A question faced by many dairy farmers is whether or not they should grow their own forages. In most cases, dairy farms already own or have access to many acres on which they spread their manure. It makes sense they would utilize that same acreage to grow some portion of the forages needed to feed their herds.
The challenges faced by all farmers are deciding which combinations of forages to grow and facing the fact that some of that forage will be high-quality with the potential to make lots of milk, while some of it will be poorer. The trick is to maximize the percentage of good forage in an effort to optimize the value of crops grown on the farm.
Forages are an absolute necessity for all ruminant diets. The primary forages used on dairy farms today are corn silage, grasses and legumes.
While corn silage can supply a large amount of the forage requirement for dairy herds, it cannot supply all of it due to its high level of starch. Therefore, dairy farmers are also required to feed hay crops coming from grasses and legumes.
Decisions on how much of any crop dairy farmers grow depends on a combination of factors, including the amount of acreage and the availability of capital, and/or the level of acceptable financial risk needed for investing in farming equipment.
Other factors include labor availability, time management and an interest in cropping, wear and tear on equipment, climate, water supply and soil quality, as well as the availability of less costly forage alternatives that affect the mix of crops grown.
However, the ultimate factor to be considered is how the growing of all crops affects feed-to-milk efficiencies and the financial bottom line of the dairy farm. In some cases, dairy farmers may find it more sensible to purchase all forages rather than growing it themselves.
Forage quality has a dramatic impact on cow health and milk production. A dairy farmer may have the land and equipment available, but if the resulting crop – be it corn silage or hay – is poor quality, the entire endeavor is counterproductive and a financial burden to the dairy operation. The majority of dairy farmers in the U.S. who choose to farm generally settle on corn as their primary crop, to be fed as silage.
Corn silage provides more calories per acre than any other crop, making it a highly efficient and affordable source of nutrients. Corn is also reasonably easy to grow. Grass and legumes are often secondary crops harvested as high-moisture haylage or dry hay, coming off of ground that is more difficult to manage. While the tonnage per acre and the quality for corn silage is somewhat predictable, the tonnage and quality of hay crops can vary greatly by season.
The question then becomes, which combination of forages is best for optimum feed-to-milk efficiencies, resulting in the best feed-to-milk margins. The answer, of course, is that it depends on the costs of forages relative to other commodity prices, as well as the price of milk at any given time.
In reality, most long-established dairy farms have a very accurate idea of how much acreage is needed to meet annual forage requirements.
Example farm
Ned Ellis milks 250 cows with about as many replacement heifers at Maple Leaf Farm in Hebron, Connecticut. For a herd of that size, Ellis knows he needs over 5,000 tons of corn silage per year and, consequently, farms 275 acres to reliably produce that much tonnage. Ellis can count on about 20 tons to the acre for his corn crop. However, some years, when the weather cooperates, he does better than that.
The extra tonnage allows him to have some carryover into the next year, and instead of growing more corn for silage, he has, in recent years, taken about 60 acres and produced earlage to replace a portion of the purchased corn grain in the herd diets.
In some years when the market price for corn is high, having the earlage has helped offset purchased feed costs. In years when the market is down, there wouldn’t be a dramatic advantage to producing earlage.
Ellis also farms 150 acres of hay – a combination of grasses and alfalfa – with some of it going to haylage and some going to bales. Again, with his many years of experience, he has a very accurate idea of how much tonnage those acres produce in a normal year to meet his forage needs.
Most dairies can improve profitability by improving forage quality. Properly balanced rations that increase forage consumption in dairy cows have been shown to improve income-over-feed costs, improve milk components, decrease acidosis and foot problems, lower vet bills and culling rates and increase lactations per cow.
It has been proven many times that by feeding cows high-quality forages, especially cows in early lactation, net profits will increase through the lowering of more expensive supplement costs. Milk production would also increase due to the improvement of rumen function. Ellis knows that producing his own high-quality forage goes hand in hand with keeping feed costs under control and maintaining a healthy and productive herd.
Quality: Four criteria
The quality in forages (alfalfa or grass) encompasses four main criteria: high digestibility, effective physical fiber, palatability and good fermentation, in the case of haylage.
The digestibility of forages essentially centers around the maturity of the plant at the time of harvest. The more mature a plant becomes, the higher the levels of fiber and lignin. The key to improving the digestibility, and therefore the quality of forages, is harvesting before the alfalfa or grass has had time to bloom or go to seed.
It doesn’t always pay to grow more forage than a herd needs. A major challenge to making milk on high-forage diets is to maximize the feed intake of the forage. Due to “rumen fill,” there’s a limit to how much forage a cow can digest every day. Attempting to make them eat more will only lower total dry matter intake and milk production.
For many years the trend in the dairy industry, when grain and commodity prices were low, was to minimize the amount of forages fed, due to their variability in quality, and instead feed more commodity byproducts. A certain amount of grains and other commodities can cover up the shortcomings of forages.
However, in the past decade, with the volatility of grain, commodity and milk prices, dairy farmers are finding it to their advantage to reconsider the value of growing their own high-quality forages. 
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John Hibma
- Ruminant Nutrition Consultant
- outh Windsor, Connecticut
- Email John Hibma
