奶牛外貌评分与产奶量相关性研究

某奶牛场随机取30头奶牛,测定其305天产奶量及10个体型外貌评分性状,计算产奶量与体型性状之间的相关系数,求得产奶量的各自通径系数,研究奶牛10个体型性状与生产效率性状之间的关系。结果表明,整体评分与305天产奶量之间存在弱正相关（P〉0．05）;10个评分性状中,后乳房高度和宽度与305天产奶量呈极显著相关（P〈0．01）。乳房中隔和乳房深度与305天产奶量呈显著相关（P〈0．05）。整体外貌评分、后乳房宽度、乳房中隔越高则产奶量也越高,后乳房高度和乳房中隔是对产奶量起主要作用的性状。     

奶牛体型外貌评定方法

奶牛体型外貌评定是对奶牛体况进行无偏见评定的一种方法。中国奶协与中加奶牛综合育种项目进行磋商后决定 ,根据中加项目点采用加拿大的９分制奶牛体型外貌评定方法的运用情况 ,在全国更大范围组织推广 ,在此基础上 ,制定出适合中国国情的奶牛体型外貌评定方法。具体评定按奶牛体型外貌评定表进行。（见附表）通过体型外貌评定收集的数据将用于奶牛场的管理和公牛的后裔测定。奶牛的使用年限及淘汰其体型外貌是影响因素之一。由于后备母牛的饲养成本大幅度上升 ,奶牛的使用年限及淘汰与牧场的经济效益息息相关。精确性和持续性是进行有效的…     

EXCEL在奶牛线性外貌评分中的应用

1　原理概述EXCEL具有强大的计算和统计分析功能 ,并具有操作方便简单、界面美观、易于掌握等特点。因此EXCEL这一软件已在世界范围内广泛应用。运用EXCEL进行奶牛线性外貌评分正是凭借EXCEL所具有的功能 ,结合荷斯坦奶牛线性外貌评分法 ,让育种工作人员甚至一般人员都能迅速、准确完成这一育种工作。2　程序功能可将荷斯坦奶牛的 1 5个主性状线性评分自动检索转化成相应的百分制给分。而且可以根据转化来的每个性状百分制给分 ,迅速算出每头奶牛的 4个部分各自百分制得分以及整体百分制得分。这里 1 5个主性状依次分别指 :1乳房悬…     

基于EXCEL的奶牛体型外貌线性评分系统

利用EXCEL简单、方便的函数功能和录制宏功能,自动检索奶牛体型外貌线性评分并转化成相应的功能分,再根据各性状不同的权重转化为个体之间可相互比较的百分制数值;该程序可对牛群分别进行乳房排序、体躯结构排序、肢蹄排序、乳用特征排序和整体排序,能快速、准确地对奶牛的生产性能做出客观、科学的评判,并为选配提供一定的参考依据.     

荷斯坦奶牛体型线性性状与产奶量的相关性分析

对新疆荷斯坦奶牛的产奶量与体型线性性状进行了相关。通径分析。结果表明，荷斯坦奶牛的乳房纵沟深，后乳房宽，后乳房高与产奶量呈中等正相关，体高，体长，尻宽，尻长与产奶量呈弱相关；后乳房宽，乳房纵沟深是直接影响产奶量的重要性状，且是正身作用；后乳房高对产奶量起负面影响。其间接作用大。     

主成分分析在奶牛产奶量选择中的应用

应用主成分分析法分析了荷斯坦奶牛体尺及乳房性状的8个指标，选取了累计贡献率达85％以上的前5个主成分，并分析了5个主成分与产奶量的相关关系。结果表明，主成分Ⅰ有可能成为荷斯坦奶牛产奶量选择的指标。     

奶牛生产寿命和产奶量的相关性研究

本研究利用陕西省西安市现代农业开发区第二奶牛场1990年～2002年间249头已淘汰奶牛的胎次及产奶量记录等资料,对奶牛的生产寿命即第一胎次至淘汰的泌乳天数和生产效益的关系进行了研究。结果表明,奶牛的生产寿命与终生产奶量之间存在强正相关,相关系数为0．99。奶牛的使用年限和产奶量之间存在显著的曲线相关(P＜0．05)。此外,研究结果表明,该奶牛场奶牛不同胎次产奶量以第5胎次为最高。     

