27 March 1998


By Mike Williams

CHOPPING or pre-cutting units on round balers have become one of the machinery success stories of the 1990s, with almost 25% of customers choosing a baler with chopping knives, despite the extra cost.

The 25% figure, based on AEA data for 1997, is the national average including arable areas, where there is less demand for chopping, and the percentage must be much higher in the mainly livestock areas, where chopping is preferred for silage bales.

Demand for chopping units has grown mainly from the experience of farmers who were willing to give it a try, and evidence from independent trials has been in short supply. The first UK trials were organised at the IGER, Aberystwyth, where silage from both chopped and standard round bales was fed to beef cattle.

The improved palatability of chopped silage helped to achieve a 25% improvement in liveweight gain, and the quality of the chopped material equalled good clamp silage, the research team said.

Some farmers who have tried chopped bale silage have found additional benefits, and Richard and Ted Bentley say the biggest advantage of using the Roto Cut slicing unit on their Claas Rollant 46 baler is reduced waste when the silage is fed.

The Bentley brothers bought their baler three years ago and use it in silage and straw on their 113ha (280-acre) Elms Farm at Fleckney, Leicester, and for contract silaging for neighbours.

With clamp capacity on their farm for only 200t, the rest of their grass goes through the baler. They make about 2000 silage bales a year – just over half on a contract basis – and the chopping mechanism is used for about 90%. They also make about 2000 straw bales each year.

First and second cut

"Almost all the first and second cut silage bales are chopped," Richard Bentley explains, "but we do not bother when baling the third cut because that is short enough anyway."

Silage at Elms Farm is fed to the pedigree Shorthorn dairy herd and beef cattle. Bales are placed in ring feeders, and the biggest advantage of chopping is waste reduction during feeding, says Richard Bentley.

"When the Rota Cut is working we always use all the blades, and this means most of the silage is in 5 or 6in lengths," he says. "That makes it much easier for the cows to pull silage out of the bale, but they do not drag it out in long pieces which fall on the ground and get trampled in the muck."

Another benefit is heavier bales due to the density increase. This cuts the number of bales to be wrapped and handled, and Richard and his brother think there may be better palatability as well. They also chop some straw bales, making them easier to spread for bedding, but last year much of the straw was brittle and did not need chopping.

Ted Bentley, who operates the baler behind a 90hp Case 5120 tractor, said chopping slows down the baling operation, but the difference is only about 5%.

"When the knives are working they slow down the flow of material, but it does not make a lot of difference," he says. "We also need to keep the knives sharp, but it is a fairly easy job which takes about 20 minutes and we do it twice a year. We have not replaced any knives after three seasons, and I think they will last a few more years yet."

Malcolm Weaver started his contract silage making service at Bishops Castle, Ludlow, Shropshire, in 1984 with a round baler and what he claims was the first bale wrapper in the county. Last year he bought his first round baler with a chopping unit realising there was interest in chopped bale silage in the area.


"I was surprised by the level of interest in chopping. We baled 10,000 silage bales last year, and 7000 of them were chopped, which was a lot more than I expected," says Mr Weaver.

"Our standard charge for baling and wrapping is £3.45p a bale without chopping and £3.75 with chopping included. We claim the bale density goes up by 9% or 10% with chopping, which reduces the number of bales and covers the extra charge for chopping. Some manufacturers claim the density increase is as high as 25% but I do not believe it."

Feedback from last years customers revealed other benefits from using the John Deere 580 balers chopping unit. There were comments about improved palatability, and Mr Weaver says this is because the extra density excludes more of the air to improve the fermentation. Some customers also like the fact that cattle at the feed barrier can pull the short material out of the bale more easily, especially from the core of the bale.

"One of my customers supplies a few silage bales to someone who uses a hand barrow to take silage into a lambing shed for a small flock of ewes. It was hard work getting small amounts of silage off the bale, but it is much easier now the bales are chopped."

Mr Weaver also encouraged his customers to try the chopping unit on some of their straw bales, and some wanted to use the chopped straw in feeder wagons, but the results were disappointing. The straw was not as well chopped as they hoped and the knives quickly lost their edge.

Even in silage, the blades need sharpening once each day as a minimum, and the ideal is twice daily for maximum cutting efficiency, he says. For the 1998 silage season Mr Weaver has bought a second set of 14 blades – they cost more than £21 each – allowing him to put in a fresh set during the day and avoid loss of baling time for sharpening. He estimates a two-year working life or about 32,000 bales from a set of blades. &#42

Above: Contractor Malcolm Weaver says chopping increases bale weight by about 10%.

Below: One of the Berkley produced chopped silage bales with the wrapper removed.

Left: Ted, left, and Richard Berkley check the silage from one of their chopped bales. Reduced waste when feeding is considered to be a big advantage.

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