Annual forages

Annual forage crops are easy to seed, establish quickly and are increasingly being used as insurance to compliment inconsistent perennial forage supplies. In mixed farming operations, forage annuals provide more flexibility than perennials because they represent a short-term land commitment.

Annuals can be seeded alone for hay or silage or as a companion crop with perennials. They can also be used to extend the grazing season in a rotational grazing system. 

Seeding in spring or fall with combinations of warm- and cool-season crops can provide quality grazing throughout the year. Standing corn can provide excellent winter grazing, while fall-seeded winter cereals can be grazed as early as mid-May, and spring-seeded annuals can be grazed four to six weeks after seeding. Delaying seeding dates of spring cereals or using mixtures of spring and winter cereals together with bale or swath grazing can provide additional flexibility for optimizing time of use.

When using annuals for grazing, stocking rate depends on soil fertility and precipitation. Swath grazing stocking rates will depend on crop yield and on how well animals utilize the swathed forage. Stocking rates for swath grazing will range from 60 to 100 days/acre.

Past experience can provide the basis for setting a stocking rate, or a calculation can be conducted using an estimated yield and animal consumption rate. Some typical stocking rates for broad geographical areas of the province are provided in Table 1.

Table 1: Typical stocking rates for annual pastures and the number of animals and acres per animal needed for each soil zone in Saskatchewan

Annuals are especially useful as emergency feed supplies during droughts, when perennial productivity is low or has gone dormant. When cut and stored as greenfeed, these forages also provide supplemental feed during prolonged cold winters.

Annuals must be seeded each year and require inputs like fertilizer, so they are more expensive to graze than perennials. But utilizing annuals as stockpiled forage, or for swath or bale grazing, is less expensive than the costs of harvesting and feeding stored hay or greenfeed in paddocks.

The general rule when using annual crops for forage production is to use slightly higher seeding rates than those used for crop production purposes.

Similarly, annual crops used for forage should be fertilized to the same level as the crop would be if used for grain production. A soil test will provide specific fertility recommendations for a well-balanced fertility program and will help to ensure optimal annual forage production.

Most commonly used annual crops provide safe, nutritious, and productive pasture, silage, and greenfeed; however, environmental factors such as frost and drought, as well as some plant diseases, can adversely affect the quality of these crops for livestock feed.

If you are using annuals for silage or green feed, it is essential you harvest at the right stage (Table 2) to optimize their nutritional quality and avoiding animal health risks.

Table 2: Harvest Stage of Annual Crops for Greenfeed or Silage