16 June 1995

Big benefits claim for high yielders fed updated ingredient

By Sue Rider

HIGH yielding dairy cows could benefit from an updated version of an existing feed ingredient launched by Volac International.

The firm points to early lactation cows or those under particular stress, for example at housing, as most likely to gain from its use.

The product, known as Megapro Gold, is Volacs existing protected fat Megalac, balanced with a protected protein, and milk sugar (lactose). Trials show an extra 4-6kg of milk a cow a day and improved fertility from supplement-fed cows than those offered the standard ration alone.

Volac calculates the net benefit to be worth £100 a cow over a 120-day lactation. It also cites a 2kg a day lift in dry matter intakes and better cow health. Volacs technical director, Dr Steve Taylor, explains: "High yielding cows fail to eat sufficient dry matter in early lactation to support milk production. That energy gap makes it difficult to sustain peak yield. It can also cause loss in body condition and poor fertility."

Dr Taylor claims Megapro Gold has been formulated to overcome these shortfalls. "The energy and protein it provides are protected in the rumen and released in the lower gut for better use by the cows," he says.

"When energy supply is limited by dry matter intakes the only way to get more into the cow is to increase the energy density of her feed. Feeding excess cereals upsets rumen function, leading to acidosis, appetite loss and reduced fibre digestion. Conventional fats supply three times the energy of cereals but coat the rumen bugs restricting fibre digestion." But the digestible undegradable energy in Megapro Gold is said to be a combination of palm oil fatty acids and calcium to protect that fat against rumen breakdown. Only in the acidic lower gut is the calcium dissolved to release the fatty acids.

To balance that energy the Megapro Gold supplies undegradable protein (treated rapeseed meal) to the lower gut.

The lactose in the product provides readily available energy for the rumen bugs to help them use rumen degradable protein. "The lactose mops up free nitrogen, which could improve fertility and dry matter intakes," says Dr Taylor.

Trials at the University of Nottingham show a 6kg a cow a day lift in milk for supplement-fed 7000-litre cows 10 weeks into lactation. Farm data shows a 4kg boost. Megapro Gold is supplied as a 7mm pellet in 25kg bags at £350/t delivered and is recommended for high yielding cows at 1-2kg a day in early lactation. &#42