DHI牛奶测定技术在奶牛生产中的作用

DHI牛奶测定技术在我国经过近十年的推广实施已具一定的规模和影响 ,可应用于奶牛乳房健康管理、奶牛饲料营养调整、选种选配、牧场的日常管理等。1　 DHI牛奶测定技术的概念与意义DHI(Dairy Herd Improvement牛群改良 )牛奶测定技术是奶牛饲养的核心技术。旨在加强牧场的管理基础和遗传基础 ,提高奶牛生产的产量、质量和效率。主要通过每月一次对泌乳牛的牛奶测试 (测试牛奶脂肪、蛋白、乳糖和体细胞数 ) ,记录牛只基础资料 ,运用先进的牛群管理软件形成数据化的信息报告 ,最后以这些信息报告来指导生产和管理。2　 DHI牛奶测定技术…     

Procedure for Blood Glutathione Peroxidase Determination in Cattle and Swine

An improved testing system has been developed for direct measurement of glutathione peroxidase activity in heparinized whole blood at 37°C. Without loss in net yield the consumption of reagents has been found to be considerably lower with the new technique than with previously described techniques. Within the range 0–700 mKat/1 the GSH-Px activity in red cells may be measured with a high degree of accuracy and reproducibility without preceding separation and washing. The stability of the enzyme in bovine and porcine whole blood at 22°C, 4°C, and —20°C was determined.     

PCR技术及其在牛早期胚胎性别鉴定中的应用

本文对PCR(聚合酶链式反应)的基本原理、优点、方法及其在牛胚胎性别鉴定中的应用情况进行了扼要综述。     

Effect of Gestational Age and Fetal Position on the Possibility and Accuracy of Ultrasonographic Fetal Gender Determination in Dairy Cattle

The possibility and accuracy of transrectal ultrasonographic determination of foetal gender were studied by identifying and locating the genital tubercle, scrotum or mammary gland in 15 dairy cows at 49-168 days post-breeding. Ultrasound examinations were performed weekly. Each examination was made without references to the results of the examinations in the previous weeks. At each examination, an attempt was made to view the foetus in frontal, cross-sectional, and sagittal planes. The expected foetal gender was compared with that observed at birth. Gestational age affected significantly the possibility of foetal gender determination. The possibility of foetal gender determination increased from 26.7% at day 49 to 100% at day 56 of gestation. Between days 56 and 98, foetal gender determination was possible in all cases. Thereafter, the ability to determine foetal gender decreased with development of pregnancy and was impossible in all cases by days 161 and 168. The overall accuracy of foetal gender determination was 97.3%. Foetal gender determination between days 49 and 63 depended on the location of the genital tubercle in a frontal view of the foetus. By day 70, all foetal positions could be used for foetal gender determination. However, by progress of gestation, the usefulness of frontal view for sex determination decreased, while that of cross-sectional view increased. Accordingly, the best time for foetal gender determination in dairy cattle is between days 56 and 98 of pregnancy.     

奶牛隐性乳房炎与胎次、年龄关系的探讨

奶牛隐性乳房炎是一种复杂的导致奶牛业经济损失最严重的疾病,是奶牛养殖过程中的常见病之一,其发病率高。为了摸清南通红梅乳业牧场隐性乳房炎的发病情况,笔者用北京亚临床乳房炎快速诊断液做试验,从胎次、年龄等两个方面分别调查了隐性乳房炎的头阳性率、乳区阳性率,并进行卡方分析,得出奶牛隐性乳房炎的发病率同胎次、年龄等因素之间存在着密切的关系,随着胎次和年龄的增加隐性乳房炎的发病率呈上升趋势。     

牛双胎的研究与应用

牛双胎可显著的提高生产效率，对母牛和犊牛没有明显的不良影响，不利之处是异性双胎造成母犊不孕、。双胎是可以遗传的，双亲的影响较大；不同品种间的双胎率差异显著；另外胎次、季节、营养均影响双胎率。目前常用的提高双胎率的方法是通过遗传选择、激素诱导、激素免疫、胚胎移植等方法。但如果结合标记辅助选择法（MAS）、性别控制、及转基因与克隆技术将有助于快速提高双胎率，提高生产效益。     

我国不同地区肉牛舍夏季环境状况测定

对全国不同地区的8个肉牛场的牛舍夏季环境状况进行检测,测定了牛舍内外的温度和舍内的湿度、风速、照度以及CO2、NH3浓度。研究结果表明：我国北方牛舍环境状况较好,中原地区环境状况次之,基本能满足肉牛生长育肥的环境需求,南方牛舍环境存在高温高湿的问题,需采取适宜的防暑措施。     

我国不同地区肉牛舍夏季环境状况测定

对全国不同地区的8个肉牛场的牛舍夏季环境状况进行检测,测定了牛舍内外的温度和舍内的湿度、风速、照度以及CO2、NH2浓度.研究结果表明:我国北方牛舍环境状况较好,中原地区环境状况次之,基本能满足肉牛生长育肥的环境需求,南方牛舍环境存在高温高湿的问题,需采取适宜的防暑措施.     

