Alfalfa (40% NDF) and orchardgrass (60% NDF) hays supported similar milk production levels when they replaced corn grain in rations at the University of Minnesota.
Alfalfa was fed at levels ranging from 15% to 35% of ration dry matter; orchardgrass, at 10-30% of dry matter. Fifty cows averaged 86 days in milk at the start of the eight-week study.
Researchers report that, within alfalfa and orchardgrass treatments, 3.5% fat-corrected milk production decreased with increasing hay inclusion rate; rate of decline was similar between the two species. Cows averaged 98 and 82 lbs of milk/day at the lowest and highest hay inclusion levels, respectively.
Milk production declined at a faster rate for alfalfa as dietary NDF increased. The range in ration NDF was 29.5 to 35.6% for alfalfa; 29.9 to 39.8% for orchardgrass, say the researchers.