电击晕处理对肉鸽屠宰应激及宰后鸽肉品质的影响

为探究电击晕处理对肉鸽屠宰应激和宰后鸽肉品质的影响，本实验选取相同饲养条件下日龄为28 d的肉鸽，以击晕电压0 V为对照组，通过测定血液生化指标和肌肉理化指标，分析不同击晕电压(50～90 V)对肉鸽应激反应和宰后胴体品质的变化。结果表明：电击晕处理组肉鸽屠宰后血液中肌酸激酶(creatine kinase,CK)、促肾上腺皮质激素(adrenocorticotropic hormone,ACTH)和乳酸脱氢酶(lactate dehydrogenase,LDH)水平与对照组相比整体上均有一定程度的下降，在击晕电压60 V时总体达到最低水平；血液中皮质酮激素质量浓度随着击晕电压(0～90 V)的增大先降低后增加，在电压超过70 V时高于对照组，说明70 V以上的电击晕处理会增加肉鸽的屠宰应激水平；电击晕处理对宰后鸽胸肉的pH值影响不显著，与对照组相比，宰后24 h鸽胸肉亮度(L^*值)略有降低而红度(a^*值)增大，60～70 V电压处理组鸽肉的滴水损失率、蒸煮损失率及剪切力均保持在较低水平，此时鸽肉的保水性和嫩度相对较好。综上，60～70 V的...     

Residual blood in lamb muscles

The effect of slaughter method on the residual blood content of the M. longissimus dorsi, the microbiological status of the meat and its tenderness was examined with lambs. There were no differences in any of the characteristics examined between the various stunning procedures used, even though there were marked differences in the amount of blood collected after slaughter.     

不同屠宰方式对新疆多浪羊肉品质的影响

以新疆多浪羊为研究对象,对比分析传统屠宰（对照）和3 个不同电压（90、127 V和220 V）击晕屠宰 （分别计作EST 90、EST 127、EST 220）对多浪羊肉品质的影响。结果表明：EST 90处理组成熟过程中pH值下降 速率最快,血液中的皮质醇浓度、肌酸激酶和乳酸脱氢酶活力最高,羊应激反应最剧烈,宰后1、7 d的蒸煮损失率 最高（P＜0.05）;EST 127处理组的持水力最好;电击晕对多浪羊肉嫩度有一定影响,宰后7 d各处理组嫩度显著 改善,而EST 127处理组表现最佳;EST 220处理组放血不充分,且胴体表皮有多处血斑形成;电击晕屠宰对多浪羊 肉色泽无显著影响（P＞0.05）。综合分析实验结果,EST 127处理组持水力与嫩度较优,羊应激反应较小,肉品质 相对较好,因此EST 127处理适合应用于多浪羊的屠宰加工。     

An analysis of data relating to pig carcass quality and indices of stress collected in the European union

Information from about 5500 pigs killed in five European countries was used to examine the relation of different measures of carcass and meat quality to one another and their relation to biochemical indices of stress in blood collected at slaughter. There were large differences in the prevalence of potentially PSE meat in pigs from the five countries and evidence of a wide range of stress encountered at slaughter. Relationships between the same measurements made in different muscles were generally good and consistent between countries. There were no apparent relationships between indices of stress and characteristics associated with PSE meat. In contrast, greater stress tended to be reflected in more DFD meat. Based on the association between the level of skin blemish and increased muscle ultimate pH values a probable factor contributing to this was fighting between mixed groups of unfamiliar animals.     

屠宰过程中改良畜禽肉品质的研究进展

肉品质是人们对肉类多种质量特性的综合评价,要改良畜禽肉品质必须从多方面考虑.在屠宰过程中,作好临宰前的准备工作,改善畜禽的击晕方法,改进放血技术和烫毛方式,采用多种方法降低胴体污染,这些措施都能有效地改良畜禽肉的品质.     

屠宰工艺对冷却肉滴水损失的影响

系统地分析了生猪屠宰工艺对冷却肉滴水损失的影响.综述了禁食、致昏、戳刺、放血和胴体冷却与冷冻等工艺对冷却肉滴水损失的影响,探讨了提高冷却肉肌肉保水性的措施.     

