Feeding Grasses to Dairy Cows
What forage type is best to produce on your farm?
In North America, alfalfa and corn are the main forages grown for dairy cow rations. However, there is increasing interest in the use of grasses. Why is there this interest in grass production? The answer can be divided in two sections: agronomic aspects and nutritional aspects.
In this article, we will address the agronomic aspects and what drives interest in the use of grasses. Dairy producers that want to grow grasses should consult with their crop consultant to determine the forage type that best fits their soil resource base. In terms of agronomic aspects, Research Agronomist Geoff Brink from the United States Department of Agriculture (USDA) summarizes them as:
- Adapted to a wide range of soils. Where soil resource limitations may limit the potential for growing alfalfa or cornsilage, grass may be a good alternative
- Fewer pest problems than alfalfa
- Dry faster than alfalfa
- Highly responsive to N
- Nutrient management; home-grown feed and opportunity to apply manure
As with any forage, it is important to understand the growth and development needs of grasses. When selecting species and varieties, winter survival traits, tolerance to poor drainage and yield are some of the important aspects to look for. Trials done by the University of Wisconsin provide a good summary regarding these aspects across different species of cool-season grasses (Table 1).
Table 1 - Selecting a species and variety
University of Wisconsin yield trials; southcentral Wisconsin. From Growing Grasses for Dairy Rations. Dairy-Forage Toolbox Seminar 2010 World Dairy Expo. Geoff Brink. Research Agronomist, USDA-Agriculture Research Service.
1-60 to 70% of annual yield produced in first cut.
2-Poor tolerance to heat and drought.
It is apparent from this table that not all grasses are the same. Deciding what forages should be produced on the farm is largely a decision based on the types of soil and climate. In many areas, there are significant forage crop acres that are not suited to alfalfa production but can be used very effectively for growing grass. Research has shown that grass can be a good alternative for dairy diets in terms of production. In our next article, we will present some information related to the nutritional value of grasses when used in diets of dairy cows.