The Effect of Feather Condition on Blood Parameters and Egg Quality Traits in Brown Commercial Laying Hens Housed in Enriched Cages

Abstract

The study's objective was to investigate the effect of feather condition on blood and egg quality traits of laying hens. A total of 45 Lohmann brown laying hens were randomly selected at 60 weeks of age and grouped based on total feather scores obtained from scoring 6 different body regions of the birds: the head, neck, breast, back, wings, and tail. According to the total feather score, the experimental groups consisted of low (6 - 12, L), moderate (13 - 17, M), and high (18 - 24, L). The number of lymphocytes, monocytes, heterophils, eosinophils, basophil cells, and heterophil/lymphocyte (H/L) ratio were determined at 61 weeks of hen age. Quality traits of eggs were analyzed at 68 weeks of hen age. The results indicated that feather condition significantly influenced monocytes, and heterophils (P<0.01). However, the impact on H/L ratio, lymphocytes, and eosinophils was not significant (P>0.05). There were differences in the egg weight, redness of eggshell, shape index, and shell thickness among the feathering groups (P<0.01; P<0.05). Shell-breaking strength, albumen index, Haugh unit, yolk index, and yolk color score were similar among the feathering groups (P>0.05). In conclusion, the findings of this study revealed that moderate feathering was not negatively associated with a stress response in the birds. Furthermore, while the feather condition can modulate some external egg traits, it does not lead to variations in any internal egg quality traits. However, further studies over a longer duration are required to refine these findings.