胶乳凝集抑制试验快速鉴定肉种类研究

以羧化聚苯乙烯胶乳作载体,将动物血清分别共价交联到载体微球表面,制成免疫微球。将此微球同相应抗血清配对,进行胶乳凝集抑制试验以鉴定牛肉、马肉、羊肉、狗肉和猪肉。通过对162份牛肉、43份马肉、100份猪肉、34份羊肉、30份狗肉、10份骡肉、4份驴肉和7份山羊肉的鉴定,制备的5种胶乳试剂敏感性均为100％。除马肉胶乳试剂和羊肉胶乳试剂有种属内交叉反应外,其它胶乳试剂特异性为100％。实验具有良好的重复性,试剂稳定性强,易于保存。5分钟内出结果,操作简便,适于基层单位应用。     

用“冷凝法”快速鉴别家畜的分割肉块

当前市场上,出现用低价的马肉、驴肉或母猪肉的分割肌肉块,顶替牛肉、羊肉高价出售的现象较为普遍。为了把在感官上难以鉴别的牛肉、马肉、羊肉、驴肉和母猪肉的分割肌肉块,科学地加以鉴别。我们参考有关资料根据牛、马、羊、驴和母猪的脂肪在凝点之间的差别,利用“冷凝法”加以鉴别。现将试验结果报告如下:     

牛肉和马肉快速鉴别方法通过技术鉴定

针对目前肉类交易中存在着以马肉充当牛肉出售,严重损害消费者利益的不法行为及缺乏简便,快速、准确、实用的鉴别方法的实际情况,解放军兽医大学卫检系与长春市动物检疫站联合开展了《羧化胶乳凝剂抑制试验快速鉴别牛肉和马肉的研究及鉴别包     

应用呈色反应鉴别牛马骡肉的实验

<正> 随着集市贸易的开放,以马、骡肉混于牛肉中出售的,掺假作伪情况很有可能发生,为了加强这方面的监督和管理,对牛、马肉的鉴别应予虑考。鉴于用沉淀反应进行     

四川畜禽肉类加工发展史略

四川畜禽肉类资源丰富。1992年,四川畜禽肉类构成中,猪肉435.12万吨、牛肉9.52万吨、羊肉4.31万吨、禽肉44.28万吨、兔肉3.59万吨、驴肉44吨、骡肉18吨、马肉137吨。禽肉中,鸡肉22.73万吨,鸭肉11.42万吨,鹅肉10.11万吨。当前,畜禽肉类加工有:腌腊制品、冷加工制品、禽肉制品、熟食制品等几大类,以猪肉加工为大宗。     

用呈色反应鉴别牛马骡驴肉

随着各地集市贸易市场的开放,可能有极少数的肉贩子,挂羊头卖狗肉,以假乱真,将骡马肉混入牛肉中出售,以获取高利。过去兽医在集市上对牛、马、骡、驴肉一般多用感官鉴定,虽极简便,但非有一定经验,不足以正确判断。根据马、骡肉中含动物淀粉的特性,用碘液进行呈色反应辨别,以起对肉贩之监督和管理作用。     

用呈色反应法鉴别牛、马、骡肉

近年来,由于市场上牛肉价格持续上涨的原因,有些不法商贩廉价收购马、骡,逃避检疫,私自屠宰,冒充牛肉上市欺骗消费者,牟取暴利。因此,正确鉴别牛、马、骡肉对动物检疫员来说是非常重要的,以便早发现早处理,避免消费者遭受损失。区别牛、马、骡可以从以下方法加以鉴别。1材料⑴5%氢化钾溶液;⑵0.5%碘溶液;⑶硝酸:比重为1.30～1.40。2操作将待检肉除去肌膜和结缔组织,各取50g剪碎后分别装入烧瓶内,加入50mL、5%氢氧化钾溶液,置于水溶液中,加热煮沸、搅拌,煮成肉液。待肉液冷却后过滤,取滤液19mL,置于100mL三角烧杯中,加入1mL硝酸、加塞、震…     

