Abattoirs played an important role in surveillance of various diseases of human and animals. Surveillance at the abattoir allows for all animals passing into human food chain to be examined for unusual signs, lesions or specific diseases (Alton et al., 2010). Monitoring and other conditions at slaughter has been recognized as one way of assessing the disease status of herd; however, this source of information is not fully exploited worldwide (Mellau et al., 2010), especially in ascertaining the extent to which human is exposed to certain zoonotic diseases in addition to estimating the financial implications of organ condemnations (Jobre et al., 1996; Chhabra and Singla 2009).

Meat inspection is conducted in the abattoir for the purpose of screening animal products with abnormal pathological lesions that are unattractive and unsafe for human consumption. Meat inspection assists in detecting certain diseases of livestock and prevents the distribution of infected meat that could give rise to disease in animal and human being and to ensure competitiveness of products in the local market (Hinton and Green, 1993). Abattoir data can be a source of valuable information on the incidence and epidemiology of animal diseases. This can help to know to what extent the public is exposed to certain zoonotic diseases and estimate the financial losses incurred through condemnation of affected organs (Raji et al., 2010; Cadmus and Adesokan, 2009; Singla and Juyal, 2014).

The main causes of organ condemnation during post mortem inspection are diseases originated by parasites, bacteria and viruses. Flukes in liver and hydatid cyst in lung, liver and kidney are mainly involved (Mezegebu, 2003; Teka, 1997; Sirak, 1991). Parasites in the tropics are responsible for far greater loss to meat industry than any other diseases (Jobre et al., 1996). Similarly, like many other tropical countries in Africa, it is well known that parasitic diseases are the major factors responsible for low productivity in livestock in Ethiopia (Jobre et al., 1996; Abebe, 1995).

In Ethiopia, many studies have been undertaken to identify the major disease conditions encountered during antemortem and postmortem inspection and to determine the economic importance of organ and carcass condemnation (Jatenie et al., 2014). For instance, Fasciolosis, hydatid cyst, C. bovis, pneumonia, emphysema, hydronephrosis, cirrhosis, hepatitis, calcification and abscess were the major causes of organs condemnation in cattle slaughter at Adigrat municipal abattoir (Alembrhan and Haylegebriel, 2013). At Gonder ELFORA abattoir, the financial loss due to edible organ and carcass condemnation was estimated to be 1,268,579 USD (21,565,849 ETB) per annum. Fasciolosis and hydatidosis were the major causes for condemnation that lead to huge economic losses (Genet et al., 2012).

A report from Jimma showed that an average amount of 10,156.71 USD (172,664.09 ETB) was lost annually due to organ condemnation of cattle at the abattoir. Liver condemnation takes the higher proportion of all the losses accounting for 92.7% of all the losses at Jimma Municipal abattoir (Amene et al., 2012). Similar economic loss analysis by Fasil (2009) showed annual economic loss of 8826.41 USD (150,048.98 ETB) at Gondar Municipal abattoir. Another report in cattle slaughtered at Mekelle municipal abattoir revealed an estimated annual economic loss of 13110.86 USD (222,884.58 ETB) (Amene et al., 2012). Hence, it would be essential to have comprehensive information on occurrence of various    diseases/causes   and  their  economic  loss  to establish appropriate strategy for prevention and controls. Causes of organ condemnation were not extensively studied in Hawassa Municipal Abattoir. Therefore, the objectives of the present study were: to identify the major causes of organ condemnation and to calculate the direct financial loss attributed to the condemned organs in cattle slaughtered at Hawassa Municipal Abattoir.

Study area

The present study was conducted from October 2015 to May 2016 with the aims to identify major causes of organ condemnation and to calculate the direct financial loss due to condemnation in cattle slaughtered at Hawassa municipal abattoir. Hawassa city is located between 4° 27’ and 8° 30’N latitude and 34° 25’ and 39° 1^’ E longitude which is 275 km from south of Addis Ababa. The agro-ecology of the area is “woinadega” (semi-arid) having an altitude ranging from 1650 to 1700 m above sea level (masl). The average minimum and maximum temperature is 20.1 and 34°C, respectively (CSA, 2003).

Study population

The study animals were cattle slaughtered at Hawassa municipal abattoir for local consumption. These cattle were brought to the abattoir from different districts near Hawassa. These animals were kept under extensive production system in which the cattle were allowed to graze freely. The breeds of cattle were local and cross.

