When comparing feed pellet mills for sale, ask for measured durability and fines data from the same feed recipe. A shiny pellet can still crack during cooling, bagging, and transport. Request a durability test result, plus the tester type and sample conditions. ASABE Standard S269.5 describes methods for measuring pellet durability, density, and moisture; results are meaningful only when testing conditions are disclosed. Small details matter.
Fines deserve their own check. Screen a cooled sample and record the percentage that passes the chosen screen, rather than relying on appearance alone. There is no single fines threshold that suits every farm, formulation, or delivery system. A mill producing a high initial pellet rate may still create extra fines after handling. Test at the outlet and again after a realistic transfer. That comparison can be revealing.
For poultry, 3–4 mm pellets are common in grower and finisher diets. Aviagen’s 2022 Ross Broiler Nutrition Specifications list this diameter range for those stages. Treat it as a practical reference, not a universal requirement: bird age, feed formulation, and feeding equipment all matter. Ask suppliers to run your intended recipe, then inspect pellet length, breakage, and fines after cooling. I would not choose a mill from one attractive sample; repeatability is the harder question.