水在奶牛饲养中的重要作用

奶牛的饮水量与其体格、年龄、活动量、产奶量以及环境等因素有关，饮水不足会降低奶牛干物质的采食量，进而影响生产性能。为了提高奶牛的饮水量，要保证水源的清洁卫生、水温适宜、水的压力和导电性适度，以及考虑在全混日粮中添加水分。奶牛对水质问题比较敏感，污染物、细菌类、化学品和矿物质等均会影     

奶牛的水营养

水在奶牛机体代谢中具有极其重要的作用,对奶牛的健康和生产性能有着重要的意义.本文综述了水在奶牛体内的代谢特征,影响奶牛饮水量的因素,奶牛饮用水的水质及饮水量的计算,总结了奶牛饲养过程中有关饮水的实践经验和理论研究结果.     

奶牛生产中的饮水科学

水是一种重要的营养物质，对奶牛的健康和产奶性能以及牛奶品质影响非常大，随着人们生活水平的提高不仅对牛奶需求增大，对牛奶的品质也日益关注，生产优质无害牛奶的前提是良好的饮用水源，而国内大多数奶牛场对奶牛饮水问题却不够重视，本文对奶牛科学饮水问题作出阐述。     

奶牛生产中的饮水科学

水是一种重要的营养物质,对奶牛的健康和产奶性能以及牛奶品质影响非常大,随着人们生活水平的提高不仅对牛奶需求增大,对牛奶的品质也日益关注,生产优质无害牛奶的前提是良好的饮用水源,而国内大多数奶牛场对奶牛饮水问题却不够重视,本文对奶牛科学饮水问题作出阐述。     

水是家禽生产中的重要投入

近年来我们作了很多努力来提高家禽生产的标准，对鸡场卫生，鸡的饲喂和饲料生产等过程中细节问题的注意，已经大大降低了污染水平，然而，水，家禽生产中的这一重要营养成分，却常常遭到忽视。笔从非常实用的角度对水的化学处理和在供水过程中发生的污染情况作了独特的观察和论述。     

水在奶牛生产中的作用

本文论述了奶牛饮水这一重要的理念,并从饮水的数量、质量、温度、诱导饮水等几个方面论述了提高饮水量的具体措施,以科学地指导奶牛生产。     

用氨化稻草饲养水奶牛试验

用氨化稻草饲养水奶牛试验陈宇平，陈奕成（广东省吴川县畜牧局５２４５００）水奶牛是否高产稳产除遗传因素外、饲料是一关键因素。对稻草进行氨化、碱化处理是改善饲料因素的一个重要方法。为此，在湛江市畜牧局的支持、指导下，吴川县畜牧局于去冬今春在吴川县畜牧试验...     

奶牛胎水过多的诊治

2003年11日24日我院收治了1头怀孕5个半月的黑白花奶牛。临床表现为腹围异常膨大，呼吸困难，经诊断和治疗确诊为胎水过多症。此病在临床上较为罕见。     

确保奶牛高产的饮水量技术措施

以数据简要论述了奶牛饮水比饲料更为重要的理念.采取从饮水的数量、质量、温度、诱导饮水等方面来提高饮水量的具体措施,以科学地指导奶牛生产.     

氧化应激对奶牛的危害及其防治

氧化应激是当机体遭受到体内外各种有害刺激时,氧化系统和抗氧化系统失衡,自由基的产生量超过机体的清除能力,抗氧化系统不能及时清除过多的自由基而造成的。氧化应激与多种疾病的发生相关。奶牛的代谢水平高,更易发生氧化应激。本文就奶牛氧化应激的产生、氧化应激对奶牛的影响以及如何抑制奶牛氧化应激做一综述。     

Adjusting for heterogeneity of experimental data in genetic evaluation of dry matter intake in dairy cattle

