Influence of slaughter season and sex on fatty acid composition, cholesterol and α-tocopherol contents on different muscles of Barrosã-PDO veal

The influence of slaughter season and sex on intramuscular total lipids (ITL) neutral lipid (NL) and phospholipid (PL) compositions, cholesterol and α-tocopherol contents were evaluated in Biceps femoris (Bf), Longissimus dorsi (Ld) and Supraspinatus (Ss) muscles from 92 Barrosã-PDO (Protected Denomination of Origin) calves. ITL content in Bf muscle was affected by slaughter season and sex whereas NL content was only affected by slaughter season. Neither sex nor slaughter season influenced cholesterol and α-tocopherol contents in the muscles under study. Concerning NL composition, sex was an important source of variation on the proportions of total SFA and MUFA in all muscles. Irrespective of the considered muscle, males had higher total SFA but lower total MUFA and MUFA/SFA contents than females. Slaughter season influenced C18:2 cis-9 trans-11 (CLA) content in Bf (P < 0.01) and in Ss muscles (P < 0.05) with calves slaughtered in autumn showing higher values than their counterparts. Total MUFA, n-3 PUFA and n-6/n-3 ratio contents in Ld muscle were also affected by slaughter season. Regarding PL composition, slaughter season × sex interaction affected total SFA, PUFA/SFA and n-6 PUFA contents in Bf and Ss muscles. In addition, this interaction influenced total MUFA (P < 0.05) in Bf muscle and total PUFA (P < 0.01) in Ss muscle. CLA content in PL from Ld was influenced by sex (P < 0.05) and by slaughter season (P < 0.01), with females slaughtered in autumn presenting the highest content. These results clearly indicate that sex and slaughter season are important factors that influence the fatty acid composition of Barrosã-PDO veal.     

The effects of gender and castration of females on performance and carcass and meat quality of heavy pigs destined to the dry-cured industry

The effects of gender and castration of females (IF, intact females; CF, castrated females; CM, castrated males) on performance and carcass and meat quality were studied in crossbred pigs (Landrace × Large White dams × Duroc sires) slaughtered at 119.2 (experiment 1) or 131.6 (experiment 2) kg body weight. Intact females had better feed conversion and less carcass fat than CF and CM. Trimmed shoulder yield was higher for CM than for CF with IF being intermediate. Primal cut yield and meat quality were similar for all treatments. Proportion of linoleic acid in backfat was lower in CF than in IF or CM and the differences were significant when pigs were slaughtered at 131.6 kg. The higher fat content and the fatty acid profile favor the use of castrated females and males over intact females for the production of heavy pigs destined to the dry-cured industry.     

Presence of Clostridium difficile in pigs and cattle intestinal contents and carcass contamination at the slaughterhouse in Belgium

The objective of this study was to evaluate the presence of Clostridium difficile in intestinal and carcass samples collected from pigs and cattle at a single slaughterhouse. C. difficile was isolated in 1% and 9.9% of the pig and cattle intestinal contents and in 7.9% and 7% of cattle and pig carcass samples respectively. A total of 19 different PCR-ribotypes were identified, among them types 078 and 014. Seven of 19 ribotypes correlated with the PCR-ribotypes involved in human C. difficile infections in Belgium. This study confirms that animals are carriers of C. difficile at slaughter and ribotypes are identical than those in humans, and that carcass contamination occurs inside the slaughterhouse.     

Time to collapse following slaughter without stunning in cattle

Time to physical collapse was examined in 174 cattle which were restrained in the upright position and then released immediately from the restraint following the halal cut. The frequencies of swelling and false aneurysm in the cephalic and cardiac severed ends of the arteries were recorded. Fourteen percent of the cattle collapsed and stood up again before finally collapsing. The average time to final collapse for all the cattle was 20 s (sd ± 33). In 8% of the animals time to final collapse was ?60 s. Seventy-one percent of the cattle that took more than 75 s to collapse had false aneurysms in the cardiac ends of the severed carotid arteries. The frequency of swelling at the cephalic severed ends of the carotid arteries in 129 cattle was 7%. Failure to collapse within 60 s was associated with swelling of the cephalic ends of the carotid arteries.     

