Prevalence of parasite
Out of the 200 samples analysed for the presence of gastrointestinal parasites from the farms, 75 are male and 125 are females. At least one parasite was present in 160 of the analyzed samples amounting to 80% parasite prevalence. Thus, eggs of gastrointestinal nematodes (GIN) recovered from the samples as eggs in the genus of
Moniezia, Cooperia, Oesophagostomum, Parelaphostrong ylus, Trichurus, Heamonchus, Nematodirus, Ostertagia, Toxocara and other strongyles (Fig 1)
. The differentiation of srongyle eggs were done morphologically with the aid of microscopic using aforementioned keys.
Eimeria oocysts were spotted in 65 of the total number of samples analyzed. It was also observed that eggs of GIN in the genera of
Heamonchus were the most encountered (80) accounting for 40% prevalence (Table 1). Our results of high prevalence are similar to those of
Kulišić et al. (2013) and
Mphahlele et al., (2021) and gastrointestinal parasite infection has a direct effect on the health and productivity of animals, thereby causing a reduction in output and, consequently, a decrease in the owner’s and community’s income (
Mathewoset al., 2022). The predominance of
Haemonchus over other GIT parasites has also been reported by
Tariq et al. (2008) and
Wani et al. (2011) in Kashmir Valley. The major reason for this prevalence can be connected to the fact that
Haemonchus females are principally fertile egg layers (laying about 10,000 eggs a day)
(Tramboo et al., 2015). The high prevalence of GIT parasites observed in the current study could be as a result of the accessibility of appropriate climatic conditions such as fairly high temperatures and rainfall that support the lengthy survival and development of an infective larval stage of most nematodes (
Shearer and Ezenwa, 2020;
Mphahlele et al., 2021).
Effect of age on gastrointestinal parasites prevalence
The results showed that younger animals are more susceptible to gastrointestinal parasites infection than the older animals (Table 2), animals under the age of 2 years generally gave a result of above 90% prevalence in terms of infection and this shows that there is a statistically significant relationship between the age of animals and prevalence (P<0.05). The higher prevalence in younger sheep is in agreement with the results of
Abebe et al., (2018) who reported significantly higher GIT parasites prevalence in younger animals in Ethiopia but disagree with that of
Tramboo et al., (2015) as they established an overall higher prevalence in older animals than younger ones. The high prevalence of parasites in younger animals indicates a high degree of susceptibility, unlike the adults which acquire immunity to some of these GIT parasites.
Poly-parasitism of gastrointestinal parasites
Out of the 200 examined sheep, 95 (47.5%) were cross infected with two parasites, 10 of the analyzed samples (5%) were infected with three gastrointestinal parasites and 60 (30%) were infected with one gastrointestinal parasite while 40 (20%) were negative for the presence of GI parasites. The present study has indicated the presence of mixed infection with two or more GIT parasite genera in sheep and this is in agreement with the findings of other researchers
(Asif et al., 2008; Samuel et al., 2016). Polyparasitism has been proposed to be a vital source of morbidity and loss of production in sheep
(Samuel et al., 2016). Additionally, the incidence of interaction and compromisation of the immune system of the host by polyparasitism has been detailed to intensify their vulnerability to other diseases or parasites
(Wang et al., 2006). Therefore, polyparasitism is a significant issue in sheep production in the present study area.
Effect of animal sex on prevalence
In terms of animal sex, observations revealed that all the parasites encountered were found in the faecal samples of the male animals except for
Oesophagosuturom while three of the 12 encountered parasites namely Ostertagia,
Trichurus and
Oesophagostomum were not found in any of the female animals across the farms. Though, the interpretations were not substantial. The effect of sex on the vulnerability of sheep to infections could be ascribed to innate tendency and distinctive proneness due to hormonal regulation. The total number of samples collected from male animals tested during the study was 75 and 58 were positive for at least one endoparasite while 102 out of 125 samples taken from the female animals yielded a positive result accounting for 81.6% prevalence therefore a higher prevalence of major gastrointestinal parasite infection was observed in female animals though the p-value (0.33) suggests that the relationship between the sex and prevalence is not statistically significant (P>0.05) (Table 3). This is a result of the same exposure of both sexes and they are as well from the same agroecology. The influence of sex on the susceptibility of sheep to infections could be ascribed to innate tendency and distinctive proneness as a result of hormonal regulation. The existing gender-wise remarks are in agreement with the finding of
Tariqet al. (2008) and
Gauly et al., (2006) who described the occurrence of gastrointestinal parasite infection in sheep as higher but not statistically significant in females than in their male counterparts.
