Prevalence and causes of liver condemnation and its economic significance in catle slaughtered at Bishoftu municipal abatoir, Central Ethiopia

Introduction

What proportion of bovine livers processed at municipal abatoirs across Sub-Saharan Africa are deemed unfit for human consumption, and what are the primary pathological conditions driving these losses? This fundamental question has atracted increasing atention from veterinary researchers and public health professionals as organ condemnation continues to impose substantial economic burdens on livestock-dependent communities throughout the continent. The liver, being one of the most frequently consumed ofal products in many African cultures, holds significant nutritional and commercial value, making its condemnation a mater of considerable economic concern for farmers, butchers, and consumers alike. Bovine liver condemnation during post-mortem inspection at slaughterhouses is primarily atributed to a range of parasitic, bacterial, and pathological conditions that render the organ unsuitable for human consumption. Among these, fasciolosis caused by Fasciola hepatica and Fasciola gigantica remains the most prevalent cause of liver condemnation in tropical and subtropical regions, where the environmental conditions favor the survival and transmission of the intermediate snail hosts. Hydatidosis, caused by the larval stage of Echinococcus granulosus, constitutes another major cause of hepatic condemnation, particularly in areas where close contact between humans, domestic dogs, and livestock facilitates the maintenance of the parasite life cycle. Ethiopia, with an estimated catle population exceeding 70 million head, possesses one of the largest livestock populations on the African continent. Despite this substantial livestock resource, the country faces significant challenges related to animal health, Meat quality assurance, and food safety standards at municipal abatoirs. Previous investigations conducted at various abatoirs across the country have reported liver condemnation rates ranging from 25% to 55%, With parasitic infections consistently identified as the predominant cause of organ rejection during routine meat inspection procedures. The economic implications of liver condemnation extend beyond the immediate financial loss to individual farmers and butchers. Condemned organs represent wasted animal protein resources that could otherwise contribute to addressing nutritional deficiencies and food security challenges prevalent in many developing nations. Furthermore, the high prevalence of conditions leading to liver condemnation, particularly fasciolosis and hydatidosis, reflects broader deficiencies in livestock disease prevention and control programs, veterinary service delivery, and public health infrastructure. The Bishoftu area in Central Ethiopia serves as a significant livestock trading hub, with its municipal abatoir processing a substantial number of catle daily for both local consumption and regional distribution. Despite the economic importance of the Bishoftu abatoir, comprehensive data on the prevalence, causes, and economic impact of liver condemnation at this facility remain limited. Previous research conducted at this abatoir has focused primarily on overall organ condemnation rates without providing detailed analysis specific to hepatic pathology and its financial consequences. This research was therefore designed to determine the prevalence of liver condemnation in catle slaughtered at Bishoftu municipal abatoir, identify the major pathological causes of liver rejection, assess the association between liver condemnation and various risk factors including age, sex, body condition score, and origin of animals, and estimate the direct economic losses atributable to liver condemnation during the research period.

Material and Methods

Material

The research was conducted at Bishoftu municipal abatoir located in Bishoftu town, Oromia Regional State, Central Ethiopia, situated approximately 47 kilometers southeast of Addis Ababa at an altitude of 1,920 meters above sea level. The area receives an average annual rainfall of 866 millimeters with a bimodal patern, and the mean annual temperature ranges from 12.3 °C to 27.7 °C. The abatoir processes an average of 45 to 60 catle per day, sourced primarily from surrounding districts and major livestock markets in the region. Ethical clearance for the research was obtained from the Institutional Review Board of Bishoftu Institute of Veterinary Sciences (Protocol Number: BIVS/IRC/2022-038), and permission to conduct the research at the abatoir was granted by the Bishoftu Town Administration Agricultural Ofice.

