Introduction

Sheep and goats are mainly found in arid and semi- arid areas of sub-Saharan Africa. They play a vital role in rural economies through the provision of meat, milk, household income, manure and skin. Compared to cattle and camels, sheep and goats contribute a larger proportion of readily available meat in the diets of pastoralists. They have been estimated to provide up to 30% of the meat and 15% of the milk supplies in sub-Saharan Africa where thrive in a wide range of ecological regions often in conditions too harsh for the beneficial rearing of cattle. Small ruminants have also been reported to survive better under drought conditions than cattle due to their low body mass and low metabolic requirements which in turn minimize their water requirements and maintenance needed in arid and semi-arid areas. The frequent droughts and large tsetse infected areas in sub-Saharan Africa requires more small ruminants in order to supplement cattle production (Wesongah et al., 2003).

The estimated 25.01 million of sheep and 21.9 million of goats in Ethiopia (CSA, 2009) provide an important contribution to the national economy (Alemayehu et al., 1995). Although small ruminants represent a great resource for the nation, the productivity per animal is low. Small ruminant diseases, poor management and lesser efforts provided to improve the performance of the animals are to be responsible for the reduced productivity (Admosun, 1992).

Stomach and intestinal worms occur in all species of animals. Young and malnourished animals of both sexes and lactating animals are most suitable to these parasites. Stomach worms affect specially camels, goats and sheep. Different types of worms are transmitted when an animal eats grass or drinks water contaminated with larva or eggs. The problem is especially common in the rainy season (IIRR, 1996).

Even though, Ethiopia endowed with large number of sheep and goats population, little attempts has been made in the past to study the health aspect of these animals. Lack of well established data on the magnitude, distribution and predisposing factors of small ruminant GIT helminthes in the study area initiated this study project. Therefore, the main objectives of this study were to identify the major GIT parasites of small ruminants and to determine the prevalence of those parasites in the study area in relation to different risk factors.

Materials and Methods

Study Area

Study Population

Sample Size and Sampling Method

Study Methodology

Statistical Analysis

Results

Out of 384 animals (219 sheep and 165 goats) examined, 353 (91.9%) were harboring one or more GIT parasites. With respect to the species prevalence of GIT parasites, 200 (91.3%) sheep and 153 (93.8%) goats were found to harbor one or more parasites. In this study species, sex and age were considered as risk factors and revealed no significant difference (P>0.05) with the variation in species, age and sex of the animals (Table 1).

Figure 1

Table 1: Prevalence of GIT Parasites in relation to their sex, age and species of the animals

The degree (severity) of parasitic infection was determined from the total fecal egg count. A total of 338 fecal samples were subjected to EPG count by using McMaster egg counting chamber and found 137 (40.53%) were lightly, 164 (48.52%) moderately and 37 (10.95%) massively affected. An attempt was also made to see the existence of significant difference in degree of parasitic infection with the variation of species, sex and age of the animals. However, it was found that no significant difference (P >0.05) in the EPG count with the variation of risk factors (Table 2).

Figure 2

Table 2: Degrees of GIT Parasitic infection with different risk factors

Postmortem examinations were conducted in some butcher houses and restaurants to appreciate the adult parasites and to relate the coprological findings with the postmortem findings. The total number of animal examined was 43 (23 sheep and 20 goats). From these 21 sheep and 19 goats harbored one or more adult parasites. The overall prevalence of GIT parasites during postmortem examination was 93.01% (40) and the species level prevalence was 91.30% (21) and 95% (19) in sheep and goats respectively.

In this study ten types of GIT helminth parasites were identified during the study period based on their morphology described by Soulsby (1982) and Urquhart et al. (1996) (Table 3).

Figure 3

Table 3: Relative prevalence of GIT parasites examined in sheep and goats

Discussion

The present study found that the prevalence of GIT helminthes was 91.32% and 93.29% and at post mortem analysis 91.30% and 95% in sheep and goats respectively. This result coincides with the results of (Gebreyesus, 1986; Esayas, 1988; Tesfalem, 1989; Melkamu, 1991; Bayou, 1992; Yoseph, 1993; Genene, 1994; Getachew, 1998; Hailelul, 2002). They have reported a prevalence of 96.38% in goats of Ogaden range lands, 90.41% and 82.13% in sheep and goats in and around Wolayita Soddo, 88.1% and 84.32% in sheep and goats in and around Mekele, 91.43% in sheep in and around Kombolcha, 90.94% and 94.85% in sheep and goats of Gonder, 92.23% and 94.1% in sheep and goats of Mendayo district of Bale, 93.22% and 92.24% in sheep and goats of four Awrajas of Eastern Shoa, 90.23% and 88.33% in sheep and goats of Buno province and 85.79% in sheep in and around Asella respectively.

Out of 338 sampled shoats 10.95% massively, 48.52% moderately, and 40.53% were lightly affected. There is no significant difference in EPG among different age groups, sex and species. Majority of infected animals had fecal egg count in the range of 50-800 EPG and only few proportions of animals had fecal egg count over 1200. This is inline with Amenu (2005) and Hailelul (2002) who reported higher prevalences of 94.29% and 86.67% with a mean EPG of 1045.8 and 1016 in sheep and goats respectively. The maintenance of high infection rates of GIT helminthes in shoats in the study areas was associated with the presence of favorable environmental conditions for the existence and development of the parasitic GIT helminthes larvae.

