Search Results (13)

Meat condemnation at slaughterhouses reflects the rate of animal diseases, economic losses, and potential public health risks. In northern Nigeria, however, longitudinal and model-based assessments of condemnation patterns using routine abattoir data remain limited. This study aimed to quantify species- and disease-specific meat condemnation rates, examine short-term temporal variation during the study period, and identify predictors of condemnation at the Sokoto State Main Abattoir. A retrospective panel analysis of aggregated abattoir data with repeated temporal observations was conducted using abattoir meat inspection records from January to June 2025. Condemnation rates per 1000 animals slaughtered were calculated by species, disease category, and month. Short-term temporal variation within the study period and associated factors were evaluated using negative binomial regression with an offset for slaughter volume. These rates reflect the number of condemned organs recorded relative to the number of animals slaughtered, as multiple organs may be condemned from a single animal during post-mortem inspection. Model adequacy was assessed through dispersion diagnostics, multicollinearity checks, residual analyses, sensitivity analyses, and predictive calibration using observed versus model-predicted rates. A total of 317,685 animals were slaughtered during the study period, with 1628 condemnation cases, corresponding to an overall condemnation rate of 5.12 per 1000 animals slaughtered (95% CI: 4.88–5.38). Condemnation rates varied markedly by species, with camels exhibiting the highest monthly rates (140.05 per 1000 animals slaughtered), followed by cattle (51.80 per 1000 animals slaughtered), sheep (40.62 per 1000 animals slaughtered), and goats (22.19 per 1000 animals slaughtered) during the study period. Disease-specific analyses identified contagious bovine pleuropneumonia, fascioliasis, hydatidosis, and tuberculosis-like lesions as major contributors to condemnation. Temporal patterns demonstrated non-linear monthly variation, with elevated rates in mid-study months. The final negative binomial model showed good calibration, with close agreement between observed and predicted rates across species and diseases. Meat condemnation at the Sokoto State abattoir demonstrates substantial heterogeneity by species, disease, and time. Priority conditions such as contagious bovine pleuropneumonia (CBPP), fascioliasis, hydatidosis, and tuberculosis-like lesions warrant targeted control efforts. These findings reinforce the value of routinely collected abattoir data as a practical and robust component of animal health surveillance in resource-limited settings. Full article

Slaughterhouse by-products are promising feedstocks for anaerobic digestion due to their high lipid and protein content. However, their complex structures often limit hydrolysis, and excessive pretreatment can induce inhibitory conditions. This study evaluates the effects of ball-milling (BM), ball-milling with water (BM + water), and combined thermal hydrolysis and ball-milling (THP + BM) on the digestion performance of a mixed substrate of slaughterhouse and agricultural wastes. The results demonstrate that all BM-based pretreatments significantly improved digestion kinetics, reducing the lag phase by 26–66% and shortening the T₅₀ values by approximately 40% compared to the untreated substrate. While no statistically significant differences were observed in the ultimate methane yield, the onset of methanogenesis was markedly accelerated in the BM and BM + water treatments. In contrast, despite achieving superior solubilization, the THP + BM treatment failed to provide proportional kinetic enhancements. This was attributed to a severe initial metabolic imbalance—characterized by a pH drop below the inhibitory threshold (6.33)—which induced physiological stress and delayed the functional recovery of methanogens. These findings indicate that while ball-milling effectively facilitates digestion initiation by enhancing physical accessibility, the intensity of combined thermal-mechanical processes must be strategically optimized. For high-strength organic biomass, managing pretreatment severity is crucial to prevent initial acid stress and maximize process efficiency. Full article

This bibliometric study evaluates scientific production between 2015 and 2025 inclusive on anaerobic digestion of pig slurry and slaughterhouse wastewater for biomethane generation. A total of 1.414 documents were identified for pig slurry and 250 for slaughterhouse wastewater, reflecting a marked imbalance in research attention. For pig slurry, the literature shows strong consolidation, with consistent focus on biogas yield optimization, emission mitigation, and agricultural valorization of digestate. By contrast, slaughterhouse wastewater research is comparatively limited, fragmented across technical case studies, and often concerned with process inhibition, pretreatment strategies, and integrated treatment systems. Despite this disparity, both residues are recognized as important feedstocks for renewable energy recovery, with co-digestion offering particular promise in terms of process stability and biomethane enhancement. Full article

