Since my last article, How to Make Alfalfa Better, appeared, several seemingly compelling articles appeared in the “popular dairy press” about the necessity or at least the value of alfalfa to supply protein for relief of the high protein (soybean) prices. I want to break down these ideas on the basis of what we are doing at Forage Innovations.
Let’s first look at what we think should be some of the goals of a forage program:
- Yield – Obviously, yield is King! We must produce enough (or as near as enough) as we possibly can to feed our cows.
- Quality – We need high-quality forage to provide the healthiest diets possible for our cows. We use the metric of Digestible Tons per Acre (dNDF). dNDF is simply the digestibility (NDFD 30) times the NDF produced per acre. We can produce about twice as much dNDF as can be done with a corn/alfalfa rotation.
- Application of Manure – In the practical sense, this may be the most valuable part of the Rethinking Rotations way of farming. And, environmentally, it won’t get any less important in the near future. What a blessing it is to have all, or most all your manure applied at times when harvest or planting is the primary thing on your mind. Plus, when spreading on growing crops, nutrients can be completely absorbed for the benefit of these crops. See also: The Grass Report.
- The Value of First Year Corn – It is a tremendous advantage to have all your corn silage be first year corn. First-year corn is one of the most production and less expensive crops we can raise. Therefore, the key is to feed only half of all your forage as corn silage. Other crops must then be found to equal or exceed its digestibility and yield of corn silage. Our candidates are cool season and warm season grasses, red clovers, and small grains. See also: Why Following Sorhum-Sudan with Corn silage is Such a Good Idea.
- Roots – Many excellent forage choices have more complex and massive root systems than either corn or even alfalfa. Using these crops as mentioned above provide the quickest way to maintain and build organic matter. See also Grass: The Root of Regenerative Agriculture. We solidly believe in having living roots in the ground all year long.
So, getting to the matter at hand. There is more than one way to skin a cat. When current high-producing diets have morphed to be overwhelmingly high percentages of corn silage compared to alfalfa, the alfalfa protein is 100% used. However, it is more of a molehill compared mountain.
Assuming alfalfa haylage at 22% Crude Protein and Corn Silage at 7.5% CP, Table 1 shows the total CP of the mixture of the forages. At 20% Alfalfa and 80% Corn Silage, the percent CP is only 10.4%.
Table 1: Crude Protein in mixtures of 22% CP Alfalfa Haylage and 7.%% CP Corn Silage
|Haylage % of forage mixture||15||20||25|
|Corn Silage % of forage||85||80||75|
|CP % of mixture||9.68||10.4||11.13|
Using grasses and clovers, we can see the total forage CP is actually higher. Therefore, two of the ways to skin cat 1. Produce higher protein in your alfalfa, or 2 Lower the inclusion rate of the lowest protein feed. If as our recommendations are followed, corn silage is fed at approximately 50% of the forage then the rest is warm and cool season grasses plus red clover.
The resultant forage as seen in Table 2, protein is higher then the combination of alfalfa and corn silage at the usual levels. See Table #2. The resulting forage are not only, but also higher in digestibility and higher in bypass protein.
Table 2: Crude Protein in mixtures of 17% CP Grass Haylage and 7.5%% CP Corn Silage
|Grasslage % of forage||45||50||55|
|Corn Silage % of forage||55||50||45|
|CP % of mixture||11.78||12.25||12.73|