Prevalence of Gastrointestinal Parasites and Associated Factors in Zebu Calves Among Pastoralists in Isiolo County Kenya

Abstract

Helminthosis is a gastrointestinal infection caused by nematodes, cestodes and trematodes, which causes sub-optimal production, reproduction, early culling, work capacity, extra cost of treatment, reduced market values of the affected animals and death. The aim of our study was to investigate the prevalence of gastrointestinal parasitic infections by screening for helminth eggs and coccidian oocysts using MacMaster technique and the associated factors among zebu beef calves in Isiolo County Kenya. A cross-sectional study was conducted in 2020 between November and December in Isiolo North and Isiolo South sub-counties. Garbatulla and Burat wards in Isiolo North and Kinna in Isiolo South were purposively selected due to high number of large herds compared to other areas. A total of 411 calves from 34 herds aged between 3 weeks and 12 months were randomly selected. Calf level and management and environmental data were collected through semi-structured questionnaires, observations and by taking measurements. Faecal samples were obtained from the rectum or immediately after defaecation for laboratory analysis. In the laboratory, faecal egg counts were estimated using the McMaster faecal floatation technique. Descriptive and logistic regression data analyses was done using STATA version 13. In logistic regression, factors with a p-value ≤0.05 in the final models were considered significant, hence retained. The overall prevalence of GIP infection was estimated at 66.9% (275/411). Concurrent helminthosis and coccidiosis prevalence was slightly low, estimated at 16.5% (68/411). Coccidia was the most prevalent type of infection estimated at 45.7% (188/411) while the prevalence of helminths was 38.4% (158/411). Strongyle infection was predominant among other helminths detected with a prevalence 29.4% (121/411) followed by Strongyloides 6.5% (27/411), Monezia 2.7% (4/411), Toxocara 1% (4/411) and Trichuris 0.2% (1/411). xi The factors associated with GIP infections in the final multivariate logistic regression analysis for coccidia were: Location, with Isiolo North recording a higher prevalence than Isiolo South (OR=4.906, p-value=0.000, CI=2.033-11.84), availability of drinking water was associated with lower prevalence compared to calves not provided with drinking water (OR=0.282, p-value=0.000, 0.168-0.472), calves in areas covered with lush pastures recording a higher prevalence than in areas covered with dry pastures (OR=2.604, p-value=0.009, CI=1.273-5.328), calves raised in dry floor having lesser risk of infection compared with calves raised in wet floor condition (OR=0.208, p-value=0.000, CI=0.094-0.462), calves in farms receiving extension services from animal health providers recorded a lower prevalence of coccidiosis than calves in farms without extension services (OR=0.208, p-value=0.023, CI=0.239-0.896). Calves in larger herd sizes of 20 cattle and above were at a higher risk of coccidiosis than calves raised in smaller herd sizes of less than 20 cattle (OR=1.004, p-value=0.022, CI=1.001-1.008). For strongyle infection, the factors associated in the final model were: co-infestation with other gastrointestinal helminths and coccidiosis, with coinfected calves having a higher risk of strongyle infection than non-coinfected calves (OR=27.23, p-value=0.000, CI=12.76-60.62). Calves aged between 9 to 12 months were at the higher risk of strongyle infection compared to calves aged between 3 weeks to 4 months (OR=26.7, p-value=0.000, CI=10.32-68.78), also calves aged between 4 to less than 9 months, were at a higher risk of strongyle infection than younger calves aged between 3 weeks to less than 4 months (OR=19.7, p-value=19.7, p-value=7.69-50.59), calves raised in larger herd sizes were associated with a lower risk of strongyle infection compared with calves raised in smaller herd sizes (OR=0.99, p-value=0.000, CI=0.98-1.0). Calves raised in farms with extension services available recorded a higher prevalence of strongyle infection compared to xii calves raised in farms where extension services were unavailable (OR=3.74, p-value=0.005, CI=1.499-9.333). The results of this study indicated that prevalence of gastrointestinal parasitic infections in calves is high, dominated by strongyles and coccidian infections and management/environmental factors and animal factors were associated with the infections. Robust integrated control program is therefore important to curb the infections which should include proper clinical and laboratory diagnosis, deworming with anthelmintics especially during rainy seasons, and treatment of calves with anti-coccidial drugs, grazing management and isolation of infected animals.