Auditing animal welfare at slaughter plants

The OIE Welfare Standards on slaughter transport, and killing of animals for disease control are basic minimum standards that every country should follow. The OIE, European Union, and many private standards used by commercial industry have an emphasis on animal based outcome standards instead of engineering based standards. Numerical scoring is used by both private industry and some governments to access animal welfare at slaughter plants. Five variables are measured. They are: 1) Percentage of animals effectively stunned on the first attempt, 2) Percentage rendered insensible, 3) Percentage that vocalize (bellow, moo, squeal) during handling and stunning, 4) Percentage that fall during handling, and 5) Percentage moved with an electric goad. Each one of these critical control points measures the outcome of many problems. A good animal welfare auditing system also has standards that prohibit really bad practices such as dragging, dropping, throwing, puntilla, and hoisting live animals before ritual slaughter. On farm and transport problems that can be measured at the slaughter plant are: percentage of lame animals, percentage of thin animals, percentage of dirty animals, percentage with sores, bruises or lesions, death losses, morbidity, and percentage of birds with broken wings and legs.     

Rest before slaughter ameliorates pre-slaughter stress-induced increased drip loss but not stress-induced increase in the toughness of pork

One factor affecting meat quality is pre-slaughter stress. We investigated the effects of exercise stress on drip loss and toughness in relation to resting times of 0, 1 or 3 h following exercise on a treadmill. This exercise stress was regarded as combined physical and physiological stress. Exercise stress increased the muscle temperature, reduced the creatine phosphate, ATP and glycogen content of pigs slaughtered immediately after stress exposure. These conditions lead to a reduced pH early post mortem and an increased drip loss, while only 1 h of rest after exercise stress normalised these effects. However, an overshooting effect was noted when pigs were rested for 1–3 h before slaughter, emphasising the importance of critical control of the resting period when studying exercise stress-induced effects on meat quality. Furthermore, meat from exercise stressed pigs, irrespective of resting, had increased toughness compared to controls, indicating that the toughness was not related to drip loss in meat from exercise stressed pigs.     

Occurrence of Yersinia enterocolitica and Campylobacter spp. in slaughter pigs and consequences for meat inspection,slaughtering, and dressing procedures

The purpose of the present investigation was to assess the occurrence of Yersinia enterocolitica and Campylobacter spp. in the lymphoid tissues and intestinal tract in pigs and the risk for contamination during the compulsory meat inspection procedures and the procedures during slaughtering and dressing. Another objective of the investigation was to compare traditional isolation methods, the use of a polymerase chain reaction (PCR) method (BUGS'n BEADS™ bacterial DNA isolation kit) and an ELISA method (VIDAS CAM) as tools in risk management in the slaughterhouse.

The results indicate that the compulsory procedure for the incision of the submaxillary lymph nodes represents a cross-contamination risk for virulent Yersinia. In the screening of 97 animals in 1999, 5.2% of the samples were positive, and by the sampling of 24 samples in 2000–2001, 12.5% of the samples were positive. In the last case, Y. enterocolitica O:3 was found in the kidney region in one of the subsequent carcasses that was only touched by the meat inspection personnel before sampling. In addition, incision of the mesenteric lymph nodes might represent a cross-contamination risk since 8.3% of the samples were positive.

The association between antibody titres and the occurrence of virulent yersiniae in the tonsils (21–18) was striking, with virulent yersiniae found in the tonsils in most pigs with high titres.

The contents of the stomach, ileum, caecum, and colon also represent contamination risks for Y. enterocolitica O:3 if the slaughterhouse personnel cuts into the viscera with their knives by accident; the frequency of virulent Yersinia varied from 4.2% to 16.7% within these sections.

