Frequent inspections ward off problems
The knives on this vertical mixer are almost completely worn away, dramatically reducing their usefulness.
Total mixed ration (TMR) mixer wagons are the workhorse of any dairy. Do the math:
- A 1,000-cow dairy will mix six to eight batches per day.
- If each batch weighs 15,000 lb., the machine will mix up 120,000 lb. of TMR daily.
- After six months, the TMR mixer will have processed more than 400 semi-truck loads of feed.
"Bottom line: After six months, don’t expect the wagon to perform like the day it arrived on the dairy," says Jeff Weyers, a dairy global technical specialist with Vi-Cor and a former private nutritionist based in Texas.
"Ninety-nine percent of the dairies I visited this year had some issue with feed mixing," he says. They ranged from dull cutting knives and worn kicker plates, to dead spots in the mixers to incomplete discharge.
Most of the problems were due to poor maintenance or running the wagons improperly or too slowly in an attempt to conserve fuel.
To correct these issues, Weyers says employees must check the mixers daily. "Make a habit of looking in the mixer prior to the first load of the day," he says. "The feeder needs a basic understanding of what the components (knives and kicker plates) look like and how they function."
Operators should know how many knives should be on each auger and when they need to be
replaced. The same goes for the kicker plates. Due to the weight and cutting pressure of the feed mix, the kicker plate, leading edge and knives near the bottom will wear out first.
Inspecting the wagon’s mixing action during loading is important. "The most obvious thing is to look for ‘dead spots,’ meaning feed that is not moving," Weyers says.
"If a dead spot is apparent, first make sure the tractor’s rpms are high enough," he says. "Simply increase tractor rpm by 500 and inspect the difference in feed agitation."
Also, monitor loading technique. "When loading wet ingredients or ingredients with low inclusion rates, it’s best to load down the sidewall of the wagon," he says. Ingredients have a tendency to stick to the augers if dumped directly in the middle.
"Always have some sort of spreader bar for loading liquid ingredients," he adds.
It’s also best to run the mixer while loading to prevent ingredients from stratifying. Allow three to five minutes of mixing after the last ingredient is added.
Farmers frequently ask "Which brand of mixer is best?" Weyers says all brands work well, if they are properly maintained. Often, it boils down to dealer proximity for parts, repairs and a replacement mixer in case of a breakdown. "The more familiar you are with a brand, the quicker you will recognize problems," Weyers adds.
Also, how much dry hay or straw is in your ration?
Vertical augers are best if you include a lot of dry material. But horizontal wagons work fine if you’re not feeding much dry forage.