Intestinal microbiome, performance and product quality in brown and white Lohmann layer chickens at the end of the laying phase

In this study, aging effect on gut microbiota, production performance, and product quality in two commercial laying strains Lohmann Brown and Lohmann White under intensive farming system in the Kurdistan Region were evaluated. At 90 weeks of age, a population of 504,000 hens was examined with respect to changes in composition of microbiota, egg production, carcass traits, and reproductive physiology. Inter-strain substantially disparity was demonstrated by the statistical analyses. White Lohmann chickens showed improved feed conversion efficiency and egg production due to a significantly higher abundance of beneficial lactic acid bacteria (LAB) in their cecal contents. On the other hand, the Brown Lohmann had a heavier egg, better body weight and carcass yield with better thigh, back muscle rate. Their reduced rate of mortality suggests better tolerance at late production stages. Nevertheless, their cecal microbiota showed an elevated proportion of Enterobacteriaceae, reflecting an unfavorable gut ecology. Reproductive organ assessment showed that White hens displayed more developed ovaries, whereas Brown chickens had larger oviducts, which likely contributed to the larger size of their eggs. Results indicated that viable plate counts and product quality in late life are more spatially associated with gut colonization than with the gut colonization levels determined by strain resistance, overall levels of host health, or the effects of age on the host morphology. These findings justify the use of customized dietary and microbiological strategies in order to ensure longevity of productive performance in aged layer flocks.