Despite a difficult start to the season and problems with drought for some growers, most of the UK’s maize crops have delivered decent yields and good quality.
“There were concerns that the maize crop would be very variable following the challenging growing season but most people have harvested reasonable yields with good quality in evidence too,” says Wilson Hendry of Grainseed.
“We’ve seen starch contents of up to 35% combined with freshweight yields approaching 20t/acre in some cases, so many producers will have an abundant supply of home-grown energy from maize this year.”
That’s not been the case with grass, however. While some producers managed to take good early cuts, Mr Hendry said many had to rely on some late-cut material to boost forage stocks – so there is a wide range of feeding qualities on-farm.
“The only way you’re really going to be able to keep things in balance and make sure you’re making full use of your home-grown feeds is to keep testing all your forages and be prepared to change track with rations accordingly.”
There will be an understandable temptation for many to open clamps early to improve cow nutrition. But this risks exacerbating the problem of acidosis through feeding material that has not fermented properly, says Mr Hendry.
“If you can, hold off opening clamps as long as possible and when you do, good clamp management will be essential to minimise wastage. Maize, in particular, always feeds better after Christmas.”
Although leaving clamps until then might not be feasible for many, Mr Hendry says it is still worth bearing in mind. In particular, digestibility of the grain is much higher and cows can access the energy much more easily the longer you leave it.
“Minimising losses is important, so keep faces clean, don’t leave material lying on the ground and if you’re in an exposed area double gravel bag the edge of the film on top of the clamp to prevent air ingression.
“In areas where starlings are a problem, keep the face protected by dropping the secure cover netting down each day to prevent them eating the maize grains.
“Regular analysis will also tell indicate whether you’re likely to encounter potential problems with acidosis. Options should be discussed with a nutritionist to help ensure all rations are properly formulated.
“A lot of the risk can be removed simply by making sure you have sufficient fibre such as straw in the ration and balancing metabolised protein and energy. You should also be prepared to use rumen buffers such as sodium bicarbonate, if necessary.”
Professor Mike Wilkinson, nutrition consultant to the Maize Growers Association (MGA), advises testing forages monthly. Regular testing can identify unexpected variations in quality which can help explain changes in intake or milk yield, he says.
“Be prepared to act on the results and use these only until the next analysis is available the next month. Don’t create a rolling average based on cumulative data as you’ll be deluding yourself if you do.
“Silage quality changes with storage time and from the front to the rear of the clamp, so regular sampling is essential. Testing is not costly and if you’re an MGA member there is a discounted price for this.”
Maize silage should be left in the silo for at least 30 days after clamping, he advises. Starch availability increases in the first 30 days after clamping and fibre is also being broken down, so digestibility also increases.