Assessing the Variability of Energy Metabolisability in Barley, Rye, and Wheat Varieties for Broiler Diets

This trial assessed the variability of energy metabolisability in four varieties of barley, rye, and wheat based on changes in energy and nutrient flow estimations in excreta. Twelve diets were created by combining 40% of each cereal variety and 60% of a common mixture, divided into enzyme-supplemented and non-supplemented versions, resulting in 24 experimental diets that included TiO₂ and Yb₂O₃ as indigestible markers. A total of 432 one-day-old broilers were distributed into 72 cages and fed a single diet from day 1 to 15. Experimental runs were conducted from day 16 to 25 using a crossover design. Diets were alternated between enzyme-supplemented and non-supplemented for each cage. Excreta samples were collected on days 20 and 25. Energy metabolisability was highest (p < 0.001) in wheat (83.3%), followed by barley (77.8%) and lowest in rye (70.6%). The variety influenced energy metabolisability in barley and wheat (p < 0.001) at a wider range than predicted by NIR analyses. The variety influenced the increment of energy in response to enzyme supplementation in barley diets (p < 0.05), with varieties having low metabolisability values showing higher responses. TiO₂ and Yb₂O₃ did not differ in estimating nutrient flow. This study quantifies energy variability among and within cereals and identifies potential variation factors.