Feed enzymes and wheat-based diets in laying hens

Abstract

In Trial 1, four different commercial enzyme products were added to standard commercial layer diets, based on two different types of wheat, "normal" wheat and "pinched" wheat. Diets were fed to Isa Brown laying hens from twenty-five weeks of age. In Trial 2 (50 to 65 weeks of age), all diets were based on pinched wheat or pinched wheat containing 20% cereal rye. Measurements of egg and egg shell quality were conducted at five-weekly intervals. Apparent metabolisable energy and excreta moisture were measured every 5 weeks from 30 to 65 weeks of age. The AME of the diets was similar for the two types of diet in both trials. AME increased to 40 weeks of age, remained relatively stable and then decreased slightly. Excreta moisture was not affected by enzymes in either trial. Egg and egg shell quality varied significantly as the birds grew older and was significantly better for normal wheat than pinched wheat and for wheat+rye versus wheat. Shell breaking strength was slightly lower for Biofeed Wheat and Avizyme, shell reflectivity was higher for Roxazyme and Kemzyme, and percentage shell and shell thickness was higher for Kemzyme. Yolk colour showed minor variation among the enzyme treatment groups. Production was not affected by type of diet or enzymes in either trial. Both type of grain and the addition of enzymes have the potential to affect egg and egg shell quality.