Straw processor optimises milk yield potential A revolutionary straw chopper, designed and manufactured in the UK, is expected to prove popular with large-scale dairy farms and contractors. David Williams reports.

Tomahawk C12 Calibrator • Straw processing capacity; 11t/hr at up to 20 per cent moisture. • Hammer mill action; 56 rotor-mounted 15mm boron steel hammers. • Rotor speed; 2,000rpm. Hammer tip speed; 73m/second. • Eight vee-belt drive to rotor. • Hydraulic oil capacity; 150 litres. However good the mix quality, straw which remains longer than other ration constituents can be sorted and rejected by cattle, preferring other ingredients which means only part of the allocated ration per head is actually consumed and rumen capacity is partly utilised.”

Dry cows in peak condition

Teagle’s Tomahawk C12 Calibrator is designed to chop straw to an optimum length for dry cows to boost condition ahead of calving.

Teagle’s Tomahawk bale processor range has gained a superb reputation for quality and performance during 30 years’ production and is a firm favourite with UK farmers, attracting a generous market share. Most are used to prepare straw for bedding, spreading direct into pens and feeding baled or clamped silage to livestock. The new Tomahawk C12 Calibrator is different. Not only is it

Teagle’s most innovative product to date, but it has also required the greatest investment in research and development. “Feeding straw as part of a mixed ration prepared by a mixer wagon is quite hit and miss,” explained Teagle UK sales manager Jim Squires. “It ties up the tractor for long periods each day and, unless blades are maintained from brand new, ability to chop straw thoroughly is limited.

A large oval-shaped feed hopper makes loading of bales of any size and shape easy.

Design objectives Essential to Calibrator design were; • Ability to take round or square bales • Top-loading • Power requirement of 120hp+ • Chop control system • Ability to operate in the field and load into lorries or trailers • Capable of 8–12t/hr • Road transportable The first prototype was built in March 2014 and, in September 2015, a more advanced version incorporating hydraulics and electronic control was produced. A range of screen sizes allows chop length of 2–10cm to be easily achieved.

Optimising dry cow condition ahead of calving stresses contributes to better health, fewer problems and lower vets’ bills, argues Penzance, Cornwall-based farmer Gavin Rodda. The family farm trading as JS Rodda & Son has been involved with the Calibrator’s development since the initial prototypes commenced work, almost two years ago. Livestock nutritionist Andy Hawken of Three Counties Feeds works with the Roddas ensuring high yields of quality milk are maintained. He explained that even if cows consume long straw, it offers less benefit than short-chopped straw. “Inclusion of concentrate in the dry cow diet can have a number of benefits including an opportunity to balance protein, helping the cow acclimatise to a diet for the lactation. It’s important to avoid too many changes in diet around the time of calving and structural fibre is also needed. The ends of a piece of straw scratch and stimulate the rumen,” he explained. “So, even if you can get the cow to consume long straw, the benefit is limited as each piece has only two ends per stem. By chopping each straw into smaller lengths, each with two ends, we increase rumen stimulation and maintain peak condition ready for calving and milk production. “Also, if the rumen is only part full only the lower section is kept active but if we can achieve a full rumen and keep it stretched by feeding straw with the rest of the ration, then the total inner surface is stimulated and feed processing efficiency increases.”

Consistent chop quality Chopping action is provided by a high capacity hammer mill. Bales of any size or shape can be placed in the top-mounted oval hopper, which

rotates the bale exposing a section to the flailing hammers. Hopper rotation speed adjusts straw feed rate and different size screens regulate chop intensity and straw length. Chopped straw is discharged onto a belt conveyor with a maximum 4.2m discharge height for loading straight into trailers or hoppers, or on to piles for use later.

Hammer flails chop the straw with length adjusted using swappable screens.

The Calibrator requires at least 120hp, but processes large square bales in under 2 minutes, saving almost 40 minutes compared with a typical mixer wagon. Teagle claims chopped straw output up to 11t/hour for straw up to 20 per cent moisture, and an integral speed regulator maximises straw feed rate while maintaining optimal rotor speed. The chopped straw is then added to a ration for mixing by conventional mixer wagon, with feed prepared including straw of ideal length in just 10 minutes or so. Built-in hydraulics with an integral cooling pack drive the hopper and elevator. An auto-reversing fan helps keep the cooling screen debris-free.

Remote control The Calibrator can be operated from the tractor cab, but innovative Bluetooth control from a Teagledesigned touchpad provides remote operation from up to 50m. This allows the bale loader operator to adjust the Calibrator during work, including adjusment of feed rate as bale quality and condition varies. The Calibrator automatically stops the feed if the chopper becomes overloaded and a flashing light on the chopper alerts the operator. Teagle expects the Calibrator to appeal to large dairy farms, and to contractors providing a service to multiple farms. The unit is continued over...

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