应用免疫学技术鉴别鲜牛肉和马肉的试验研究

目前,市售肉品中,常见有马肉充当牛肉出卖的现象,这不仅严重地损害了消费者的利益,也不利于对疫病的控制。因此,急待解决肉类品种鉴别的问题。为了鉴别牛肉和马肉,常可通过肉的外部形态特征、骨骼解剖学特征及淋巴结的特点进行鉴别。但为了准确地鉴别肉类,应进行试验室的研究工作。国外以酶联免疫吸附试验测定和放射免疫法检查,但需要贵重的器材,而且     

牛肉与马肉的鉴别方法

有些不法肉贩以低价收购老马和病马宰杀上市,充当牛肉出卖,损害了群众的利益。作者根据多年肉检工作经验和体会,介绍用感官鉴别牛肉与马肉的方法如下: 一、肌肉的观察:牛肉的肌纤维较细,肌束横断面的切面较小,肌肉间夹杂有脂肪,质地结实;马肉的肌纤维较粗,肌束横断面的切面较大,肌膜明显,肌肉间无脂肪,质地松软。二、色泽的观察:牛肉呈微棕红色,年     

牛肉与马肉的简易鉴别

近年来,一些不法肉品经营者,以马肉充当牛肉,或在牛肉中混入马肉,损害消费者利益。为保护消费者利益,特介绍一种简单的牛马肉鉴别方法。用镊子夹取待检脂肪２～３ｇ,用火柴或打火机直接热熔,脂肪受热后变成液体,滴入盛有凉水的玻璃器皿或水杯中,如水面上立刻呈现出腊样硬凝片者,证明是牛肉。马肉不会有此种现象。如果没有脂肪,可取结缔组织,以同样方法进行检验。由于结缔组织不易熔化,所以将烧热的结缔组织迅速插入凉水中,如果水面上立刻呈现出腊样硬凝片,同样证明该肉是牛肉。此法鉴别牛肉与马肉,迅速准确。牛肉与马肉的简…     

Detection and effects on platelet function of anti-platelet antibody in mule foals with experimentally induced neonatal alloimmune thrombocytopenia

Horse mares carrying mule foals were immunized during the last trimester of pregnancy with whole acid-citrate-dextrose-anticoagulated donkey blood to experimentally induce neonatal alloimmune thrombocytopenia. Thrombocytopenia occurred in the neonatal mule foals born to immunized horse mares within 24 hours after ingestion of their dams' colostrum. Mule foals born to mares not immunized with donkey blood did not develop thrombocytopenia. These findings suggest that antibodies may have been directed against a donkey platelet antigen present in the mule foals but not present in their dams. The objectives of this study were to determine whether anti-platelet antibody could be detected in mule foals with experimentally induced neonatal alloimmune thrombocytopenia, to identify any platelet proteins recognized by serum antibody in these foals, and to determine if platelet function was altered by sera from these mule foals. An indirect enzyme-linked immunosorbent assay demonstrated significantly higher absorption at 1:200 of platelet-bindable immunoglobulin G in serum from thrombocytopenic mule foals, compared with nonthrombocytopenic mule foals. Sera from thrombocytopenic and nonthrombocytopenic mule foals produced similar binding patterns in western immunoblots with donkey platelet proteins separated on sodium dodecyl sulfate polyacrylamide gels. Maximal platelet aggregation and relative slope of aggregation in response to collagen were significantly inhibited after incubation with sera from thrombocytopenic mule foals. These results suggest that mule foals with induced alloimmune thrombocytopenia have serum antibodies that bind to platelets and may compete with collagen binding sites to impair platelet aggregation.     

Possible morphological differentiation of horse and mule kidneys from those of donkey and hinny

By means of plastic injections it was possible to determine that the kidneys of horse and mule have terminal recesses while those of the donkey and hinny have no terminal recesses.     

Differentiating among horse (Equus caballus), donkey (Equus asinus) and their hybrids with combined analysis of nuclear and mitochondrial gene polymorphism

