The Prevalence and Economic Impact of Bovine Fasciolosis in Mekelle Municipal Abattoir

Introduction

Ethiopia owns huge number of ruminants having high contribution for meat consumption and generates cash income from export of live animals, meat, edible organs and skin. In spite of the presence of huge ruminant population, Ethiopia fails to optimally exploit these resources due to a number of factors such as recurrent drought, infrastructures problem, rampant animal diseases, poor nutrition, poor husbandry practices, and Open Access Journal of Veterinary Science & Research

shortage of trained man power and lack of government policies for disease prevention and control [1]. Fasciolosis is an economically important parasitic disease, which caused by treaties of the genus Fasciola that migrate in the hepatic parenchyma, and establish and develop in the bile ducts [2]. Fasciola is commonly recognized as liver flukes and they are responsible for wide spread of morbidity and mortality in cattle characterized by weight loss, anemia and hypoproteinemia. The two most important species, Fasciola hepatica found in temperate area and in cooler areas of high altitude in the tropics and subtropics and Fasciola gigantica, which predominates in tropical area. Fasciola hepatica is found in area above 1800 m.a.s.l. In between these altitude limits, both species coexists where ecology is conductive for both snail hosts, and mixed infections prevailed [3]. Generally, the distribution of fasciolosis is worldwide, however, the distribution of F. hepatica, is limited to temperate areas and highlands of tropical and sub- tropical regions [4]. The definitive hosts for F. hepatica are most mammals among which sheep and cattle are the most important once. The geographic distribution of trematode species is dependent on the distribution of suitable species of snails. The genus Lymnaea in general and L. truncatula in particular is the most common intermediate hosts for F. hepatica. This species of snail was reported to have a worldwide distribution [5]. The presence of fasciolosis due to F. hepatica and F. gigantica Ethiopia has long been known and its prevalence and economic significance has been reported by several workers [6, 7, 8, 9]. F. hepatica is the major cause of liver fluke disease in Ethiopia. Studies so far conducted on faciolosis in Ethiopia were mostly based on coprological examination and abattoir surveys, in general, infection of domestic ruminants with F. hepatica and F. gigantica cause, annual losses over US $3 billion to livestock production and the food industry worldwide [10]. The annual loss due to endo- parasite is estimated about 700 million Eth Birr [11]: particularly bovine fasciolosis cause a financial loss of approximately US. $ 64 million annually due to production but current evidences show that a rough estimate of the economic loss due to faciolosis in bovine is 350 million birr / year [12]. Estimation of the economic loss due to fasciolosis at a national or regional level is, however, limited by lack of accurate estimates of the disease prevalence, complexity in disaggregating and quantifying the direct and indirect effects of the disease and lack of a common methodology for assessing the economic loss [13]. The annual loss due to endoparasites, including fasciolosis in Ethiopia is estimated at 700 million birr [14, 9]. Decreased productivity alone (excluding mortality losses) due to bovine fasciolosis is estimated at 300 million Birr [12]. Preliminary data on economic loss due to fasciolosis in cattle indicates a reduction in production efficiency by 8%and over 20% in mild and sever infections respectively [13]. Acute loss associated with fasciolosis has also been recorded in cattle in east Africa. It causes a substantial economic loss, which include; death, loss in carcass weight, reduction in milk yield, condemnation of affected live, decline in production (reproductive) performances predisposition to other diseases and cost of treatment [14]. However; limited information is available about its prevances and its economic significance in the study area. Therefore, the objectives of this study were to study the prevalence of bovine fasciolosis and assess direct (liver condemnation) and indirect (carcass weight) economic losses caused by fasciolosis in the study area.

Results and Discussions

In this study, the prevalence of fasciolosis in cattle at Mekelle municipal abattoir was 39.9% (267/668). The prevalence of fasciolosis in adult and young cattle was 79% (211/267) and 21% (56/267) respectively (Table1). The result indicated that there was no statistical significant difference (p >0.05) between age groups. The difference in fasciolosis prevalence based on the origin of the animals was not significance (p>0.05) (Table1).The study made on the body condition of the animal, out of the total examined animal, 10.4%, 79.4%, and 15.9% of body score 1, 2 and 3 respectively found positive the result indicated that there were a significant difference i.e. (p< 0.05) (Table1). The prevalence rate obtained in Tigray region was lower than the reports of several workers including 88.57 % and 80% from PME and coproscopy respectively [18] and 81% [19] in Debre Brhane, 77.8% [20] and 22.7 % [21] in Dembi Dello, 75.1% in Gondar [22] , 61.97% in Bahar Dar [23] and 57.58% in Jimma [24] cited in [25] .The lower prevalence rate obtained in this study may be due to the semi arid nature of the environment in which condusive ecological factors for the development and multiplication of the intermediate host snails might be absent. Pathologic lesion were differentiated and categorized into three group as 96 (35.8%) 112 (42.2%) and 59 (22%) lightly, moderately and severely affected respectively based on the criteria previously described by Orgunrinade and Adegoke [26] and cited by Yilma and Mesfin [8]. However, liver with any fasciolosis lesion were totally condemned and adapted in this study. The result revealed that the predominant fluke species involved on the infested liver 166 (62.1%) 34 (12.73%) 31 (11.9%) and 35 (13.1%) F.hepatca, F.gigantica, Mixed infection and immature fluke respectively were found. The result of the post –mortem survey indicated that the dominant fluke in this study area was fasciola hepatica. This may be associated with origin of cattle which came mostly from high lands and Open Access Journal of Veterinary Science & Research

middle altitude areas such as, southern Tigray, where there may be availability of suitable snail habitat due to areas around Lake Hashenge, site serve as good source of pasture where a number of animals frequently congregated during the dry season, and other irrigated sites might be favorable ecological condition for lymeneatrancatula, and the recognized intermediate host of F. hepatica in Ethiopia.

from FST, and again this result is almost similar to the earlier prevalence observed in this, 37 %, area by Hailay [25] (Table 2). Earlier studies conducted on fasciolosis in Ethiopia were mostly based on coprological examinations and abattoir surveys [10] (Table 3). Lower sensitivity of Coprological examination this basically because eggs are not detected until 13 -15 weeks after infection when much of the liver damage has already occurred. In addition, eggs are released sporadically from bile ducts, and consequent incorrect sampling can lead to false negative results as described by Kaufmann (1996) (Table 4).

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Estimation of the economic loss indicated loss of Ethiopian birr 2,121.57 due to liver condemnation and 120,292.9 birr due to carcass weight loss and a total of 122,414.47 birr during the study period and this play main role in degradation of the economic values of individuals and the country. This indicated that the estimated loss due to the disease in the abattoir was quite considerable in an area of semi-arid environment such as the Tigray where fasciolosis is considered to be of less challenge.

Conclusion

The result of the study on bovine fasciolosis at Mekelle municipal abattoir reveals that fasciolosis significantly prevalent parasitic disease affecting the health and productivity of animals, and the disease remain an important health problem to the animals in the study area. The PME is very higher and more confirmatory than that of the result obtained by FST. Additionally the annual loss due to fasciolosis is critical to the economy of livestock industry in this country as well as to the study area

Acknowledgments

I am highly indebted to staff of Mekelle municipal abattoir and Mekelle regional laboratory for their kind reception, preparing equipments and materials for the project work and good willing to use their laboratory with unfavorable condition. All contributions and supports are gratefully acknowledged.