Although the time has passed to harvest soybeans as haylage to feed to dairy cows, South Dakota State University assistant professor David Casper says it’s something to keep in mind in another drought year or if a producer is interested in growing the bean as feed.
Because soybeans are a legume, he said those harvested as forage will contain greater amounts of crude protein compared to corn silage and small-grain silage.
The former vice president of nutrition for Agri-King for 14 years had good luck feeding it to herds when he worked in Florida and Georgia.
“We made a lot of milk with those herds using it as a forage source,” he said.
Farmers in those Southern states would grow the soybeans specificallly for feed, Casper said.
Because of the longer growing season in the South, there would be multiple crops, and the dairy producers generally would harvest corn silage and then put the soybeans in the ground for forage.
This past summer, many area dairy producers were concerned about feed in the Brookings area and what to do with drought-stressed soybeans if they didn’t make it to completion.
Casper offered the green soybean solution to dairy producers. But timely rains in early August saved the soybeans in the Brookings area and in many other areas north of Interstate 90 in South Dakota, making the point moot.
Soybeans harvested for feed can make a great diet addition, Casper said.
The nutritive value of a soybean plant is comparable to that of early-bloom alfalfa with high protein and digestibility.
Lactating dairy cows and growing heifers can have similar performance when given either soybean haylage or alfalfa forage.
Palatability is not usually a concern when feeding soybean forage unless the forage is moldy or dusty.
Casper said moisture content is important if a producer chooses to ensile as haylage or baleage. The recommendations are similar to alfalfa silage at 35 percent to 45 percent dry matter. The use of a good inoculant (silage fermentation aid) is recommended.
The nutrient composition of soybean haylage can average about 19 percent. This soluble protein concentration of soybeans fits well with corn silage-based rations. It also can be a good source of calcium and phosphorus for dairy cattle.
Down South, Casper fed as much as 35 pounds per cow per day of soybean haylage on an “as fed” basis and part of a well-balanced ration.
Because of the high nutrients, costs savings can be realized by feeding less protein and minerals to the animals.
He said it can be a great complementary forage to drought-stressed corn silage.
One major limitation is that producers need to check herbicide labeling to make sure it is safe to feed the soybeans to dairy cows. Casper has a list of the safe herbicides on the igrow.org website.
With feed costs soaring, Casper said forage inventories and quality will be a key to allowing dairy producers to survive in the next months.
Casper believes in giving dairy cows the “rocket fuel” to increase milk production and said forage quality cannot be too good.
“As commodity prices rise, we have to have the expectation that forages will supply more nutrients than we wanted them to supply in the past,” he said.
To reduce the cost of producing milk, Casper said forage has to make up a greater percentage of the composition of a cow’s diet.
Casper is gearing up to continue his research into how much of the “rocket fuel” can be fed to dairy cows and what can be expected for performance.
He has planted specific corn hybrids at the SDSU research farm to start the effort.