Decoding halal and jhatka slaughter: novel insights into welfare and protein biomarkers in slow-growing broiler chicken

BACKGROUND

The first evidence of blood biochemical and proteomic changes in slow-growing broiler chicken subjected to ritual slaughter like halal (HS) and jhatka (JS) without stunning and commercial slaughter with electrical stunning (ES) was decoded.

RESULTS

Significant stress indicators like cortisol and triiodothyronine were markedly elevated in JS birds, whereas increased (P < 0.05) levels of lactate dehydrogenase and creatine kinase were observed in JS and ES birds. Two-dimensional gel electrophoresis coupled to MALDI-TOF MS elucidated the overabundance of glyceraldehyde-3-phosphate dehydrogenase and l-lactate dehydrogenase that are positively correlated with stress in JS broilers. Bioinformatic analysis explored the multifaceted landscape of molecular functions.

CONCLUSION

The study has uncovered that ritual slaughter performed without stunning against commercial slaughter with ES practices elicit varying levels of stress as evident from blood biochemistry and novel protein markers. © 2024 Society of Chemical Industry.

Assessing meat quality and textural properties of broiler chickens: the impact of voltage and frequency in reversible electrical water-bath stunning

The implementation of the head-only electrical stunning procedure in poultry processing has been aimed at enhancing eating, ethical, and religious quality. However, inconsistencies in voltage and frequency standardization, along with variations in previous research outcomes, have led to numerous cases of both under-stunned and over-stunned birds. Thus, this study aimed to comprehensively evaluate the effects of varying voltages and frequencies during electrical water bath stunning on carcass quality, meat attributes, and textural properties in broiler chickens. A cohort of 240 healthy female broilers (Cobb 500, 42-days-old, 2 kg ± 0.1 kg) was meticulously selected from a commercial farm. The birds underwent exposure to different stunning voltages (2.5, 10.5, 30, and 40 V) and frequencies (50 and 300 Hz). Subsequent analyses were conducted on meat samples to assess physicochemical properties, carcass quality, and textural attributes. The findings revealed a higher incidence of petechial hemorrhage (P < 0.05) in birds stunned at 10.5 V compared to other voltage. Notably, no broken bones were recorded in birds subjected to high voltages (30 and 40 V). Low frequency (50 Hz) significantly increased the occurrence of petechial hemorrhage and simultaneously resulted in pectoralis major muscle with decreased redness (a*). Birds subjected to the 10.5 V stunning treatment exhibited a lower cooking loss percentage. Significant interactions between voltage and ageing (V × A) were observed. Birds stunned at 30 V and aged for 7 d displayed highest drip loss compared to a one-day ageing period across different voltage levels. This interaction also impacted pH values, with birds subjected to 10.5 V showing significantly lower (P < 0.05) pH at d 7 of ageing. The meat hardness was influenced by the V × A interaction, wherein birds stunned at 10.5 V exhibited lower hardness after one day of ageing compared to other voltage levels. Red wing tips, lightness (L*), adhesiveness, and resilience were also significantly impacted (P < 0.05) by the interaction between frequency and voltage. A notable 3-way interaction was observed for gumminess and chewiness (F × V × A), where the 2-way interaction between frequency and voltage (F × V) affected both parameters differently at various ageing periods. Additionally, there was a significant interaction (P < 0.05) between frequency and voltage influencing shear strength and yellowness.

Analysis of the suitable thawing endpoint of the frozen chicken breast using video recording analysis, shear force, and bioelectrical impedance measurement

