Production and egg quality as influenced by mash or crumbled diets fed to laying hens in an aviary system

Department of Animal Nutrition and Management, Swedish University of Agricultural Sciences, Uppsala. Annsofie.Wahlstrom@huv.slu.se

Effects of feeding a crumbled diet compared with a mash diet on laying performance and egg quality of two hybrids of laying hens, a total of 3,204 birds, kept in an aviary system from 20 to 80 wk of age, were investigated. The two diets had the same composition and calculated nutrient content. Two hybrids, Lohmann Selected Leghorn (LSL) and SLU-1329 (a two-line cross of Leghorn x Rhode Island Red), were housed in six pens each of an aviary system with groups of 269 and 265 birds, respectively. There was a total of three replicates per treatment (diet x hybrid). Birds fed the mash diet compared with those fed the crumbled diet had a significantly higher proportion of misplaced eggs, inferior feed conversion ratio (FCR), and higher energy consumption per kilogram egg mass produced (collectable misplaced eggs included). The latter birds had higher body and egg weight, suggesting a higher nutritive value for the crumbled diet. Higher egg mass production and a more intensive yolk color were also found for the birds fed the crumbled diet compared with the mash diet. Hybrid affected production and egg quality traits the most. The LSL also showed significantly higher excreta DM compared with SLU-1329. Interactions between diets and hybrids were found regarding the proportion of misplaced eggs, dirty eggs, egg weight, and FCR. Some of the interactions may indicate other genetic and nutritional factors affecting bird performance in aviary systems more than is normally seen in cages.