This study assessed the application of whole lipolytic cells in the pretreatment of slaughterhouse wastewater to reduce its lipid content. The fungal biomass of Rhizopus oryzae was evaluated in the hydrolysis of slaughterhouse wastewater containing high lipid concentrations, focusing on the biomass’s concentration and the effect of using an emulsifier and surfactant. The use of the whole-cells lipase of Rhizopus oryzae grown in a residual vegetable oil medium proved effective in the hydrolysis of slaughterhouse wastewater, generating concentrations of free fatty acids (FFA) ranging from 40.36 to 90.14 mM. The action of lipase in the hydrolysis of slaughterhouse residues indicated its effectiveness in pretreating lipid-rich liquid residues, potentially boosting the microbiota of this anaerobic treatment. The results showed that lipase activity without surfactant exhibited a similar performance to that of Triton X-100 in the hydrolysis of liquid residues. However, the combination of lipase and surfactant could represent a promising strategy to optimize free fatty acid production from slaughterhouse residues, strengthening anaerobic treatment processes and potentially enhancing the overall efficiency of waste management systems. Full article

The use of purified slaughterhouse wastewater in carp ponds, and the use of wastewater from the pond for the irrigation of agricultural fields, was the basis for the construction of an integrated system of agricultural production as a sustainable solution for the food and fish production industries. The negative side of such integrated production systems is the concern related to the safety of fish meat produced in such a system. The aim of this research was to determine the concentration of heavy metals and metalloids in the wastewater from the slaughterhouse, in the pond water and sediment, in the carp tissue and in the water leaving the pond, and to evaluate the effectiveness of the integrated system and the safety of the produced fish. Sampling was carried out in spring and autumn. The mean concentrations in all water samples (µg/L) were: As (12–125), Cd (0.12–4.2), Hg (1.14–14.21), Pb (<0.1–17.2), Cu (<0.1–44.6), Fe (17.02–425.2) and Zn (2.91–186.2), with the highest numbers in the wastewater, where it was above the prescribed limit values for the wastewater discharged from the slaughterhouses into natural recipients in both samplings. The efficiency of the wastewater treatment plant for heavy metals and metalloids was very high, in the range of 87% to 98%. The water from the pond corresponded to class 3 in terms of the concentration of heavy metals and metalloids both in spring and autumn, and can be used freely for breeding cyprinid fish species. The water from the irrigation canal corresponded to class 2/3 and can be used for irrigation. The mean concentrations of heavy metals and metalloids in the sediments (mg/kg) were: As (3.00–4.88), Cd (0.16–0.96), Hg (0.21–1.47), Pb (0.77–2.29), Cu (49.60–60.90), Fe (3.94–5.32) and Zn (92.8–115.20). The content of heavy metals in different organs of carp differed significantly depending on the season. The trend of heavy metal accumulation in common carp muscles in spring was: Zn > Fe > Cu > Pb > Hg > Cd > As, and in autumn: Zn > Fe > Cu > Pb > As > Cd > Hg. Metal concentrations in the examined fish samples were far below the WHO guidelines. It can be concluded that carp produced in a pond supplied with purified wastewater from the slaughterhouse industry, in terms of the concentration of residues of the tested heavy metals and metalloids, is safe for human consumption. Full article

Slaughterhouse solid waste is one of the sources of greenhouse gas (GHG) today. Crop residue decomposition or incineration has a great impact on global warming. Therefore, it is urgent to study the possibility of better environmentally friendly approaches to solid waste management and its safe disposal. The digestion of this type of solid waste in a decomposing process from organic content allows the recovery of valuable resources (such as biogas) and the use of the digestate in various fertilizer industries. In this study, two substrates were studied to determine their biomethane (BMP) potential in anaerobic digestion. The substrates were fermented and digested anaerobically and biogas production was measured. Methane yield of the slaughterhouse substrates had a lower methane yield between 232.2 and 250.8 mL/gVS and 53.6 to 57.9% biodegradability. Harvest substrates produce between 167.1 and 274.9 mL/gVS with a biodegradability of 39.1 to 64.3%. Co-digestion of both substrates at a ratio of IS 1:2 (RR:WS 3:1) generated a higher yield 289.1 ml/gVS and 66.9%. biodegradability of A kinetic analysis was carried out using Gompertz models, transfer and logistic function for methane production biodegradation. Full article

