RESULTS
Overall Prevalence of Haemonchosis
In the present investigation, a total of 384 sheep and goats were assessed for the presence of Haemonchosis. The results revealed that 160 of the animals were positive, while 224 were negative, indicating an overall prevalence rate of 41.67% (Table 1).
Table 1
Overall Relative prevalence of Haemonchosis in sheep and goats at in Afgoye district lower Shabelle Somalia.
Total animals examined | No positive | No negative | Prevalence% |
384 | 160 | 224 | 41.67% |
Relative prevalence of Haemonchosis on the basis of sheep and goat species
The relative prevalence of Haemonchosis, a parasitic condition, in two different species: sheep and goats. In the study, a total of 246 sheep were examined, with 118 of them testing positive for Haemonchosis, resulting in a prevalence rate of 30.73%. Similarly, 138 goats were examined, and 42 of them were found to be positive, indicating a prevalence rate of 10.94% (Table 2). There was no significance difference between sheep and goat occurring on Haemonchosis (χ2 = 2.235, P = 0.135).
Table 2
Relative prevalence of Haemonchosis on the basis of sheep and goats species in Afgoye district lower Shabelle Somalia.
Species | No of animals examined | No of positive | Prevalence (%) | Chi-square | P-value |
Sheep | 246 | 118 | 30.73% | 2.235 | 0.135ns |
Goat | 138 | 42 | 10.94% | | |
Total | 384 | 160 | 41.67% | | |
*Significant, p < 0.05 ns not significant The graph below illustrates that the distribution of test results, in terms of the ratio of negative to positive outcomes, differs between the goat and sheep species. Goats show a more skewed distribution towards negative results compared to sheep (Fig. 1). |
Relative prevalence of Haemonchosis based on location in sheep and goats
In the study, presences of prevalence rate of Haemonchosis based on location in sheep and goats within the Afgoye district of Lower Shabelle, Somalia. In Markazka: Out of 80 animals examined, 36 tested positive for Haemonchosis, resulting in a prevalence rate of 9.38%. In Jambalul: Among the 72 animals examined, 40 tested positive, leading to a prevalence rate of 10.42%. In If iyo aqiro: Within the 68 animals examined, 33 tested positive, resulting in a prevalence rate of 8.59%. In Buulalow: Out of 60 animals examined in this location, 32 tested positive, indicating a prevalence rate of 8.33%. In Beeruxa: Among the 53 animals examined, only 3 tested positive for Haemonchosis, resulting in a low prevalence rate of 0.78%. In Carbiska: Within the 30 animals examined, 12 tested positive for Haemonchosis, yielding a prevalence rate of 3.13% and Afgoye: Out of 21 animals examined, 4 tested positive for Haemonchosis, resulting in a prevalence rate of 1.04% (Table 3). The chi-square result indicated there was no significance difference between the locations (χ2 = 11.324, P = 0.079).
Table 3
Relative prevalence of Haemonchosis based on location in sheep and goats within the Afgoye district of Lower Shabelle, Somalia
Locations | No of animals examined | No of positive | Prevalence (%) | Chi-square | P-value |
Markazka | 80 | 36 | 9.38% | 11.324 | 0.079ns |
Jambalul | 72 | 40 | 10.42% | | |
If iyo Aakhiro | 68 | 33 | 8.59% | | |
Buulalow | 60 | 32 | 8.33% | | |
Bayru ruuxa | 53 | 3 | 0.78% | | |
Carbiska | 30 | 12 | 3.13% | | |
Afgoye | 21 | 4 | 1.04% | | |
Total | 384 | 160 | 41.67% | | |
*significant, p < 0.05ns not significant |
The graph below shows the distribution of test results, classified as negative or positive, across various geographic areas. Afgoye has the most dramatic asymmetry, with a much higher number of negative results than positive. Markazka shows a more appropriate mix of negative and positive test results. The remaining places have varied levels of difference between negative and positive test results (Fig. 2).
Haemonchosis and its risk factors.
