It’s startling to consider that the cost of fuel to feed dairy cows can reach hundreds or thousands of pounds each month. But there is also an opportunity to cut these costs by 30-50 percent. James Brough, UK & Ireland General Manager for KEENAN, considers how different diet feeders have different fuel demands.

Author: James Brough, UK & Ireland General Manager

On writing this (June 2023), the price of red diesel stands at 78ppl, almost 20ppl down from 96.26ppl reported in May 2023. Irrespective of this welcomed price drop, fuel is a cost that can soon rack up to thousands of pounds on many farms.

When tightening the belt in a bid to bolster profit margins, cutting fuel costs is perhaps not first to mind or a priority.

Controlling feed costs, which typically account for 60 percent of total variable costs, should still be a priority. But there is also huge opportunity to make savings from reducing fuel used to produce total mixed rations (TMR’s).

The spend on fuel to produce TMR’s

A tractor can use between 15 and 30 litres worth of fuel for every hour running a diet feeder. That stacks up to £11 and £23 per hour based on today’s fuel price.

Scale that up to a monthly cost and most farms will be spending hundreds if not thousands of pounds on fuel to produce TMR’s every month.

You may be surprised to hear that from diet feeder to diet feeder, there is scope to reduce fuel usage by 30-50 percent in most typical scenarios.

Whilst we don’t have trial data to prove this, there is an array of different case studies that can back this up. Here’s a formula to work out your monthly cost on fuel:

The influencers on fuel usage

There are two factors that impact fuel consumption:

1. REV'S PER MINUTE (RPM)

As illustrated in the graph below, the lower you can keep the tractor engine’s RPM (engine speed), the less fuel it’s going to consume to drive the diet feeder.

Credit: Research Gate

2. HORSEPOWER REQUIREMENT

As illustrated in the graph below, a diet feeder with a lower power input or torque requirement will again consume less fuel.

If you want this explained simply but in detail, check out this video.

Fuel economy: vertical auger vs horizontal paddle diet feeders

There’s a fundamental difference between the mechanism of a horizontal paddle diet feeder compared to the vertical auger diet feeder. 

When processing a ration, a vertical auger diet feeder has to physically lift 85-90 percent of all the whole ration in one go. A horizontal paddle diet feeder, on the other hand, has 6 paddles with only 3 paddles lifting feed at any one time, so only has to lift half the ration weight.

With this, the KEENAN MechFiber paddle mixer runs at 350RPM, which only requires approximately 1,400-1,500 revs. The average vertical auger tub machine on the other hand, requires the full 540RPM speed using up to 2,100 revs for the same size load.

Adding to this, the horizontal paddle mixer has a lower power input/torque requirement than a vertical auger diet feeder. This facilitates further fuel savings.

The way the KEENAN Vertical Auger diet feeder gets around this is by using a 2-speed gearbox fitted as standard at the front end. This enables the operator to run the machine in a lower gear until the wagon is half empty before moving to a higher gear. This results in a more efficient handling of the greater power requirement. Note that this does mean you need to run the machine for longer to reach the same desired outcome.

Farmers who are refuelling less often

David Thomson, at Kirkton of Beath Farm in Fife, Scotland, switched from a non-KEENAN vertical auger to a KEENAN MechFiber380.

Despite the new machine being 30 percent bigger, their fuel usage dropped from 26 litres to just 18 litres per day. On today’s fuel price, the 8 litre saving amounts to £6.24 per day or £2,278 per annum.

Tom Chanter, Farm Manager at Greendale Farms in Somerset is mixing 3 loads per day to feed their 1,200 beef finishers.

Switching from a non-KEENAN twin auger tub to a KEENAN MechFiber400, Tom is using 21 litres less diesel each day. On today’s fuel price, that amounts to a significant saving of £16.38 per day or £5,979 per annum.

Think you’ve got scope to reduce your fuel costs?

Here’s some things to consider:

1. Have you the right tractor on the machine?
2. Are your blades sharp enough? Are any blades missing?
3. Is your machine the right type and size?

If you’re in doubt, don’t miss the chance to save yourself hundreds or even thousands of pounds each month.

Contact your local KEENAN specialist here.