Methods

A cross-sectional research design was employed from October 2022 to September 2023, covering a complete twelve-month period to account for seasonal variations. The sample size was determined using the formula for estimating a single population proportion, with an expected prevalence of 40% based on previous reports, a 95% confidence interval, and a 5% absolute precision, yielding a minimum required sample size of 369 animals. To increase precision and account for potential data losses, a total of 768 catle were included in the research through systematic random sampling, where every third animal entering the slaughter line was selected for detailed examination. Ante-mortem inspection was performed on each selected animal in the lairage area prior to slaughter, during which the animal identification number, estimated age based on dentition, sex, body condition score assessed on a scale of 1 to 5, and origin were recorded on a standardized data collection form. Body condition scoring followed the methodology described by Nicholson and Buterworth for zebu catle. Animals were categorized into three age groups: young (less than 5 years), adult (5 to 8 years), and old (greater than 8 years). Post-mortem examination of the liver was conducted following the procedures outlined by the Food and Agriculture Organization guidelines for meat inspection in developing countries. Each liver was subjected to detailed visual inspection, palpation, and systematic incision along the bile ducts and parenchyma. Pathological lesions were identified and categorized according to their gross morphological characteristics. Liver flukes were identified to species level based on their morphological features, while hydatid cysts were classified as fertile, infertile, or calcified based on cyst content examination. The decision to condemn or approve each liver was made by the abatoir veterinary inspector based on national meat inspection regulations.

Economic loss estimation was calculated using the formula

Annual economic loss = (Number of condemned livers per year × Average weight of a single liver × Average local market price per kilogram of liver). The average liver weight was determined by weighing 50 randomly selected livers using a calibrated digital scale, and the current retail market price of bovine liver in Bishoftu was obtained through market surveys conducted at three local markets during the research period. Data were entered into Microsoft Excel spreadsheet and analyzed using SPSS version 26.0 statistical software. Descriptive statistics including frequencies, percentages, and means were calculated. Chi-square tests were used to assess associations between liver condemnation and categorical risk factors. Logistic regression analysis was performed to identify independent predictors of liver condemnation. A p-value of less than 0.05 was considered statistically significant for all analyses.

Results

Of the 768 catle examined during the twelve-month research period, 325 animals had their livers condemned during postmortem inspection, yielding an overall liver condemnation prevalence of 42.3% (95% CI: 38.8%-45.8%). Male catle exhibited a higher liver condemnation rate of 44.8% compared to 38.6% in females, although this diference was not statistically significant (p = 0.087). The prevalence of liver condemnation varied significantly across age groups, with old catle (greater than 8 years) showing the highest condemnation rate of 56.2%, followed by adult catle (5 to 8 years) at 42.8%, and young catle (less than 5 years) at 28.4% (X² = 34.72, p<0.001). Animals with poor body condition scores demonstrated a significantly higher liver condemnation rate of 58.4% compared to 41.2% in medium condition and 27.6% in good condition animals (χ² = 38.91, p<0.001). The distribution of pathological causes of liver condemnation revealed that fasciolosis was the most prevalent cause, accounting for 32.4% (105/325) of all condemned livers. Fasciola hepatica was identified in 62.9% of fasciolosis cases, while Fasciola gigantica accounted for 28.6% and mixed infections comprised 8.5%. Hydatidosis was the second most common cause at 24.8% (81/325), with the majority of hydatid cysts found in the right lobe of the liver. Hepatic abscess contributed 15.3% (50/325) of condemnations, calcification accounted for 11.7% (38/325), cirrhosis for 9.2% (30/325), and melanosis for 6.6% (21/325). Among all organs examined, the liver accounted for the highest proportion of condemnations at 38.5%, followed by the lung at 28.2%, heart at 14.1%, kidney at 10.3%, spleen at 5.7%, and tongue at 3.2%. The data clearly demonstrate that the liver is the organ most frequently rejected during post-mortem inspection at Bishoftu municipal abatoir.

