浅谈饲料因素与牛奶品质的关系

牛奶具有特殊的营养价值，其成分可分为水和固形物两部分，固形物包括乳蛋白、乳脂肪、乳糖、矿物质、维生素等多种物质。固形物含量的多少影响着乳质的优劣。正常牛奶中各种成分的组成大体上是稳定的，但是某些因素也会对乳质产生影响，例如牛的品种、个体、地区、泌乳期、畜龄、挤奶方法、饲料、季节、环境及健康状态等。本文仅就饲料营养成分对乳质的影响作一综述。１饲料营养与乳脂的关系乳脂率是衡量乳质优劣的重要指标，它受日粮的影响最为敏感，在主要固形物中变化范围最大。乳脂是由两种基本类型的前体合成的，其中，约一半的脂肪是…     

饲料与环境参数对牛奶质量的影响

牛奶的成分分为水和固型物两部分，固型物包括脂肪、蛋白质、乳糖、矿物质和维生素等，其成分含量的多少，影响着牛奶的质量。     

饲料与环境对牛奶质量的影响

牛奶的成分分为水和固形物两部分，固形物包括脂肪、蛋白质、乳糖、矿物质和维生素等多种物质。固形物各种成分含量的多少，影响着牛奶的质量。     

饲料等因素对牛奶质量的影响

牛奶的成分分为水和固形物两部分。固形物各种成分含量的多少，除受遗传因素影响外，饲料等因素对其影响很大，现简介如下。     

霉菌对饲料营养成分等的影响

长有霉菌的饲用谷物,因营养成分的减少、真菌病和霉菌毒素中毒症,给牛生产带来威胁。真菌病是真菌直接感染动物体而引起的疾病。霉菌毒素中毒症是摄入霉菌毒素而引起的中毒症状。不过,最常见的影响是采食量减少、体增重下降、下痢、流产和死亡等。     

饲料中黄曲霉毒素检测及其对牛奶品质的影响

黄曲霉毒素是一种霉菌产生的毒素,易存在各类饲料和食品中。本研究采用免疫亲和柱-荧光光度法对牛奶中的黄曲霉毒素M1进行测定,而饲料中的黄曲霉毒素B1采用酶联免疫法检测,研究结果发现：本实验中的黄曲霉毒素M1的荧光光度计的最佳光谱发射波长为450 nm,分析阴性牛奶产品的黄曲霉毒素M1含量,确定数据的精确性,牛奶回收率为76.67%～93.33%,变异系数为0.45%～2.8%,满足我国制定的检测标准,该方法操作简单、快速和安全。奶牛饲料中青绿饲料、粗饲料、能量饲料和蛋白饲料样品的黄曲霉毒素B1的测定率为100%,奶牛饲料中被检测的青绿饲料、粗饲料、能量饲料和蛋白质饲料阳性样品中黄曲霉毒素B1的含量分别为11.45、4.25、5.24和7.58 μg/kg,均小于20μg/kg（国家卫生部门制定标准）,属于轻度污染|不同类型牛奶样品中阳性最高值为0.201 μg/kg,阳性最低值为0.004 μg/kg,平均值最大为0.084 μg/kg,严重超过我国卫生部门制定的标准。[关键词]饲料|黄曲霉毒素|牛奶品质     

牛奶品质与饲料营养

牛奶是我们每天早餐的必需品,可以带来能量,牛乳具有很高的营养成分,不但物美价廉,而且有利于机体的吸收。奶中的蛋白质主要是白蛋白、酪蛋白、球蛋白、乳蛋白等,其中所含的20多种氨基酸中有人体必须的8种,奶蛋白质是全价的蛋白质,消化率98%。但一般的牛奶保质期都比较短,容易出现变异,牛奶变异成分不但受所处环境的影响,而且还受到遗传因素的影响。因此,选择适合奶牛的药品、适量的饲料添加剂,在此基础上保持环境的整洁,对提高牛奶质量具有很大的影响。     

饲料成分与牛奶质量的关系

1 饲料中的碳水化合物与奶质的关系 乳脂是牛奶成分中最不稳定的组成部分,其浓度受饲料中的淀粉和纤维的相对制约。淀粉能增强奶牛瘤胃发酵,降低pH值,促进丙酸的生成。丙酸是糖原的前体物质,也是作用于胰岛分泌胰岛素的物质,作为     

饲料营养对猪肉品质的影响

１ 猪肉品质常用评价指标及其组织生化基础１．１ 肉色 是反映肌肉生理、生化和微生物学变化的综合指标。主要决定于肌肉中的肌红蛋白（Ｍｂ，约７０％～８０％）和血红蛋白（Ｈｂ，约２０％～３０％）含量，也受外界光照和氧化的影响。两种蛋白质呈色的实质在于其分子内的亚铁血红素（Ｆｅ２＋）与氧的结合使肌肉表现不同颜色。如果猪肉与空气充分接触，形成氧合Ｍｂ，肉呈亮红色；缺氧时，Ｍｂ中的Ｆｅ为氧化态，称变性Ｍｂ，肉色为暗褐色。１．２ ＰＨ值 ＰＨ直接影响肉的颜色、嫩度、烹煮损失和肉的保藏期。正常情况下，猪死后，要通过…     

饲料中添加沸石粉对奶牛产奶量及乳成分的影响

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 )。     

茶饲料对鸡蛋品质的影响

茶是具有独特功效的天然植物,将其添加到饲料中具有良好的应用效果。在家禽生产方面,不仅能提高免疫能力、生产性能,又能增强家禽产品的品质。本文简要概述茶饲料对鸡蛋品质的影响,以期对生产实践有一定的参考。     

畜禽采食量的调节

采食量是影响畜禽生产性能的主要因素;动物根据食物提示因子决定是否采食,根据采食后的消化生理反应决定采食多少;影响采食量的因素是多方面的,包括日粮营养、饲养管理、环境等;瘦素、NPY、增食欲素、生长素等是近年来在人的肥胖领域研究较多的食欲调节肽物质,能否或如何应用于畜牧生产尚需摸索.     