Out of 43(23 sheep and 20 goats) post mortem examination performed, 21 (91.30%) sheep and 19 (95%) goats were found affected with one or more of helminthes. This was agreed with Yoseph (1993) who reported 93.33% in sheep of Asella, Dereje (1992) who reported 9(90%) sheep and 10(98.18%) in goats in and around Wolaita Sodo, Genene (1994) 100% in sheep and goats of northern Omo, and Hailelul (2002) who reported prevalence of 100% and 95.24% in sheep and goats in and around Wollaita Soddo.

The prevalence of Heamonchus spp. was 69.5% and 65%in sheep and goats respectively. This was agreed with Hailelul (2002) who reported 61.63% and 54.76% in sheep and goats respectively in and around Wollaita Soddo, Ahmed (1988) who reported 88.23% prevalence in goats of East wollega zone at Mechara settlement area. This result is relatively higher than to the present finding. The difference between the findings of these studies might be due to difference in the age, sex and species of examined animals and also the climatic condition of the area.

The prevalence of Trichuris spp. was 47.8% and 45% in sheep and goats respectively. This result agreed with Hailelul (2002) and Esayas (1988) who have reported 36.04% in sheep and 28.57% in goats and 36.04% prevalence of Trichuris species in sheep and goats in and arround Wollaita Soddo and in goats of Ogaden respectively.

The prevalence of Trichstrongylus species during the qualitative fecal examination was 43.5% and 55% in sheep and goats in this study respectively. This result is inline with the work of Yoseph (1993) who reported prevalence of 54.76% in sheeps of Asella. This result also incoherence with Hailelul (2002) who reported prevalence of 22.09% in sheep in and around Wolaita Sodo and Esayas (1988) who reported prevalence16.59 in goats of Ogaden. The above authors reported relatively lower prevalence than the present findings. This difference might be attributed to the difference in animal species, age and environmental conditions for the parasitic stage of larvae growth.

Oesophagostomum species was detected on 52.2% and 45% of the sheep and goats in the study area respectively, and this was in agreement with Hailelul (2002) who reported prevalence of 74.42% in sheep in and around Wolaita Sodo and Esayas (1988) who reported prevalence of 61.13% in Ogaden goats. These results are relatively higher than the present finding and the difference between the findings of these studies might be due to the age and sex of animals examined.

Bonostomum species with prevalence of 26.1% and 35% recovered during qualitative fecal examination in sheep and goats respectively in the present study and this was in agreement with Esayas (1988) who reported 59.38% in goats of Ogaden, Hailelul (2002) who reported 41.86% in sheep in and around Wolaita Sodo and Yoseph (1993) who reported a prevalence of 40.48% in sheep of Asella.

The prevalence of 17.4% and 25% of Chabertia species recorded during the present study in sheep and goats respectively. This was incoherence with Yoseph (1993) who reported a prevalence of 2.88% in sheep in and around Asella. This difference may be also due to the age and species of examined animals. With the same fashion the prevalence of Ostertagia species in the present study was 26.1 % and 25%in sheep and goats respectively. This result relatively agrees with the work of Amenu (2005) who reported a prevalence of 15.6% in sheep and goats of three different agro ecological zones of southern Ethiopia.

Strongyloid species was detected in 13.04% and 20% of the sheep and goats in the study area respectively, and this was inline with the work of Amenu (2005) who reported a prevalence of 1.1% in sheep and goats of three different agro ecological zones of southern Ethiopia. This result is much lower than the present finding. This difference might be due to the difference age of examined animals and geographical and environmental location of the area.

The prevalence of cestode parasites, monezia species in this study was 30.4% and 40% in sheep and goats respectively. This result is inline with Hailelul (2002) who reported 26.04% in sheep and 23.81% in goats in and around Wolaita Sod and Esayas (1988) who reported 16.13% prevalence of monezia species in goats of Ogaden. The results by the above authors are relatively lower than the present finding. The difference might be due to the difference in age.

The prevalence of Avetellina species was 39.1% and 40% in sheep and goats respectively. This result is in agreement with Hailelul (2002) who reported 13.45% and 11.90% in sheep and goats in and around Wolaita Sodo, and Esayas (1988) who reported 7.86% prevalence of Avitellina species in goats in Ogaden. These results are lower than the present finding. The difference between the findings of this study might be due to the difference in the age of the examined animals.

Conclusions and recommendations

The present study conducted on small ruminant GIT helminthosis in and around Bedelle area shows that GIT helminthosis of shoats are the most prevalent disease in the area affecting the well being of the animals. During the present study an overall prevalence of 91.32% and 93.89% coroscopically and 91.30% and 95% by postmortem examination in sheep and goats respectively were harboring one or more GIT parasites. Species, age and sex were considered as risk factors; however there is no significant difference in the prevalence of the parasite due to these risk factors. EPG analysis was undertaken to know the degree of infection. Of the 338 animals examined 137(40.53%) were lightly, 164 (48.52%) moderately and 37(10.95%) massively affected. From the above findings and conclusive remarks the following recommendations are forwarded:

To get clear epidemiological picture of GIT parasitic helminth, comprehensive study should be launched in the area where sheep and goats are abundant and practically participating in cash incomes, sources of food, skin and manure to farming communities and play significant role in these sector.

Strategic treatment is appropriate, effective and broad spectrum anthelmintic should be practice at the beginning and after the end of the rainy season. Such treatment regime is strategic to get rid of the parasites burden of the animals and minimize pasture contamination by dropping fecal egg count.

Additionally, the field veterinarians and stockowners should be aware of the importance and burden of GIT helminthosis in sheep and goats.

Acknowledgements

The authors would like to thank Jimma University, College Agriculture and Veterinary Medicine for financial support to execute this research work. It is also our pleasure to extend our gratitude to Veterinary Parasitology laboratory, Bedelle Regional Laboratory for its technical and material support in the realization of this study.