Risk Factor: Sex
In sheep, 210 females were examined, 81 of them were positive and their prevalence rate was 20.09%. Among males, 58 male sheep were examined, 28 of them were positive and their prevalence was 7.29%. In goat, 86 females were examined, 35 of them were positive and their prevalence was 9.11%. Similarly, in males goats 30 males were examined, 16 of them were positive and there prevalence was 5.18% (as shown as Table 4). There was no significance difference between male and female (χ2 = 0.463, P = 0.496)
Risk Factor: Age (year)
1 year: Within the 109 animals examined that were 1 year old, 44 tested positive for Haemonchosis, resulting in a prevalence rate of 11.46%. 1–4 years: Among the 156 animals examined in the age range of 1–4 years, 44 tested positive, yielding a prevalence rate of 11.46%. The chi-square value and p-value for this age group are not specified. Greater than 4 years: Out of th 119 animals examined that were older than 4 years, 72 tested positive for Haemonchosis, indicating a prevalence rate of 18.75% (as shown as Table 4). There was significance association between age groups (χ2 = 7.573, P = 0.023).
Risk Factor: Type of grazing Free:
Among the 158 animals examined in free grazing conditions, 80 tested positive for Haemonchosis, resulting in a prevalence rate of 20.83%. Mixed: Within the 130 animals examined in mixed grazing conditions, 64 tested positive, leading to a prevalence rate of 16.67%.
Zero: Out of the 96 animals examined in zero grazing conditions, 16 tested positive for Haemonchosis, yielding a prevalence rate of 4.17% (as shown as Table 4). There was significance association between type of grazing (χ2 = 8.587, P = 0.013).
Risk Factor: Body condition
Poor: Within the 138 animals examined with poor body condition, 68 tested positive for Haemonchosis, resulting in a prevalence rate of 17.71%. Middle: Among the 149 animals examined with average body condition, 56 tested positive, indicating a prevalence rate of 14.58%. Good: Out of the 97 animals examined with good body condition, 36 tested positive for Haemonchosis, resulting in a prevalence rate of 9.38% (as shown as Table 4). There was no significance association in body condition (χ2 = 1.338, P = 0.512).
Table 1
Relative prevalence of Haemonchosis based on risks factors in sheep and goats at in Afgoye district lower Shabelle Somalia.
Risk factors | No of animals examined | No of positive | Prevalence (%) | Chi-square | P-value |
Sex-Species |
Sheep |
Female | 210 | 81 | 20.09% | 0.463 | 0.496ns |
Male | 58 | 28 | 7.29% | | |
Goat | | | | | |
Female | 86 | 35 | 9.11% | | |
Male | 30 | 16 | 5.18% | | |
Age (year) |
1 year | 109 | 44 | 11.46% | 7.573 | 0.023* |
1–4 year | 156 | 44 | 11.46% | | |
Greater than 4 | 119 | 72 | 18.75% | | |
Type of grazing |
Free | 158 | 80 | 20.83% | 8.587 | 0.013* |
Mixed | 130 | 64 | 16.67% | | |
Zero | 96 | 16 | 4.17% | | |
Body condition |
Poor | 138 | 68 | 17.71% | 1.338 | 0.512ns |
Middle | 149 | 56 | 14.58% | | |
Good | 97 | 36 | 9.38% | | |
*significant, p < 0.05 ns not significant |
DISCUSSION
The recent study conducted in the region disclosed a prevalence rate of 41.67% for Haemonchus contortus in small ruminants. Specifically, the prevalence in sheep was 30.73%, while it was 10.94% in goats, indicating a persistent high rate of haemonchosis in the area. These results surpass previous reports from other regions of Somalia. For example, Abdi-Soojede reported a prevalence rate of 36.06% in blackhead sheep in the Mogadishu Benadir region (Abdi - Soojeede 2019). Furthermore, our study's findings are higher than Moktar et al. (2023), which documented a 23.4% prevalence rate of haemonchosis in goats in the Afgoye district, Lower Shabelle, Somalia (Moktar, Ibrahim et al. 2023).
In comparison, the current findings are somewhat lower than those reported from various regions in Ethiopia. For instance, Musema Mussa documented a prevalence of 46.1% in the Mitto district (Mussa 2023). While Fentahun and Luke found an 80.21% prevalence in Gonder (Fentahun and Luke 2012).
Shankute and Melauke reported a 77.38% prevalence at the Helmex-Export Abattoir (Shankute, Bogale et al. 2013). Mengist, Abebe, recorded a rate of 71.3% in and around Finoteselam (Mengist, Abebe et al. 2014). Additionally, Abebe and Agrow observed a 90.1% prevalence rate in sheep and goats slaughtered at the Haramaya municipal abattoir (Shimelis Argaw, Desta Beyene et al. 2014). Lastly, T. Endale, T. Tadele, and G. Belay reported a 67.2% prevalence at the Asella municipal abattoir (Teshome, Tolosa et al. 2020).
