Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 10/9/2002
Publication Date: 10/9/2002
Citation: Miles, D.M., Miller, W.W., Branton, S.L., Maslin, W.R. 2002. Effect of ammonia gas concentration and duration on meat-type chicken cornea [abstract]. Proceedings American College of Veterinary Ophthalmologists. 1 p.
Technical Abstract: The purpose of the research was to determine the effect of increasing ammonia gas concentrations and duration of exposure on broiler chicken cornea. Two separate trials were conducted where sixty day-old, male, commercial broiler chicks were placed in each of eight environmentally controlled chambers on 10 cm of fresh, kiln dried pine shavings and supplied continuous food and lighting. Anhydrous ammonia was metered into six of the chambers to maintain 25, 50, and 75 ppm (2 chambers for each level). No ammonia was added to the remaining two chambers (control). At the beginning of each trial, ten birds were randomly selected from each chamber, permanently identified and had weekly ocular examinations through the remainder of the study. The examiner was blinded to the chamber origin of each bird. At four weeks, ammonia treatment was stopped and birds were grown to market weights. Birds exposed to 25 ppm ammonia demonstrated keratitis at 3 weeks of exposure similar to keratitis observed in birds exposed to 75 ppm ammonia for 1 week. No anterior uveitis was observed in birds from the 25 ppm ammonia chambers. Severe keratoconjunctivitis and uveitis were observed in birds exposed to 50 ppm and 75 ppm ammonia for 1 week. Severity of the keratitis and uveitis tended to worsen dependent on duration of exposure and concentration of ammonia. Body weights were most affected by the 75 ppm level; this group was 75% of the control at 3 weeks of age, but had recovered to 90% of the control at 7 weeks. Birds exposed to low levels of ammonia gas demonstrate ocular disease and higher concentrations of ammonia gas increase the severity of ocular disease and reduce growth rates.