Campylobacter was detected in the gastrointestinal tract of all pigs, and the high contamination of tonsils (66.7%) and intestinal tract (100%) might represent an occupational health hazard.

There was no statistical difference between the traditional method for isolation of Y. enterocolitica [International Organization for Standardization, 1994. Microbiology—General Guidance for the Detection of Presumptive Pathogenic Yersinia enterocolitica (ISO 10273). International Organization for Standardization, Genève, Switzerland (16 pp.)] and the BUGS'n BEADS™ detection method for virulent Y. enterocolitica. Likewise, there was no statistical difference between the traditional method for isolation of Campylobacter spp. [Nordic Committee on Food Analysis, 1990. Campylobacter jejuni/coli. Detection in Food. Method No. 119, 2nd ed. Nordic Committee on Food Analysis, Esbo (7 pp.)] and the BUGS'n BEADS™ detection method or the VIDAS CAM method for detection of Campylobacter spp.     

Management of slaughter houses in northern Nigeria and the safety of meat produced for human consumption

This work attempts to document the first comprehensive report on the conditions and management of major slaughter houses of northern Nigeria as well as the safety of meat produced for public consumption in these abattoirs. The study was carried out in seventeen major slaughter houses from 14 out of the 19 states that form the northern part of Nigeria and the Federal Capital Territory (FCT), Abuja. Selection of abattoir from each state was based on its socio-economic importance to the local community in terms of number of animals slaughtered and quantity of meat supply to the area and also the level of commitment of each abattoir management to cooperate with the objectives of this research. On-the-spot assessment of the operational facilities and process operations was employed using videos and photographs for data collection on visit to each abattoir. A joint prospective meat inspection and focus group discussion (8–12 abattoir personnel) was carried out to highlight the problems of the slaughter houses. The study revealed absence or dilapidated conditions of basic abattoir infrastructures such as lairage, hoisting facilities, supply of potable water, constant electricity, drainage and waste disposal systems. Good hygienic practices were totally absent. Animals were not being examined regularly before or after slaughter leading to unsafe meat being released for public consumption and conveyed out of the abattoir using unhygienic means of transport. Waste disposal was indiscriminate and hazardous to the environment, while the authorities concerned were not making any effort to curtail the situation. Diseases of public health and economic importance that were most frequently encountered included Tuberculosis, CBPP and Helminthoses. It was concluded that, none of the major abattoirs in northern Nigeria met the minimum hygienic standard of operation as recommended by the Codex Alimentarius and they could not have supported the production of safe meat and meat products for human consumption.     

Effect of different stunning systems on meat quality of light lamb

The present study was proposed to compare the effect that different types of stunning (TS) had on the quality of refrigerated meat from light lambs of the Spanish Manchega breed at 24 h and 7 days post-mortem. Lambs were electrically stunned (ESL; n = 10), using CO₂ (GSL; n = 10) or slaughtered without previous stunning (USL; n = 10). Measurements on meat quality were carried out by evaluating pH, colour coordinates (L^*, a^*, b^*), water holding capacity (WHC), cooking loss (CL), shear force (SF) and drip loss (DL). At 24 h post-mortem, no significant differences were found in any of the variables studied. However, at 7 days post-mortem, meat quality was affected by the different TS: pH, CL and DL were lower (P < 0.001) in the USL group and GSL obtained the lowest a^* (redness) and b^* (yellowness) values (P < 0.01) than in the other groups. Ageing of meat affected SF in the ESL group (P < 0.01), although there were no significant differences due to treatments at any of the ageing times.     

生猪屠宰HACCP体系的建立

通过对南京肉联厂生猪屠宰分割线上的工序、设备和工人的微生物污染状况的检验以及大量的资料查询，确定了候宰检验、麻电击昏、刺杀放血、入库快速冷却和分割这5个工序为关键控制点，并建立了相应的生猪屠宰分割线上的HACCP计划。