The study's results exhibit a noteworthy disparity when contrasted with prior findings reported by Tewodros F and Girja L, who documented prevalence rates of 81.2% in sheep and 73.5% in goats in Gonder town (Fentahun and Luke 2012). Mulugeta T, Batu G, and Bitew B reported prevalence rates of 69.5% in sheep and 65% in goats in and around Bedelle, (Tefera Taye, Batu et al. 2011). while Haileleul documented rates of 61.63% in sheep and 54.76% in goats in and around Wolaita Soddo (N 2002). Furthermore, L. Workineh, B. Takele, and D. Fanta reported prevalence rates of 63.68% in sheep and 50.74% in goats at the Mojo Luna export abattoir (Workineh Legesse and Tolossa 2019).
The variations in the prevalence of haemonchosis in small ruminants can be attributed to a range of factors, as highlighted by Abebe, R., Mekuria, including differences in agro-ecological conditions, husbandry practices, environmental factors, sample size, study methodologies, veterinary service coverage, and quality (Abebe, Gebreyohannes et al. 2010).
This study revealed that the prevalence of H. contortus was greater in sheep than in goats, with a percentage of 30.73% in sheep and 10.73% in goats. The discrepancy between these two groups may be attributed to several factors, including the grazing habits of sheep, which tend to graze closer to the ground and therefore have more exposure to infectious larvae (L3) of H. contortus from contaminated grazing areas. In contrast, goats prefer to eat shrubs and small trees, which may lead to a lower ingestion of larvae compared to sheep. This study also found that female small ruminants were more likely to be infected with H. contortus than males, although the difference was not statistically significant (χ2 = 0.463, P = 0.496).
This finding is consistent with previous research conducted in Genchi district, which reported infection rates of 90.2% in females and 82.9% in males (Emiru, Amede et al. 2013). Furthermore, studies in and around Ejere town and Gonder town reported higher infection rates in females compared to males (Olufunmilayo, Olayide et al. 2015, Bekuma and Dufera 2019).
The susceptibility of female small ruminants to Haemonchus contortus is heightened due to their negative energy balance during lactation, which impairs their ability to fight off parasitic infections. Moreover, ewes and does experience a considerable decrease in parasite resistance during late pregnancy and shortly after giving birth due to hormonal and photoperiod effects, making them more vulnerable during the periparturient period. On the other hand, male small ruminants are frequently confined indoors for fattening during this time. Haemonchus infections can be attributed to the substantial egg production of adult females, leading to rapid larval contamination of pastures and consequent outbreaks of haemonchosis (Roeber, Jex et al. 2013)
The prevalence of infection was slightly higher in sheep and goats older than 4 years (18.75%) than in those aged 1 year and 1–4 years, which both had rates of 11.46%. There was a significant association between these age groups (χ2 = 7.573, P = 0.023). The higher prevalence of haemonchosis in adults may be due to younger small ruminants being more responsive to anthelmintics, while adults might develop resistance to common treatments during seasonal changes. Further research is needed to understand the underlying causes.
The research examined the prevalence of Haemonchus contortus infection based on grazing methods: free grazing resulted in the highest incidence at 20.83%, followed by mixed grazing at 16.67%, and zero grazing at 4.17%. A significant relationship was found between grazing methods and infection (χ2 = 8.587, P = 0.013).
Furthermore, the study found that sheep and goats with poor body condition were more likely to have H. contortus infection, at 17.71% and 14.58%, respectively, compared to those in better condition. Animals with poor body condition are more susceptible to parasitic diseases due to their weakened immune systems. This finding aligns with the results of previous studies in Mekelle town, Bahir Dar municipal abattoir, and Jimma Horro district, which reported higher infection rates in animals with poor body condition (Negasi, Bogale et al. 2012, Moges Sewalem 2017, Dugassa, Imana et al. 2018). On the other hand, animals in good body condition have stronger immunity, which enables them to resist gastrointestinal parasites and inhibits parasite reproduction (Gizachew, Fikadu et al. 2014).
CONCLUSION AND RECOMMENDATION