Epidemiology of nematode parasites of sheep around Jimma, southwestern Ethiopia

Prevalence and risk factors associated with gastrointestinal parasites in goats (Capra hircus) and sheep (Ovis aries) from three provinces of China

Gastrointestinal (GI) parasites in small ruminants, especially goats and sheep, have caused significant socio-economic and public health challenges worldwide. The aim of the present study was to investigate the diversity and prevalence of GI parasites in goats and sheep in Jiangsu, Shaanxi and Hunan provinces of China, and to assess whether the age of animals, sampling season and feeding mode influence the distribution and infection of GI parasites. A total of 1,081 fecal samples collected from goats (n = 835) and sheep (n = 246) were detected by saturated saline flotation technique and nylon sifter elutriation and sieving method for eggs/oocysts, respectively. Based on the morphological observation of eggs and oocysts, one tapeworm, five nematodes, three trematodes and nineteen coccidia were identified, of which seven helminths belong to zoonotic parasites. The infection rate of parasites was 83.4% (902/1081) in total samples, 91.6% (765/835) in goats, and 55.7% (137/246) in sheep. The infection rate of coccidia was 71.0% (767/1081), and that of helminths was 56.2% (607/1081). The dominant species was E. alijeri (67.3%, 562/835) in goats, E. parva (30.1%, 74/246) in sheep. The highest prevalent helminths were Trichostrongylidae spp. in goats (58.3%, 487/835), and Moniezia spp. in sheep (22.76%, 56/246). Of 902 positive samples, 825 (91.5%, 825/902) contained multiple (2-10) parasites. The feeding mode, sampling season and regions were relevant risk factors which have significant influence on the occurrence of GI parasites in goats and sheep. The risk coefficient of parasite infection in autumn was 2.49 times higher than spring (Odds ratio = 2.49, 95% CI = 1.51-4.09, p < 0.001). Compared to raising on the high beds, the goats and sheep raising on the ground had the higher risk of parasite infection (OR = 3.91, 95% CI = 2.07-7.40, p < 0.001). The risk coefficient of parasite infection in Shaanxi and Hunan was 3.78 and 1.25 times higher than that in Jiangsu (OR = 3.78, 95% CI = 2.01-7.12, p < 0.001; OR = 1.25, 95% CI = 1.21-1.29, p < 0.001). These data are significant for the development of prevention strategies to minimise economic losses from small ruminant production and to reduce the risk of water and food infecting humans as vectors of zoonotic parasitic diseases.

Gastrointestinal nematodes infections and anthelmintic resistance in grazing sheep in the Eastern Inner Mongolia in China

Gastrointestinal nematodes (GIN) are a crucial restraint to grazing sheep production worldwide. This study was conducted to determine the infections and anthelmintic resistance (AR) of GIN in pasture-based sheep in the Eastern Inner Mongolia, China. GIN eggs were tested from 600 grazing sheep feces of 10 farms using saturated saline flotation method and McMaster's method. The egg hatch test (EHT) and the faecal egg count reduction test (FECRT) were used to evaluate resistance of GIN to anthelmintics. We found that the average infection rate was 79.2% (range: 45%-100%). The grand mean faecal egg count (FEC) was 1813.2 eggs per gram (EPG) (range: 0-32400 EPG). There were significant differences in GIN infection among different breeds of sheep. The sequence of infection intensity and infection rate were Small fat tail > Ujimqin > Ju Ud (p<0.05). The 50% effective doses (ED50) of albendazole(ABZ) and levamisole (LMS) for expelling were 5.670 µg/mL and 0.302 µg/mL, respectively. The percentage reductions of avermectin (AVM), ivermectin (IVM), ABZ and LMS were 81.28%, 86.49%, 76.21% and 96.59%, respectively. The most predominant parasite genus in all four anthelmintics was Haemonchus. In these tested areas, mixed infections of GIN in grazing sheep were very common. AR, especially in Haemonchus, was a serious problem in these sheep flocks. Thus, actions are urgently required to taken to mitigate the worsening situation.

Investigations into nematode parasites of goats in pastoral and crop livestock systems of Ethiopia

We generated epidemiological information on the prevalence of nematode parasites and possible resistance/resilience of goats in three areas, Bati, Shinille, and Borana, of Ethiopia. A total of 350 breeding does were randomly selected and monitored for one year. Fecal egg counts (FEC), packed cell volume (PCV), body weight (BW), body condition score (BC), and fecal larvae identification were done. In Borana, the long rainy season had higher FEC, lower PCV, lower BC, and smaller BW compared to dry and short rainy seasons (p < 0.01). For Bati and Shinille, the differences between the seasons were significant (p < 0.01) but not clear-cut. Breed differences were also evident (p < 0.01) on FEC, PCV, and BW. The mean FEC for Borana goat was 158.5 ± 1.12, whereas for Bati it was 38.9 ± 1.12. Age differences did not have effect on FECs, PCV, and BC. No differences in parasite load, as reflected by FEC, was verified between male and female goats. In the wet season, large numbers of larvae were recovered from the study sites except for Bati. In the three sites, Haemonchus contortus followed by Trichostrongylus colubriformis were the dominant species. In the dry season, however, very little number of larvae was recovered, only of H. contortus in Bati and of H. contortus and T. colubriformis in Borana. Generally, the level of nematode infection was low. Therefore, nematode parasites are not a major problem and strategic control program using broad spectrum anthelmintic is not advisable. Rather, monitoring parasite load and selective de-worming should be sufficient to reduce productivity loses and pasture contamination.

Impact of treatment of gastrointestinal nemathelminths on body weight of sheep and goats

Gastrointestinal nemathelminths affect productive as well as reproductive performance of a wide range of ruminants. To assess the impact of anthelmintic treatment on gain in body weight (b. wt.) of sheep and goat, a study was conducted using two different flocks of sheep and goats each maintained in semi intensive system. Infected animals in both the flocks were divided into three groups each. Group I and II in each flock were treated with levamisole (@7.5 mg/kg b. wt. subcutaneously) and fenbendazole (@5 mg/kg b. wt. orally), respectively. Animals of group III were kept as untreated control. Individual b. wt. and faecal egg count were recorded up to 42nd day post treatment. Results showed 100 % reduction in faecal egg count of sheep on day 7 after treatment with levamisole and on day 10 after treatment with fenbendazole. In goats, the reduction in faecal egg count was 82.60 % after treatment with levamisole and 78.87 % after treatment with fenbendazole on day 14 post treatment. The study also revealed mean increase of 29.57 and 22.67 % in b. wt. of sheep treated with levamisole and fenbendazole respectively 42nd day post treatment whereas mean b. wt. of infected untreated control groups decreased by 7.14 %. Similarly, there was an increase of 10.71 and 14.47 % in mean b. wt. of goats 42nd day post treatment with levamisole and fenbendazole, respectively whereas mean b. wt. of untreated control group decreased by 15.38 %. More weight gain was recorded in sheep as compare to goats after treatment as compared to the untreated control group, which may be due to some drug resistance in goat and required clarification by further studies in these ecological zones of Udham Singh Nagar.