不同宰杀方式对草鱼肉呈味水溶性成分的影响

以不同宰杀方式草鱼的背部肉为对象,采用高效液相色谱法和氨基酸自动分析法研究不同宰杀方式（自然、急杀、去鳃）对草鱼背部肉核苷酸类化合物和游离氨基酸含量的变化,并测定背部肉pH值、糖原和乳酸的含量。结果表明：自然、急杀、去鳃3 种宰杀方式的草鱼背肉苦味氨基酸含量占总游离氨基酸含量分别为78.95%、68.60%、69.44%,部肉的鲜度K值分别为20.28%、15.49%、12.13%,自然死亡组腺嘌呤核苷三磷酸含量最低,肌苷酸含量最低,鲜度最差。草鱼背肉中pH值的变化与乳酸含量的变化呈负相关,乳酸含量的变化与糖原含量的变化呈负相关,自然死亡的草鱼肉乳酸含量最高,pH值最低。不同宰杀方式对草鱼背肉呈味水溶性成分影响较大,自然死亡的草鱼肉滋味最差,急杀致死和去鳃致死组滋味差别不明显。因此,在加工过程中,要避免鱼血渗入肌肉,造成鱼肉土腥味产生。     

GENETICS OF PIG MEAT QUALITY: A REVIEW

This paper is a review of current knowledge about genetic effects on technological and eating qualities of pork. These effects have been recognized as primordial sources of variation of meat quality in the porcine species. Nevertheless, some significant advances have recently been obtained in this area. This literature survey reveals that:
The halothane sensitivity gene (HALⁿ) explains to a large extent the overall genetic variation in technological quality and eating quality of pork. Evidence is accumulating that the halothane sensitivity gene is not completely recessive regarding its effects on quality traits. Producing slaughter pigs heterozygous at the HAL locus may result in deficiencies in meat quality, probably depending on slaughter conditions and perhaps also on slaughter weight.
Breed differences in technological and sensory qualities of pork partly result from the large breed variation in incidence of halothane sensitivity, but other factors are implied, particularly ultimate pH and intramuscular fat content of meat.
The major dominant gene RN^-is probably at the origin of the previously described "Hampshire effect" on meat quality.
Heritability of most traits referring to the technological quality of meat is low to moderate (0.15 to 0.30), whereas heritability of intramuscular fat content is high (0.40 to 0.50). A genetic antagonism exists between technological quality of pork and growth or body composition traits. The halothane sensitivity gene is the major factor responsible for the "meat quantity — meat quality" genetic antagonism.     

Halal and kosher slaughter methods and meat quality: A review

There are many slaughter procedures that religions and cultures use around the world. The two that are commercially relevant are the halal and kosher methods practiced by Muslims and Jews respectively. The global trade in red meat and poultry produced using these two methods is substantial, thus the importance of the quality of the meat produced using the methods. Halal and kosher slaughter per se should not affect meat quality more than their industrial equivalents, however, some of their associated pre- and post-slaughter processes do. For instance, the slow decline in blood pressure following a halal pre-slaughter head-only stun and neck cut causes blood splash (ecchymosis) in a range of muscles and organs of slaughtered livestock. Other quality concerns include bruising, hemorrhages, skin discoloration and broken bones particularly in poultry. In addition to these conventional quality issues, the “spiritual quality” of the meat can also be affected when the halal and kosher religious requirements are not fully met during the slaughter process. The nature, causes, importance and mitigations of these and other quality issues related to halal and kosher slaughtering and meat production using these methods are the subjects of this review.     

宰前倒挂应激对鸭血凝胶特性的影响

宰前倒挂因能有效提高屠宰效率成为肉鸭宰杀前必经的一个工艺过程，但倒挂往往会加剧肉鸭的应激程度，影响其血液品质，已成为工厂生产中亟待解决的问题。因此，本实验旨在借助血液学与凝血相关指标探究宰前倒挂应激对鸭血凝胶特性的影响。在屠宰前，将40 只樱桃谷鸭随机分为2 个处理组：对照组和宰前倒挂组（宰前倒挂2.5 min），屠宰后采集血样并制备血凝块，随后分析血液指标（应激指标、血液学指标、凝血指标）以及鸭血凝胶特性。结果表明，宰前倒挂组鸭血中皮质酮激素及促肾上腺皮质激素的水平均高于对照组，说明实验所建立宰前倒挂模型成立。倒挂应激后，红细胞计数、血小板计数、血红蛋白质量浓度增加，红细胞比容、平均红细胞体积及平均血小板体积增大；凝血酶原的水平极显著上升（P＜0.01），组织因子的水平显著上升（P＜0.05）。宰前倒挂最终导致鸭血凝胶化加快，鸭血凝胶体系中水分迁移速率增大，结合水与自由水比例减少，不易流动水比例增大，质构特性和保水性变差。研究揭示了宰前倒挂应激通过影响鸭血的血液学指标和凝血系统从而改变其凝胶行为及凝胶特性，可为工厂改善应激对鸭血凝胶品质的影响提供理论依据。     

