With the onset of the spring calving season dairy farms are busy places with not only the rush of young stock, but also the feeding of both dry cattle and those in the early stages of lactation.

Complete diet feeding is one answer to easing the management of herds that may have differing dietary requirements.

It is also widely considered to help ruminants make better use of feed ingredients if they are mixed rather than fed separately, leading to increased total solids in the milk.

Feeding at Gurteen Agricultural College

A popular type of machine by which to blend the fodder and concentrates is the tub or vertical mixer wagon which, at first sight, would appear to offer little scope for variation between makes, however, the devil, as always, is in the detail.

Gurteen college twin tub wagon
The Kuhn 20.2 CS has a capacity of 20 cubic metres which can be increased by the replacement of the top hay ring

Recently, Kuhn held a demonstration day at Gurteen Agricultural College in conjunction with the local dealer, Alan King Agri Sales of Roscrea.

Kuhn had brought along a 20m3 twin tub mixer wagon from its Profile range and a Primor trailed straw blower to put through their paces.

Agriland got to see an example of the Kuhn feeder in action - check out our video below.


Mixing vertically

The basic tenet of complete diet feeding is that the ration is prepared so that each animal receives exactly the same level of nutrition.

Feeding Kuhn twin tub
The bottom plate of the mixer forms the chassis with the axles attached by subframe. The left had weigh cell is located behind the black disc

Naturally, this starts with getting the correct ratio of ingredients into the tub and Kuhn's system is based on having a load cell on each axle as well as one on the drawbar.

With these three sensors the company claims that the ration can be weighed to the nearest kilogramme, the total being displayed on the machine itself and a bluetooth connected screen in the loader cab, which has a range of around 90m.

Kuhn diet feeder  Feeding
The screen in the cab displays the weight of the ingredients as they are loaded

There are various levels of digital sophistication which allows remote downloading of rations and record keeping, depending on the intensity of stock management in place.

The ingredients are best added in ascending order of inclusion, starting with the least and working up the the main forage item which, in this case, is pit silage.

The mix being prepared on the day was for dry cows as they had only the one early calf at the time Agriland visited.

Twin augers feeding Kuhn
The top flight of each auger is set at a steeper angle which aids mixing according to Kuhn

This included a certain amount of straw which had already been teased out of the bale by the straw blower.

Kuhn is quick to point out that although the Primor 3570 does have a reducing effect on straw length, it is sold as a blower rather than a chopper.

twin augers feeder
Each auger is mounted on two bearings running in an oil bath with reservoirs located on the RH side of the tub

That said, the use of straw that has been teased from a bale and passed through the fan blades does save a great deal time and fuel when compared to the use of unprocessed straw.

The college had the mixer attached to a John Deere 6155M which provides 155hp. This is ample for this size of mixer, Kuhn suggests that 7hp per m3 is a good guide to power requirement.

Feeding kuhn tractor
The options for feeding out are numerous

The options available for feeding out the mix are numerous. The doors can be located at various points on the tub while the belt be driven either way and have an elevator attached for feeding into troughs.

beet, straw silage
The final test as the ladies, and gentleman, tuck into the feed

A casual examination of the feed being put in front of the animals showed a consistent mix with the beet portion evenly distributed throughout the silage and the straw finely ground down.

Blowing straw

Straw blowers might appear one of those items which bring convenience but are hardly essential and therefore appear well down the bucket list of many farmers.

Kuhn straw blower
The straw blower has many uses, here it is breaking up a bale for use in the mixer wagon

Yet, that would be ignoring not only the time and effort which they save, but also the more efficient use of straw as it is laid down in the bedding areas as a consistent blanket rather than randomly scattered lumps.

Not only does this consistency reduce wastage of the bedding, but when it comes to spreading, there are no chunks of dung that lie around on the field all winter waiting for the warmer weather to return before eventually rotting away.

Why buy a blower?

The decision to buy will be influenced on whether straw is regarded as a valuable input or just a handy waste product that doesn't necessarily require a machine to process it.

Bedding, straw blower
Bedding down the easy way. Straw can be blown up to 18m

On the demonstration day, one bale was evenly and generously placed over an areas of four pens that normally took one and half when rolled out by hand.

Whether less straw being used would mean that the job would need to be done more often couldn't be determined immediately, yet it seemed unlikely as the machine left a deep clean litter that was evenly spread.

Two bale capacity

The blower being shown was a Primor 3570M trailed machine that is suitable for smaller tractors which might not have the weight to counterbalance a mounted unit, especially if being used to feed silage.

Kuhn Primor blower
The Primor 3570M can hold 2 round bales or a square bale up to 2.7m long

A minimum of 60hp is recommended when on straw, however, if it is to be used for feeding silage, then another 10hp at least is recommended.

Being the sort of machine that is likely to be used in lots of short, regular sessions, finding a used tractor to keep attached to it needn't be a great expense. Otherwise, time saved over spreading by hand could easily be lost in hitching it to the tractor every day.

Self loading

This particular machine is a two bale model that can be self loaded if the bale is positioned on the ground. The rear door can be operated from inside the cab or there are duplicate controls mounted on the side at the rear.

polybelt drive to feed roller Feeding
The polybelt drive to the feed roller is claimed to be robust and reliable

It has an eight blade blower which can be set to run at two speeds with the drive to the feed roller being by a five V polybelt that is hydraulically engaged. A wide angle PTO comes as standard.