Red Clover Silage Boasts Benefits Over Alfalfa Silage
| Alfalfa is still the most important
forage fed to U.S. dairy cows, but red clover may be a better alternative.
Feeding studies at the U.S. Dairy Forage Research Center, in Madison,
Wisconsin, are showing the benefits of feeding cows red clover silage.
ARS dairy scientist Glen A. Broderick
reports that switching cows from alfalfa to red clover silage could help reduce
excess nitrogen in manure, a benefit to the environment.
Typically, more than half the protein in alfalfa silage breaks down into
nonprotein nitrogen (NPN). NPN is used less efficiently than intact protein by
the cow during lactation. If not used to make milk, the excess nitrogen is
excreted from the animal. Red clover silage, on the other hand, has just 60
percent of the NPN of alfalfa, on average. That's because red clover has an
enzymepolyphenol oxidasethat reduces protein breakdown in the silo.
To reduce excess nitrogen in the environment while meeting cows' nutritional
requirements for milk production, dairy scientists at ARS' research farm in
Prairie du Sac, Wisconsin, conducted five feeding trials. In the first three
studies, cows produced somewhat less milk when fed red clover silage because
they ate less of it and ingested almost 20 percent less protein. But the
situation improved in the two other studies. The cows produced the same amount
of milk on less feed. Cows produced an average of 68 pounds of milk per day on
54 pounds of dry matter from the alfalfa diet, but they produced 69 pounds of
milk per day on only 49 pounds of dry matter from the red clover diet.
"This translates to a 10-percent increase in feed efficiency and a
10-percent greater energy value for cows fed red clover silage," says
Broderick. Also, dry matter and fiber digestibility averaged 6 percent and 20
percent more, respectively, in cows fed red clover.
Protein efficiency was 17 percent better on red clover than on alfalfa over the
course of the latter two trials. Even if this improvement applied only to the
first half of lactationwhen cows are fed the most proteinnitrogen
excretion would be reduced by about 1.5 tons per year on a 100-cow dairy farm.
Red clover grows better than alfalfa in the acidic soils that are common in the
Midwest. In Wisconsin alone, soil tests indicate that 68 percent of the fields
tested would require liming to raise pH to a level adequate to grow alfalfa.
Other pluses: Red clover seed is cheaper than alfalfa seed for producers, and
red clover will now be easier to grow, thanks to the improved resistance and
persistence of new varieties developed by ARS plant breeder Dick Smith. (See
Clover Puts Pastures in the Pink," Agricultural Research,
December 1996, p. 9.) In the summer of 2000, ARS released these newer
varieties, which should persist 12 to 15 months longer than older red clover
varieties. Seed will be available to farmers in about 2 years.By
McGraw, Agricultural Research Service Information Staff.
This research is part of Food Animal Production (#101) and Water Quality and
Management (#201), two ARS National Programs described on the World Wide Web at
Glen Broderick is with the USDA-ARS U.S. Dairy Forage Research Center, 1925 Linden Dr. West, University of Wisconsin, Madison, WI 53706; phone (608) 264-5356, fax (608) 264-5147.
"Red Clover Silage Boasts Benefits Over Alfalfa Silage" was published in the July 2001 issue of Agricultural Research magazine.