Sample size and sampling method

Sample size for the present study was determined by using the formula described by Thrusfield (2007). Since there was no previous data on the prevalence of organ condemnation in the study area, 50% prevalence was taken for sample size determination with 5% precision.

Where: N = required sample size, Pexp =expected prevalence, d = desired absolute precision.

Accordingly, the sample size was determined to be 384 heads of cattle. Systematic random sampling was used.

Study design

Cross-sectional study was carried out to estimate the cause of organ condemnation and to calculate the direct financial loss due to condemnation in cattle slaughtered at Hawassa municipal abattoir.

Study methodology

Ante mortem Inspection

Randomly selected animals were subjected to routine ante mortem inspection during which various risk factors such as body condition, breed and age of animals were scored. The body condition score of animals was classified according to Nicholson and Butter (1986). Accordingly, animals were grouped into poor, medium and good body conditioned. Estimation of age was carried out by examination of teeth eruption and categorized into adult and old.

Post mortem inspection

The post mortem inspection was conducted based on the guidelines set on manual on meat inspection for developing countries (FAO, 1994). Accordingly, the liver, lung, heart, spleen, kidney and tongue were examined through visualization, palpation and systematic incision for any pathological lesion(s).

Assessment of direct financial loss

The total financial loss due to organ condemnation was computed based on the condemnation rate of each type of examined organs, average number of animals slaughtered in the abattoir per year from retrospective data of the abattoir, and condemnation rate of each organ. Average local market price of each organ was collected by questionnaire from the butcheries in Hawassa town, Ethiopia. The data obtained from Hawassa municipal abattoir indicated that the average annual slaughter rate of cattle at the abattoir was 19,000 heads of cattle/year. Consequently, the total direct financial loss was calculated by the following formula set by Ogunrinade and Ogunrinade (1980):

EL = ἑsrk x Coy x Roz

Where EL is estimated annual economic loss due to organ condemnation from domestic market; srk is annual cattle slaughter rate of the abattoir; Coy is average cost of each liver/lung/heart/kidney/tongue/spleen; Roz is condemnation rates of liver/lung/heart/kidney/tongue.

Data management and analysis

Collected data were recorded on specially prepared forms and entered into excel spreadsheet (Microsoft ® office excel 2013) and analyzed by statistical software, SPSS version 20. Descriptive statistics was used to determine the condemnation rate of each organ, defined as proportion of organ condemned to the total number of that particular organ examined. Chi-square test was done to study association between the causes of condemnation and risk factors (breed, body condition score and age). The significance level was set at 0.05.

Out of 384 slaughtered cattle, 171 (44.5%) liver, 137 (35.7%) lung, 36 (9.4%) spleen, 26 (6.8%) heart, 25 (6.5%) kidney and 9 (2.3%) tongue were condemned due to gross abnormalities (Table 1) and found to be unfit for domestic markets and human consumption. The common macroscopic lesions encountered on liver were 21.1% Fasciolosis, 9.4% hydatidosis, 7.3% cirrhosis, 3.9% calcification, 1.5% abscess and 1.3% local necrosis. Lung was rejected due to pneumonia, hydatidosis, emphysema, abscess and hepatization with the rate of 10.2, 12.8, 10.2, 1.5 and 1.0%, respectively. Splenitis and splenomegaly were responsible for condemnation  of  6.5 and 2.9% spleens, respectively. In the case of kidneys, 4.2, 1.5 and 0.8% were condemned due to nephritis, hemorrhage and infarction, respectively. Edema, pericarditis and hemorrhage caused the condemnation of heart at the rate of 2.9, 2.9 and 1.0%, respectively. 1.0 and 1.3% of the tongue examined were condemned due to C. bovis and abscess, respectively. Condemnation rate due to hydatidosis was higher in lung (12.8%) than liver (9.4%) (Table 1).

Rejection rate of all examined organs were higher in local than cross breed cattle. Liver was rejected at the rate of 39.8 (153/384) and 4.7% (18/384) in local and cross breed cattle, respectively. About 31.8 (122/384) and 3.9% (15/384) of lungs were condemned in local and cross breed cattle, respectively. The rejection rate of spleen, heart, kidney and tongue in local breed cattle were found to be 9.1 (35/384), 6.3 (24/384), 6.0 (23/384) and 1.8% (7/384), respectively. In cross breed cattle, the rejection rate of these organs was found to be 0.3 (1/384), 0.5 (2/384), 0.5 (2/384) and 0.5% (2/384), respectively. There was no statistically significant difference in rejection rate of organs between breed of animals (p>0.05).

