Characterisation of gastrointestinal helminths and their impact in commercial small-scale chicken flocks in the Mekong Delta of Vietnam

Abstract

Commercial small-scale chicken farms using all-in-all-out production but operating with low standards of hygiene/biosecurity are increasingly common in Vietnam. These conditions facilitate transmission of gastrointestinal helminths. However there are no published data on these parasites in these systems. The aims were: (1) to determine the prevalence/burden of gastrointestinal helminths in small-scale commercial flocks in commercial small-scale flocks in the Mekong Delta region; and (2) to investigate the association between worm burdens and birds’ weight and disease status. Randomly selected chickens (n=120) (‘normal’ flocks) were investigated at the end of their production cycle (∼18 weeks), as well as 90 chickens with signs of respiratory and/or severe disease. The gastrointestinal tract of chickens was dissected and all visible helminths were identified. 54.2% and 54.4% healthy and diseased chickens contained helminths. Diseased, colonized chickens harboured a higher mass of helminth worms (3.8 ±SD 8.6g) than colonized, healthy chickens (1.9 ±6.3g). Eight species were identified, three nematodes (Ascaridia galli, Cheilospirura hamulosa and Heterakis gallinarum), four cestodes (Hymenolepis, Raillietina cesticillus, Raillietina echinobothrida, Raillietina tetragona,) and one trematode (Echinostomatidae). Heterakis gallinarum was the most prevalent helminth (43.3% and 42.2% in healthy and sick chickens, respectively), followed by A. galli (26.7% and 41.1%). Colonized chickens weighed 101.5g less than non-colonized birds. Colonisation was significantly higher during the rainy months (May-November) for both H. gallinarum and A. galli. Anthelminthic usage was not associated with reduced helminth burdens. We recommend upgrading cleaning and disinfection and limiting access to ranging areas to control helminth infections in small-scale commercial chicken flocks.

The Study on Prevalence of Gastrointestinal Helminths (Cestodes, Nematodes, and Trematodes) in Chickens, Dalomana District, Bale Zone, Southeast Ethiopia

“…The prevalence of Heterakis gallinarum in the current study was 54 (37.5%). This was in line with the work of Solomon and Yobsan 32 , who recorded 33.43%, and Nguyen et al 33 who reported 43.3%. It was lower than the reported rates of 83.3% 7 and 51.6% in Ethiopia 17 , and higher than the previous study in Jimma Ethiopia 9.4% 20 .…”

“…It was lower than the reported rates of 83.3% 7 and 51.6% in Ethiopia 17 , and higher than the previous study in Jimma Ethiopia 9.4% 20 . Heterakis gallinarum has a major effect on the health of chickens by sharing feed, thus causing stunted growth and low productivity, which may be related to damage to the intestinal mucosa 33 . The parasite sometimes causes major irritation and inflammation to the mucosa, thus interfering with the absorption of food and showing on the caeca marked inflammation and thickening of the mucosa with petechial hemorrhages.…”