共查询到20条相似文献，搜索用时 62 毫秒
1.
目的：为研究酒精阳性乳的病因及其机制。在酒精阳性乳中,奶牛的血钙水平直接影响乳钙水平。有资料报道,奶牛酒精阳性乳与血清和乳的钙水平有关。方法：可以采用乙二胺四乙酸二钠滴定法,测定血清和乳中钙的含量。结果：试验结果表明,各组间相比较,血清钙中差异显著,乳钙中没有差异。结论：血液中钙含量的升高,导致了乳中钙含量的升高,从而引起牛乳稳定性的降低,导致出现酒精阳性乳。 相似文献
2.
奶牛酒精阳性乳是指在鲜乳中加入68％、70％、72％的酒精后，会产生絮状凝块的乳。酒精试验是收购鲜奶时的常规检验方法，酒精阳性乳加热会凝固，又不能用于乳品加工。 相似文献
3.
酒精阳性乳是指挤出的牛奶在20℃奶温下与等量的70%(68%～72%)酒精混合,产生细微颗粒或絮状凝乳的总称。本文简要介绍了造成酒精阳性乳的主要因素及防治措施,对奶牛养殖户和乳品加工企业在鲜乳生产收购时准确判断提供依据。 相似文献
4.
5.
奶牛低酸度阳性乳和高酸度乳、乳房炎乳、冻结乳同属酒精阳性乳，如用68％、70％或72％的酒精与等量鲜乳混合后呈阳性变化(产生凝絮)。由于低酸度酒精阳性乳发生因素较为复杂，且可用作乳制品加工原料，而与高酸度乳、乳房炎乳、冻结乳有根本的区别。笔者结合多年诊疗体会，对出现低酸度酒精阳性乳奶牛的临床表现和发生原因总结如下： 相似文献
6.
酒精阳性乳是指在鲜乳中加入68～70%酒精后,产生絮状或凝块的乳。此种乳酸度高,通常在24°T以上,加热发生凝固。所以不能用于乳制品加工。因此68～70%酒精试验是鲜乳收购时的一种常规有效的检验方法。酒精阳性乳的产生原因,鲜乳在挤乳、收集、装灌及运输过程中不合卫生要求,或保存未及时冷却,乳中微生物迅速繁殖, 相似文献
7.
酒精阳性乳是指用68%或70%酒精与等量的牛乳混合产生微细颗粒或絮状凝块的牛乳.根据酒精阳性乳酸度的差异,可将其分为高酸度酒精阳性乳和低酸度酒精阳性乳2种. 相似文献
8.
乳品厂常用酒精试验作为检验牛乳品质优劣的一个指标,同时也用来作为评定牛乳酸度变化的依据。取一定量68%~72%的酒精于试管内,加入等量的牛乳混合振摇,出现白色颗粒或絮状物的为阳性,即为酒精阳性乳。市场上鲜牛奶的酸度一般要求不超过20＆#176;T,对制造炼乳的原料一般要求不超过18＆#176;T。凡属酒精阳性乳,不论其酸度高低、加热凝固与否,皆按不合格牛乳品处理的做法是不妥的。 相似文献
9.
奶牛酒精阳性乳的临床调查分析 总被引：4，自引：0，他引：4
酒精阳性乳是指用68％或70％酒精(生产上常用72％酒精)与等量牛乳混合而产生微细颗粒或絮状凝块的牛乳。根据酒精阳性牛乳酸度的差异．可将其分为高酸度酒精阳性乳和低酸度酒精阳性乳两种。高酸度酒精阳性乳其发生原因是因牛乳在收藏、运输等过程中，由于卫生消毒不严．未及时冷却．乳中微生物迅速繁 相似文献
10.
