Effect of electrical stunning frequency and current waveform in poultry welfare and meat quality

Abstract

This study aimed to evaluate the effects of different stunning frequencies and electrical current waveforms on chicken welfare and meat quality. Two-hundred-thirty-two Cobb broilers, 48 d of age and 2.76 ± 0.47 live-weight, were randomly assigned into 4 stunning treatments - 2 frequencies (300 Hz and 650 Hz) and 2 current waveforms (direct current [DC] and alternating current [AC]). Broilers were electrically stunned in a water bath in a commercial slaughterhouse (70 V, 100 mA). The electronarcosis and stunning efficiency were confirmed by assessment of visual parameters (absence of rhythmic breathing, ocular reflex, and coordinated wing flapping) and blood parameters (lactate, glucose, creatine kinase, sodium, and potassium), which were measured after bleeding. The incidence of traumas and injuries was assessed after plucking. Meat quality analysis was performed in Pectoralis major (PM), with determinations of pH, breast yield (PMY), water holding capacity (WHC), water absorption capacity (WAC), thawing loss (DL), cooking loss (CL), shear force (SF), and instrumental color (a*, b*, L*, C*, and h). The interaction between waveform and frequency was significant (P < 0.05) only for lactate, sodium, and lightness (L*). Lactate and sodium levels decreased at 300 Hz-DC. Meat lightness increased at 300 Hz-DC. The individual effect of frequency was significant for glucose, creatine kinase, potassium, WHC, PMY, b*, C*, and h. Regarding waveform, AC decreased plasma glucose and DC decreased creatine kinase and WAC. In general, stunning frequency exerts greater influence than waveform on the welfare and meat quality parameters of broilers. The use of frequency at 650 Hz proved to render animals efficiently unconscious and to promote greater meat quality.

The Influence of Broilers’ Body Weight on the Efficiency of Electrical Stunning and Meat Quality under Field Conditions

“…Takahashi [ 42 ] reported higher WHC in breast meat of broilers stunned with high frequencies. Our results, in line with findings of Siqueira [ 33 ] and Karunanayaka [ 31 ], confirm that PMD breast samples have lower WHC than normal ones.…”

“…Among signs of stunning ineffectiveness, the presence of corneal reflex was the most frequently detected in this study. By using lower frequencies, other authors reported higher percentages of animals with a positive corneal reflex [ 22 , 33 ]. The eye reflex was recognized by several authors as the physical reflex most reliable in evaluating unconsciousness [ 10 , 11 ], although its absence does not necessarily indicate the absence of pain.…”

Transformation of quality aspects throughout the chicken meat supply chain

“…More specifically, this relates to better body composition, higher breast meat yield and lower abdominal fat. Animal (poultry) welfare concerns have gained importance by many actors in the meat chain such as consumers, producers, and retailers of animal-based food products, mainly in the European Union (Lambooij et al, 2014;Siqueira et al, 2017). Speaking about the farmers' role and a potential lack of awareness of the attributes that are mostly demanded by consumers, this issue can lead to missing the focus of their efforts, which, in turn, means that quality is not deployed to generate downstream value in the meat chain (Simons et al, 2003).…”

Temperature, but not excess of glycogen, regulates “in vitro” AMPK activity in muscle samples of steer carcasses

“…Lactate concentration was determined by using the lactate oxidase method (Lactate Liquiform, Labtest Diagnóstica S.A.), according to Siqueira et al, [26]. Briefly, 100 mg of muscle samples frozen in liquid nitrogen were homogenized in 20 mM citrate-50 mM phosphate buffer, EDTA 2.5mg/ml pH 6.8.…”