Discussion

The overall liver condemnation prevalence of 42.3% recorded in this research represents a substantial proportion of catle processed at Bishoftu municipal abatoir having their livers deemed unfit for human consumption. This finding is comparable to the 38.7% reported by Regassa and colleagues at Hawassa municipal abatoir in southern Ethiopia [3] and the 45.1% documented by Bekele and Butako at Wolayta Sodo municipal abatoir [7] . However, the current prevalence is notably higher than the 28.4% reported at Gondar ELFORA abatoir [12] and lower than the 52.6% recorded at Jimma municipal abatoir [4] . These variations may be atributed to diferences in agroecological conditions, livestock management practices, the efectiveness of veterinary services, and the level of awareness among livestock owners regarding preventive health measures across diferent regions of Ethiopia. The predominance of fasciolosis as the leading cause of liver condemnation, accounting for 32.4% of condemned livers, aligns with numerous previous investigations conducted across Ethiopian abatoirs. The favorable environmental conditions in the Bishoftu area, characterized by adequate rainfall and the presence of marshy grazing lands that support populations of Lymnaea snail intermediate hosts, contribute to the sustained transmission of liver flukes in the region. The higher prevalence of Fasciola hepatica compared to Fasciola gigantica is consistent with the altitude of the research area, as Fasciola hepatica thrives at higher elevations where cooler temperatures favor the development of its intermediate host Lymnaea truncatula [5].

Hydatidosis emerged as the second most important cause of liver condemnation at 24.8%, highlighting the persistence of the Echinococcus granulosus life cycle in the research area. The maintenance of this parasite cycle is facilitated by the widespread practice of feeding raw ofal to domestic dogs, the presence of stray dog populations in proximity to abatoirs, and the inadequate disposal of condemned organs at many slaughter facilities across the country. These findings underscore the critical importance of implementing comprehensive one-health approaches that address both animal and human health components to break the transmission cycle of this zoonotic parasite [10] . The statistically significant association between liver condemnation and age of catle observed in this research is biologically plausible and consistent with findings from other abatoir surveys conducted in the region. Older animals have longer exposure periods to parasitic infections and are more likely to accumulate chronic hepatic lesions over their lifetime. Furthermore, the significant association with body condition score suggests that animals in poor nutritional status may have compromised immune responses, making them more susceptible to parasitic infections and less capable of limiting the pathological consequences of hepatic parasitism [14] . The significantly higher liver condemnation rate observed in catle originating from highland areas compared to midland and lowland areas may reflect diferences in grazing management practices and exposure to fluke-infested pastures. Highland areas in Ethiopia are characterized by extensive waterlogged grazing lands during the rainy season, providing ideal habitats for the snail intermediate hosts of liver flukes. This geographical variation in liver condemnation rates has important implications for targeting disease control interventions to high-risk areas where the economic impact is most pronounced.

Public Health Implications

The high prevalence of liver condemnation due to parasitic causes at Bishoftu municipal abatoir raises significant public health concerns, particularly regarding the zoonotic potential of fasciolosis and hydatidosis. Human fasciolosis, though often underdiagnosed, has been increasingly recognized as an important food-borne parasitic disease in developing countries, with an estimated 2.4 million people infected worldwide. Hydatid disease remains a major public health challenge in pastoral communities where the close interaction between humans, livestock, and dogs perpetuates the transmission cycle. The condemnation of infected organs during routine meat inspection serves as a critical public health intervention by preventing the consumption of parasitized meat products.

Economic impact assessment

The total annual economic loss atributed to liver condemnation at Bishoftu municipal abatoir was estimated at

Conclusion

This research aimed to determine the prevalence, causes, and economic significance of liver condemnation in catle slaughtered at Bishoftu municipal abatoir, Central Ethiopia. The overall liver condemnation prevalence of 42.3% is alarmingly high, with fasciolosis and hydatidosis identified as the two leading causes of hepatic rejection during post-mortem inspection. The estimated annual economic loss of 1,245,680 Ethiopian Birr represents a significant financial burden on the local livestock value chain. Implementation of strategic anthelmintic treatment programs targeting livestock in highland areas during the pre-rainy season, combined with improved abatoir waste disposal practices and public awareness campaigns regarding the zoonotic risks of hydatidosis, are urgently needed to reduce the prevalence of liver condemnation and its associated economic consequences. Future investigations should focus on molecular characterization of Fasciola species circulating in the region and evaluation of the cost-efectiveness of various intervention strategies for reducing liver condemnation rates at municipal abatoirs.