A novel and brief method of differentiating among horse (Equus caballus) and donkey (Equus asinus) and their hybrids (mule, E. asinus × E. caballus and hinny, E. caballus × E. asinus) with combined analysis of nuclear and mitochondrial gene polymorphism (CANMGP) was reported in the present report. A nuclear gene, protamine P1 gene of donkey was sequenced and compared with the known horse sequence from GenBank while a published equid mitochondrial gene, cytochrome b gene of donkey was compared with that of horse. In each of the two genes, a fixed nucleotide substitution within an exon that could be recognized by Dpn II restriction enzyme was found between the two species. Two pairs of primers were designed for amplifying the fragments within the two genes containing the informative nucleotide positions in 65 horses and 41 donkeys and 38 hybrids and conditions of polymerase chain reaction and restriction fragment length polymorphism (PCR‐RFLP) analysis were optimized. Horse, donkey and mule and hinny had their own specific cleavage patterns after the PCR‐RFLP analysis was performed, which made it very easy to identify them from each other. As multiplex PCR can be conducted with the two pairs of primers and only one restriction enzyme is involved in PCR‐RFLP analysis, the method described in the present study is a convenient way to identify horse and donkey and their hybrids. The idea involved in the method of CANMGP can be also used to differentiate other animal species or breeds and their hybrids.     

Progesterone and equine chorionic gonadotropin concentrations around the time of pregnancy loss in mares impregnated by donkeys or stallions

The objective of this study was to compare the incidence of pregnancy loss of mares carrying a mule embryo with that of mares carrying a horse embryo. The possible causes of such mortality were evaluated through serial ultrasonographic evaluations and hormonal monitoring, paying special attention to the role of premature regression of the endometrial cups and its relation to inadequate luteal function.

Twenty-eight mares impregnated by stallions and 19 mares impregnated with donkey semen were evaluated ultrasonographically every week from day 20 to day 150 of pregnancy. The viability of the product was assessed each time, and the diameter of the embryonic vesicle was measured from day 25 to day 60. Blood samples for progesterone and equine chorionic gonadotropin (eCG) determination were taken every week.

Both progesterone and eCG concentrations during normal pregnancies wegre significantly lower in the mares inseminated with donkey semen than in the mares impregnated by stallions (P<.05). In 7 of the mares carrying mule conceptuses to term, the concentrations of eCG remained basal throughout the study. In the other animals from this group, the levels of this hormone did increase but returned to baseline much earlier (on day 77 of pregnancy) than in the mares served by stallions (on day 126 day of pregnancy). There was no significant difference between the growth rate of embryonic vesicles of mares carrying mule embryos and that of mares carrying horse embryos (P>.05).

The incidence of pregnancy loss was significantly higher (P<.05) in mares carrying a mule embryo (36.8 %) than in mares carrying a horse embryo (21.4%); it occurred on average on day 93 of pregnancy in mares carrying mule embryos and on day 43 on mares carrying horse embryos. There was only 1 case in which pregnancy loss was associated with concentrations of both eCG and progesterone that were much lower than the average for the normal pregnancies of the same group, and this was in a mare carrying a horse embryo. The most frequent cause of pregnancy loss was premature luteal regression due to primary luteolysis, as evaluated via peripheral progesterone concentrations. This occurred in 2 mares carrying horse embryos and in 4 mares carrying mule embryos. Three mares carrying mule embryos and 1 carrying a horse embryo had abortions that were not preceded or accompanied by any alteration in progesterone or eCG levels and were thus classified as fetal deaths of non-endocrine origin.

It is concluded that the incidence of pregnancy loss is higher in mares carrying a mule embryo than in mares carrying a horse embryo. However, this is not due to the low progesterone concentrations associated with the premature regression of the endometrial cups that occurs in mares with interspecific pregnancy.     

The Role of Equine Chorionic Gonadotropin in the Stimulation of Luteal Steroidogenesis in Mares Carrying Horse or Mule Pregnancies

The stimulatory role of equine Chorionic Gonadotropin (eCG) in the production of steroid hormones was evaluated during the first 4 months of pregnancy in mares impregnated by either stallions or jack donkeys. Twenty mares were divided in two groups: Mares in the first group were inseminated with stallion semen (horse pregnancies), and those in the second group were inseminated with donkey semen (mule pregnancies). Blood samples were collected twice weekly from day 30 to day 120 of pregnancy to determine the concentrations of eCG, progesterone, androstenedione, and testosterone. Analysis of variance for repeated measures was used to compare the concentrations of each hormone between groups. Linear regression models that considered the linear and quadratic effects of week of gestation as well as the linear and quadratic effects of the concentrations of eCG on the production of each steroid hormone were carried out. Concentrations of eCG, progesterone, and androstenedione were higher in horse than in mule pregnancies (P < .01 for eCG and P < .05 for progesterone and androstenedione). Testosterone concentrations were also higher in horse pregnancies than in mule pregnancies at weeks 7, 9, and 10 (P < .05). Regression analysis indicated that eCG had considerable stimulatory effects on the secretion of progesterone and androstenedione and weaker effects on the secretion of testosterone. The results suggest that eCG stimulates luteal production of progesterone, androstenedione, and testosterone in horse and mule pregnancies, these effects being more evident in horse pregnancies than in mule pregnancies due to the higher concentrations of eCG in horse pregnancies.     

