Head-only electrical stunning of poultry using a waterbath: a feasibility study

Biomarker discovery and authentication of cold-slaughtered chicken through classical analytical procedures and mass spectrometry based proteomic approaches

1. This study evaluated the suitability of routine analytical procedures and used mass spectrometry-based proteomic approaches to distinguish meat from dead chicken/ cold-slaughtered birds (CS), electrically stunned and slaughtered birds, as per standard protocols (ES), and birds slaughtered according to halal guidelines (HS).2. Meat from CS birds had lower (P < 0.05) pH, water-holding capacity and higher (P < 0.05) lipid oxidation, haem iron content, residual blood and total viable counts relative to ES and HS meat indicating poor quality.3. The results demonstrated the presence of unique protein bands on SDS-PAGE only in CS meat that can be used for routine screening.4. Protein analysis using MALDI-TOF mass spectrometry identified haemoglobin subunit alpha-A and alpha-D; Adenylate kinase isoenzyme 1 as reliable and stable marker proteins for authentication of dead chicken meat under raw and cooked conditions and halal slaughtered chicken, respectively.5. The methods used may be employed by the food safety and regulatory agencies for regular screening of meat quality and to authenticate CS or HS chicken.

Are spiritual, ethical, and eating qualities of poultry meat influenced by current and frequency during electrical water bath stunning?

With the continuous rise of Muslim and Jewish populations and their increasing preference for ritually slaughtered poultry meat, the industry is forced to redefine its existing product-centric quality standard toward a new consumer-centric dimension of quality. The new dimension is mainly attributed to ensuring animal welfare and ethical treatment (ethical quality), spiritual quality (such as halal status, cleanliness), and eating quality standards set by religion. To meet consumer quality requirements while maintaining high production performance, the industry has incorporated newer technologies that are compatible with religious regulations such as stunning methods like electrical water bath stunning. However, the introduction of new techniques such as electrical water bath stunning has been met with mixed reactions. Some religious scholars have banned the use of any stunning methods in religious slaughter, as halal status is believed to be compromised in cases where birds have been stunned to death before slaughter. Nevertheless, some studies have shown the positive side of the electrical water bath stunning procedure in terms of preserving eating, ethical, and spiritual quality. Therefore, the present study aims to critically analyze the application of various aspects of electrical water bath stunning such as current intensity and frequency on various quality attributes, namely, ethical, spiritual, and eating quality of poultry meat.

Shaping Poultry Meat Quality Attributes in the Context of Consumer Expectations and Preferences-A Case Study of Poland

The optimisation of poultry meat quality attributes at the industrial level requires getting to know the changing customer needs and expectations to justify further measures taken in the future to improve the production process. This article was aimed at the following: (1) to identify and assess consumer expectations and behaviour in relation to the quality criteria for poultry meat offered on the market in Poland, and (2) to identify the significance of the sensory characteristics of poultry meat, mainly variegated colours on its surface, as a criterion for creating the expected quality in a shop. The study results showed that the attributes which significantly lower the quality and commercial value of meat are the defects noticeable on the fillet surface, namely discolouration and hematomas, which are mainly caused during the poultry stunning. The absence of noticeable bruising or hematomas and a uniform colour on the fillet surface are the main attributes of high-quality poultry meat retail cuts, which are expected by consumers. A recommendation for poultry meat producers is that bruising and hematomas need to be eliminated and that the offer should be adjusted to Polish consumers' expectations about the quality attributes of the meat offered on the market. The elimination of these meat defects will be possible, e.g., through the introduction of innovative technical solutions into the poultry stunning process, which will improve meat quality at its production stage.

Diversity, not uniformity: slaughter and electrical waterbath stunning procedures in Belgian slaughterhouses

Data on slaughter and stunning protocols in Belgian poultry abattoirs were collected, and subsequently the survival rate after electrical waterbath stunning in 1,400 animals across 7 selected slaughterhouses was determined. The majority of the abattoirs applied electrical waterbath stunning (72%), whereas the other methods were gas stunning (13%), head-only stunning (6%), and dry stunning (3%). In 6% of the slaughterhouses, the birds were killed without previous stunning, according to religious rites (i.e., ritual or religious slaughter). Although religious slaughter occurred in a substantial number of abattoirs, the customers of the majority of them allowed stunning, provided the animals were not killed by the stunning procedure. Substantial variation both in electrical waterbath devices and technical settings (electrical current type, wave type, voltage, frequency) combinations was observed. These settings did not only differ between slaughterhouses, but also between subsequent visits to the same slaughterhouse. Despite this variation, all systems comprised a constant voltage, multiple bird stunner. The minimum average electrical current that every chicken should receive at a certain frequency, as stated by the European Regulation No 1099/2009, was not achieved for each animal monitored due to the bird's characteristics and the different applied stunning settings, with the exception of all ISA laying hens and broiler breeders in one particular slaughterhouse. The survival rate ranged from 96.0 to 100%, 97.0 to 100%, 68.0%, 72.0 to 85.1%, and 5.6 to 52.4% in 5-wk-old broilers, 6-wk-old broilers, LSL laying hens, ISA laying hens, and broiler breeders, respectively. Monitoring of unconsciousness after passing through the waterbath was not always performed and when it was, there was no uniformity in the applied criteria. It was concluded that a large variation in slaughter and stunning practices exists among slaughterhouses in Belgium. Further research should explore the effect of the different settings on inducing a successful stun and on carcass quality, and assess if the observed variation also exists in other EU member states.

