By FW reporters
SELECTING the right type of wheat and feeding adequate sugar will allow producers to maximise cheap wheat use in winter rations without compromising rumen function, according to experts.
In July, Wales-based senior ADAS nutritionist Ken Stebbings started receiving inquiries from milk producers wanting to exploit wheat, which might be coming off the combine at less than £60/t.
It is possible to feed up to 10kg of cereal dry matter/ head/day to dairy cows without rumen upsets. Historical advice to strictly limit wheat use was based on the fact that at one time most of the wheat offered had been rejected by millers and contained high gluten levels, he explains.
"Feed wheat does not become chewing gum in the rumen and is a better bet, even when barley costs £5/t less, which is why compounders use so much of it."
Selecting wheat on variety type also allows producers to maximise its use in winter rations, says Warks-based ADAS researcher Angela Moss. "Not all wheats are the same in terms of nutritive value."
Soft wheat varieties tend to be more slowly fermented in the rumen than hard wheats at a similar crude protein content. Higher nitrogen wheat also tends to be more slowly degraded when compared with low nitrogen wheat, says Dr Moss.
"Therefore, a low nitrogen soft wheat, which is more rapidly fermented is more appropriate for maize silage based rations, as it complements the more slowly fermented maize starch."
But she advises using a mix of soft and hard wheat to provide a range of fermentation rates for grass silage-based rations.
However, US nutritionist Larry Carver of Quality Liquid Feeds warns that excess dietary starch reduces fibre breakdown in the rumen. "This will only increase rationing difficulties with low quality grass silages."
He advises feeding about 0.25-0.5kg/cow of sugars, such as lactose and molasses to boost fibre digestion. This will allow cows to use more energy from forage.
While these sugar feeds are often rejected on cost unit energy, there is a valuable contribution to rumen function. Maintaining rumen function is more crucial this winter with low D-value grass silages.
Similarly, Mr Stebbings is aware of claims made about the digestive benefits of feeding caustic and urea treated grains, but warns that such treatments dont change the 10kg upper safety limit on the inclusion of cereals. *
Rapidly fermented soft wheats are more appropriate for maize silage-based rations, says Angela Moss.
• Up to 10kg/day/head.
• Variety important.
• Also feed sugar.