The addition of feed enzymes to layer diets based on wheat or wheat plus rye

Four different commercial enzyme products were added to either a standard commercial wheat-based layer diet or the same diet with 20% of the wheat substituted with cereal rye. Diets were fed to Isa Brown laying hens from 50 to 65 weeks of age. Measurements of egg and egg shell quality, apparent metabolisable energy and excreta moisture were conducted at five-weekly intervals. Digesta viscosity was measured at the end of the trial. The AME of the diets was similar and relatively stable. Excreta moisture was not affected by the addition of feed enzymes. Egg and egg shell quality varied significantly as the birds grew older and was significantly better for the wheat+rye diet as compared with the wheat diet. There were few effects of enzymes on egg and egg shell quality except that Kemzyme resulted in lower albumen quality and lighter shell colour. Production was not affected by type of diet but the Roxazyme treatment had the highest production. Both type of diet and the addition of enzymes affected egg and egg shell quality.