The objectives of the present study were (i) to find the best fitted model for repeatedly measured daily dry matter intake (DMI) data obtained from different herds and experiments across lactations and (ii) to get better estimates of the genetic parameters and better genetic evaluations. After editing, there were 572,512 daily DMI records of 3,495 animals (Holstein cows) from 11 different herds across 13 lactations and the animals were under 110 different nutritional experiments. The fitted model for this data set was a univariate repeated‐measure animal model (called model 1) in which additive genetic and permanent environmental (within and across lactations) effects were fitted as random. Model 1 was fitted as two distinct models (called models 2 and 3) based on alternative fixed effect corrections. For unscaled data, each model (models 2 and 3) was fitted as a homoscedastic (HOM) model first and then as a heteroscedastic (HET) model. Then, data were scaled by multiplying with particular herd‐scaling factors, which were calculated by accounting for heterogeneity of phenotypic within‐herd variances. Models were selected based on cross‐validation and prediction accuracy results. Scaling factors were re‐estimated to determine the effectiveness of accounting for herd heterogeneity. Variance components and respective heritability and repeatability were estimated based on a pedigree‐based relationship matrix. Results indicated that the model fitted for scaled data showed better fit than the models (HOM or HET) fitted for unscaled data. The heritability estimates of the models 2 and 3 fitted for scaled data were 0.30 and 0.08, respectively. The repeatability estimates of the model fitted for scaled data ranged from 0.51 to 0.63. The re‐estimated scaling factor after accounting for heterogeneity of residual variances was close to 1.0, indicating the stabilization of residual variances and herd accounted for most of the heterogeneity. The rank correlation of EBVs between scaled and unscaled data ranged from 0.96 to 0.97.     

奶牛新陈代谢模型研究进展

本文对奶牛新陈代谢模型研究进展进行了综述。     

牛源环孢子虫的形态学特征观察

对首次在乳牛粪便中发现的疑似环孢子虫卵囊的形状、大小、抗酸染色和孢子化等形态学特征进行了观察，探讨了该原虫的纯化方法。结果显示，牛源环孢子虫卵囊呈球形，直径6～10μm。直接涂片时可见卵囊内含折光性较强的成团小球体，呈桑椹胚状，淡绿色。碘液染色不着色。经改良抗酸染色后，卵囊着色变化较大，呈淡红色、深红色或不着色。新排出的未孢子化卵囊培养后可观察到孢子化的卵囊，内含2个孢子囊，每个孢子囊内含有2个折光性较强的子孢子。这些特征与人或其他动物的环孢子虫一致。环孢子虫感染阳性的粪便经Sheather＇s蔗糖漂浮法浓集后，再经蔗糖密度梯度离心，可以得到较为纯净的卵囊。     

中药治疗奶牛乳房炎的研究现状与展望

综述了中药治疗奶牛乳房炎的临床应用、机理和特点,认为中药治疗奶牛乳房炎采用辨证施治方法,毒副作用小且不易产生耐药性;指出了中药治疗奶牛乳房炎存在的问题,主要是基础研究薄弱、生产工艺落后、无固定标准、药品质量难以保证等.由于中药治疗奶牛乳房炎疗效确实,因而潜力巨大.     

甘蔗渣作为粗饲料对奶牛生产性能、养分消化和采食行为的影响

文章旨在评价甘蔗渣作为粗饲料对泌乳奶牛采食量、消化率、采食行为、泌乳量、乳成分及微生物蛋白合成等方面的影响。试验选择10头初始体重为(450±25.6)kg,泌乳天数为(143.7±30.7)d的杂交奶牛为研究对象,试验采用5×5拉丁方设计,饲喂周期为5个21 d(1~14 d为适应期,15~21 d为数据采集期)。试验日粮分为对照日粮、45%、50%、55%和60%甘蔗渣日粮。结果:对照组与45%和50%甘蔗渣组干物质、有机物、总可消化养分摄入量、干物质和有机物消化率无显著差异(P>0.05),而55%和60%甘蔗渣组干物质和有机物消化率最低(P<0.05)。甘蔗渣组与对照组对中性洗涤纤维摄入量和表观消化率的影响具有显著差异(P<0.05),其中45%甘蔗渣组奶牛的非纤维碳水化合物摄入量和消化率与对照组相似(P>0.05)。日粮甘蔗渣添加水平对营养物质的摄入量和消化率呈显著线性降低(P<0.05)。60%甘蔗渣组较对照组显著降低了奶牛反刍时间,显著提高空闲时间(P<0.05)。奶牛的反刍时间、反刍和采食效率随日粮甘蔗渣添加水平的升高显著线性降低(P<0.05),而空闲时间随饲粮中甘蔗渣含量的增加线性增加(P<0.05)。结论:日粮添加甘蔗渣降低了奶牛日产奶量,但添加水平为45%~50%时可以使奶牛泌乳量达到12 kg/d。     

