Fat-correct milk jumps 3.5 lb. per cow
A meta-analysis of 36 peer-reviewed studies of yeast culture feed additives involving more than 700 cows shows the stuff works.
Gerald Poppy, a Ph.D. veterinary student at Colorado State University and director of dairy business for Diamond V, conducted the meta-analysis. The earliest study included was from 1990. The meta-analysis technique combines the results of multiple studies to sniff out statistical significance where it might not be present in individual small-scale studies.
Poppy’s findings: Yeast culture added to rations early in lactation (up to 70 days in milk) resulted in 3 lb. more milk per cow per day.
Later-lactation cows saw increases of 2 lb. of milk per day. Butterfat and protein pounds increased as well. That led to an average increase of 3.5 lb. per cow per day of fat-corrected milk and 3.6 lb. per cow per day of energy-corrected milk across the entire lactation.
Dry matter intakes in the first 70 days in milk went up 1.4 lb. per cow per day, but decreased 1.7 lb. in later lactation. The early increases in intake meant cows returned to positive energy balance sooner, and had a 3% jump in feed efficiency because of the 3-lb. improvement in milk production. The decreases in intake later in lactation led to a 6% increase in feed efficiency because milk production still increased 2 lb. per cow per day with less feed.
The meta-analysis could not detect any differences in dosages. "We recommend utilizing the Original XP or Original YC product, which is a bulkier concentration, because we feel that 0.5 oz. or less product cannot be adequately mixed on most farms in a total mixed ration mixer to get proper distribution," Poppy says.