Electroencephalographic assessment of concussive non-penetrative captive bolt stunning of turkeys

1. The aim of this study was to evaluate the electroencephalographic (EEG) and behavioural responses of turkeys stunned with three different concussive non-penetrative captive-bolt guns prior to slaughter. 2. A total of 31 slaughter weight ex-breeding female turkeys (29 weeks of age; mean body weight 13.32 ± SD 0.65 kg) were stunned with the Cash Poultry Killer (CPK) (n = 10), Turkey Euthanasia Device (TED) (n = 10) and Zephyr EXL (n = 11). 3. Mean peak kinetic energy was highest for the CPK compared to the TED and Zephyr EXL (75.9 ± 4.5, 28.4 ± 0.4 and 24.4 ± 0.7 J, respectively). 4. A total of 29 (94%) of the turkeys were rendered unconscious following captive bolt stunning, with total power of the EEG (Ptot) significantly reduced from baseline values (reductions of 67% CPK, 84% TED and 76% Zephyr EXL, p < 0.01) and waveforms becoming isoelectric after periods of transitional EEG. However, two birds shot with the CPK and Zephyr EXL had periods of behavioural/reflexes (rhythmic respiration, nictitating membrane reflex, neck tension) and EEG activity (43-47 and 36-60 + s after the shot, respectively) indicating incomplete concussion and return of consciousness. In one bird, the shot was incorrectly positioned (Zephyr EXL), while the other appeared to be related to a defective cartridge (CPK). 5. In conclusion, all three captive bolt gun models were effective in producing unconsciousness in turkeys, provided they were positioned correctly and power loads performed according to their specifications.

Assessment of the effectiveness of head only and back-of-the-head electrical stunning of chickens

The study assesses the effectiveness of reversible head-only and back-of-the-head electrical stunning of chickens using 130–950 mA per bird at 50 Hz AC.

Three trials were conducted to compare both stunning systems: (a) behavioural assessment of return of consciousness, (b) insensibility to thermal pain, and (c) assessment of return of brain activity with visually evoked potentials (VEPs).

Assessment of behaviour suggested that the period of unconsciousness following head-only electrical stunning was shorter in hens compared to broilers.

Stunning across the back-of-the-head delayed the time to return of brainstem function compared to stunning with standard head-only electrodes. Additionally, back-of-the-head stunning produced a more prolonged period of electroanalgesia compared to head-only.

Based on examination of return of brain function with VEPs in hens, back-of-the-head stunning produced a shorter-lasting stun than standard head-only. However, even for standard head-only, the stun was notably shorter than previously reported. In some birds, brain function had returned within 9 s after the end of stunning.

The results suggest that some birds may recover consciousness prior to or during the neck cut. Based on these findings, back-of-the-head stunning and standard head-only stunning of hens should not be recommended without further development.

Cone restraining and head-only electrical stunning in broilers: effects on physiological responses and meat quality

Two experiments were conducted to evaluate a new electrical stunning system for broilers. The objective of the first experiment was to evaluate the behavioral, neural, and physiological responses of 27 broilers after head-only electrical stunning while their bodies were restrained in cone-shaped holders. In the second experiment, quality of meat from 30 broilers after head-only electrical stunning in a cone-shaped restrainer was compared with that from 30 broilers stunned in a conventional water bath. Broilers were restrained in the cone with their heads positioned to facilitate a correct stun, followed by a neck cut by hand. After stunning, each broiler displayed a tonic phase, followed by minimal brain activity during bleeding. On average, heart rate was 258 ± 51 beats/min before stunning. The heart was observed to malfunction after cutting. According to the correlation dimension analyses, the score remained low. Within a confidence limit of 95%, taking into account the number of birds with a reliable electroencephalogram (n = 27), the chance of an effective stun and exsanguination with all broilers lies between 0.90 and 1.00 using a sinusoidal AC current of 264 ± 29 mA (∼130 V). After a brief learning period, operators were able to easily position the broilers in the cone in a commercial setting. The pH after chilling was 0.5 units lower (P < 0.05) in the head-only stunned group compared with the group stunned in a conventional water bath. After head-only stunning, 60% of breast fillets showed no blood splashes and 3% showed severe blood splashes compared with 20 and 27% after conventional water bath stunning. No differences in temperature and color were observed between the 2 groups. It is concluded that broilers could be restrained in a cone, followed by correct head-only stunning, neck-cutting, and unconscious shackling afterward under laboratory and commercial slaughterhouse conditions. When this procedure was used, meat quality was better compared with broilers stunned in the conventional water bath.