黑龙江省主要栽培的禾本科牧草对奶牛的营养价值评价

通过对常见的13种栽培禾本科牧草的常规营养成分测定及用尼龙袋法测定的干物质在瘤胃72 h降解率(RDMD)的测定,结果表明:l)用营养成分和RDMD等指标进行评定,2个冰草Agropyron cristatum品种营养价值最高,猫尾草Phleum pratense次之,3个披碱草Puccinellia tenuiflora品种居中,羊草Leymuschinensis和墨西哥玉米Zea mays较差,谷莠子Setaria anceps和稗草Echinochloa crusgalli最差。2)禾本科牧草RDMD与ADF、ADL含量呈极显著负相关(P<0.05)。利用回归方程可以用ADF、ADL含量来预测禾本科牧草的RDMD。3)应用干物质采食量(DMI)、产奶净能(NEL)估测模型计算了各种禾本科牧草的分级指数(GI)值,并参照豆科和禾本科牧草质量分级标准对研究测定的禾本科牧草等级进行划分,其结果是:符合优质牧草等级的有高冰草、中间冰草,符合中等牧草等级标准的有无芒雀麦Bromus inermis、垂穗披碱草、东北羊草、吉生羊草、百特猫尾草、猎犬披碱草、润宝高丹草Sorghum×Sudan。属于劣质牧草的有粗穗披碱草Elymus dahuricus、墨西哥玉米、稗草、谷莠子。4)用单一的营养指标如化学成分、干物质降解率不能准确地评价牧草的营养价值。只有综合考虑DMI、养分含量、消化率和有效能才能对牧草的营养价值做出正确的评价。使用GI值能明显区分养分含量差异很小的不同种类牧草,这说明分级指数是评价牧草营养价值的最权威指标。     

全混合日粮对奶牛产乳性能的影响

试验选用了12头奶牛,根据产奶量、泌乳天数和胎次相近的原则分为试验组和对照组,研究全混合日粮对奶牛产乳性能的影响。试验结果表明,试验组4％标准乳产量比对照组提高1 24kg,差异显著(P<0．05),乳脂率及乳脂、乳糖和乳固形物含量也分别比对照组显著提高11．60％、17．50％、13．21％和9．86％(P<0.05)。     

Use of thermal imaging for identification of foot lesions in dairy cattle

The objective of this study was to investigate the use of infrared thermography (IRT) for detection of foot lesions in dairy cattle. Thermal images of the rear feet of 139 lactating dairy cows were taken with a thermal camera and evaluated using imaging software. Foot lesions identified in the study included white line disease (WLD), sole ulcer (SU) and digital dermatitis (DD). Temperatures at the coronary band (CBT) and the skin (ST) were recorded. Cows were scored for locomotion on a scale of 1–5 (1?=?normal and 5?=?severely lame). CBT was higher for all types of foot lesion (34.1?±?2.3, 33.8?±?1.6 and 33.1?±?1.6°C for WLD, SU and DD, respectively) than for healthy (32.6?±?1.9°C) feet. ST was higher only for WLD (33.2?±?2.0°C) compared to healthy feet (31.5?±?1.7°C). ΔT (temperature difference between CBT and ST) was higher for SU (2.1?±?0.8°C) than healthy feet (1.1?±?0.9°C). Locomotion scores (LSs) were similar between healthy cows (2.2?±?0.7) and DD (2.4?±?0.7) but greater for SU and WLD cows (3.0?±?0.9, 3.0?±?0.8) than healthy cows. The threshold values established for CBT and ST were 33.5°C (sensitivity?=?77.8%, specificity?=?65.2%) and 33.7°C (sensitivity?=?44.4%, specificity?=?92.9%) for SU, and 34.4^oC (sensitivity?=?28.1%, specificity?=?88.6%) and 31.8°C (sensitivity?=?60.7%, specificity?=?55.4%) for overall lesion, respectively. These results indicate that IRT can be a useful tool for detection of SU, but not WLD and DD. In addition, CBT and ΔT were the best indicators for the detection of foot lesions.     

奶牛营养平衡与需要量

随着我国奶牛业的快速发展,奶牛对日粮营养平衡的要求越来越高,而正确理解奶牛的营养需要对制定营养平衡的日粮配方非常重要。本文主要从能量、蛋白质、纤维、矿物质和维生素方面探讨奶牛的适宜营养需要量。