Seasonal Effects on the Prevalence of Gastro-Intestinal Helminth Infections in Two Local Chicken Genotypes from Two Agro- Ecological Zones in Sudan

Abstract

Parasitic diseases pose significant threats to the free-ranging chickens. This study aimed to determine the presence and intensity of helminth parasites, and to estimate the seasonal effects in two free ranging chickens, Large Baladi (n=80) and Bare-neck (n=77), in two agro-ecological zones in Sudan, Khartoum and Gadarif. The gastrointestinal tract was opened to quantify the presence and intensity of helminth infections. The results revealed that the overall prevalence of helminthes was 94.9%. Nematode infected 83.4 % of chickens, whereas 88.5% had cestodes. The only nematode was Heterakis gallinarum with prevalence of 83.6% in Large Baladi and 81.8% in Bare-Neck. There was no significant interaction (P>0.05) among effects of regions, genotypes and seasons on the worm burden of H. gallinarum except the larva counts. The occurrence of helminthes was higher during the rainfall season than in the summer season; and the rate of helminth infection in Khartoum was greater than in Gadarif. Moreover there were no significant differences in average worm counts, sex, and length of worms in genotypes (P>0.05). The prevalence of Raillietina tetragona was 63.1 %, Raillietina cesticullus 63.1 %, showed no significant difference (P>0.05) between the two genotypes and seasons. Whereas Raillietina echinobothrida (P = 0.027) was significantly different. Moreover R.echinobothrida 56.1 % and Hymenolepis cantaniana 18.5 % showed significant difference between genotypes and regions (P=0.005 and 0.001), respectively. It is therefore, concluded that there is a high prevalence of parasitic helminth infections in Sudan with no difference between the examined indigenous genotypes.