Prevalence of mites and their impact on laying hen (<i>Gallus gallus domesticus</i>) farm facilities in Egypt, with an analysis of deltamethrin residues in eggs and tissue

Abstract

This study was carried out on six laying hen farms, three mite-infested and three mite-free at Dakahlia and Damietta governorates in Egypt to demonstrate: (i) prevalence of different species of mites on laying hen farms; (ii) effects of mite infestation on chicken health and production; (iii) efficacy of deltamethrin (DMT) on treatment of mite infestation and (iv) residues of DMT in eggs and meat. The results showed that 12 mite species were detected in the mite-infested farms, this is the first record in Egypt, and that Dermanyssus gallinae was the highest identified species from 295 (40.9%) of 720 samples. There was a significant effect (P ≤ 0.05) of mites on the mortality %, feed consumption, egg production % and the tested haematological parameters. DMT had no impact on production performance, while transient respiratory signs post-spraying were recorded. The mites induced severe skin lesions. Egg samples showed the highest residue levels of DMT, followed by muscle and skin at P ≤ 0.05. It can be concluded that the mite species, as a first record, had a deleterious impact on the performance of the Egyptian laying hen farm facilities. Moreover, that DMT (Butox^® 50 EC, Intervet Co., France) spraying was ineffective by one-time application, every 1 or 2 months in mite-infested laying hen farms, particularly when heavily infested. Furthermore, DMT residues in laying hen eggs and tissue should be considered to avoid the potential risk for humans.