60 years of published research.

A meta-analysis in the Journal of Dairy Science pooled 46 studies going back to 1998. The consistent finding: as forage particle size decreased, milk production went up, about half a kilogram per cow per day. That is not one study. It is forty-six pointing the same direction.

It compounds across the herd and the lactation. A pound of milk per cow per day is real money once you multiply it out.

Research out of Canada found that every 2% increase in cows sorting against the long particles in a TMR is associated with a 0.9 kg/day drop in fat-corrected milk, nearly two pounds, per cow, per day. If the ration drifts long, cows pick out the grain and leave the fiber, and you are losing production without tracking it.

The fix is consistency: a particle size uniform enough that there is nothing to sort against. A 500-cow dairy that got serious about TMR consistency documented $50,000–$60,000 a year in savings (Penn State).

University of Guelph studied straw chop length in dry-cow transition diets, short chop (about 2 cm) versus long (about 8 cm). The cows on the shorter chop ate more, sorted less, and had lower ketosis markers coming into fresh.

Dry cows are the hardest group to keep eating, they are bored and will pick through a ration all day. Chopping the straw fixes it: intake holds, body condition holds, and they transition cleaner.

NDSU’s Carrington station found cattle on chopped straw bedding had 49% better feed efficiency over winter than cattle on long straw, with real measurable savings. Chopped bedding insulates better and stays drier, so animals spend less energy staying warm and put it into gain instead.

On the dairy side, bedding particle size drives moisture retention, which drives bacterial growth, which drives somatic cell count. One study found Strep. uberis survived 35 days on straw but only 7 on sawdust, management and material matter.

Oklahoma State extension puts hay waste at open-bottom feeders at up to 21% of bale weight. A 2021 Missouri/Sexten study showed waste dropping from 20% with a typical ring feeder to 6% with a better design. On a 1,500 lb round bale, 20% waste is 300 lb on the ground.

Run it through a HayBuster and into the bunk, and cattle cannot kick it, trample it, or bed on it. The waste number heads toward zero.

Reducing feedstock particle size improves anaerobic-digestion methane yield by 10–84% depending on the material (DBFZ Germany, Aarhus University). Smaller particles mean more surface area for the bacteria, fewer floating layers, and less wear on pumps and agitators.

The catch is processing the wet, stringy material at all. HayBuster’s Anvil screens cut against a solid edge instead of through holes that plug, so manure-with-straw and old bales feed cleanly into the reactor.