We monitored liver damage in cattle (cows, heifers, fattening bulls, and calves culled from the herd), pigs (sows, finishing pigs, and piglets culled from the farm), sheep (ewes and lambs), goats (does and kids), rabbits, and poultry (end-of-lay hens, broiler chickens, turkeys, domestic ducks, and domestic geese) in the period from 2010 to 2021. All animals (n = 1,425,710,143) reared on Czech farms and slaughtered at slaughterhouses in the Czech Republic were included in the analysis. We determined the total number of damaged livers for individual categories of animals and also analyzed separately the incidence of damage of acute, chronic, parasitic, and other origin. The overall incidence of liver damage was higher in adult animals compared to fattening animals in all species. In cattle and pigs, the incidence was also higher in young animals culled from the herd compared to fattening animals. When comparing adult animals by species, the incidence of liver damage was highest in cows (46.38%), followed by sows (17.51%), ewes (12.97%), and does (4.26%). When comparing fattening animals by species, the incidence was highest in heifers (14.17%) and fattening bulls (7.97 %), followed by finishing pigs (11.26%), lambs (4.73%), and kids (0.59%). When comparing young culled from the herd by species, it was higher in piglets (32.39%) than in calves (17.6 %), and when poultry and rabbits were compared, the incidence was highest in turkeys (3.38%), followed by ducks (2.20%), geese (1.09%), broiler chickens (0.08%), and rabbits (0.04%). The results indicate that fattening animals have a better liver condition than mature animals and that culled young have a worse liver condition than older fattening animals. Chronic lesions represented the dominant proportion of pathological findings. Parasitic lesions occurred, first and foremost, in animals grazed on meadows with likely parasitic invasion, i.e., in ewes (7.51%), lambs (3.51%), and heifers (1.31%), and in animals in which antiparasitic protection is limited in view of the protection of meat from antiparasitic residues, i.e., finishing pigs (3.68%). Parasitic damage to the liver was rarely detected in rabbits and poultry. The results obtained represent a body of knowledge for measures to improve the health and condition of the liver in food animals. Full article

The production of bioactive peptides from hemoglobin via peptic hydrolysis is a promising alternative to valorizing slaughterhouse blood proteins. Nevertheless, it has some limitations such as low yield, high cost of enzymes, and the use of chemical reagents. The latter is aggravated by the pH increase to inactivate the enzyme, which can affect the bioactivity of the peptides. Thus, this study aimed to evaluate the effect of pulsed electric fields (PEF) on the pepsin inactivation and biological activities (antimicrobial and antioxidant) of hemoglobin hydrolysates. Bovine (Hb-B) and porcine (Hb-P) hemoglobin were hydrolyzed with pepsin for 3 h and treated with PEFs to inactivate the enzyme. The degree of hydrolysis (DH) did not show significant changes after PEF inactivation, whereas peptide population analysis showed some changes in PEF-treated hydrolysates over time, suggesting residual pepsin activity. PEF treatments showed no significant positive or negative impact on antimicrobial and antioxidant activities. Additionally, the impact of pH (3, 7, and 10) on bioactivity was studied. Higher pH fostered stronger anti-yeast activity and DPPH-scavenging capacity, whereas pH 7 fostered antifungal activity. Thus, the use of hemoglobin from the meat industry combined with PEF treatments could fit the circular economy concept since bioactive peptides can be produced more eco-efficiently and recycled to reduce the spoilage of meat products. Nevertheless, further studies on PEF conditions must be carried out to achieve complete inactivation of pepsin and the potential enhancement of peptides’ bioactivity. Full article

Commercialization in the meat-processing industry has emerged as one of the major agrobusiness challenges due to the large volume of wastewater produced during slaughtering and cleaning of slaughtering facilities. Slaughterhouse wastewater (SWW) contains proteins, fats, high organic contents, microbes, and other emerging pollutants (pharmaceutical and veterinary residues). It is important to first characterize the wastewater so that adequate treatment techniques can be employed so that discharge of this wastewater does not negatively impact the environment. Conventional characterization bulk parameters of slaughterhouse wastewater include pH, color, turbidity, biochemical oxygen demand (BOD), chemical oxygen demand (COD), total organic carbon (TOC), total suspended solids (TSS), total nitrogen (TN), total phosphorus (TP), and coliform counts. Characterization studies conducted have revealed the effects of the pollutants on microbial activity of SWW through identification of toxicity of antibiotic-resistant strains of bacteria. Due to the high-strength characteristics and complex recalcitrant pollutants, treatment techniques through combined processes such as anaerobic digestion coupled with advanced oxidation process were found to be more effective than stand-alone methods. Hence, there is need to explore and evaluate innovative treatments and techniques to provide a comprehensive summary of processes that can reduce the toxicity of slaughterhouse wastewater to the environment. This work presents a review of recent studies on the characterization of SWW, innovative treatments and technologies, and critical assessment for future research. Full article

