Pellet quality is primarily defined by a pellet’s ability to maintain its shape during the various stages of handling and transport from the mill to the farm—poor physical quality leads to pellets breaking apart or wearing down, which generates dust and fine particles.
These fines cause several problems: they can lead to nutrient segregation, unbalancing the animal’s diet; irritate the nasal passages of ducks and rabbits; and clog automated systems like robot milkers or feeders. In contrast, high-quality pellets are hard and durable, with minimal breakage. To measure this quality, two key metrics are used: durability and hardness. Durability refers to a pellet’s resistance to breaking during transport, and it is tested in two common ways: one method involves blowing 100 grams of pellets in a New Holmen Pellet Tester for 30 to 60 seconds, then calculating the percentage of intact pellets remaining; the other method places 500 grams of pellets in a KSU tumbling can, tumbling them for 10 minutes, and then measuring the percentage of intact pellets.
Hardness, which measures a pellet’s resistance to crushing force, is tested using specialized instruments like the Acme Penetrometer and the Kahl Hardness Tester, which apply controlled pressure to the pellet and record the force required to break it.