Abattoir waste use in livestock diets: Uganda’s current situation

In this study, we investigated the various ways slaughter wastes are utilized, problems encountered in order to give insights in future prospects of abattoir wastes as livestock feeds. A total of 100 abattoir workers were interviewed through semi-structured questionnaires covering Kampala, Wakiso and Mukono districts in Uganda. Results revealed that majority of abattoir work force were middle-aged adults between 30-45 years contributing 37% of total workers. There was a significant association between abattoir workers responses in relation to the proportion of livestock slaughtered (Chi square 147.55; df =2; p<0.0001) in the abattoirs. With reference to cattle, 1.06 and 1.01 more sheep and goats were slaughtered respectively in the dry season in comparison to the wet season. Blood was mostly disposed as animal feed ingredient (blood meal) by 40% of the respondents while rumen contents were mostly sold as manure by 59% of the respondents. Only 16% of the respondents processed rumen contents for livestock feeding. 92.3% of bones were sold for dog feeding while 7.7% of bones were processed for livestock feed ingredients. Polythene bags were reported the biggest contaminants found in slaughter wastes. Stench from slaughter wastes contents was the biggest problem encountered with handling of waste products by (62%) of the respondents. The handling of abattoir wastes was still rudimental at most abattoirs as envisaged by lack of proper handling facilities at the abattoirs. There is need for regular enforcements to ensure proper abattoir waste disposal mechanisms for enhanced livestock use.


Introduction
Abattoirs are designated licensed places for hygienic meat processing (Alonge, 2005). As a consequence of abattoir operations, several inedible byproducts that are unfit for direct human consumption both of organic and inorganic nature are generated (Zhang et al., 2017). These byproducts are potential animal feed ingredients if subjected to precautious further processing (Mwesigwa et al., 2020a). However, in most abattoir operations especially in developing countries the major aim is to maximize edible meat products for human consumption leaving the byproducts to the detriment of land degradation, environmental pollution and biodiversity devastation (Ojekunle and Lateef, 2017). Several measures have been undertaken by a number of regulatory bodies to ensure that abattoir byproducts are disposed in manner that adheres to environmental safety and health standards. In Uganda, these enforcements are mainly done by the local government veterinary officers (DVOs), public health officers (PHOs) and the national environmental management authority (NEMA). Despite the intergovernmental agency interventions to ensure abattoirs products remains safe to both consumers and the environment, there are concerns of laxity in implementation of these measures by both enforcement agencies and abattoir operators that has put consumers and environment at risk (Kyayesimira et al., 2019). This has not only left most abattoirs to operate at questionable healthy standards but also put livelihoods that depend on abattoir operations at great risk. In this study, we investigated abattoir wastes as source of livestock feeds, different ways the wastes are being utilized and challenges faced in order to give insight of the current state and future prospects of waste management in the central region of Uganda.

Description of the study areas
The study was carried out in the districts of Wakiso, Mukono and Kampala, which constitute part of central Uganda. Kampala, the capital city of Uganda is found 45 km north of the Equator at 0°19'6"N and 32°34'60"E ( Fig. 1). Wakiso district is located 20 kilometers northwest of Kampala, at 00 24N, 32 29E coordinates, while Mukono district is located 27 km from Kampala at 00°20′N, 32°45′E.

Data collection
Data was collected by means of interviews targeting abattoir operators/workers. The interviewees included a diverse category of people including veterinary doctors, health inspectors, abattoir chairpersons and people working in abattoirs. The sample size was determined according to formula by Yamane (1967).
Where, n is the sample size; N is the population size and e, is the acceptable standard error; e=0.05.
The sample size was calculated based on 95% confidence level. Considering a population of about 130 abattoir workers around the central districts in Uganda, a total of 100 participants were interviewed, 37 from Kampala, 37 from Wakiso and 26 from Mukono.
Both qualitative and quantitative data were collected using a structured questionnaire with both open and closed end questions. Qualitative data included, sex, marital, education status, type of animals slaughtered, abattoir waste utilization and potential constraints. On the other hand, quantitative data were family size, number and type of animals slaughter in wet and dry season.

