Is Your Mixer Leaving Money on the Bunk Floor?

Feed costs are the highest single operating expense on dairy farms today. They are also the greatest opportunity for expense savings on a farm by focusing on the difference between milk revenue and feed costs, or your income over feed costs (IOFC). An immense amount of time and money goes into a successful planting and harvest. You don’t want that work to go to waste. Minimize shrink and ensure the feed that lands in front of your animals is the homologous mixture designed by your nutritionist. From the first step before planting to the last bite of TMR, we want the process to be both accurate and precise.

The Scale

You can have the perfect ration for your forages and animals, but if you don’t regularly check your scales you won’t know exactly what you are putting in front of the animals. “Accuracy is not related to the precision with which the scale may be read or set. The scale’s accuracy is determined by the mechanism (load cells) use to weigh the mixer box, not the digital display,”1.

There are two types of errors when it comes to your scale.

Inconsistent Scale

This is when your scale is reading the weights incorrectly by adding a consistent percentage. For example, the scale may be adding or subtracting 10% of all your feeds. While the ration will still be as formulated, this can cause major issues with feed inventories, change the desired refusals, and lead to additive costs1.

For example, you assume a damaged or non-working load cell still seems pretty accurate, so you go ahead business as usual. In reality, this could be reading 10% off on each ingredient. If your TMR has an average value of $110 per ton, with a 20 ton average load you would see $220 per load of waste. At 8 loads a day you are looking at $1,760. Over the course of a month, this equals $52,800.

Consistent weight being added or subtracted

This is where your scale adds or subtracts a fixed amount of weight to every ingredient in your ration. For example, adding 500 lbs extra to one ingredient at an amount of 2,000 lbs is entirely different than adding an extra 500 lbs of an ingredient at an amount of 5,000 lbs. These errors can lead to drastic changes in the percentages of feeds relative to one another and alter the composition of the diet. Shrink for this error is inversely proportional to the ingredient inclusion rate1.

For example, our Dairy One team went to a farm earlier this year that takes part in biannual audits. They found the calibration of the scale was off. After looking back through the reports on TMR tracker, they found the problem had been going on for four weeks. They believe what happened was the mixer was left uncovered one day and got filled with snow and rain. The mixer was then zeroed out first thing one morning because it was reading 1600 lbs. For the next four weeks, every ration started at  -1600 lbs.

Luckily for this farm, they had followed a recommendation of loading haylage first into the ration. Although still an issue for the TMR composition and inventories, this loss would have been amplified if the ration had started with soy or other more expensive ingredients. The farm had noticed the cows were not eating like they should have been and adjusted the ration accordingly, not knowing that the mixer was off and altering the diet.

It is for this reason, along with many others, that Craig Todd, IFS Support Specialist at Dairy One, recommends farms have an audit done on their mixers at least biannually, “and if they do not want to do it biannually, everyone should have it done annually.”

Keeping the money off the floor

Preventive maintence

Total mixed rations and feed delivery systems from the Large Dairy Herd Management Journal suggests the following routine maintenance for preventative care2.

  • Daily: Check oil reservoir levels, grease power takeoff, check and clean magnets, and clean radiator screens as needed on trucks and tractors and loaders
  • Weekly: Grease telescoping driveline, check tire pressure, and oil chains
  • Monthly: Check wheel hub oil level, hydraulic line leaks, conveyor chain tension, and grease conveyor bearings
  • Quarterly: Check for tire wear, fluid coupler oil level, driveline steady bearing, loose or damaged wiring, loose or missing fasteners, auger knife wear, condition of guards, auger knife bolt wear, auger knife wear flighting wear, auger kicker plate wear and scale calibration.
  • Every 6 months: Check conveyor pan wear and grease wheel hubs
  • Annually: Change axle bath oil and planetary gearbox oil, and grease planetary gearbox.

Something quick and easy that Todd highly recommends to most farms is to do what he calls a quick test, daily if not weekly. “I tell farms that what I like to do is come up with a known weight that can easily be hung on the side of a mixer. They can hang it on all four corners to make sure the mixer is weighing correctly. Quite often I find just a little problem on the mixer that can change just days after an audit, so it is important to do regular preventative maintenance,” says Todd.

Mixer audits

We know this can be time-consuming, and gradual changes day after day may be difficult to pick up. That is why we offer a feed management audit. Let our team do the heavy lifting for you. A feed management audit from Dairy One includes:

  • Meter test of all load cells
  • Bridge resistance, bridge balance, and load percentage test
  • Known load calibration
  • Thorough inspection of all cables and scale heads
  • Visual inspection of the mixer including PTO guards, safety shield, draw bar, frame, etc.

Many farms will use our team for these audits as a first line of defense either for preventative maintenance or when there is an issue. We look at a lot of different mixers on farms who have a range of management styles, and we are not in the market of selling load cells. “We’re looking at wear points in and around the mixer that can wreak havoc on the quality of your TMR,” says Todd.

Load cells must be evenly loaded to work properly.  If the frame of your truck or trailer mixer is broken or flexes improperly, load cells will not ‘feel’ weight correctly.  Todd has found cracked frames and missing bolts that force the mixer to put undue weight onto specific load cells, causing highly inaccurate readings.  He once found a conveyor mount welded to the frame in a way that took the weight off the load cells!

Track your errors

After you’ve taken the steps to prevent and catch problems early, you’ll still want to keep a close eye on the amount of feed going out. FeedWatch and other feeding programs can quickly give you a list of each and every ingredient loaded with the actual amount fed and the target amount fed.  Look at these lists all the time. You will catch instances where your scales become inaccurate and learn different tricks to be more accurate. Dairy One can arrange for this list to be automatically emailed to feeders and feed supervisors daily through FeedWatch. If you look at the list every day, you will quickly identify situations where feed technicians or equipment are operating improperly.

Regular audits of your feed management systems can help you find problems before they happen and reduce your downtime. Schedule maintenance at a time that works for you and avoid the extra cost of emergency service and parts orders. To schedule a feed management audit or learn more about FeedWatch, email [email protected] or call 607-252-7550.

1 Harner, J. P., Zulovich, J. M., Kammel, D. W., & Tyson, J. T. (2017). Feed center system design and management. Large Dairy Herd Management, 279-296. doi:10.3168/ldhm.0319              

2 Oelberg, T. J., & Stone, W. C. (2017). Total mixed rations and feed delivery systems. Large Dairy Herd Management, 751-770. doi:10.3168/ldhm.0855