中国黄牛骨龄与齿龄关系的研究

为研究中国黄牛骨龄与齿龄之间的关系,本文对1204头不同品种的中国黄牛进行了宰后齿龄判定和骨质化程度判定,然后对照《中国牛肉等级标准》（简写为CHN）和《美国牛肉等级标准》（简写为USA）得出骨龄,比较骨龄与齿龄的一致性。结果表明,根据CHN和USA判定出的骨龄总体上与齿龄有较好的一致性;对于24月龄以下的鲁西牛和秦川牛,根据CHN判定出的骨龄与齿龄一致性较差,而大于24月的试验牛骨龄与齿龄一致性较佳;对于30月龄以下的试验牛,根据USA判定出的骨龄与齿龄绝大部分一致,而30－96月龄的试验牛,骨龄与齿龄一致性较差;此外,黄牛品种对骨龄与齿龄之间的一致性不同。     

超声波技术在养牛业上的应用

超声波是频率高于20000 Hz的声波,在传播过程中具有方向性好、功率大、穿透性强,会引起空化作用等特点。作者结合超声波原理及其在传播过程中的特性,着重分析探讨了超声波在现代养牛业仪器清洗、繁殖监控和疾病诊断、活体肉质性状检测中的应用,并对其在未来的发展进行了展望。     

奶牛X、Y精子分离及胚胎性别鉴定技术的研究进展

近年来,奶牛胚胎移植技术的大范围推广应用,大幅度提高了国内外奶牛产业的发展速度。随着奶牛X、Y精子分离技术和性别鉴定的进一步研究,可以通过人为地干预或操作,使母牛按照人们的愿望繁殖所需的高产母牛犊,让特定品质的奶牛发挥自己的优势,对畜牧生产意义深远。笔者对该项技术的研究进展和应用前景作以总结,以供参考。     

肉牛EPD评价及其应用

EPD值是估计种值的一半，它是基因BLUP理论的一个容易理解和应用的，种畜遗传传递力的值，很直观的反映种畜价值在其后代中的体现。EPD在肉用种公牛价值评定上应用广泛，它地同一品种内个体间的比较，钭从出生到胴体的所有重要经济性状的EPD估计后，以出版和（或）上计算机网的方式发布，肉牛生产者根据自己的不同需要选用种牛，我国肉牛育种的资料，数据收集的相对难度可能是制约EPD应用的主要因素。     

肉牛育肥饲养管理技术推广应用

肉牛生产在我国畜牧养殖产业中扮演十分重要的角色,随着农牧产业结构不断调整,提高肉牛生产性能就成为目前需要重点解决的问题。该文主要结合实际情况,分析了肉牛育肥饲养管理技术,并论述了技术推广应用效果,以进一步加快先进技术的推广应用。     

肉牛育肥饲养管理技术推广应用

目前肉牛生产逐步由过去传统育肥向现代化育肥饲养转变。通过科学正确的技术和管理措施提高肉牛的育肥效果,已经成为当前肉牛养殖的重要发展方向。该文主要结合作者多年的技术推广经验,分析了肉牛育肥饲养管理技术,以进一步加速该项技术的推广应用。     

Chiral Inversion of (R)-Ketoprofen: Influence of Age and Differing Physiological Status in Dairy Cattle

The chiral inversion of ketoprofen has been previously demonstrated in cattle, but no studies have been performed on different ages and metabolic situations in the animals. The aim of this work was to study any modifications of the stereoconversion of ketoprofen that occur by reason of age, lactation or gestation in dairy cows. Holando Argentino cattle were divided into three groups: 8 cows in early lactation, 8 pregnant cows and 8 newborn calves. Four animals from each group received the enantiomer R-(–)-ketoprofen by intravenous administration; the other four animals received the S-(+) enantiomer, all at doses of 0.5 mg/kg. Blood samples were collected at standardized times after dosing and assayed for ketoprofen by high-performance reversed-phase liquid chromatography (HPLC). The percentage inversion of R-(–)-ketoprofen to S-(+)-ketoprofen was 50.5% (SD ± 2.4) in the preruminants, 33.3% (SD ± 1.7) in cows in early lactation and 26.0% (SD ± 5.1) in cows in gestation. These results indicate a differing enantioselective metabolic behaviour for one compound in one species under different physiological situations.