The rate of liver condemnation was higher in animals with medium body condition, 23.2% (89/384) followed by good, 14.3% (55/384) and poor body condition, 7.0% (27/384). Similarly, the rate of lung condemnation was higher in animals with medium body condition of 19.0% (73/384) followed by good, 12.8% (49/384) and poor body condition, 3.9% (15/384). The rejection rate of spleen, heart, tongue and kidney were higher in medium conditioned animals than good, and poor conditioned animals (Table 2). Except for heart (X²=7.318; df=1; p= 0.007), there was no statistically significant difference in rejection rate of organs among animals with different body condition score (p>0.05).

The rejection rate of liver, lung spleen, heart, kidney and tongue were found to be higher in old than adult animals. In old animals, 31.2% (120/384) liver, 24.7% (95/384) lung, 5.2% (20/384) spleen, 5.5% (21/384) heart, 3.4% (13/384) kidney and 1.5% (6/384) tongue were condemned. In adult animals, the condemnation rate of 13.3 (51/384), 11.0 (42/384), 4.2 (16/384), 1.3 (5/384), 3.1 (12/384) and 0.8% (3/384) were recorded for liver, lung, spleen, heart, kidney and tongue, respectively. The rejection rate of liver and lung were significantly higher in old animals than in adult (liver X²=4.256, df=1, p=0.039; Lung X²=6.899, df=1, p= 0.009).

The annual direct financial loss due to organ condemnation in cattle slaughtered at Hawassa municipal abattoir was estimated to be 15,843.89 USD (342,228.00ETB) (Table 3).

Nephritis, hemorrhage and infraction were the major causes of kidney rejection in this study. The results of this finding were in agreement with the study done by Yesihak et al. (2015). However, Jatenie et al. (2014) reported that C. bovis and hydatidosis were the main cause of kidney rejection. The main cause of tongue condemnation was C. bovis and abscess which is in agreement with other study reported by Lati et al. (2015) from Wollega. Organ condemnation rates did not show statistically significant difference (P > 0.05) in  breed  and there was no statically significant difference (p>0.05) between BCS and condemnation of liver, kidney, tongue, spleen and lung but it was statically significant for heart (p<0.05). Condemnation rate of lung and liver showed statistically significant difference between age groups of animals (p<0.05) but not for spleen, heart and tongue in the age groups of animals. Variation in the proportion of organs condemned due to gross pathological changes may be due to differences in agro-ecological condition of the animal environment that could be favorable to the causative agent, livestock management system and improper disposal of condemned organs. The total financial loss calculated in this study due to organ condemnation was 15,843.89 USD (342,228.00ETB) per year which have extreme difference with the report done by Nebyou et al. (2014) from Nekemte, Ethiopia with loss of 5,435.97 USD (106,536.9 ETB) per year. The difference in the financial loss estimated in various abattoirs may be due to the variation in the prevalence of disease, mean annual number of cattle slaughtered in different abattoir which was higher in Hawassa municipal abattoir, and also, the variation in the retail market price of the organ.

The authors have not declared any conflict of interests.

Organ condemnations cause big economic losses in the cattle industry. In this study, the rates of condemnation of organs were higher in liver followed by lung, spleen, heart, kidney and tongue. Major causes of total condemnation of organs were fasciolosis, hydatidosis, pneumonia, emphysema, cirrhosis, calcification, nephritis, splenitis, edema, C. bovis, hemorrhage and abscess. The total financial loss calculated in this study, due to organ condemnation was 15,843.89 USD (342,228.00ETB) per annum. Thus, proper meat inspections are essential to remove gross abnormalities from meat and its products in order to prevent the distribution of contaminated meat to the public.

Based on the findings of this study, the following recommendations were forwarded:

1. Promoting construction of abattoir with their appropriate disposal pits and immediate and proper disposal of condemned organ should be made.

2. Meat inspectors and abattoir workers should be well trained on handling condemned carcasses and organs.

3. Public awareness should be given to avoid eating of raw meat/organs hence for effective disease control.