With most crops clamped, producers are urged to analyse this year’s maize silage, as low fibre levels in some crops, particularly those taken early, could reduce livestock performance.
A survey of 820 samples has revealed a fall in non-digestible fibre (NDF) – down 11% this season – in addition to slight falls in dry matter, down from 29.7% to 28.8%, crude protein and D value, says Rachel Fowers, ruminant specialist at Ashbourne-based Frank Wright.
“We would normally expect NDF levels of 53%, but this year they are down to 42%.
This can result in reduced rumen stability and potentially lower milk fat percentage,” says Ms Fowers.
The unusual growing season during 2005 has seen cobs ripen ahead of stem material in some early areas leading to harvest of greener, wetter maize silage.
Such factors can increase lactic acid loading in the rumen and feeding extra digestible fibre might redress any imbalance, suggest ruminant specialists.
An easily accessed solution could be to incorporate chopped straw into cattle diets prepared using either a forage box or mixer wagon, says feed specialist John Bax of Biotal.
“Volume of straw will depend on the proportion of maize in the ration, but incorporating it ensures animals are less able to selectively pick at diets.”
As well as increasing fibre content of diets, chopped straw will encourage cudding, an activity that naturally reduces acid loading in the rumen, say advisers.
Other ingredient solutions exist, says Miss Fowers.
“To meet minimum NDF requirements, dairy producers could feed soya hulls at 1-2.75kg a head a day or palm kernel at 0.5-2.5kg depending on the level of maize in diets and feeding system used.”
Use of chopped sugar beet feed at 2-4kg a head a day could also counter low fibre in both beef and dairy diets, suggests nutritionist Ian Pickles of KW Alternative Feeds.
“There are also commercial acid buffer products available.”
Those producers feeding cereal in diets should consider caustic-treating grain for its slow release characteristics and buffering capability, he adds.
“Other steps such as feeding cracked rather than ground grain could help.”
But not all maize crops appear to have suffered a fall in fibre level.
Steyning, Sussex-based Tim Gue says despite a slight decrease in dry matter to 30% and a fall in yield to 18t/ha freshweight, this year’s maize is feeding well.
“Anecdotal evidence suggests variation in maize quality is localised, a reflection of this year’s weather pattern,” says Mr Gue.
Nutritionists agree, adding localised conditions in the weeks before harvest will have influenced maize quality.
“I’d encourage growers to ensure maize crops harvested at different stages of ripeness are analysed separately, even when they are in the same pit,” says Mr Pickles.