Coprological Examination of Haemonchus on Small Ruminant

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Published on International Journal of Agriculture & Agribusiness
Publication Date: March 15, 2019

Lakech Ewnetu
Animal Health Disease Surveillance Expert in Janamora Wereda Livestock Development Office
Janamora, Ethiopia

Journal Full Text PDF: Coprological Examination of Haemonchus on Small Ruminant (Study in Janamora Wereda).

A cross-sectional study was carried out from December, 2018 to February 2019 to determine the prevalence and associated risk factor of haemonchosis in randomly selected sheep and goat in Janamora Wereda. Fresh faecal samples were collected from 384 randomly selected sheep (n=296) and goats (n=88). The overall prevalence of haemonchus in both species of animals was 53% (204/384). At species level, 55% (164/296) sheep and 45% (40/88) goats were found positive. There was no statistically significant (χ2=3.536, p=0.171) difference observed between the two species. Similarly, the prevalence of haemonchus infection in related with age were 62% animals ˂2 years, 58% which was included in 2- 4 years and 41% animals ˃4 years old. Moreover, there was a statistically significant (χ2=13.198, p=0.001) difference observed among the three age categories while there was statistically insignificant (χ2=2.31, p=0.128) difference in males 48% (74/153) and in females 56% (130/231). In addition, the prevalence of haemonchosis in poor body condition was high (58%) in relative to good (48%) and medium (53%) in the study area. However, there was no statistically significant (χ2=2.43, p=0.297) variation observed. Furthermore, concerning the relationship between place of origin and haemonchosis were statistically significant (χ2=6.88, p=0.033) and the prevalence of During the study period, the highest prevalence of haemonchosis was recorded in those animals brought from Deresgie (62%); while the lowest prevalence was recorded in the animals that brought from Enchet Kab (49%) and Denkolako (48%). This might be due to the environmental factors such as temperature and humidity that facilitates the distribution of the parasite to the grazing pasture because of the geographical area which is easy predisposing with flood especially during the rainy season. This study showed the occurrence of infection of small ruminants of the area by abomasal nematodes suggesting the existence of pasture contamination and the availability of infective larvae during months of the study period.

Keywords: Janamora, Enchet Kab, Denkolako, Deresgie, Goat, Haemonchus & Sheep.

Sheep and goats, requiring little inputs, play vital role in rural economy through provision of meat, milk, blood, cash income, accumulating capital, fulfilling cultural obligations, manure, and contribute to the national economy through the export of live animals, meat and skins[1]. Helminth infections in domestic ruminants are major importance in many agro-ecological zones in Ethiopia and had the highest index as an animal health constraint to the poor keepers of livestock worldwide through losses due to reduced weight gains and growth rate, reduced nutrient utilization, lower meat, wool and milk production, involuntary culling, cost of treatment and mortality [2]. Gastrointestinal nematodes are recognized as a major constraint to both small and large-scale small ruminant production in developing countries, leading to significant economic losses [3]. The abomasal nematode Haemonchus contortus is particularly important and causes severe anaemia and death in severely infected animals Review of the available literature in Ethiopia strongly suggests that helminthosis has nationwide distribution and is also considered as one of the major setbacks to livestock productivity incurring huge indirect and direct losses in the country [4].
In rural and semi-rural regions livestock represent the pillar of the economy and plays a vital role in livelihood of the farming communities [5]. Of the endo-parasites, the abomasal nematode H. contortus is incriminated as the dominant cause of parasitic gastroenteritis and exerts a severe economic toll in sheep and goats [6]. The severity of the disease depends on a variety of factors, including the number of helminthes infecting an animal intensity of the infection.
Several factors are involved in the pathogenesis of haemonchosis. In terms of the development of disease, the most important factors are parasite virulence and host response. The main pathogenic mechanisms of H. Contortus are a direct lesion on the gastric mucosa and haematophagy. Ovine haemonchosis occurs in three forms: pe racute, acute, and chronic .The per acute form is less common and the infected lambs may die suddenly from severe haemorrhagic gastritis. Lambs and young sheep are commonly affected by the acute form of the disease in which animals are found dead without showing over clinical signs [7]. The prevalence of gastrointestinal nematodes (GIN) in tropical and subtropical areas has adversely affected the production potential of sheep leading to countless deaths and insidious economic losses in livestock sector. Among (GIN), H. Contortus is considered the main culprit causing anaemia and hypoproteinaemia in ruminants [8]. Even though the economic significances and prevalence of haemonchus is high there was no previously reported and documented study in the study area. Therefore, the major objectives of this study were:
 To determine the prevalence of small ruminant haemonchosis in Janamora Wereda.
 To assess the associated risk factors of small ruminant haemonchosis in the study area

