Yeast Supplementation Raised Milk Solids Output in Dairy Cows
A study cited by Haponiuk examined cows fed diets containing different starch concentrations. Under conditions involving greater fermentation pressure, adding yeast culture lowered rumen lactate, raised average rumen pH and reduced the time that pH stayed below 6.0, a level associated with subclinical acidosis.
The reported effects also involved fermentation products. Propionate is one of the principal precursors of glucose in ruminants. After absorption, it contributes to glucose production in the liver and supplies glucose to the mammary gland, where it is used mainly in lactose synthesis. Lactose is directly linked to the volume of milk produced.
Yeast cultures may also support lactate-consuming bacteria, including Megasphaera elsdenii and Selenomonas ruminantium. Their activity can help limit lactate accumulation in the rumen.
A meta-analysis covering 36 studies and 69 comparisons involving a commercial yeast culture found an average increase of about 1.18kg of milk per cow per day. The same analysis reported gains of nearly 60g a day in milk fat and 30g a day in milk protein.
Results from Brazil showed a similar pattern. Mid-lactation Holstein cows receiving 7g of yeast culture per cow each day produced an average of 28.04kg of milk daily, compared with 26.78kg in the control group. Fat production rose from 1.04kg to 1.11kg per day, while protein production increased from 0.90kg to 0.94kg.
In that Brazilian trial, the percentages of fat and protein in milk did not increase significantly. The difference was recorded in the total quantity of solids produced by each cow per day. The report described yeast culture as one component of a broader feeding strategy rather than a replacement for forage quality, dry-matter intake, the balance between fibre and fermentable carbohydrates, feed-bunk management or appropriate ration formulation.
Vaccinar has included yeast culture among the technologies used in TECNOLEITE HD+, its programme for lactating cows. The product is intended for use in high-production systems and focuses on the efficiency of the rumen environment. The article was produced by eDairyNews using information published by Kdea 360.
