Immune Response of Laying Hens Exposed to 30 ppm Ammonia for 25 Weeks

Factor Influences for Diagnosis and Vaccination of Avian Infectious Bronchitis Virus (Gammacoronavirus) in Chickens

“…Many management issues, such as congested spaces, uncontrolled temperature and humidity in the shed, poor nutrition, worm infestations, poor uniformity, and other secondary infections that reduce the bird’s immune system, can directly affect vaccination efficacy. Several studies suggested that continuous exposure to 30 ppm [ 114 ], 52 ppm [ 115 ] NH3 levels which are critical environmental stressors to laying and broiler chicken leading to reduced immunity as proven by decreased total plasma (IgA, IgG, and IgM) and complement concentrations. Furthermore, ammonia level in sheds being more than 70–100 ppm has adverse effects on chickens’ ability to yield local immunity, and birds become exposed to viral infections [ 116 , 117 , 118 , 119 , 120 ].…”

Impact of Housing Environment on the Immune System in Chickens: A Review

“…Wei et al [185] found lower ConA-and LPS-induced peripheral lymphocyte proliferation when broilers were exposed to 70 mg/kg NH 3 compared to 30 mg/kg, while Wang et al [186] did not see an effect for lower NH 3 concentrations (13, 26 or 52 ppm compared to fresh air). When compared to fresh air conditions, exposure to NH 3 between 26 and 60 ppm decreased antibody titers after NDV vaccination [186] and total serum concentrations of IgY, IgM and IgA [184,186,187]. Furthermore IgA concentrations in duodenal mucosa decreased when exposed to 70 ppm compared to 30 ppm [188].…”

“…Both gases, 60 ppm NH 3 or 20 ppm H 2 S, decreased the relative weight of bursa, spleen and thymus [172,181] and resulted in nuclear debris in the bursa of Fabricius and thymus [178,191]. Only a few studies found no influence of NH 3 on immune parameters like antibody concentrations and cytokine expression after exposing laying hens to 30 ppm NH 3 compared to fresh air [184] or on lymphoid organ weights after exposing broilers to up to 52 ppm NH 3 compared to fresh air [186] or 70 ppm compared to 30 ppm NH 3 [185].…”

“…The toxicity of these harmful gases depends on exposure concentration and duration, genetic background and overall management [184,186]. The most profound effects of high concentrations of harmful gases can be seen in the respiratory system.…”

“…McFarlane and Curtis [ 182 , 183 ] showed in an early study that relative numbers of heterophils increased, while lymphocytes and basophils decreased in broilers exposed to 125 ppm NH 3 . Similarly, laying hens and broilers showed a higher H/L ratio under 30 ppm NH 3 compared to fresh air [ 184 ]. Monocytes and eosinophils were not affected [ 183 ].…”