Impact of northern fowl mites on cage-free layer performance from 17 to 48 weeks of age

Authors: JARRETT, RACHEL - Purdue University; ERASMUS, MARISSA - Purdue University; Jones, Deana; VAN DE WATER, KAILYNN - Purdue University; MURILLO, AMY - University Of California, Davis; KARCHER, DARRIN - Purdue University

Submitted to: Poultry Science Association Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/30/2019
Publication Date: 7/15/2019
Citation: Jarrett, R.A., Erasmus, M.A., Jones, D.R., Van De Water, K., Murillo, A.C., Karcher, D.M. 2019. Impact of northern fowl mites on cage-free layer performance from 17 to 48 weeks of age. Poultry Science Association Meeting Abstract. 98(1):125.

Interpretive Summary: The northern fowl mite (Ornithonyssus sylvarium) is an obligate blood-feeding ectoparasite of poultry that can cause decreased egg production, profit loss, anemia, irritation to flocks and personnel, and death to hens in extreme cases. The present study aimed to investigate the effects of the northern fowl mite (NFM) on laying hen performance and welfare quality between the ages of 17 and 48 weeks. 800 Tetra brown hens (n=200 per room) were housed in four cage-free rooms at the Purdue University Poultry Unit. Two rooms were infested with NFM and two rooms served as controls. NFM initial infestation occurred at 24 weeks on 2% (4 hens) in each of the NFM rooms. Since no NFM were present, a second infestation on 2% of hens occurred at 35 weeks on 2% of hens. A final attempt to infest with NFM occurred at 41 weeks with all hens in NFM rooms being infested. Egg production and mortality were recorded daily and case weights were recorded weekly. Monthly Welfare Quality® assessments were taken, as well as monthly mite counts on all birds beginning at 28 weeks. Mite checks were conducted periodically on 25% (50 hens) in all rooms between weeks 25 and 38. Data were analyzed in SAS® using the Glimmix procedure and all significant statistical differences were reported at p < 0.05. Regardless of treatment, mortality increased dramatically after 21 weeks, leading to a loss of 473 hens by week 48. Case weights and egg production increased over time. NFM hen day peaked in-line with the Tetra management guide at 28 weeks but was approximately 1% lower and control hen day peaked 3 weeks later but was 3% higher. At 38 weeks of age, case weights in NFM rooms were approximately 4.63 kg higher than in control rooms (p<0.05). The NFM population spiked shortly after infestation at 28 weeks and again at 36 weeks (1-10 mites/bird). From 28 weeks on, 60% of birds received an overall feather score of 2 during Welfare Quality® assessments, meaning that feathers were missing in at least one area of 5 cm or greater. This was due to pecking behaviors in all four rooms. There was no correlation between feathering and NFM (p>0.05). Cannibalism and pecking in both treatments led to feather loss, high mortality, low NFM populations, and likely impacted production parameters.

Technical Abstract: The northern fowl mite (Ornithonyssus sylvarium) is an obligate blood-feeding ectoparasite of poultry that can cause decreased egg production, profit loss, anemia, irritation to flocks and personnel, and death to hens in extreme cases. The present study aimed to investigate the effects of the northern fowl mite (NFM) on laying hen performance and welfare quality between the ages of 17 and 48 weeks. 800 Tetra brown hens (n=200 per room) were housed in four cage-free rooms at the Purdue University Poultry Unit. Two rooms were infested with NFM and two rooms served as controls. NFM initial infestation occurred at 24 weeks on 2% (4 hens) in each of the NFM rooms. Since no NFM were present, a second infestation on 2% of hens occurred at 35 weeks on 2% of hens. A final attempt to infest with NFM occurred at 41 weeks with all hens in NFM rooms being infested. Egg production and mortality were recorded daily and case weights were recorded weekly. Monthly Welfare Quality® assessments were taken, as well as monthly mite counts on all birds beginning at 28 weeks. Mite checks were conducted periodically on 25% (50 hens) in all rooms between weeks 25 and 38. Data were analyzed in SAS® using the Glimmix procedure and all significant statistical differences were reported at p < 0.05. Regardless of treatment, mortality increased dramatically after 21 weeks, leading to a loss of 473 hens by week 48. Case weights and egg production increased over time. NFM hen day peaked in-line with the Tetra management guide at 28 weeks but was approximately 1% lower and control hen day peaked 3 weeks later but was 3% higher. At 38 weeks of age, case weights in NFM rooms were approximately 4.63 kg higher than in control rooms (p<0.05). The NFM population spiked shortly after infestation at 28 weeks and again at 36 weeks (1-10 mites/bird). From 28 weeks on, 60% of birds received an overall feather score of 2 during Welfare Quality® assessments, meaning that feathers were missing in at least one area of 5 cm or greater. This was due to pecking behaviors in all four rooms. There was no correlation between feathering and NFM (p>0.05). Cannibalism and pecking in both treatments led to feather loss, high mortality, low NFM populations, and likely impacted production parameters.