Cereal grinding is a major cost in layer feed production. Hammer mills and roller mills are both used in grinding cereals, and each type of grinder offers different advantages and disadvantages. But, when selecting the best-fit equipment for any feed mill, it is important to know if the specific type of grinding will have an impact on layer productivity. Things get slightly more complicated when one considers that all three major cereals (maize, wheat, barley) are used in layer feed production, and each cereal reacts differently to grinding methods, perhaps giving ground to differences in layer productivity.
To this end, a study was conducted to determine the influence of method of cereal grinding on production and egg quality. A total of 420 Hy-Line Brown egg layers were used in a complete randomized design with six treatments arranged as a 3 × 2 factorial. Main factors were type of cereal (maize, wheat, or barley) and grinding procedure (hammer mill or roller mill). Each treatment was replicated seven times, and the experimental unit was an enriched cage with ten hens. Production was recorded every four weeks from 24 to 59 weeks of age; egg quality was measured at 40 and 56 weeks of age.
For the entire experimental period, feed intake was higher in layers fed wheat or maize than in layers fed barley (110.8 and 110.7 vs. 109.7 grams per day; P = 0.014), but most of the differences were observed when the cereal was roller milled (P = 0.009 for the interac-tion). Also, egg production was similar for the three diets when the cereal was hammer milled but tended to be lower for the barley than for the wheat or maize diets when the cereal was roller milled (P = 0.09 for the interaction). None of the other productive or egg quality traits were affected by dietary treatment.
It is unclear why roller milled barley did not support performance equal to that obtained by hammer milled barley. If barley is going to be the major cereal in a layer hen diet, then it should be hammer milled. For maize and wheat, either type of grinding supports equal performance in egg-laying hens.