不同屠宰方式对蒙古羊应激及羊肉食用品质的影响

以内蒙古蒙古羊为研究对象,对比分析抹脖子屠宰、掏心式屠宰及电击晕屠宰对蒙古羊应激及羊肉食用品质的影响,利用生化分析仪等仪器对蒙古羊血液指标及食用品质进行测定。结果表明：经电击晕后屠宰,肉羊血液中乳酸含量、皮质醇含量、乳酸脱氢酶活性及肌酸激酶活性显著低于其他2 种方式,肉羊在屠宰过程中应激反应也最小;相比于抹脖子及掏心式屠宰2 组,电击晕组羊肉的蒸煮损失率较低,而嫩度高于抹脖子组,且与掏心组差异不显著,红度值（a*）高于上述2 组,且电击晕组羊肉的硫代巴比妥酸反应物值最低;营养方面,电击晕及掏心式屠宰可提高羊肉中不饱和脂肪酸的含量。因此,从肉羊屠宰食用品质及经济效益等方面比较,电击晕屠宰方式可以减小肉羊应激反应,提高肉羊屠宰企业的经济效益,符合动物福利屠宰要求。     

宰前饮用复合磷酸盐水对延边黄牛肉血清生化、肌纤维结构及蛋白质表达的影响

通过对宰后延边黄牛肉血清生化、肌纤维结构及蛋白质表达的测定,考察宰前饲喂延边黄牛复合磷酸盐水对其生理生化指标的影响。结果显示:宰前饮用0.10%的复合磷酸盐水可降低延边黄牛肉的肌纤维面积和周长,并显著降低宰后Troponin-T表达量,提高Creatine Kinase表达量,对改善宰后延边黄牛肉的血液生化指标有显著作用,可在一定程度上减少宰前应激,改善肉质。     

Texture of beef M. semitendinosus heated before,during and after development of Rigor Mortis

Samples of beef M. semitendinosus were heated at different rates at times up to 3 days after slaughter and the texture determined instrumentally. Rapid heating soon after slaughter produced normal shear values for cooked meat but slow heating gave very tough meat. At later times, shear values were unaffected by the heating rate and decreased with increasing time after slaughter. Multivariate analyses of the effects of holding-time after slaughter, heating rate, pH, sample length and weight before and after heating, showed that variations in shear values of meat heated within 18 h after slaughter were largely due to the combined influences of shortening and of muscle pH after heating.     

宰前及屠宰过程中影响猪肉品质的主要因素

影响猪肉品质的因素有遗传因素和环境因素。主要从宰前管理、屠宰环节等环境因素的角度综述其对猪肉品质的影响,旨在为生产出安全、优质的猪肉产品提供理论依据。     

Influence of gas stunning and halal slaughter (no stunning) on rabbits welfare indicators and meat quality

This study assessed the effect of gas stunning which has not been conducted until now in comparison with slaughter without stunning on the welfare and meat quality of rabbits. Eighty male New Zealand White rabbits were divided into two groups of 40 animals and subjected to either halal slaughter without stunning (HS) or gas stunning using 61.4% CO₂, 20.3% oxygen and 18.3 % nitrogen (GS). Analysis of the sticking blood revealed that both slaughter procedures caused a substantial increase in the levels of catecholamines, hypercalcemia, hyperglycemia, lactic acidemia and an increase in enzyme activities. The ultimate pH of the Longissimus lumborum muscle did not differ between treatments. GS exhibited higher lightness and cooking loss, and lower glycogen and MFI than HS. This indicates that both GS and HS can be significant stressors although the amount of stress may be below the threshold to negatively affect rabbit meat quality.     