配合饲料质量营养平衡是关键

1　营养平衡与饲料产品的质量1 1　营养物质间的平衡关系　尽管各种营养物质之间有拮抗 ,有协同 ,关系极为复杂 ,但重点掌握好以下几方面 ,对饲料产品质量营养平衡会有益处。1 1 1　水　水是最重要的营养物质。但在实际生产中 ,人们往往忽视水的质量。高氟地区水中氟的含量 ,盐碱地区水中Cl、Na、K等矿物盐的含量 ,受污染水源中细菌数量及水中各种有害成分的存在 ,都可在某种程度上影响动物生产水平。因此 ,在设计饲料配方时 ,水对饲料各种营养成分 ,特别是微量成分的干扰应引起重视。1 1 2　能量　能量为动物维持生命活动和生长发育…     

Effects of malic acid on feed intake, milk yield, milk components and metabolites in early lactation Holstein dairy cows

The objective of this study was to evaluate the effects of malic acid (MA) on feed intake, milk yield and composition, blood metabolites and energy balance in early lactation Holstein dairy cows from 1 to 63 day in milk (DIM). Twenty-eight multiparous Holstein dairy cows, blocked by lactation number, previous 305-d mature equivalent milk production, and expected calving date, were arranged into four groups in a randomized block design. Treatments were: control (without MA), LMA, MMA and HMA with 70, 140 and 210 g malic acid per cow per day, respectively. The supplement of food grade MA (99.8% of MA) was hand-mixed into the top one-third of the daily ration. Cows were fed ad libitum a total mixed ration consisting of equal proportion of forage and concentrate. Milk yield increased (P = 0.04), but feed intake and milk components were not affected (P > 0.05) by MA supplementation. The energy balance, expressed as the difference between energy input and output, tended to be higher (P = 0.08) for MA supplemented cows during the 63-DIM period MA and supplemented cows showed a trend (P = 0.07) toward less loss of BW during the 63-day period, especially during the first 21-day of lactation. Concentrations of plasma glucose and serum insulin were higher for cows fed LMA, MMA, and HMA relative to control and linearly (P < 0.01) increased with increasing MA supplementation. Concentrations of non-esterified fatty acids (NEFA), beta-hydroxybutyrate (BHBA) and urine ketones were lower for MA-supplemented cows at 7, 14 and 21 DIM of lactation and linearly (P < 0.01) decreased with increasing MA supplementation. Although feed intake was not affected, milk yield increased, MA-supplemented cows experienced higher concentrations of plasma glucose and serum insulin, lower concentrations of plasma BHBA and NEFA, and lower concentrations of urine ketones, suggesting that nutrient digestibilities and energy availability may have been improved.     

Effect of feed restriction on dairy cow milk production: a review

In the dairy cow, negative energy balance affects milk yield and composition as well as animal health. Studying the effects of negative energy balance on dairy cow milk production is thus essential. Feed restriction (FR) experiments attempting to reproduce negative energy balance by reducing the quantity or quality of the diet were conducted in order to better describe the animal physiology changes. The study of FR is also of interest since with climate change issues, cows may be increasingly faced with periods of drought leading to a shortage of forages. The aim of this article is to review the effects of FR during lactation in dairy cows to obtain a better understanding of metabolism changes and how it affects mammary gland activity and milk production and composition. A total of 41 papers studying FR in lactating cows were used to investigate physiological changes induced by these protocols. FR protocols affect the entire animal metabolism as indicated by changes in blood metabolites such as a decrease in glucose concentration and an increase in non-esterified fatty acid or β-hydroxybutyrate concentrations; hormonal regulations such as a decrease in insulin and insulin-like growth factor I or an increase in growth hormone concentrations. These variations indicated a mobilization of body reserve in most studies. FR also affects mammary gland activity through changes in gene expression and could affect mammary cell turnover through cell apoptosis, cell proliferation, and exfoliation of mammary epithelial cells into milk. Because of modifications of the mammary gland and general metabolism, FR decreases milk production and can affect milk composition with decreased lactose and protein concentrations and increased fat concentration. These effects, however, can vary widely depending on the type of restriction, its duration and intensity, or the stage of lactation in which it takes place. Finally, to avoid yield loss and metabolic disorders, it is important to identify reliable biomarkers to monitor energy balance.     

加工工艺对饲料营养价值及动物生产性能的影响

饲料是畜禽生产上开支最大的一项，在我国饲料支出约占总成本的６５％～７０％，通过恰当的加工方法可以获得较好的经济效益。饲料加工的目的正是为了充分发挥饲料营养价值的潜力，提高产品质量和饲养效果。饲料加工对动物营养的影响一直是饲料加工工艺学家和动物营养学家关心的问题，将加工工艺学和动物营养学有机结合起来能够更大提高动物生产性能。１粉碎粉碎的主要目的是增加饲料接触消化酶的表面积，以使之更易于消化，这也是饲料搅拌、制粒和接受其它处理所必需的。目前许多研究结果表明：粉碎对饲料营养价值和畜禽的生产性能有明显的…