西门塔尔奶牛产奶量与其体型线性性状的相关、通径分析

本文通过对某牛场２０头西门塔尔牛产奶量与其体型线性性状进行相关，通径分析。结果表明，尻长、乳房深、体高、胸围、乳头长与其产奶量呈弱正相关，尻宽与产奶量接的于中等正相关、尻长、尻宽、乳头长是影响产奶量的重要性状且是正向人艇，体高、胸围是影响产奶量的重要性状起负面作用，尻长、尻宽对产奶量的直接作用大。     

西门塔尔奶牛产奶量与其体型线性性状的相关、通径分析

通过对某牛场20头西门塔尔牛产奶量与其体型线性性状进行相关、通径分析.结果表明尻长、乳房深、体高、胸围、乳头长与其产奶量呈弱正相关,尻宽与产奶量接近于中等正相关,尻长、尻宽、乳头长是影响产奶量的重要性状且是正向作用,体高、胸围是影响产奶量的重要性状起负面作用,尻长、尻宽对产奶量的直接作用大.     

饲喂不同日粮对奶牛产奶量的影响研究

在规模养殖户饲养的奶牛中选择年龄在4～6岁,体重、胎次、泌乳时间等基本一致的荷斯坦泌乳牛18头,根据农户的饲喂条件,分为三组,每组6头。试验A组饲喂全价配合饲料和玉米秸秆青贮,试验B组饲喂混合饲料、粗饲料和玉米秸秆青贮,对照组C组采用一般的常规饲喂(有啥喂啥)方式,观察饲喂不同日粮对奶牛产奶量的影响效果。试验结果：试验A组奶牛头均日产奶量19．82kg,个体产奶量6045kg,试验B组头均日产奶量工17．27kg,个体产奶量5267kg,对照C组头均日产奶量12．41kg,个体产奶量3785kg;试验A组和B组头均日产奶量比对照C组增加7．41kg和4．86kg,个体产奶量分别增加2260kg和1482kg。     

过瘤胃保护蛋氨酸对奶牛生产性能的影响及经济效益分析

本研究采用在生产条件下的对比饲养试验,通过研究日粮中添加本实验室研发的过瘤胃保护蛋氨酸产品对泌乳高峰期和泌乳中期高产荷斯坦奶牛产奶量和乳成分的影响,验证了产品的性能与使用效果,并对经济效益进行了分析。试验选择2～5胎之间、日产奶量30kg以上、处于泌乳高峰期的荷斯坦奶牛20头,随机分为两组,试验组每头每天添加本实验室研发的过瘤胃保护蛋氨酸产品75g。试验结果表明:日粮中添加过瘤胃保护蛋氨酸产品可明显提高荷斯坦奶牛的产奶量(3.0kg/头.d,P0.05)和极显著提高牛奶的乳蛋白含量(0.27个百分点,P0.01),使乳脂肪含量略有降低(0.13个百分点,P0.05),对乳糖含量和乳干物质含量影响很小。在高产奶牛泌乳高峰期日粮中添加过瘤胃保护蛋氨酸能够获得可观的经济效益(8.54元/头.d)。     

添加混合油料籽实对奶牛生产性能及CLA的影响

选取年龄、体重、胎次、泌乳期及泌乳量基本一致的荷斯坦奶牛8头,随机分为2组,每组4头牛,进行为期45d的饲养试验。本试验预试期为15d,正试期为30d。试验组为添加整粒胡麻籽与整粒棉籽的混合物,胡麻的添加量为972g/(d·头),棉籽的添加量为2169g/(d·头);对照组不添加任何油料籽实。胡麻与棉籽的添加用以研究添加油料籽实对奶牛生产性能及乳脂脂肪酸组成的影响。研究结果表明:本试验条件下,加入胡麻籽与棉籽的混合物能提高奶牛产奶量,其中非校正产奶量比对照组提高4.7%,4?M产奶量比对照组提高7.3%,但与对照组差异均不显著(P>0.05);乳脂率提高了3.5%,乳脂产量提高了7.4%,与对照组之间差异也不显著(P>0.05);对于乳蛋白率,试验组比对照组提高了2.7%,乳蛋白产量提高了9.0%,但差异不显著(P>0.05);对于乳糖率,试验组比对照组下降了3.7%,乳糖产量比对照组提高了3.6%,差异不显著(P>0.05);乳中总干物质率比对照组提高了0.17%,无脂干物质率比对照组降低了0.96%,但与对照组差异不显著(P>0.05);试验组总的短链脂肪酸比对照组减少了16.8%,总的中链脂肪酸比对照组减少了11.6%,而长链脂肪酸比对照组增加了17.5%。其中试验组短链脂肪酸中的C14比对照组降低了21.5%,与对照组差异显著(P<0.05),其它短链及中链脂肪酸均与对照组差异不显著(P>0.05),长链脂肪酸中的CLA含量比对照!组提高了14.3%,但差异也不显著(P>0.05)。     

