A perspective on the electrical stunning of animals: are there lessons to be learned from human electro-convulsive therapy (ECT)?

Animals have been slaughtered by humans since time immemorial. Over the last few generations attention has been focused on minimizing the animal's pain and suffering during slaughter. Based on the assumption that loss of consciousness due to electrical stunning combined with exsanguination is a humane technique of slaughter, this procedure has become one of the most widely employed methods in commercial meat production, being used in almost all species. In recent years, some shortcomings with this method of minimizing the animal's suffering have been noted. Electrical stunning is probably more akin to human electro-convulsive therapy (ECT) than to epilepsy, and some of the negative aspects of unmodified ECT may be present during electrical stunning, further questioning the use of electrical stunning in the slaughter of animals.     

Strategies to promote farm animal welfare in Latin America and their effects on carcass and meat quality traits

Several initiatives, including research and development, increasing stakeholders' awareness and application of legislation and recommendation, have been carried out in Latin America to promote animal welfare and meat quality. Most activities focused on the impact of pre-slaughter conditions (facilities, equipment and handling procedures) on animal welfare and meat quality. The results are encouraging; data from Brazil, Chile and Uruguay showed that the application of the improved pre-slaughter handling practices reduced aggressive handling and the incidence of bruised carcasses at slaughter in cattle and pigs. These outcomes stimulated some to apply animal welfare concepts in livestock handling within the meat production chain as shown by the increasing demand for personnel training on the best. To attend this demand is important to expand local studies on farm animal welfare and to set up (or maintain) an efficient system for knowledge transfer to all stakeholders in the Latin America meat production chains. However, it is clear that to promote the long-term progress in this field is important to deliver practical solutions, assuring that they match the technical and financial conditions of those who are the target of training programs.     

Content of polyamines in by-products of slaughter pigs

The concentrations of putrescine, spermidine and spermine were assessed in various by-products of slaughtered pigs (Pietrain × Landrace breed, with a carcass weight of 90–105 kg). A total of 210 samples of muscular tissues (heart, tongue, diaphragm and esophagus) and inner organs (liver, kidney, spleen, lung, salivary gland and pancreas) were tested. Polyamine concentrations in non-skeletal muscles of pigs were similar to the polyamine concentrations reported for skeletal muscle. Inner organs, however, were characterized by approximately three times higher polyamine concentrations. These data can be useful to assess the alimentary polyamine exposure of humans or pets. The median spermidine: spermine ratio (weight base) was >0.1, and, thus, higher than that observed in skeletal muscles.     

Efficiency and proximate composition of meat in male and female nutria (Myocastor coypus) in an extensive feeding system

The major carcass traits and chemical composition of muscle samples were evaluated in three age groups (6, 9 and 13 months) of nutria (Myocastor coypus). A total of 18 males and 18 females were weighed and slaughtered on the farm, then pelted, eviscerated and frozen. Intramuscular meat samples were taken from the loin and thigh muscles. The carcass yield (CY) was calculated and the total protein (TP), crude fat (CF) and crude ash (CA) content were determined in the laboratory on a dry matter basis. The average CY, without the head, was 53.3%, and was highest for 9-month-old animals (53.6%). In females, the average CY was slightly higher (52.9%) than for males (51.8%). The mean TP content in meat was approximately 21.7% in the loin and 21.1% in thigh muscles. The intramuscular CF content was higher in thigh samples. Older animals had a higher CF content and the CF content was lower in males than in females.     

Effect of live weight and sex on physico-chemical and sensorial characteristics of Merino lamb meat

Forty-eight lamb carcasses were divided into four groups (n = 12) according to slaughter weight (24 and 29 kg) and sex (male and female). Colour, pH, moisture, and intramuscular fat were not affected (p > 0.05) by slaughter weight or sex. With respect to fatty acid composition, slaughter weight had significant effects on C12:0 (p < 0.01), C14:0, C16:0, and C18:1 n-9 (p < 0.05) in Longissimus lumborum (LL) muscle. The percentage of C12:0 and C14:0 decreased as slaughter weight increased, while C16:0 increased. In Semimembranosus (SM) m., only C18:3 n-3 and C20:2 n-6 were affected (p < 0.001) by slaughter weight. Total PUFA in LL m. was greater (p < 0.01) in females than in males. Although in general, sensorial quality was not significantly affected by slaughter weight or sex, meat from lighter lambs (24 kg) had greater general acceptability than meat from heavier lambs (29 kg).     

Effects of slaughter weight on carcass composition and meat quality in pigs of two different growth rates

Three hundred and forty (340) Duroc×(Landrace×Yorkshire) crossbred piglets were allotted to a 2×2×3 factorial design experiment. The independent variables were the growth rate (fast: around -10 days at 100kg and slow: around +2 days at 100kg), based on two different EBV's (estimated breeding value) of the sire-line for age, the sex (barrows and gilts) and the live weight at slaughter (107, 115 and 125kg). A sub-population of 119 pigs (10 carcasses per treatment) was selected for the carcass and meat quality evaluation trials. As live weight increased there were significant increases in hot carcass weight and dressing percentage (P<0.05). Lean, fat and bone proportions were not affected by weight. Gilts had higher lean proportion (P<0.05) than barrows. Furthermore, carcasses of fast growing pigs were fatter (P<0.05) than those of slower growing ones. Loin muscle pH, drip loss and reflectance values did not vary significantly with any of the treatments. Intramuscular fat was higher in barrows (P<0.05) than in gilts and soluble collagen content decreased with increasing weight (P<0.05). Muscle protein (%) increased (P<0.05) from 107 to 115kg and gilts had a higher (P<0.05) content than castrates. No evidence was found that increasing slaughter weight detracts from carcass characteristics or meat quality.     

