Abstract
Necropsy of gastrointestinal tract of 125 free-range chickens from a subtropical and humid zone of northwestern India revealed four nematode spp. (Ascaridia galli, Heterakis gallinarum, Capillaria spp. and Cheilospirura hamulosa) and four cestode spp. (Raillietina cesticillus, Raillietina echinobothrida, Raillietina tetragona and Amoebotaenia cuneata) The overall prevalence of the helminth parasites was 72.0%. Amongst various helminth species encountered in the region, A. galli emerged out as the most prevalent, followed by H. gallinarum, R. cesticillus and R. echinobothrida. The impact of helminthic infections on body weight gain in growing chickens was investigated. One hundred growing chickens, aged 40 days were randomly assigned to two groups (treated and untreated controls) of 50 birds each. The birds in treated group were given fenbendazole at 7.5 mg per kg body weight in drinking water, while the birds in other group served as untreated controls. At the end of the 90 days of the field trial, the mean body weight gain of untreated controls was 1232.2 ± 7.28 g (13.7 g/day) compared with 1617.6 ± 5.43 g (18.0 g/day) in the treated group. It was associated with a significantly (P < 0.05) higher mean worm burden (32.92 ± 6.12) in untreated controls than the treated group (2.46 ± 1.14). The prevalences of helminthic species and their impact on body weight gain in growing backyard chickens have been discussed.