碘与酒精阳性乳相关性的探讨 总被引：2，自引：0，他引：2
当前我国奶牛业发展很快 ,而因奶牛酒精阳性乳的发生造成乳的废弃使奶牛业损失很大。目前 ,奶牛酒精阳性乳的发生原理还不清楚 ,本试验力图探讨其发生原理。试验通过对酒精试验 ,乳脂率 ,导电率及酸度值的测定发现 ,奶牛酒精阳性乳的发生率与气候变化有密切关系 ,酒精阳性牛乳的乳脂率高于正常乳 0 .3～0 .5个百分点 (p <0 .0 5)。给酒精阳性乳奶牛投服自制补碘丸剂 ,治愈疗效高达 80 %以上 ,提示酒精阳性乳的发生与甲状腺功能降低有关。我们认为 :奶牛酒精阳性乳的发生主要归因于甲状腺功能低下 ,通过适当补碘提高甲状腺功能 ,促进甲状腺素的分泌 ,维持正常乳腺功能 相似文献
11.
For food evaluation the determination of the number of Staphylococcus aureus (hereinafter S. aureus) colonies is insufficient in view of present scientific knowledge. The results, advantages and shortcomings of diagnostic methods are demonstrated on an example of three methods of detection of staphylococcal enterotoxins in milk and milk products. 133 strains were investigated by the method of biotyping of S. aureus strains. Four strains of S. aureus were included in biotype A, seven xin-producing strains were isolated seventeen times by detection of 96 S. aureus strains were not included in any biotype, the other strains belonged to biotypes C and E. This method can be used as an auxiliary method of evaluation of foods containing S. aureus bacteria. The agar-gel precipitation method of enterotoxin detection in isolated strains of S. aureus has just restricted validity. The enteroto-strains. The main shortcoming of this method is a fact that the result concerning the isolated strains need not be identical with the result of enterotoxin detection in food. Direct assays of staphylococcal enterotoxins in milk and milk products using an enzymoimmunological method seem to be the most promising, mainly due to their high sensitivity (0.0001-0.001 micrograms.ml1-) and other advantages. Positive and negative results are presented on an example of two model trials with winter sheep milk cheese. 相似文献
12.
The survival of Brucella abortus in milk and milk products 总被引：1，自引：0，他引：1
13.
There are a number of factors that must be considered in any attempt to control animal drug residues in milk and milk products. Dairy herds vary greatly in number of cows. Milk from individual cows and farms is pooled, diluting drug residues that may be present in the milk from a single treated cow. Management techniques, including the handling, administration, and record keeping of animal drugs, vary greatly from one dairy to another. It is important that both veterinarians and nonveterinarians adhere to adequate milk discard times for animal drugs used to treat dairy animals. Observance of appropriate safeguards at the farm level, such as record keeping and clearly identifying treated animals, is critical for controlling and preventing the presence of illegal animal drug residues. Within the framework of the Federal Food, Drug, and Cosmetic Act and the Public Health Service Act, the FDA is working with state and other regulatory agencies and industry to better ensure the absence of illegal animal drug residues in milk and milk products. Preventive measures concentrate on minimizing the need to administer animal drugs to lactating cows, and diverting milk containing drug residues from the human food supply. Monitoring programs concentrate on screening milk and tracing violations to the individual producer. Minimizing illegal drug residues in milk and milk products requires close cooperation between farmers, veterinarians, the dairy industry, the pharmaceutical industry, and regulators. 相似文献
14.
奶牛的产后瘫痪，是奶牛分娩后突然发生的急性低血钙症。以知觉消失、四肢瘫痪为主要特征，多产、产奶量高、青壮年的奶牛易发，如果治疗不及时，常导致死亡。近几年笔者对22例发病牛进行了诊断治疗，并对奶牛日常饲养管理状况进行调查分析，现将诊治体会报告如下。 相似文献
15.
16.
随着人们生活水平不断提高,对奶的需求也在逐步增加,乳牛饲养在辽宁省迅速发展起来.为满足市场需求解决供求之间的矛盾,在大力发展乳牛数量的同时,要不断改进乳牛的培育方法. 相似文献
17.