This study focuses on analyzing the texture properties and bioelectrical impedance characteristics of frozen chicken breasts during low-temperature thawing, meanwhile, we also compared the differences in physiochemical properties. Frozen chicken breasts were thawed at 4 ± 2°C for 2, 4, 6, 8, and 10 h separately, then the physiochemical properties (color, pH, water-holding capacity, water distribution), the texture properties (easy-to-cut level), and the bioelectrical impedance were determined and analyzed. The easy-to-cut level of the samples was evaluated by the sensory panel and two indexes, one is Warner-Bratzler shear force measured by texture analysis machine, and the other is cutting speed value calculated by the consumer-oriented cutting behavior analysis using frame-by-frame video recording analysis method. These two methods were used to characterize the easy-to-cut level of the frozen samples during thawing from the industrial processing and home cooking standpoint. Strong correlations were observed between the easy-to-cut level and the bioelectrical impedance of the frozen chicken breasts during thawing. The impedance magnitude at 100 kHz showed a high correlation coefficient (R2  = .9417) with Warner-Bratzler shear force, and the impedance magnitude at 50 Hz showed a high correlation coefficient (R2  = .8658) with cutting speed. Our results indicated the acceptability of using bioelectrical impedance to evaluate the easy-to-cut thawing endpoint for both industry processing and home cooking.

Traditional halal meat production without stunning versus commercial slaughter with electrical stunning of slow-growing broiler chicken: impact on meat quality and proteome changes

Impact of traditional halal meat production without stunning (NST) and commercial slaughter with electrical stunning (ST) of 100 slow-growing broiler chicken on blood plasma and different biochemical, enzymatic, hormonal, meat quality, and proteomic changes was evaluated. The results revealed lower (P < 0.05) postmortem pH values and higher redness (a*) scores for ST samples relative to NST group. Myofibrillar fragmentation index and bleeding efficiency (%) were lower (P < 0.05) in ST compared to NST samples. The ST group had higher (P < 0.05) creatinine, total protein, alanine aminotransferase (ALT), and triiodothyronine (T3) than NST group, however, no difference (P > 0.05) in blood glucose, lactate dehydrogenase (LDH), creatine kinase (CK), thyroxine (T4), cortisol, and aspartate aminotransferase (AST) was observed relative to NST samples. The 2-dimensional gel electrophoresis (2-DE) coupled to MALDI-TOF MS of meat samples has identified 14 differentially abundant proteins between 2 groups. Proteins demonstrating positive correlation with stress namely adenylate kinase isoenzyme-1, Rho guanine nucleotide exchange factor (NST), and apolipoprotein A-I (ST) were overabundant. From the current study, it is concluded that electrical stunning of broilers prior to slaughter or traditional halal slaughter without stunning does not adversely affect the meat quality.

Determining the Possibilities of Reducing Visible Quality Defects in Commercial Elements of Turkey Carcasses Using an Alternative Stunning Device

The development of the quality and commercial value of poultry meat is related to the formation of visible quality defects (hemorrhages) in muscles during the first stage of production (stunning). The production of meat with an unusual appearance for the consumers affects their purchasing decisions and, consequently, the company's economics. The aim of this research was to determine the possibility of reducing visible quality defects (large and small hemorrhages) in commercial turkey carcass elements (fillet, loin, wing) using an alternative device (AD) for the electrical stunning of animals in comparison to the quality effects obtained using the conventional device (CD) in plant X. The factors differentiating the experiment were the electrical current frequency (AD: 125, 400, 800, and 1600 Hz; CD: 50 Hz) and process time (9 and 18 s). The increase in electrical current frequency used in the alternative device stunner (own construction) resulted in changing the percentage share of defective turkey meat production. The greatest reduction of minor and severe meat defects and improvement of its quality were obtained for the alternative device at f = 800 Hz and t = 9 s-considered optimal for specific industrial conditions. Extending the time of stunning turkeys to 18 s had a positive effect on visible quality defects in the evaluated commercial elements of the carcass; however, its application in practice will depend on the efficiency of the slaughter line of the plant. A comparative analysis of the results of the impact of the frequency of electric current in the alternative device and plant X on the improvement of meat quality showed a justified need to commercialize the research results and replace the device currently used in the plant with an alternative one.