Cattle slaughtering produce large amounts of wastewater containing high concentrations of organic matter and nutrients and requires significant treatment before disposal or reutilization. However, the nutrients contained can be valued as a medium for microalgal biomass generation. In this work, hydrodynamic cavitation (HC) followed by membrane filtration or biological (microalgae cultivation) treatment in continuous mode were performed. From cattle slaughterhouse wastewater (CSW), by the effect of HC treatment with air injection in batch mode, more than 20% of the chemical oxygen demand (COD) was removed. In a continuous HC process, the COD content in output was 324 mg O₂/L, which is 68% lower than the supplied CSW. After that, 76% of residual COD was removed by filtration through a tubular alumina membrane (600 nm). Finally, 85% of residual COD after HC treatment in 24 h in a batch mode was removed by microalgae. On the other hand, the COD concentration in the output was around 59 mg O₂/L in continuous mode, which represents 85–93% COD removal. The process involving HC and microalgae growing looks promising since in addition to water treatment, the microalgae produced could be valued in a biorefinery concept. Full article

High raw material prices and rivalry from the food industry have hampered the adoption of renewable resource-based goods. It has necessitated the investigation of cost-cutting strategies such as locating low-cost raw material supplies and adopting cleaner manufacturing processes. Exploiting waste streams as substitute resources for the operations is one low-cost option. The present study evaluates the environmental burden of biopolymer (polyhydroxyalkanoate) production from slaughtering residues. The sustainability of the PHA production process will be assessed utilising the Emergy Accounting methodology. The effect of changing energy resources from business as usual (i.e., electricity mix from the grid and heat provision utilising natural gas) to different renewable energy resources is also evaluated. The emergy intensity for PHA production (seJ/g) shows a minor improvement ranging from 1.5% to 2% by changing only the electricity provision resources. This impact reaches up to 17% when electricity and heat provision resources are replaced with biomass resources. Similarly, the emergy intensity for PHA production using electricity EU27 mix, coal, hydropower, wind power, and biomass is about 5% to 7% lower than the emergy intensity of polyethylene high density (PE-HD). In comparison, its value is up to 21% lower for electricity and heat provision from biomass. Full article

Energy sustainability and environmental protection in general are at the heart of engineering and industry discussions. Countless efforts have been devoted to improving the energy efficiency of industrial processes and specifically to harnessing their waste energy sources. One such source is waste from agro-industrial processes, which is frequently characterized by increased temperatures and high polluting potential. There are multiple available choices for exploiting energy from such waste, but this paper proposes a new alternative technique that substantially improves the efficiency. Based on the technology of leveraging a hot liquid effluent for heating a process fluid, this system introduces a third liquid to be revalorized by drying that is placed in between the hot and cold liquids. By adding stirrers inside the heat exchanger, the thermal resistance of the third fluid is reduced to a negligible level. Thus, this system has almost the same advantages as the previous one, but with the added benefit that it allows drying of a third fluid. One of the specific applications of this proposed technology is using heat from waste effluents to obtain dried food products. In the present work, it was used to dry slaughterhouse blood to obtain so-called “blood meal”, a product with a high added value that is used as pet food or organic fertilizer, and also has many other industrial applications. As shown here, the new technique outperforms existing alternatives in terms of energy efficiency and economic profitability. Full article

Properly managed biopiles can be used for slaughterhouse-residual degradation and bacterial pathogen inactivation, which otherwise represent a major health risk in the environment. Biopiles were used to dispose of slaughterhouse-residuals and determine the occurrence and persistence patterns of indicators of pathogenic bacteria. The indicator bacteria included the family Enterobacteriaceae, total coliforms, Escherichia coli, nalidixic acid-resistant E. coli, and Streptococcus fecalis. The slaughterhouse-residual biopiles remained static for 164 d in 2006 and 141 d in 2007. In biopile effluent samples, exponentially decreasing populations of the indicator bacteria were observed. Indicator bacteria presence in biopile and soil samples suggested their retention and persistence in, but not migration from, the media. Though the family Enterobacteriaceae, total coliforms, and Escherichia coli shared behavioral correlations, they exhibited different fates in all media compared to S. fecalis, which was observed to persist and re-grow. The behavior of inoculated nalidixic acid-resistant E. coli suggested that inactivation was the primary process in the biopiles. However, the biopiles constituted continual sources of the indicator bacteria due to their persistence in isolated and protected locations, and changes in dominant species. While biopiling slaughterhouse-residuals was effective to inactivate >99% (log reductions) of indicator bacteria, tertiary methods and biopiling phases should be employed to ensure inactivation of pathogenic bacteria in animal waste biopiles. The fate of bacterial indicators in this system exhibited trends not-as-yet observed for animal waste biopiling activities, which generates numerous questions for further research. Full article