Topical application of garlic reduces northern fowl mite infestation in laying hens

Northern fowl mites (NFM) are external parasites that can lower egg product ion and cause anemia and even death in laying hens. An experiment was condu cted with New Hampshire Red and Single Comb White Leghorn laying hens. Hens were individually caged and provided a complete laying diet and water ad l ibitum. Hens were assigned to groups in a way that assured that treatments, within each breed, would be applied to comparable numbers of birds with li ght and heavy mite infestations. Each hen was sprayed around the vent with either water or 10% garlic juice in water. Spraying continued each week for 3 wk. During the fourth week, each bird was scored for the presence of NFM on its skin and feathers. a small snippet of feathers was removed from bel ow the vent of each hen and placed in a labeled petri dish with a round, wh ite filter paper insert. The NFM content of each dish was scored by two ind ividuals approximately 1 h after sampling. There was no significant differe nce in the NFM scores for hens based on breed or future treatment. After th e birds were treated for 3 wk, there was no significant difference in exter nal NFM scores based on breed. There were significantly fewer NFM on the bi rds treated with garlic juice compared with controls, based on external and petri dish scoring (P < 0.002 and P < 0.04, respectively). The reduction i n external NFM score was also significant (P < 0.004), with controls declin ing approximately 0.2 units, whereas garlic-treated hens had a 1.8-unit dec rease in external NFM score. Topical application of garlic juice may be an effective way to decrease NFM in laying hens.