Nano-Sized Selenium Maintains Performance and Improves Health Status and Antioxidant Potential While Not Compromising Ultrastructure of Breast Muscle and Liver in Chickens

The poultry industry is looking for the most effective sources of selenium (Se) for commercial use. Over the past five years, nano-Se has attracted a great deal of attention in terms of its production, characterisation and possible application in poultry production. The objective of this study was to evaluate the effects of dietary levels of inorganic and organic Se, selenised yeast and nano forms of selenium on breast meat quality, liver and blood markers of antioxidants, the ultrastructure of tissue and the health status of chickens. A total of 300 one-day-old chicks Ross 308 were divided into 4 experimental groups, in 5 replications, with 15 birds per replication. Birds were fed the following treatments: a standard commercial diet containing inorganic Se in the form of inorganic Se at the level of 0.3 mg/kg diet and an experimental diet with an increased level of Se (0.5 mg/kg diet). The use of other forms of Se (nano-Se) versus sodium selenate significantly influences (p ≤ 0.05) a higher collagen content and does not impair physico-chemical properties in the breast muscle or the growth performance of the chickens. In addition, the use of other forms of selenium at an increased dose versus sodium selenate affected (p ≤ 0.01) the elongation of sarcomeres in the pectoral muscle while reducing (p ≤ 0.01) mitochondrial damage in hepatocytes and improving (p ≤ 0.05) oxidative indices. The use of nano-Se at a dose of 0.5 mg/kg feed has high bioavailability and low toxicity without negatively affecting the growth performance and while improving breast muscle quality parameters and the health status of the chickens.

ELECTRONARCOSIS PROTOCOLS IN BROILER CHICKENS FOR THE HALAL MARKET

This study considered the parameters of the Halal market to evaluate different protocols for broiler electronarcosis regarding time to return of consciousness, bleeding efficiency, and carcass and meat quality. Was performed an experiment in a broiler slaughterhouse. One hundred and eighty-four 43 days old male broilers of the Cobb® strain were used. The experimental design used was completely randomized with 46 broilers for each protocol. The protocols used: 80 v and 600 Hz; 50 v and 1,000 Hz; 60 v and 1,000 Hz; 70 v and 1,000 Hz. Time to return of consciousness, bleeding efficiency, bruising, presence of broken bones in pectoral muscle, and meat quality were evaluated. Birds subjected to stunning by the 50 v / 1,000 Hz protocol showed the shortest time to return of consciousness after electronarcosis, and high incidence of breast hemorrhage. Birds subjected to the 60 v / 1,000 Hz protocol had a higher percentage of broken bones in the Pectoralis minor. The 50 v and 1,000 Hz electronarcosis protocol fits better to the halal market due to the shorter time to return of consciousness and improved bleeding efficiency. This study suggests new proposals for stunning protocols to serve the halal market.

Nano selenium improves humoral immunity, growth performance and breast-muscle selenium concentration of broiler chickens

Context Selenium (Se) is an essential trace element and plays pivotal roles in poultry nutrition. Aims The present study was designed to compare the impact of dietary supplementation of different sources of Se on growth performance, Se concentration of breast meat, and immune response of broiler chickens. Methods In total, 300 1-day-old as hatched broilers were randomly allocated to six dietary treatments, with five replicates of 10 birds per each. The experimental diets were as follows: (1) corn–soybean meal-based diet supplemented with 0.30 mg/kg of sodium selenite, (2) basal diet supplemented with 0.30 mg/kg of Se-enriched yeast, and (3–6) basal diet supplemented with 0.15, 0.30, 0.90 and 1.50 mg/kg of nano-Se respectively. Humoral immunity was assessed by antibody titer against a 5% sheep red blood-cell suspension and cellular immunity was measured by administration of phytohaemagglutinin-p at 38 days. Key results Results indicated that during the periods from 1 to 10 days, from 11 to 24 days, from 25 to 42 days and from 1 to 42 days, average daily gain, average daily feed intake, and feed conversion ratio did not differ among the treatments (P &gt; 0.05). Assessment of orthogonal contrasts at the whole phase of feeding showed that the average daily gain in the broilers fed organic Se was significantly (P &lt; 0.05) higher than that in those fed inorganic Se, as well as nano-Se in comparison to organic Se; such effects were not observed in earlier feeding stages. Se supplementation significantly increased the Se concentration of breast muscle (P &lt; 0.0001). The birds that received 1.50 mg/kg of diet nano-Se showed higher (P &lt; 0.05) total immunoglobulin and IgG titers in primary and secondary immune responses against sheep erythrocytes respectively. Toe web swelling after 24 h and 48 h of receiving phytohaemagglutinin-p was not affected by Se supplementation (P &gt; 0.05). Conclusions In conclusion, the addition of nano-Se gave better results than did inorganic (sodium selenite) and organic (yeast selenium) forms of Se in performance traits, breast meat Se concentration and antibody response of broilers. Implications Novel elemental nanometer particulates, including nano-Se, exhibit new characteristics and a different mode of actions in comparison with organic and inorganic forms of Se sources in poultry diets. Inclusion of the nano form of Se in broiler diets and study of productive performance, immunity responses and meat quality leads to improve balanced broiler diets formulation in view of Se.

