Ammonia stress and histopathological changes of broiler internal organs under closed environment

ABSTRACT

The current experiment established to figure out the effect of ammonia exposure for two intermittent periods [1st at 22-26 days old with 120-ppm and 2nd at 31-35 days old with 150 ppm] / 24 hours, on the bird internal organs [liver, spleen,lung,air sac and bursa fabricus from the histo-pathological aspect under controlled broiler ecosystem through summer. The micrographs of Control birds were remarked by the moderate features, that shown on liver at 28 and 42 days old .Spleen revealed mild features along 4-6 weeks old, moderate ones were only at 21 days. Bursa fabricius showed mild changes at 21 and 42 days .moderate ones at 28 and 42 days .while the severe changes were few at 28,35 and 42 days old that were contributed to the normal growth regressive behavior of this lymph organs, with age. Lung and air sacs showed mild changes at 3-6 weeks old and the moderate changes were only on lung at 2-5 weeks old. The micrographs of ammonia stressed birds revealed that liver post 1st exposure showed moderate histological changes at 26 days old with no remarked changes at both 35 and 42 days old except the mild changes. On regard to spleen, the moderate changes were at 26 and 35 days old while mild changes were at all ages .Bursa fabricius showed mild changes at 30 and 35 days old,the moderate changes were at 26 .35 and 42 days old, in addition the severe changes were shown at all ages. Lung micrographs revealed, mild changes at 26 days old .moderate changes were at 26,30 and 35 days old and the Severe changes were noticed at 35 days old,the effects looked cumulative and related to growth stage. Air sacs, remarked by mild changes at 26, 30 and 42 days old, moderate and severe changes were at 35 days old .Lung and air sacs were the most affected internal organs post 2nd period of ammonia exposure [26,30 and 35 days old] with moderate and severe histological changes with regard to the difference in degree of affections. Conclusively, ammonia gas was detrimental to broiler internal organs tissues architectures either due to the unexpected elevated level in control birds [8 ppm at 11 and 16 days old] or the experimental levels [120-150 ppm / 2 exposures] with regard to the birds age lesions intensity, organ specificity, environment kind and management,The results confirmed the harsh effect of ammonia exposure on lung and air sac tissues that were more prominent post 2nd exposure. The reversible effects on hem tissues [liver and spleen].The complex responses of BF to ammonia for its nature as lymph organ and involvement in immune responses and natural growth regressive behavior. Proper environmental management especially sources of indoor ammonia generation and emission could properly enable bird to recover and restore its normal tissues morphology and functions as shown during rest period to a great extent