酒精试验对水牛乳品质评价的可应用性探讨

通过测定水牛乳的滴定酸度、乳成分及64%、66%、68%、70%（V/V）酒精试验,分析酸度及乳成分对水牛乳酒精阳性发生率的影响,探讨酒精试验用于水牛生乳计价及拒收依据的可行性。结果表明,64%的酒精更适用于水牛乳,但仅能作为初步或辅助的品质评价手段;通过分析乳成分对不同酒精浓度下低酸度酒精阳性乳发生率的影响,表明蛋白质、乳糖加灰分含量越高,低酸度酒精阳性乳发生率越高,但脂肪含量对低酸度酒精阳性乳的发生无显著影响。     

如何提高牛乳品质

作者从营养调控、日粮因素、管理措施等影响牛乳品质的因素作一综述，并阐明提高牛乳品质的相应对策。     

牛乳品质的营养调控

发展畜牧业的根本目的 ,在于为人类生产数量更多、品质更好的肉、乳、蛋、毛等动物产品 ,故通过营养调控动物产品的品质 ,是动物营养学家近年来研究极为活跃的一个领域 ,本文旨在对牛乳品质的调控研究进行概述。1　调控牛乳组成牛乳中脂肪和蛋白质含量 ,是最重要的 2个质量指标。乳脂肪是牛乳中最主要的成分之一 ,脂肪热值高 ,并且是维生素Ａ、Ｄ、Ｅ、Ｋ的携带者和传递者 ,它含有相当数量的必需脂肪酸。乳脂含有大量的Ｃ 1 4∶0 (1 0 %～ 1 2 % )和Ｃ 1 6∶0脂肪酸(2 5 %～ 30 % ) ,而单不饱和及多不饱和脂肪酸含量相对较低。医疗界人士认…     

影响牛乳品质的因素

当今牛乳品质的优劣备受消费者和媒体关注,牛乳品质优劣受多种因素制约,了解这些影响因素,便于在乳与乳制品生产过程中进行卫生监督与检查,以提高产品的质量,保证人们食用安全。     

提高牛乳品质的对策

１乳成分变动的因素１．１乳成分产生的机理牛乳乳成分的原料均来自于血液,矿物质和维生素类可直接为乳成分,其他牛乳特有成分,均在乳腺细胞内合成。原料来自于摄取饲料及牛体组织,饲料在以第１胃为首的消化器官内分解、消化、吸收后,进入血液,在整个身体代谢中进行调整,最后送乳腺。输送到乳腺的原料物质,通过乳腺细胞表面毛细血管网,为乳腺细胞吸收,以进行牛乳合成。此外,在泌乳初期等高泌乳期,对于摄取饲料不足部分,由体组织（主要为体脂肪）营养成分进行补充。乳蛋白质中,由乳腺细胞利用血液中氨基酸合成的有酪朊（占整个…     

水牛乳营养成分浅析

对水牛品种、区域分布、水牛乳营养成分进行了综合论述,并对水牛乳中的蛋白质、脂肪、矿物质、维生素以及生物活性成分进行分析,为我国水牛乳的发展及研究提供参考。     

低酸度酒精阳性水牛乳对酸奶品质影响的研究

以正常乳为时照,对低酸度酒精阳水牛乳用于加工酸奶的可利用性进行了研究.在对正常水牛乳及低酸度酒精阳性水牛乳的理化特性进行分析的基础上,用这两种水牛乳按相同工艺条件分别加工成酸奶,对产品进行理化指标测定和感官评价.结果表明:采用低酸度酒精阳性乳与正常水牛乳加工的酸奶,除弹性有显著性差异(P＜0.05)外,其它指标均与正常乳无显著性差异(P＞0.05).     