Differentiation of meat according to species by the electrophoretic separation of muscle lactate dehydrogenase and esterase isoenzymes and isoelectric focusing of soluble muscle proteins

Species identification of fresh meat can be readily achieved by serological techniques with the limitation that closely related species, such as sheep/goat, cattle/buffalo and horse/donkey, cannot be differentiated.
We have examined electrophoretic techniques with particular reference to the identification of meat from closely related species. The results showed that beef and buffalo meat and meat from red and grey kangaroos could be clearly distinguished by isoelectric focusing on polyacrylamide gel or agarose in the pH range 5.5 to 8.5. Sheep and goat meat, and horse and donkey meat could not be differentiated by this technique, but were clearly distinguished from each other by their esterase isoenzyme profiles obtained after electrophoretic separation on cellulosic membrane strips. Results from this latter technique were available in one hour.
We believe that species identification of fresh meat should involve an initial screening test by serological techniques followed by confirmation of the identity of suspect samples by electrophoretic techniques.     

肉制品中牛源性成分PCR检测方法的建立及其应用

根据牛特异性线粒体DNA片段,设计合成1对引物,以生、熟牛肉为材料,建立了肉制品中牛源性成分的PCR检测方法,并用该法对市售的67份牛肉制品进行检测。结果显示,所检牛源性成分在271 bp处出现预期的条带,扩增片段经Sau3AⅠ酶切分析确认,获得的214和57 bp片段与预期一致;运用该引物均可扩增出水牛肉、牦牛肉、奶牛肉、黄牛肉单一的相同大小的DNA条带,而对羊、马、狗、驴、兔和鸭等14种动物肉的DNA扩增则呈阴性,其检测灵敏度达到53.2 fg/μL DNA;利用该法对67份牛肉制品进行检测,检出率为100％。结果表明,该法快速简便,且具有较高的特异性和敏感性,可用于市售牛肉制品中牛源性成分的鉴定。     

Luteoprotective Role of Equine Chorionic Gonadotropin (eCG) During Pregnancy in the Mare

The effects of repeated cloprostenol administration were compared in mares impregnated by horses and mares impregnated by donkeys in order to assess the role of eCG on the development of pregnancy‐associated resistance to the luteolytic and abortifacient effects of PGF2α. Eleven mares impregnated by donkey (mule pregnancy) and 9 mares impregnated by horse (horse pregnancy) were used. Six mares with mule pregnancy and four with horse pregnancy were injected with cloprostenol (0.25 mg) when they were between day 65 and day 75 of pregnancy, and the treatment was repeated 48, 72 and 96 h latter. The rest of the mares remained as controls. Concentrations of eCG were 10 times higher (p < 0.001) in mares impregnated by horses than in mares impregnated by donkeys, and they were not affected by cloprostenol treatment. Luteolysis was completed 30 h after the first cloprostenol injection in mule pregnancies, while mares with horse pregnancies required 96 h and three cloprostenol injections to complete luteolysis. Regression analysis revealed significant associations between eCG concentrations at time 0 and the time required for completion of luteolysis (p < 0.001), foetal death (p < 0.01) and foetal expulsion (p < 0.05). It is concluded that high eCG concentrations in mares impregnated by horses protect the corpora lutea of pregnancy against the luteolytic effects of PGF2α. Low eCG concentrations in mares carrying mule foetuses afford them less protection against the luteolytic effect of PGF2α, and this may be a cause of the increased foetal mortality that occurs between days 60 and 90 of pregnancy in these mares.     

Arteria maxillaris of the donkey (Equus asinus)

Gross anatomical examination of the organization of the maxillary artery was carried out in 10 formalin embalmed, latex injected adult donkeys. The results indicate that although there are variations from other domestic animals, the distribution of this artery in the donkey is similar to that of the horse.