Abstract   

    One hundred day-old broiler chicks kept in five equal groups (A-E) were given formalin (37% formaldehyde} at dose levels of 20, 10, 5, 2.5 and 0 ml/kg feed for 7 weeks. Body weight and feed intake of the birds fed 2.5 ml formalin/kg feed was non-significantly different from control whereas higher formalin levels groups had significantly lower values. Formalin at 2.5 and 5.0 ml/kg feed level did not produce clinical signs in the birds but Higher doses of formalin resulted in depression, somnolence and a staggering gait. Necrotic and ulcerative areas on the mucosa of crop, proventriculus and petechial hemorrhages were observed on the mucosa of small intestine. Liver and kidneys did not show any specific microscopic changes. The no observed adverse effect level (NOAEL) of formalin appeared to lie between 2.5 and 5 ml/ kg feed.     

Key words: Formalin, Broiler chicks, Toxico-pathological effects.