体况评分与步态评分对奶牛生产性能的影响

为探究体况评分(Body Condition Score,BCS)和步态评分(Locomotion Score,LS)对奶牛泌乳性能的影响,本试验在2016年7月至8月通过对北京地区7个奶牛场近5 000头泌乳牛进行体况和步态评分并收集相关的DHI数据,采用固定模型分析BCS和LS的影响因素及场、胎次、泌乳阶段、LS和BCS对日产奶量、体细胞数及乳成分的影响。结果表明:BCS和LS对日产奶量均有极显著影响(P0.01),BCS对乳蛋白率有显著影响(P0.05);胎次对LS有极显著影响(P0.01),而对BCS无显著影响,场-测量人、泌乳阶段对BCS和LS均有极显著影响(P0.01);LS与BCS之间回归关系显著,LS较高的个体BCS较低。在生产上可以综合运用BCS和LS加强管理,提升产奶量,改善乳品质量,使牛场获得更大的经济利益。     

荷斯坦奶牛产奶量与乳成分的相关性研究

为探讨湖北地区荷斯坦奶牛产奶量、乳成分的相关性,本研究选择2016年湖北省3个牧场的DHI数据,运用SPSS17.0中的双变量相关分析和偏相关分析,分析产奶量与乳成分的相互关系。结果表明:3个牧场产奶量与乳脂率、乳蛋白率、体细胞数、乳尿素氮呈负相关(P0.01);乳脂率与乳蛋白率、体细胞数、乳尿素氮均呈正相关(P0.01);乳蛋白率与体细胞数呈正相关(P0.01),与乳尿素氮呈负相关(P0.01);体细胞数与乳尿素氮均呈负相关(P0.01);产奶量与体细胞数简单相关系数-0.003(P0.05),偏相关系数-0.054(P0.01);体细胞数与乳尿素氮含量简单相关系数0.003(P0.05),偏相关系数-0.134(P0.01)。在产奶量与乳成分间关系研究中简单相关分析与偏相关分析结果不一致,在多个变量相关性研究中,偏相关分析更能真实反映2个变量间本质联系。     

不同青贮饲料日粮对奶牛产奶量和乳成分的影响

根据胎次相同、产奶量、泌乳时间相近的原则选择泌乳中前期奶牛30头,随机分为2组,每组15头,分别饲喂全株玉米青贮和小麦青贮饲料,研究其对奶牛产奶量和乳成分的影响.结果发现,与全株玉米青贮相比,小麦青贮组奶牛产奶量提高0.26kg/d,乳脂率、乳糖、非脂固形物和总固体均有提高,但差异不显著(P＞0.05);小麦青贮替代全株玉米青贮可实现每头奶牛每天多盈利0.31元.结果表明,小麦青贮替代全株玉米青贮能够提高奶牛产奶量和改善乳成分.     

Effect of somatic cell count on milk and protein yields and female fertility in Tunisian Holstein dairy cows

