Prevalence of bovine fasciolosis based on faecal examination and abattoir survey in Karnataka
The prevalence of fasciolosis was evaluated in bovines based on coprological examination and postmortem liver examination of slaughtered cattle and buffaloes. The faecal examination of 130 cattle and 135 buffaloes revealed a prevalence of 9.9 % in cattle and 13.3 % in buffaloes respectively. The examination of livers from cattle and buffaloes (155 each) slaughtered at the KMPMCL abattoir revealed the prevalence of fasciolosis was 20.6 % in cattle and 22.5 % in buffaloes. The results were statistically significant in faecal examination and not significant in liver examination from cattle and buffaloes respectively.
Evaluation of losses in carcasses of cattle naturally infected with Fasciola hepatica: effects on weight by age range and on carcass quality parameters.
Although fasciolosis is a relatively common disease, the productive and economic losses resulting from cattle with chronic fasciolosis are unclear. This paper aims to investigate the effect of fasciolosis on the parameters of carcass quality and discuss the hypothesis that the effects on weight differ among age ranges of cattle. For this, we analyzed abattoir data of 30,151 bovines, from 928 farms, slaughtered in Uruguay in 2016, of which 33.9% (95% confidence interval (CI): 27.3% - 41.1%) had Fasciola hepatica (liver fluke). A mixed model was built to assess whether the effect of fasciolosis on weight differs depending on the age range, using the interaction term 'age*F. hepatica'. The effect on the carcass parameters was tested using a proportional logistic regression. The interaction of age and F. hepatica was statistically significant (P<0.001). Differences in carcass weights between infected and non-infected animals were observed mostly at younger ages (up to 30 months), with the highest difference observed in the 23-30 months age range (estimated marginal mean difference of 6.34 kg). Overall, the presence of F. hepatica was positively associated with poor conformations and lower fat scores of carcasses (P<0.001). The carcasses of cattle infected with F. hepatica had 0.16 times greater odds of having worse conformation scores than carcasses of cattle without F. hepatica (proportional odds ratio (POR)=1.16; 95% CI: 1.07-1.26). Similarly, carcasses of cattle with F. hepatica had 0.30 times (POR=1.30, 95% CI: 1.23-1.39) greater odds of having poorer fat scores than carcasses of cattle without F. hepatica. Therefore, infection with F. hepatica is associated with poorer carcass quality parameters and lower weights, and the effect on weight differs across age ranges.
The pathogenic effect of experimental infections with Fasciola gigantica in cattle.
SUMMARY Sixteen young cattle, 7–13 months of age, which had not previously been exposed to Fasciola infection, were each infected with 500, 1000 or 2000 metacercariae of Fasciola gigantica. The experimental infections were followed for periods of 12 to 18 weeks. These animals were grazed on good pasture in the Kenya highlands under conditions which were similar to commercial farm practice. None of the animals which had received 500 or 1000 metacercariae showed any signs which could be attributed to fascioliasis and all remained in good condition, although they did not gain weight so quickly from 11 weeks after infection as the uninfected control animals over the same period. However, both the cattle which were infected with 2000 metacercariae showed clinical symptoms and lost weight from about 10 weeks after infection. One of these animals was slaughtered 12 weeks after infection ; the other, which had eperythrozoa in a blood smear taken at 14 weeks after infection, became progressively weaker and was slaughtered in extremis 15 weeks after infection. This animal was the only one which developed anaemia. By comparing these results with those of previous authors, attention is drawn to the wide range in pathogenicity of F. gigantica that has been recorded in previously uninfected cattle. Factors which may influence the course of the infection are reviewed and in particular it is concluded that the plane of nutrition has a greater effect than has hitherto been appreciated.