Effect of stunning conditions on occurence of PSE defects in hams of rn+/RN(-) pigs

Pigs of the same genetic type at the RN and HAL loci, i.e. rn⁺RN⁻/NN were reared in similar conditions of feeding and housing. They were slaughtered in two abattoirs (referred to as A1 and A2) using a mixture of air (30%) and CO₂ (70%), at a rate of 300 pigs per hour per slaughterline. One hundred and thirty-two pigs from 11 farms were slaughtered in A1 using a corusinga restrainer and 127 pigs from 5 farms were slaughtered in A2 with the backloading technique. pH at 40 min, 2.5 h and 24 h after slaughter and colour (L*, a*, b*) at 24 h after slaughter were measured in the semimembranosus muscle. Meat quality of the ham was scored as follows: 1, no PSE-zone; 2, doubtful; 3, PSE-zones in the semimembranosus and sometimes on the internal flexor muscles; 4, PSE-zones in all the flexor muscles. The muscle pH value was higher in A2 than in A1 at 40 min post mortem (P<0.01), but not at 2.5 and 24 h. L* (P<0.001) and b* (P<0.05) were higher in A1 than in A2. There was a remarkable difference in meat quality scores, with 50% of the hams scoring 3 or 4 in A1, vs 13% in A2. Lairage time before slaughter affected (P<0.01) the pH value at 2.5 h (5.69 vs 5.93). The values of pH1 and pH2.5 decreased with increasing the meat quality score. The values of L* and b* increased markedly with the score. The results of the present study indicate that the method of bringing the slaughter pigs to the stunning device affects the frequency and importance of PSE meat in the ham. The automated driving of groups of animals to the stunning machine combined with the backloading of a nacelle, compared to a traditional system driving pigs in single file using electrical goads and a restrainer was beneficial with respect to both meat quality and animal welfare.     

Comparison of two methods for assessing the bacteriological condition of the water supply in slaughter houses

One hundred and five water samples of drinking water quality used in slaughter houses were examined according to The Netherlands' Standard N 3043 (1956) and by the new ‘Differential Hydrobacteriogramme’ (DHB) technique. The latter procedure allows for resuscitation of debilitated cells, uses one single selective enrichment medium and various isolation media and includes confirmation of isolates. Identification of isolates demonstrated that false positives as well as false negatives were frequently obtained by the N 3043 method. Rejection rate of samples by the N 3043 and DHB methods, respectively, was 63 vs. 72 for 81 samples taken from taps, and 4 vs. 10 for 24 samples drawn from wells and mains, Based on these results the DHB technique seems particularly suitable for the monitoring of re-used waters, because it provides more information and has a higher accuracy.     

Effect of prolonged heat treatment from 48 °C to 63 °C on toughness, cooking loss and color of pork

The effect of low temperature long time (LTLT) heat treatment at 48 °C, 53 °C, 58 °C, and 63 °C for T(c) (time to reach a core temperature equal to the water bath), T(c)+5h holding time, and T(c)+17h holding time was studied in Longissimus dorsi and Semitendinosus muscles from slaughter pigs and sows. Meat toughness (Warner-Bratzler Shear Force), cooking loss and color (Minolta L*a*b*-values) was measured and in the cooking loss the amount of heat-soluble collagen and activity of cathepsin B+L was determined. Decreasing shear force and increasing cooking loss during LTLT treatment was observed between 53 °C and 58 °C. Furthermore, increasing temperature from 53 °C to 58 °C and increasing time from T(c) to T(c)+17h increased the solubility of collagen. Residual activity of cathepsin B+L in LTLT treated pork was mainly affected by temperature, showing the highest activity at 58 °C and 63 °C.     

Slaughter value and flesh characteristics of European catfish (Silurus glanis) fed natural and formulated feed under different rearing conditions

The experimental material was comprised of European catfish (Silurus glanis) individuals aged 2.5 years that were reared on natural feed in earthen ponds and individuals aged 1.5 years cultivated intensively on formulated feed in recirculating systems. Weight gain and morphometric parameters were measured along with physical and color characteristics and proximate composition of fillets. Despite the different age and diets of the fish, no differences were observed in the linear biometric indices. The total weight of the fish of both groups and their condition coefficients were also similar. In addition, no differences were reported in their body weight or head and gutted (H&G) carcass and fillet yields. Proximate composition analysis demonstrated a lack of differences in the contents of dry matter. Of the dry matter, differences were reported in the fat content, which was higher in the catfish fed formulated feed. The color of the fillets was characterized by high values of lightness, negative values of redness, and positive values of yellowness, and the fish fed formulated feed displayed higher saturation of green. The flesh of both groups of catfish demonstrated similar pH values and water retention capacity, whereas the values of thermal drip appeared to be higher in the fish fed formulated feed.