Effect of slaughter method on bleeding efficiency in chickens

The effect of inducing a cardiac arrest, at stunning, on the weight of blood collected at slaughter was examined in broiler chickens when using seven different neck cutting methods. Cardiac arrest resulted in a slower initial rate of bleeding for each neck cutting method, but by 2.25 min after neck cutting there was no effect on the amount of blood collected. The cardiac arrest treatments were associated with a higher incidence of haemorrhaging in the wings.     

Influence of the time of year on the incidence of PSE and DFD in Irish pigmeat

The conditions of PSE (pale, soft, exudative) and DFD (dark, firm, and dry) are significant causes for downgrading of pigmeat resulting in financial loss to the slaughter plant. The objective of this study was to document the variation in quality of pigmeat from one slaughter plant over a 15-month period, based on colour, appearance and pH. During 4 days of most weeks, 30 pigs were randomly selected from the slaughter line, resulting in a total number of 4560 pigs. Muscle pH between the third and fourth rib was measured 45 min, 90 min and 24 h after slaughter. Using a Minolta colorimeter (Hunter L, a, b scale), colour of the longissimus dorsi muscle was measured 24 h after slaughter. Muscle colour was also visually scored on a scale of 1-6. Carcass pH at 24 h post-mortem varied significantly with month of slaughter (P<0.04) as did colour (Hunter L, P<0.001; Hunter a, P<0.001; Hunter b, P<0.001). It was concluded that meat quality as measured by 24 h pH and colour was poorest during the months of November and December. While this may be at least partly related to weather, it is probable that the increased slaughtering rates at this time and variable resting period before slaughter had the biggest impact.     

Impact of animal husbandry and slaughter technologies on microbial contamination of meat: Monitoring and control

The microbial flora transferred to carcasses during slaughter is a reflection of the care taken on the slaughter floor and of the types and numbers of microorganisms acquired by the animal on the farm or during the period of transportation to the slaughter house. These microogranisms may include those able to cause illness in the consumer, or microorganisms responsible for spoilage of the product. Considerable progress has been made in reducing contamination at slaughter and thereby extending the shelf-life of meat. In contrast, international statistics still clearly show that meat and meat products are responsible for a major proportion of all foodborne infections. This latter aspect is not determined by the overall number of microorganisms present but by the bacterial composition of the animal's gut flora at slaughter. Preventive quality assurance along the whole productions and processing line is therefore the only effective means of controlling the microbiological safety and quality of meat. This includes hazard analysis techniques to identify critical control points and procedures for monitoring the microbiological status of both animals and carcasses since most of the critical points cannot be totally controlled. At early stages in the production line, colonisation of meat animals with pathogens should be prevented. Subsequently, good slaughter practices will ensure carcasses of good overall microbiological quality. This paper deals with microbiological monitoring systems that can be used at different stages of production and processing to control the microbiological quality of poultry and pig meat.     

Head current during and blood splashes after electrical stunning in relation to characteristics of the pig's body

In order to evaluate electrical stunning in relation to the incidence of blood splashes, meat quality and carcass quality parameters, 2035 pigs, heterozygous for the halothane gene, were observed during slaughter at a commercial slaughterhouse. The head current during electrical stunning is significantly higher (P<0.01) in gilts with a lower live weight (P<0.0001) or cold carcass weight (P<0.0001) and a higher lean meat percentage (P<0.0001). Also the incidence of blood splashes in the ham is significantly higher in gilts (P<0.0001) with a higher lean meat percentage (P=0.0028; odds ratio=1.11), a lower live weight (P=0.003; odds ratio=0.98) and a lower type number (P=0.0074; odds ratio=0.64). For barrows, no significant parameters were revealed. These results suggest that the variability in incidence of blood splashes can be explained by the variability of current density depending both on sex and body characteristics. Thus, electrical stunning can be improved by providing an energy level, based on the body characteristics of the pig.     

Factors affecting the residual blood content of meat

From estimates of the residual blood content of muscles from rats killed while stressed or under barbiturate anaesthesia it appears that, at slaughter, the stress associated with stunning and exsanguination will normally produce peripheral vasoconstriction through the action of released catecholamines. This will result in minimal retention of blood in the skeletal muscles while factors which reduce vascular tone will lead to higher levels of residual blood in meat.