Broiler stunned state detection based on an improved fast region-based convolutional neural network algorithm

An improved fast region-based convolutional neural network (RCNN) algorithm is proposed to improve the accuracy and efficiency of recognizing broilers in a stunned state. The algorithm recognizes 3 stunned state conditions: insufficiently stunned, moderately stunned, and excessively stunned. Image samples of stunned broilers were collected from a slaughter line using an image acquisition platform. According to the format of PASCAL VOC (pattern analysis, statistical modeling, and computational learning visual object classes) dataset, a dataset for each broiler stunned state condition was obtained using an annotation tool to mark the chicken head and wing area in the original image. A rotation and flip data augmentation method was used to enhance the effectiveness of the datasets. Based on the principle of a residual network, a multi-layer residual module (MRM) was constructed to facilitate more detailed feature extraction. A model was then developed (entitled here Faster-RCNN+MRMnet) and used to detect broiler stunned state conditions. When applied to a reinforcing dataset containing 27,828 images of chickens in a stunned state, the identification accuracy of the model was 98.06%. This was significantly higher than both the established back propagation neural network model (90.11%) and another Faster-RCNN model (96.86%). The proposed algorithm can complete the inspection of the stunned state of more than 40,000 broilers per hour. The approach can be used for online inspection applications to increase efficiency, reduce labor and cost, and yield significant benefits for poultry processing plants.

Effects of preslaughter shackling on postmortem glycolysis, meat quality, changes of water distribution, and protein structures of broiler breast meat

The objective of this study was to investigate the effects of preslaughter shackling on stress, postmortem glycolysis, meat quality, water distribution, and protein structures of pectoralis majors. Before slaughter, Arbor Acres broilers (n = 105, 42 days old, 2.0 to 2.5 kg) were randomly categorized into 3 treatment groups: (I) control group without shackling (NS); (II) 2.5 min shackling (SS); (III) 4.5 min shackling (LS). Each treatment group consisted of 5 replicates with 7 broilers each. Results indicated that preslaughter shackling increased (P < 0.05) plasma corticosterone and adrenocorticotropic hormone concentrations in comparison with the control group. Antemortem shackling increased (P < 0.05) activity of glycogen phosphorylase and phosphofructokinase-1 (PFK-1) accompanying with rapid glycolysis and pH decline at early postmortem. LS treatment led to myosin denaturation, decreased (P < 0.05) α-helix content, and increased (P < 0.05) β-sheet structures proportion in the myofibrillar proteins. Furthermore, meat from LS treatment had higher (P < 0.05) lightness, redness, and poorer water-holding capacity. These results indicated that the longer shackling duration (4.5 min) increased stress and the rate of glycolysis, causing myosin denaturation and changes of the secondary structure in the myofibrillar proteins, which aggravated the deterioration of meat quality.