The effects of test-day somatic cell scores (SCS) variations on milk and protein yields, and calving to first service and calving to conception intervals were studied in Tunisian Holsteins. There were 34,129, 25,700, and 18,077 test-day production records collected on first, second, and third parity cows, respectively. Records were of cows calving between 1996 and 2004 in 160 herds. Somatic cell scores and milk and protein yields were analysed using a linear model that included herd-test-day date and herd–year interactions, calving season, calving age, and calving to conception interval. Reproductive trait model included herd–year interaction, calving season, calving age, and month of insemination. Effects of SCS on milk and protein yields were studied by regressing current test-day yields on corresponding and preceding test-day SCS, while effects of SCS on fertility traits were investigated by separately regressing calving to first service and calving to conception intervals corrected for environmental and management factors on SCS corrected for actual milk yield. A cow produced around 19.0 kg (SD = 8.0 kg) and 0.6 kg (SD = 0.3 kg) milk and protein yields on a daily basis and had an average of 3.8 (SD = 2.1) SCS in the first three lactations. SCS varied consistently (p < 0.05) with herd-test-day date and herd–year interactions in all lactations. Days in milk, calving age, and calving to conception interval were all together important sources of variation (p < 0.05) for SCS mainly in the first and second parities. Test-day milk and protein yields were unfavourably affected by high SCS recorded in the same test-day and with a lesser degree by SCS observed in the nearest preceding test-day. Reduction in milk and protein productions from increased SCS varied from 0.23 to 1.76 kg and from 6 to 75 g, respectively. Likewise, increased test-day SCS lengthened both calving to first service (mean interval = 94.9 days; SD = 49.1 days) and calving to conception (mean interval = 161 days; SD = 69.6 days) intervals by 1.3 to 2.0 days for each unit increase in SCS. Using SCS in addition to milk traits as a criterion to select semen and improving veterinary care should result in increased milk and protein yields and in satisfactory fertility measures.     

Record keeping,genetic selection,educational experience and farm management effects on average milk yield per cow,milk fat percentage,bacterial score and bulk tank somatic cell count of dairy farms in the Central region of Thailand

A study was conducted to estimate the record keeping, genetic selection, educational, and farm management effects on average milk yield per cow (AYC), milk fat percentage, bacterial score, and bulk tank somatic cell count (BTSCC) of dairy farms in the central region of Thailand. Farms were located in the provinces of Saraburi and Nakhon Ratchisima and were members of the Muaklek dairy cooperative. Records from individual animals were unavailable. Thus, farm records of milk yield, milk fat percentage, bacterial score, and BTCCC were collected from July 1, 2003 through June 30, 2006. Additional record keeping, genetic selection, education, and farm management information was collected through a questionnaire in May of 2006. Data from the Muaklek dairy cooperative and the questionnaire were then merged by a farm identification number. A single trait mixed model was used to analyze AYC, milk fat percentage, and BTSCC, while a log linear model was used to analyze bacterial score. Results showed that farms that kept records on individual animals had higher (P < 0.05) milk fat percentages and lower bacterial scores than farms that did not. Farms that used genetic information (EBV) and phenotypes when selecting sires were higher (P < 0.05) for milk fat percentage than farms that used only phenotypes and personal opinion. Farms milking cows with a single unit milking machine and by hand, had higher (P < 0.05) bacterial scores and BTSCC than farms using only a single or multi unit machine. Overall farms that kept individual animal records, used EBV when selecting sires, used a single method for collecting milk, and used family labor achieved higher performance from their herds than farms that did not.     

体细胞评分与牛奶品质及产奶量的相关性分析

为了探索体细胞评分与牛奶品质及产量相关性,本研究收集了宁夏地区某4个奶牛场的DHI数据,利用SAS软件对SCS与牛奶中乳蛋白率、乳脂率、奶产量、尿素氮等指标的相关性进行统计分析.结果表明,SCS与日产奶量呈显著负相关(P<0.05),与乳脂率、乳蛋白率和尿素氮没有显著的相关性.     

奶牛前期泌乳性能与305天产奶量的相关分析

本文对西安草滩农场第四奶牛场 66头奶牛的第一泌乳期完整的原始资料进行分析 ,利用最高月产奶量、90 d奶量、高峰日、乳脂率等泌乳前期产奶指标对 30 5 d奶量进行相关分析 ,结果表明高峰日、最高月产奶量、90 d奶量与 30 5 d奶量分别呈强正相关 ,相关系数显著性检验均达到显著或极显著的程度 ,分别为 0 .367( P<0 .0 1 )、0 .41 1 ( P<0 .0 1 )和 0 .2 62 ( P<0 .0 5 ) ;乳汁率与 30 5 d奶量呈弱负相关 ,相关系数为 - 0 .2 5 5 ,达到显著程度 ( P<0 .0 5 )。本文分析的奶牛几项泌乳前期产奶指标与 30 5 d产奶量的关系密切 ,为奶牛的早期选育工作提供了实际依据。