Microbiota composition according to genus level
In this study, the gut microbiota community composition was analysed, Fig 2 shows the complete composition and abundance of Eukaryota domain presents in the feacal samples. At the genus level, the top three predominant populations in the samples analysed were Blastocystis, Mucor, Ichthyobodo and Entemoeba. In terms of the composition, Blastocystsis which has the highest abundance with 33.5% followed by Mucor (14%), Ichthyobodo (13%), Entamoeba (8%), Parelaphostrongylus (4%), Spironucleus (3.5%) and Ripella (0.6%) with the least abundance among the families. Furthermore, it was observed that four species were present in the Blastocystis genus namely
Blastocystis hominis, Blastocystis ratti, Blastocystis python and
Blastocystis cycluri. Three species present in Mucor genus namely
Mucor amphibiorum, Mucor mucedo and
Mucor indicus while the other families were represented with just a species (Table 4).
Metagenomic analysis detects three species of GIT parasite
The results obtained from the present study of GIT parasites with a metagenomic tool detailed the identification of three parasites which are new to the study area. The GIT parasites detected from the analysis are
Parelaphostrongylus odocoilei,
Ostertagia leptospicularis and
Eimeria ahsata. The krona graphs presented showed the percentage of each parasite species identified. Fig 3-6 revealed the species identified for the first time in the study area through the use of metagenomic analysis. Eggs in the genus of the three new species of parasite discovered were also identified in the microscopy analysis which shows some level of congruency between the two techniques. However, we could not identify species from other genera of parasite identified using microscopy analysis, this could be a result of the very low number of samples analysed in the metagenomic study as compared to microscopy analysis.
The high prevalence of protostrongylid infections in Dall’s sheep in Subarctic and Arctic North America was first reported by
Jenkins et al., (2006). The findings of
Jenkins et al., (2005b) further suggest that adding to muscular and respiratory pathology
, P. odocoilei also has the likelihood of causing neurological disease in thinhorn sheep
(Jenkins et al., 2005b). Ostertagia leptospicularis which is not only found in sheep but also other ruminants such as cattle and goats is a gastrointestinal nematode of the genus
Ostertagia, it develops in the abomasal glands of ruminants. The
Ostertagiaspecieshave been connected to pathophy siological changes resulting from abomasal parasitism which include a reduced acidity of the abomasal contents, which is associated with a decreased peptic digestion and bacteriostatic activity
(Hertzberg et al., 2000). The presence and prevalence of
Eimeria ashata have been reported by
Olmos et al., (2020) in Argentina,
Souza et al., (2015) in Brazil and
Reeg et al., (2005) in Germany. This is the first time the presence of
Eimeria ashata in a ruminant animal is reported. Coccidiosis has been reported as a globally important clinical and subclinical parasitic infection in ruminant animals. Coccidiosis is caused by coccidian parasites of the genus
Eimeria which add to enteric disease, particularly in young or stressed animals under poor farm management thereby leading to high mortality in young ruminant animals (
Yusof and Isa, 2016). Furthermore, investigations in many countries such as Brazil (
Souza et al., 2015) and Egypt (
Al-Alfyet al., 2020) have indicated that coccidiosis has a huge economic significance to the production of livestock owing to the clinical disease (diarrhoea) and sub-clinical disease (poor weight gain) caused by the parasite kept in large numbers under differs management methods.
