Adjust to alfalfa quality Low temperatures this spring may have reduced the yield of alfalfa stands, but may improve its quality as a forage.
South Dakota State University Extension Dairy Specialist Alvaro Garcia said plant cell wall materials deposited at low temperatures contain less lignin and are thus more digestible for the cow.
Research has shown that a one-unit increase in digestibility of the neutral detergent fiber (NDF) resulted in 0.37 pounds increase in dry matter intake and 0.55 pounds increase in 4 percent fat-corrected milk.
In another trial conducted by Michigan State University, cows were fed two alfalfa silages with similar NDF concentrations but that differed in NDF digestibility by 5 percentage points. Dry matter intake increased by 2.2 pounds per day and milk production by 4 pounds per day with the alfalfa of higher NDF digestibility.
"Diets that contain alfalfa of high fiber digestibility will require less grain supplementation to achieve similar milk production," Garcia said.
"Furthermore, alfalfa of higher fiber digestibility may not provide enough effective fiber, another reason why we should look more closely at the amount of grain being supplemented. Assessing digestibility of the NDF is thus an important parameter of forage quality that can result in savings from the feed bill."
South Dakota State University Olson's Biochemistry labs routinely perform this analysis on alfalfa samples. Ask your county Extension office for more information, Garcia said.