Effects of Two CO2 Stunning Methods on the Efficacy of Stunning and Blood Stress Indicators of Turkeys under Commercial Processing Conditions

The effect of CO₂ gas-stunning methods (G1: 30% CO2 15 sec, 55% CO₂ 40 sec, 70% CO₂ 45 sec; G2: 30% CO₂ 15 sec, 80% CO₂ 85 sec) on the efficacy of stunning, blood stress indicators and meat quality of turkeys were assessed. A total of 375 turkeys (125 heavy males, 125 light males, and 125 light females) were used. After stunning, clinical parameters (posture-loss, wing-flapping, breathing, response to toe-pinching, eye movements, and palpebral, corneal and pupillary reflexes) and glucose, lactate and cortisol levels were assessed. The G2 method showed a higher percentage of correctly stunned birds (81.3 vs. 70.7%) and lower cortisol levels (0.44 vs. 1.22 g/dL). The weight and sex had a significant influence on the behavioral and physiological responses after stunning. The G2 method was found to be acceptable for animal welfare during stunning, based on both the percentage of animals correctly stunned and dead (92% to 100%) and the blood cortisol level after stunning.

Effect of EU electrical stunning conditions on breast meat quality of broiler chickens

Electrical stunning is still the main stunning method used worldwide in commercial poultry plants. The stunning procedures in water bath stunners affect both bird welfare and meat quality attributes. The European Union (EU) Council Regulation 1099/2009 on the protection of the animal at the time of killing established the minimum current flow through an individual bird at a specified frequency to assure an effective stun that must last until the bird's death. The aim of this study was to compare the effect of the application of different stunning current flows on the prevalence of hemorrhages (classified as 1 = no lesion, 2 = moderate, and 3 = severe lesion) and some quality traits (pHu, color, drip and cooking losses, and shear force) of chicken breast meat. A total of 12 flocks of broiler chickens, each equally divided into light, medium, and heavy sizes, was submitted either to the stunning condition usually adopted before the entry into force of the current EU regulation (90 mA/bird, 400 Hz) (OLD) or to that enforced by it (150 mA/bird, 400 Hz) (NEW). Overall, the prevalence of severe hemorrhages dramatically increased in the NEW group in comparison with the OLD one (55 vs. 27%; P < 0.001) and particularly in heavy-sized birds (72 vs. 25%; P < 0.001). In general, meat quality attributes were not affected by the stunning conditions with the exception of drip loss that resulted lower in NEW than OLD birds (1.01 vs. 1.27; P < 0.001). In conclusion, the adoption of a higher current flow, as suggested by the EU regulation to protect animals at the time of killing, increases the prevalence of breast hemorrhages while maintaining meat quality traits with a possible beneficial effect on water holding capacity of fresh meat.

The effects of electrical stunning voltage on meat quality, plasma parameters, and protein solubility of broiler breast meat

This study was designed to compare the effects of different stunning voltages of pulsed direct current on meat quality of broilers. For this purpose, plasma parameters, blood loss, carcass damage, and meat water holding capacity, color, shear force, pH, and protein solubility were analyzed. A total of 400 broilers were divided into 5 treatment groups and stunned with 5, 15, 25, 35, and 45 V at 750 Hz and 10 s, respectively. Blood samples were collected immediately after cutting the neck. Pectoralis major muscles were removed from the carcass after chilling and placed on ice. Breast muscle pH and meat color were determined at both 2 and 24 h postmortem. Dripping loss, cooking loss, pressing loss, and cooked breast meat shear values were determined after 24 h postmortem. The 5 V treatment significantly increased (P < 0.05) blood plasma corticosterone and lactate concentration compared with the other groups. The carcass damage of wings, Pectoralis major, and Pectoralis minor was significant in the 5, 35, and 45 V groups. The pH of 2 h postmortem in the 5 and 45 V groups was significantly lower (P < 0.05) than in the 15 and 25 V groups. In the 5 and 45 V groups, the protein solubility and shear force value were significantly lower (P < 0.05) and dripping loss was significantly higher (P < 0.05) than the other groups.

