winter survival. Winter crops generally perform best when shallow seeded to about 1/2 to 3/4 inch depth with minimal soil disturbance into standing stubble. Shallow seeding allows for rapid seedling emergence and the standing stubble preserves moisture for the fall and provides the best environment for over-wintering. Winter cereals and annual rye grass can also be seeded in the spring and used for summer grazing. Because they require a vernilization period to produce seed, these crops remain vegetative and produce only leaves in the year of seeding. The quality of winter cereals and annual ryegrass is high and can easily be 20% protein and 75% digestibility.

Perennial grasses and legumes
The best use of stock piled grazing is in the fall before the grass is covered over by snow. In early spring yield and feed quality have declined significantly in most species. Supplementation can be used to top up feed value while still having the stock piled forage provide a significant percentage of the diet in the spring. Work done by the Western Forage/Beef Group at Lacombe found that using vegetative regrowth is the first step in a successful stockpiled grazing program.

Meadow brome grass, creeping red fescue and western wheat grass had the ability to resist the weathering process. In spite of frost, snow, snow-melt and rain they retained nutritive value longer than all other forage species. Their nutritional value maintained beef cows well into the winter months and served as a maintenance ration in the spring.

Grass species commonly found in permanent pastures such as creeping red fescue and Kentucky bluegrass, had the disadvantages of relatively low yields to begin winter. Alfalfa and clover are not a good choice for stockpiled grazing. They lose their leaves after the first frost and have a more rapid yield and nutritive value loss than all of the grass species.

www.areca.ab.ca for more information on forage options.