Data analysis
Social demographic characteristics of the abattoir work force, whether farmers separated rumen contents from discarded carcasses and the various ways slaughter wastes were utilized were analyzed using descriptive statistics. Chi Square (χ 2 ) was used to test association between abattoir workers responses in relation to the proportion of livestock slaughtered and abattoir worker's awareness of the various regulations governing their operations. If any of the chi square cells was less than 5, then fisher exact test statistics would be Int. J. Agril. Res. Innov. Tech. 10(1): 129-134, June 2020 performed. Odds ratio (OR) was used to determine the strength of association between measured variables. The association between number and type of livestock slaughtered during the wet and dry season was modeled using multinomial logistic regression.

Results and Discussion
Demographic characteristics of the respondents The majority of abattoir workers were middle aged adults between 30-45 years contributing 37% of total work force. This age bracket constitutes an energetically fit age group that is capable of executing the required intense abattoir duties as opposed to older people. People with within the age bracket of 60 to 90 years were the fewest in abattoir operations. Most abattoir workers have a Household (HH) size (1-5) people, a manageable HH number within the urban setting. This was in line with the findings of UBOS (2018) which revealed an average of 4.5 persons per household. Of the total abattoir respondents, the majority had attained at least secondary education, which concurred with the findings of Mwesigwa et al., (2020b). The majority of abattoir workers were married.

Type of livestock slaughtered
There was a significant association between abattoir workers response in relation to the proportion of livestock slaughtered (Chi square 147.55; df =2; p<0.0001). Cattle were more slaughtered than goats and sheep (Table 1). This was due to the fact that almost all abattoirs slaughtered cattle, while others mostly big abattoirs slaughtered a mixture of animals (cattle, goats and sheep) to satisfy the customer's needs. The meat from abattoirs was usually sold to small outlet butcheries that are scattered around city suburbs. Despite sheep being slaughtered at various abattoirs, it was rare to find a specific abattoir categorizing the meat from small ruminants as mutton and goat's meat. These two were usually sold as one entity 'goats meat', this was due to high preference for goats meat to mutton by most consumers around city suburbs.
The slaughtering of camels was not a common practice in Ugandan abattoirs however, this was initiated by the growing need for camel meat by the refugee Somali community. Camel meat consumption is however, projected to increase as some indigenous Ugandans have started enjoying it. Slaughtering of camels was mostly done at Wankulukku abattoir, in Lubaga division. No donkey meat was sold in the sampled abattoirs because in Uganda, the donkey is taken as poor man's walking tractor.

Livestock numbers slaughtered during the dry and wet season
The results showed that with reference to cattle, 1.06 and 1.01 more sheep and cattle were slaughtered in the dry season in comparison to the wet season (Table 2). This is a result of livestock farmers selling most of their animals following dry spell. This practice enables farmers to remain with a small number of animals that can be supported by the available pastures (Dzavo et al., 2019). In reference to goats slaughtered in dry and wet season, 1.04 more and 0.99 less sheep and cattle were slaughtered in the dry season compared to the wet season.

Regulation awareness by abattoir operators/works
There was significant association between awareness for regulatory bodies by abattoir operators (Chi square 15.91; df =2; p<0.0004). Most abattoir operators/workers were unaware of the regulations that govern their operations. This could be one of the reasons for the appalling working conditions at several abattoirs. Int. J. Agril. Res. Innov. Tech. 10(1): 129-134, June 2020 Regulations of slaughter facilities not only aim to improve hygiene but also safe guards against the spread of diseases as well as workers from occupational health hazards (Mann, 1984). This calls for continued awareness by the responsible agencies (Cook, et al., 2017;Kyayesimira et al., 2019). Abattoir operators were more aware of the regulations given by Kampala city council authority (KCCA) than regulations from other agencies. This is because KCCA has been carrying out regular enforcements aimed at keeping Kampala the capital city of Uganda clean, through this campaign abattoirs operating within the jurisdiction of the city have also not been spared.

