The Consequences Of Concurrent Infections With Ascaridia Galli And Eimeria In Broiler Chickens:- Ugwuzor Gwachi E

ABSTRACT ix Ascaridia galli and Eimeria species constitute the aetiology of ascardiosis and coccidiosis in chickens respectively, and the two diseases are the most important parasitic infections that militate against the development ofthe poultry industry. Production losses range from no weight gain, poor weight gain, weight losses, poor egg lay, mortalities and the high cost of control ofthe diseases emanating from purchase of drugs and vaccines. The effects of each of the infections singly have been greatly studied experimentally but little or no experimental studies involving both A. galli and the Eimeria species in concurrent infections is known to the authors. The study was therefore conducted to investigate the response of two-week old broiler chickens to single and concurrent infections with the parasites and the influence oftiming of the infections with the hope that the results would greatly inform the improvement of control measures ofthe infections for better productivity the birds. Six groups of 7 broiler chickens each were used. Five of the groups were either infected with A. galli only, caecal Eimeria isolate only. A. galli and caecal Eimeria isolate (A+E) at the same time, A. galli and later caecal Eimeria isolate (AE) or caecal Eimeria isolate and later A. galli (EA). The sixth group remained as the uninfected control birds. The dose levels were 1000 embryonated A . galli eggs and 12,000 sporulated Eimeria oocysts per chicken. Packed cell volume (PCV), body weight (BWt), faceal egg counts (EPG), faecal oocyst counts (OPG), caecal gross lesion score (GLS) for Eimeria infected birds, clinical signs and worm burden (WB). The infections had a negative impact on the birds evidenced by low PCV, low weight gain, reduced feed intake, dullness, bloody diarrhoea and mortalities when compared with their uninfected controls. A drop in the PCV from day 8 to day 12 of the birds infected with AE occurred following the protozoan infection. The AE group also had the least weight gain from day 12 to day 42. AE also had the least feed intake from day 10 to day 26 in comparison with all the other infected and the uninfected control birds. The greatest mortalities (5 birds) occurred in the AE group. It was concluded that the poor performance of the chickens was due to the infections, however the severity ofthe infections was greatest in the chickens that were infected with A. galli and later with Eimeria. It was suggested that A. galli caused immune downregulation of the chicken allowing the Eimeria to exert maximally its pathogenic effects on the biids. It is therefore strongly recommended that the infections should be diagnosed and controlled promptly particularly it they are concurrent as the effects can be disastrous especial!) when A. galli infection precedes Eimeria infection.