ijvp

Indian Journal of Veterinary Pathology

0250-47580973-970X

Indian Association of Veterinary Pathologists

ijvp-37-1-034

ABSTRACTS OF DISSERTATIONS OR ARTICLES

Toxicopathological studies on selenium in broilers

Tamrakar

Shonam

¹Mondal

Dr.¹

¹Degree/Year: M.V.Sc./2013, Name of the University: Chhattisgarh Kamdhenu University, Durg, Chhattisgarh

162013

371110110

2013

IndianJournals.com

The present investigation was conducted to determine the detailed toxicobiological effects of selenium on broiler performance and clinicohaematobiochemical and pathomorphological indices in broilers. The approximate lethal dose of sodium selenite was determined as 20 mg/kg body weight in broilers by acute toxicity study. Treated broilers showed toxic signs like dullness, anorexia, incoordination, hypersalivation, followed by tonic convulsion, dyspnoea, coma and death. Grossly varying degree of congestion in lungs, liver, kidneys and heart along with swollen kidneys were found in intoxicated broilers. Selenium treated broilers revealed histological alterations suggestive of toxic hepatitis and nephritis, congestion, haemorrhages, degenerative and necrotic changes in liver, kidneys, heart and brain accompanied by depletion of lymphocytic population from lymphoid organs. The subacute study of sodium selenite was performed in a total number of 120 Vencobb day old healthy broilers randomly divided into four groups of 30 each. Group I broilers were given plain feed and served as control whereas, broilers of group II, III and IV were given sodium selenite @ 2, 6 and10 ppm respectively in diet, daily for 35 days. The present study comprised haemato-biochemical, pathomorphological and immunopathological alterations in selenium induced broilers. Broilers of low and mid dose groups exhibited varying degree of dullness, depression, huddling behaviour and open mouth breathing. Broilers treated with high dose of selenium manifested severe weakness, depression, anorexia, dyspnoea, watery diarrhoea, increased discharge from beak and nostrils, marked emaciation and drowsiness. The different doses of sodium selenite influenced significantly the broiler performance i.e. feed intake, body weight gain and feed conversion ratio during the entire period of experiment. Selenium treated broilers had significant increase in relative weight of lungs, kidneys, spleen, bursa of Fabricius and brain, but significant decrease in relative weight of liver, heart and thymus. Haematologically, the selenium treated induced broilers revealed significant hypohaemoglobinaemia, decreased PCV, erythrocytopaenia, leucopaenia, increased MCV, heterophilia, eosinopaenia and leukopaenia due to lymphopaenia. But no significant variation in MCH, MCHC and basophil counts were noticed in treated broilers. Biochemical changes of Se treated broilers showed a significant hypoproteinaemia, hypoglobunaemia accompanied by increased BUN and creatinine levels. But no significant alterations in albumin and albumin: globulin ratio were found in intoxicated broilers. Enzyme indices of the intoxicated broilers had significant increase in the activities of serum transaminases (aspartate and alanine) and alkaline phosphatase. The present study exhibited significant depression of CMI in Se treated broilers as measured by DNFB skin contact sensitization test. During subacute Se toxicity, severity of pathological changes of treated broilers was dose dependent. Pathomorphological changes of induced broilers of mid and high dose groups were more severe than low dose group. Grossly varying degrees of congestion and haemorrhages in trachea, lungs, liver, kidneys, intestine, thymus, brain and heart with hydropericardum and enlargement of bursa of Fabricius and thymus were noticed in treated broilers. Histological alterations consisted of congestive and haemorrhagic changes of liver, lungs, kidneys, heart, spleen, brain and thymus indicating vascular effects of sodium selenite. Treated broilers showed severe vacuolar degeneration and necrotic changes of hepatocytes accompanied by discrete mononuclear cells infiltration which suggested toxic hepatitis. Kidneys of treated broilers had massive degenerative and necrotic changes of lining epithelium of convoluted tubules accompanied by epithelial desquamation and fatty changes indicating toxic nephritis. Intoxicated broilers revealed severe congestive and haemorrhagic changes, alveolar edema and proliferation of interalveolar septa followed by mononuclear cells infiltration reflecting toxic pneumonitis. Degenerative and necrotic changes were also found in heart and brain. Lymphoid organs of selenium treated broilers revealed severe depletion of lymphocytes from the germinal centre. Broilers of control group had no clinicohaematobiochemical, immunological and pathomorphological alterations.