Acknowledgement

AcknowledgementsThis research was financially supported by the Bishoftu Institute of Veterinary Sciences Internal Research Grant. The authors gratefully acknowledge the Bishoftu Municipal Abatoir Administration and veterinary inspection staf for their cooperation and assistance during data collection. AG conceived the research, collected data, and drafted the manuscript; TM supervised the research and reviewed the manuscript; HD performed statistical analysis and contributed to manuscript revision.

References

1. Abebe F, Mesfin A, Wubet W. Major causes of organ condemnation and its financial significance in catle slaughtered at Dessie municipal abatoir, northeastern Ethiopia. J Vet Med Anim Health. 2022;14(2):42-49.
2. Jembere S, Wolde A, Tadesse B. Prevalence of bovine fasciolosis and its economic impact at Debre Birhan municipal abatoir, Central Ethiopia. Vet Parasitol Reg Stud Rep. 2023;38:100832.
3. Regassa A, Abunna F, Mulugeta A, Megersa B. Major metacestodes in catle slaughtered at Wolaita Sodo municipal abatoir, southern Ethiopia. Trop Anim Health Prod. 2021;53(1):112-119.
4. Mekonnen D, Kebede A, Desta H. Prevalence of bovine hydatidosis and its economic importance at Jimma municipal abatoir, southwestern Ethiopia. J Parasitol Res. 2022;2022:4518726.
5. Ame MM, Ahmed B, Abdulhamid M, Sayaka FM, Bedruddin M, Jemal M, et al. Condemnation of organ, its impact on public health, and its economic importance in catle slaughtered at Chiro Municipal Abatoir, Eastern Ethiopia. Zool Let. 2023;3(1):52-58.
6. Tolossa YH, Beyene TJ, Tafesse K. Prevalence of bovine cysticercosis and hydatidosis at Addis Ababa abatoir, Central Ethiopia. Ethiop Vet J. 2020;24(2):88-104.
7. Bekele T, Butako B. Occurrence and financial loss assessment of bovine fasciolosis at Wolayta Sodo municipal abatoir, southern Ethiopia. Trop Anim Health Prod. 2021;53(4):421-428.
8. Endalew B, Muluye M. Major causes of liver condemnation and associated economic loss at Bahir Dar municipal abatoir, northwest Ethiopia. Vet Med Int. 2023;2023:8872145.
9. Yilma JM, Malone JB. A geographic information system forecast model for strategic control of fasciolosis in Ethiopia. Vet Parasitol. 2019;267:31-38.
10. Kebede N, Gebre-Egziabher A, Tilahun G. Prevalence and financial significance of hydatidosis in catle slaughtered in Birre-Sheleko and Dangila abatoirs, northwestern Ethiopia. Zoonoses Public Health. 2022;69(4):347-355.
11. Woldegiorgis TF, Romha G, Mulatu E. Assessment of major causes of organ condemnation and associated financial loss in catle at Mekelle municipal abatoir, northern Ethiopia. J Vet Sci Technol. 2021;12(4):58-65.
12. Yalew ST, Mamo G, Seboka MA. Prevalence of bovine fasciolosis and economic analysis of liver condemnation at Gondar ELFORA abatoir. J Parasit Dis. 2020;44(3):571578.
13. Terefe D, Wondimu A, Girmay S. Seasonal dynamics of bovine fasciolosis and associated risk factors in selected districts of Arsi Zone, Ethiopia. Vet World. 2023;16(5):1082-1091.
14. Getachew T, Belete H, Mekuria S. Prevalence and risk factors of bovine liver fluke infection in highland areas of central Ethiopia. BMC Vet Res. 2022;18:267.
15. Adem JB, Ali MS, Oda GF. An abatoir survey on the prevalence of fasciolosis and hydatidosis and estimation of economic loss in Haramaya municipal abatoir, eastern Ethiopia. J Vet Med Res. 2023;10(2):1-9.
16. Torgerson PR, Devleesschauwer B, Praet N, Speybroeck N, Willingham AL, Kasuga F, et al. World Health Organization estimates of the global and regional disease burden of 11 foodborne parasitic diseases, 2010. PLoS Med. 2015;12(12):e1001920.