为掌握牦牛乳常规营养成分以及不同成分间的相关关系,为下一步牦牛乳用性能选育提供理论基础,本试验对青海高原型牦牛纯放牧条件下(7月底)牦牛乳成分进行了测定,利用SPSS软件对各营养成分间的相关性进行了分析。结果表明∶纯放牧条件下,牦牛乳乳脂率为7.42±1.8956%,乳蛋白率为3.91±0.1619%,乳糖为5.88±0.2375%,非脂乳固体为10.78±0.4238%,密度为1033.45±2.3144kg/m^3,冰点为-0.7377±0.0346℃,盐为0.82±0.041%,电导率为4.74±0.0821s/m。相关性分析表明乳脂肪与密度和盐呈极显著负相关,乳蛋白质、乳糖、非脂乳固体、密度、盐两两间呈极显著正相关(P<0.01),冰点与乳糖、乳蛋白、非脂乳固体呈极显著负相关(P<0.01),冰点与密度和盐没有相关性,电导率与各乳成分之间没有相关性。 相似文献
18.
饲料中添加沸石粉对奶牛产奶量及乳成分的影响 总被引：2，自引：0，他引：2
在奶牛精料中添加 3%、5 %的沸石粉 ,研究其对产奶量及乳成分的影响 ,经过 5 0天的试验 ,结果表明 :添加 3%沸石粉的试验组产奶量比对照组提高了 3 0 9%(P >0 0 5 ) ,添加 5 %的试验组产奶量比对照组提高了 7 96 %(P <0 0 5 )。添加沸石粉的试验组与对照组相比乳脂率分别下降了 12 5 %和 15 6 %(P <0 0 5 ) ,乳蛋白分别下降了 3 8%和 3 2 %(P >0 0 5 )。 相似文献
19.
提高乳牛奶产量和奶品质的几项措施 总被引：1，自引：0，他引：1
自三鹿奶粉事件以后,人们对牛奶的品质要求更高,养牛户对乳牛的产奶量更加关注,那么我们怎样做才能更好的提高乳牛奶产量和奶品质呢?科学的饲养管理是提高乳牛的奶产量和奶品质的主要途径,喂给丰富的、易消化的饲料,可提高奶中脂肪和蛋白质的含量. 相似文献
20.
M.A.S. Gama P.C. Garnsworthy J.M. Griinari P.R. Leme P.H.M. Rodrigues L.W.O. Souza D.P.D. Lanna 《Livestock Science》2008,115(2-3):319-331
This experiment was designed to examine changes in milk fatty acids during fish oil-induced milk fat depression (MFD) and to test the theory that these changes are related to milk fat fluidity. The experiment was divided into three periods: 1) Baseline: all cows (n = 12) received a high fiber diet without fish oil (FO) for 12 days; 2) Treatment: 4 cows/group received the following treatments for 21 days: a) Low fiber diet without FO (LF), b) High fiber diet + FO (HF + FO) and c) Low fiber diet + FO (LF + FO); 3) Post-treatment: cows returned to the baseline diet and were monitored for 12 days. FO was included at 1.6% DM and HF and LF diets had 40 and 26% NDF, respectively. Milk fat content and yield were unchanged by the LF diet, but were reduced by FO diets at both dietary fiber levels and recovered in the post-treatment period. FO diets caused a pronounced reduction in stearic and oleic acid concentrations in milk fat and an equally pronounced increase in trans-18:1 fatty acid concentrations. Milk fat mean melting point (MMP) was correlated with MFD (r = 0.73) and with milk oleic acid concentration (r = − 0.92). The ratio of oleic:stearic in milk fat increased gradually and consistently in response to FO. Trans-C18:1 isomers with double bounds at carbon ≤ 10 increased with greater MFD and those with double bonds at carbon ≥ 11 decreased with greater MFD. Trans-9 cis-11 CLA explained more than 80% of MFD and was strongly correlated with trans-10 C18:1. Maintenance of MMP below 39–40 °C suggests that the mammary gland was able to secrete only milk fat with adequate fluidity and that MFD could be an adaptation mechanism to prevent secretion of milk with higher MMP. 相似文献