Separation of discarded carcasses from rumen contents
In most abattoirs, discarded carcasses were separated from rumen contents (Fig. 2).

Fig. 2. Do you separate discarded carcasses from rumen contents?
How slaughter wastes are discarded or utilized Table 4 shows the various ways how the different slaughter wastes were utilized/discarded in the sampled areas. Blood was mostly disposed as animal feed ingredient (blood meal) by 40% of the respondents while 37% of the respondents left it flow freely to drainage channels into the surrounding areas. This could be due to the increasing need of animal protein source in the feed industry. The blood was boiled and dried to produce blood meal. Abattoirs that were not producing blood meal, channeled the blood to surrounding areas along with the water while cleaning the abattoir, which becomes a serious sanitary problem (Aniebo et al., 2009).  Abattoirs that connected blood effluents to the national sewerage lines for further management were fewer (5%) than those who incinerated the blood (11%). This is because most abattoirs could not afford solid waste management charges by the national water and sewerage cooperation (NWSC), a Ugandan government agency in charge of water distribution and sewage management, this finding is in agreement with those of Tamenech and Tamirat (2017). Even the few abattoirs that were connected with the National sewage line rarely used it for their effluent management.
Rumen contents were mostly piled into pits and sold as manure for peri-urban agriculture by 59% of the respondents. This is in line with the findings by Darch et al. (2019) that fertilizers produced from abattoir wastes contribute to the plants mineral requirements for proper growth. Only 16% of the respondents sold dried rumen contents for livestock feeds. Rumen contents were first sun dried, sorted free of contaminants like polythene bags, metals and rags, then piled in sacks for sale. The sale of dried rumen contents was mainly done at Wankulukuku abattoir in Lubaga division one of the outskirt suburbs around Kampala, the Capital City of Uganda. A bag of dried rumen content was sold at 20,000 Ugandan shillings (5.2 USD). The farmer intending to buy dried rumen contents would first place an order in advance. Dried rumen contents were mostly sold to poultry and pig farmers. The bones were mostly disposed as dog food and as a calcium source (bone meal) to feed manufactures. Promotion of abattoir waste use increases revenue of abattoir operators.

Problems encountered with handling of slaughter wastes
Stench from rumen contents was the biggest problem encountered by abattoir operators (62%) followed by disposal costs (Fig. 3). This could be a result of lack of proper holding grounds. Most abattoirs lacked slaughter waste pre-treatment processes prior to waste disposal. This coupled with the length of stay before waste removal from the surrounding abattoir premises create ample time for decomposition of waste organic matter into volatile organic compounds such as ammonia and hydrogen sulphide, which creates intense undesirable off odors (Tamenech and Tamirat 2017).

Contaminants found in slaughter wastes
Polythene bags were reported the biggest contaminants found in slaughter wastes (Table 5). Prevalence of polythene bags in slaughter wastes was a result of improper disposal of polythene bags by people, which eventually found their way into the environment from where they are eaten along following grazing (Aurah, 2013). Ingestion of polythene bags by livestock could be one of the reasons for their underperformance as ingested plastic bags leads to bloat and poor appetite (Nandwa, 2014). Among the other contaminants included thorns, sodom apple and tree seeds. Abattoir workers also reported being injured by sharp objects (thorns and metals) when extruding rumen contents which eventually led to hand skin itching. This can further lead to meat contamination since most abattoir workers hardly put on hand gloves in developing countries (Mann, 1984). The presence of various contaminants in livestock wastes presents a potential health hazard to both livestock and the consumers.

Conclusion
Among the abattoir wastes, blood was the mostly used in animal feeds as blood meal. Most abattoirs still disposed wastes in an environmentally unfriendly manner, which predisposes the public to several health epidemics. There is need for increased government regulation aimed at increasing abattoir hygiene for public safety in line with confines of the law.