Danger of cutting corners.

Dairy farmers are being urged to avoid feeding cheap "convenience" cereals this winter and instead focus on fibre to prevent costly metabolic disorders in their herds.

Volac International's ruminant nutritionist Dr Naomi Gardner told a farmers' open day: "With wheat and barley at pounds 60 per tonne or even less this coming winter, there will be a huge temptation to formulate so-called `least cost' total-mixed-ration diets by introducing excess cereals to provide energy.

"Don't. A diet should include no more than 5kg freshweight of cereal grains per cow per day, plus 1kg to 2kg of long fibre ( straw with an average 5cm chop added last to the mixer wagon and not over mixed ( while additional energy requirements should be supplied in the form of Megalac, a concentrated rumen-protected fat."

Dr Gardner said: "The rumen has a 300-litre capacity and requires fibre to maintain its massive bug population in top working condition.

"Sufficient physically effective fibre must be present to form the fibre mat that floats on top of the liquid in the rumen.

"The mat performs a vital role in rumen function by physically trapping food particles for the rumen bugs to break down. If the rumen lacks adequate fibre, then undigested food particles flow out of the rumen and fail to be fully utilised by the cowa

"Feeding excess cereals should be avoided at all costs.

"Cereals break down rapidly to provide immediate energy, pH plummets and the rumen suffers impaired function. This leads to digestive upsets and metabolic disorders, such as subacute ruminal acidosis (Sara), ketosis and laminitis and may reduce her potential lifespan.

"The consequences for production are reduced yield and butterfat," she said.