牛乳品质与卫生研究

<正> 1 牛乳成分及特性1.1 牛乳成分有:水分、蛋白质、脂肪、乳糖、无机盐、磷脂、维生素、酶、免疫体、色素、气体及其他微量成分。牛乳中各主要成分的含量,就同一品种大致是稳定的,但除饲养管理外,它们还随着牛的年龄、胎次、泌乳期过程、季节等而有些变化。掌握其变化规律有利于组织牛乳生产和加工。我们曾于1981～1984年对四川省不同牛种的牛乳主要成分进行测定(%):     

动物营养与牛乳品质

牛乳具有特殊的营养价值,它是由水份、乳蛋白、乳脂肪、乳糖、矿物质、磷脂、维生素、酶类、免疫体、色素及一些其它微量成分构成的复杂的胶体系。乳成分的遗传特性较为稳定。一般来说,如果乳牛的饲料供给与饲养管理不当,不会使乳质特别是乳成分发生变化,却容易使乳产量发生变化。但是饲料中某些因素的变化也会对乳质产生影响,本文就饲料对牛乳中各种成分变化的影响作一综述。     

牛乳品质及其影响因素

<正>近年来,随着国民经济的发展和人民生活水平的不断提高,人们不再要求吃饱而是要求吃好,对乳品的消费量逐年增加,对鲜乳的品质要求更高。鲜乳营养成分比例合理,生理功能全面,对改善人们膳食结构,增加优质蛋白质和钙的供应,增进人体健康具有重要的意义。文章对牛乳品质进行了概     

Effect of water restriction on milk yield and quality in Lacaune breed ewes

The effect of water restriction on body weight, body condition score, milk yield, and milk composition and rheological characteristics in intensively reared Lacaune ewes was evaluated. After 7 days of adaptation, the trial lasted 28 days. Thirty lactating ewes (48 ± 5 months of age; mean value ± standard deviation) at the beginning of third lactation month were divided into three groups (n = 10), corresponding to the following water restriction treatment: a group control received no drinking water restriction (W100), and two groups received water to the extent of 80% and 60% of W100 daily consumption (W80 and W60 group respectively). The effects of water restriction were assessed at the beginning of experiment (D0), at D14 and D28. The W60 group resulted in a significant decrease in body weight, body condition score, milk yield and feed consumption of hay due to the experimental treatment; whereas a marked increase in both W60 and W80 groups of milk lactose, urea, sodium, sodium chloride content and titratable acidity was observed. Rheological parameters of milk, rennet coagulation time and curd‐firming time were positively affected by water restriction treatments, with a decrease in both experimental groups of the time required for the formation of a stable and firm curd. Results highlight the importance of water consumption in dairy sheep. The scarce availability of water, significantly affecting ewes milk production, is worthy of particular attention in arid area where water stress‐resistant breeds should be considered. This study underlines that milk yield, being closely linked to the availability of water of the breeding habitat due to its high water content (about 81%), could be reached in area where water is not a limiting factor without reducing the genetic expression of the animals. Less severe water restrictions, such as 20% of daily voluntary water intake, produce no detrimental effect on milk yield.     

沼泽型水牛卵泡发育波及其生殖激素变化的试验研究

运用B超跟踪观察经同期发情处理后的沼泽型水牛的卵泡发育动态,并应用放射免疫测定法(RIA)测定其发情周期中血清促卵泡素(FSH)、促黄体素(LH)、雌二醇(E2)、孕酮(P4)等生殖激素的含量,分析了沼泽型水牛的卵泡波情况,并比较了四种生殖激素在发情周期不同时间段及不同卵泡波类型之间的差异性。发现沼泽型水牛的发情周期由2个或3个卵泡波组成,以2个卵泡波为主;2个或3个卵泡波中各个波征集、选择的卵泡数之间无显著差异;血清FSH、LH、E2、P4水平在表现为不同卵泡波类型的青年水牛无显著差异(P>0.05)。     

Tropical milk production systems and milk quality: a review

We reviewed information on dairy cattle production systems in the tropics, the factors involved, and their influence on milk composition. Genetic factors had greater influence on milk production; specialized breeds produced more milk, and there was an inverse relation between the content of fat, protein, total solids, and the amount of milk produced. Season was related to the availability of forage, and the type of grazing system. Greater pasture area increased individual production, while a greater supply of feed concentrate did not increase milk production. The number of calvings positively affected milk production through the fifth calving, with subsequent declines in production. Milk production increased to a maximum and then declined as lactation progressed. Specialized systems had higher production and better hygienic milk quality; milking and container equipment are critical for maintaining milk sanitary quality. Factor interaction is highly complex, preventing the generation of specific recommendations and general principles applicable to the specific conditions for each system.