Preliminary Study on Physicochemical and Biochemical Stress Markers at Poultry Slaughterhouse

Pre-slaughter stress can result in variations in the glycogen storage and metabolic changes of muscle, responsible for quality poultry meat. Aim of this study was to investigate, as pre-slaughter stress markers and quality meat, physicochemical (pH), biochemical (muscle glycogen content), and chemical (super oxides free radicals) parameters. The carcass quality, as incidence of individual carcass defects, was also evaluated. Twenty broilers were processed with two different electrical stunning: high (250 Hz; 640 mA; 60V) (Lot C or control) and low (150 Hz; 360 mA; 60 V) (Lot A) frequency and intensity, using sinusoidal alternating current. As preliminary results, the use of low frequency and intensity induced faster pH decline post mortem and adequate acidification of pH at 3 hours (6.49 Lot C; 6.37 Lot A), better muscle glycogen reserve (0.770 μL/50 mL Lot C; 1.497 μL/50mL Lot A), and lightly more rapid muscle oxidation (IDF: 0.109 Lot C; 0.122 Lot A), (FOX: 0.131 MeqO₂/kg Lot C; 0.140 MeqO₂/kg Lot A). The incidence of individual carcass defects sufficient to cause downgrading or rejection, both in Lot C and Lot A, was generally low. In a multidisciplinary approach, to assess animal welfare and quality poultry meat, additional and feasible parameters should be implemented. Monitoring of pH, muscle glycogen reserve and superoxide free radical production measurements might be markers easier to use, routinely, in practice at abattoir. Further studies are needed to evaluate the usefulness of these parameters.

Study on the effects of electrical stunning parameters for broilers on biochemical and histological markers of stress and meat quality

This study was designed to investigate physicochemical (pH, peroxides) and histological parameters (glycogen reserve, muscle damages), as pre-slaughter stress markers and quality meat evaluators. Ross commercial broilers was processed, either without stunning (NS Lot), or by combining two current levels of 200 mA, 67 V (HV Lot), and 200 mA, 53 V (MV Lot); with two frequencies of 1000 Hz and 800 Hz, using sinusoidal alternating current. The use of high frequency (800 and 1000 Hz) induced the fastest pH decline, already at 3 h postmortem, in Pectoralis major and Quadriceps femoris of MV and HV Lot carcasses (P < 0.05). Moreover HV carcasses showed a lesser production of superoxide free radicals than the NS Lot and MV Lot carcasses (P < 0.05). Changes in the glycogen reserve and the histological muscle damages did not show significant differences in the analysed Lots. The incidence of individual carcass defects, sufficient to cause downgrading or rejection was generally low in each Lot. To assess animal welfare and quality poultry meat the pH monitoring and measurement of superoxide radical production, as additional and feasible parameters, might be markers easier to use in practice at abattoir.

Effect of fast pH decline during the early postmortem period on calpain activity and cytoskeletal protein degradation of broiler M. pectoralis major

The objective of this study was to determine the effects of fast pH decline during the early postmortem period on calpain activity and the degradation of cytoskeletal proteins in broilers. Eighty broilers were randomly categorized into two groups: physical restraint (PR) and free struggle (FS). M. pectoralis major (PM) was used for determination of calpain activity, shear value, ultrastructure of myofibrils, and the degradation of desmin, titin, nebulin, and troponin-T. The pH (6.05) of FS group is significantly low than PR group (6.38) at 0.3 h postmortem. Fast pH decline during the early postmortem period led to a decrease of μ/m-calpain activities at 0.3 and 3 h postmortem (P < 0.05), but did not affect the ultimate μ/m-calpain activity. An initial fast decrease in pH increased the degradation of desmin, titin, nebulin, and increased the 30 kDa degradation fragments of troponin-T. Therefore, the fast pH decline during the early postmortem period decreased the μ/m-calpain activity and increased the degradation of cytoskeletal proteins in broiler muscle. It is possible that the fast pH decline experienced an earlier activation of calpains that resulted in earlier protein degradation and ultimately lower shear force.