2.1. Study area
Janamora Wereda is located in North Gondar Zone of Amhara region, at the latitude and longitude of 12o59’N 38o07’E at a distance of about 180km from Gondar town. Janamora Wereda is well-known with Semien mountain National Park, Ras Dashen i.e the highest point in Ethiopia and it is a home to a number of endangered species including the Ethiopian Wolf, waliya ibex, and a wild goat which no found in elsewhere in the world. The area has an altitude range of 2900 meters above sea level. The region is marked by numerous mountains, hilly, and sloppy areas, plateaus, rivers, and many streams. Livestock population of the area comprises 100,386 cattle, 32,975 sheep, 131,041 goats, 2,540 horses, 634 mules, 7758 donkeys, 119,347 poultry. The farming system of the study area is characterized by a mixed crop-livestock production system. Transhumance, from the highlands to western lowlands, is practiced as an important strategy to secure grazing resources for the highland livestock during the dry season of the year. In the case of the lowlands, crop farming is not as intensive as high and mid-highland areas and livestock has larger contributions to the farmer’s livelihoods [2]. The study animals are small ruminant which is found in Janamora Wereda kebeles such as Deresige, Enchet Kab and Denkolako Kebeles.

2.2. Study population
The study animals were sheep and goats with different age, sex and body condition. The origins of these animals were from three randomly selected kebeles of Janamora Wereda. A total of 384 animals of sheep (n=296) and goats (n=88) were randomly selected and examined. The ages of animals were determined using owners’ information and dentition (Gatenby). Accordingly, animals were categorized as young (< 2 years) and 2-4 and adults (> 4 years) [9] And the body condition of animals were grouped as good, medium and poor [10].

2.3. Study design:
A cross-sectional study design was used to estimate the prevalence of haemonchus infection in sheep and goats in the study area. A simple random sampling technique was used to select kebeles and study animals. The sample size was determined using the formula given by Thrusfield [11] with 50% expected prevalence, a 5% desired absolute precision and 95% confidence interval.

2.4. Sampling and Coprological examination:
A total of 384 faecal samples were collected directly from the rectum of each study animal using disposable glove. The collected samples were properly labeled with the necessary information and transported to the respective veterinary clinic immediately. The floatation technique was employed to concentrate parasite eggs in the faeces and examined microscopically for presence of haemonchus eggs on the basis of their morphology [12].

2.5. Sample size determination
The desired sample size was calculated using the standard formula described by Thrusfield [11] Since there was no previous work done on this area, the expected prevalence is 50%, the minimum sample size at 95% confidence interval and at 5% precision or accuracy level the sample size is calculated to be 384 using the formula.
n = 1.962 Pexp (1 – Pexp)
Where; n: required sample size
Pexp: expected prevalence
d: desired absolute precision [9].

2.6. Data management and analysis
The data was checked, coded and entered into Microsoft excel work sheet and analyzed using SPSS software version 16.0. Descriptive statistics was used to express prevalence while chi-square χ2- test was used to compare as haemonchus prevalence rate with sex, age, body condition, species as well as place of origin.