玉屏风散对奶牛生产的影响

中草药对奶牛具有一定的防病保健作用,在奶牛生产中添加中草药制剂已经成为重要的研究方向。选用玉屏风散,通过测奶牛产奶量与体细胞变化,分析了玉屏风散对奶牛生产的影响。     

不同音乐对奶牛产奶性能影响的研究

为了研究民族音乐、轻音乐、流行音乐对奶牛产奶性能的影响,试验选取年龄、胎次、产奶量接近、饲养管理水平完全相同的荷斯坦泌乳牛32头,随机分成2组,每组16头。试验分预试期7 d,正试期60 d。预试期开始给试验组奶牛播放音乐,对照组常规饲喂,每10 d测定单产并采集奶样1次。结果表明:0~60 d,民族音乐组平均产奶量较对照组低12.61%,体细胞数较对照组高45.14%,差异极显著(P0.01)。轻音乐组平均产奶量较对照组高10.26%,差异极显著(P0.01);奶牛乳体细胞数较对照组低41.24%,差异显著(P0.05)。流行音乐组平均产奶量较对照组低0.73%;体细胞数、乳脂、乳糖、乳蛋白分别较对照组高0.94%、0.27%、0.18%、0.63%,且差异均不显著(P0.05)。说明民族音乐可显著降低奶牛产奶量并提高奶牛体细胞数,对乳糖、乳脂和乳蛋白含量影响不大;轻音乐有提高奶牛产奶量和降低奶牛体细胞数的作用,对牛奶乳成分含量的影响不大;流行音乐有提高奶牛产奶量和降低奶牛体细胞数的作用,但其作用时间和作用效果有限,对乳成分含量的影响作用不大。     

应用DHI对某奶牛群生产性能的综合分析

应用DHI对某奶牛群生产性能进行综合分析,探索在奶牛牧场管理过程中,牛奶体细胞数SCC与奶牛产奶量、健康、胎次的关系,以期应用DHI提高奶牛生产性能。应用奶牛生产性能测定(DHI)体系对900头产奶牛进行测定和分析,发现在奶牛泌乳的各个阶段,随着牛奶体细胞数增高,各胎次奶牛产奶量呈逐渐下降趋势;体细胞数随着胎次的增加而上升,奶牛产奶量随奶牛胎次的变化而变化。奶牛存在产犊间隔长,繁殖障碍和营养问题,需采取相应的改进措施。     

黄白散对奶牛产奶量及体细胞数的影响

如今,奶牛的养殖量越来越大,从此带来的疾病也越来越多,由于抗生素的滥用,使奶牛生产性能有所下降,因此越来越多的养殖户开始重视中药的防病保健作用,本文选取黄白散,对奶牛产奶量与体细胞数的变化进行检测,来探讨中药对奶牛产奶量及体细胞数的影响。     

线性模型对影响奶牛产奶性能的主要相关因素分析

利用一般线性模型研究各种因素对奶牛产奶性能的影响。牛场、胎次和产犊季节对奶牛产奶量影响差异极显著(P0.01),随着奶牛胎次的增加,奶牛产奶量增加;夏季产犊的奶牛产奶量最低,冬季产犊的最高;体细胞计数对奶牛产奶量没有显著性影响(P0.05),但随着体细胞数的增加,产奶量下降。牛场、胎次和体细胞计数对乳脂率有极显著的影响(P0.01),第三牛场平均乳脂率为4.38%,显著高于其他三个牛场;随着胎次的增加,乳脂率有下降趋势;随体细胞数增加,乳脂率升高;产犊季节对奶牛乳脂率没有显著影响(P0.05)。牛场、产犊季节和体细胞数对乳蛋白率的影响极显著(P0.01),体细胞数增加,乳蛋白率升高;夏季和秋季产犊的奶牛乳蛋白率较高,春季和冬季较低;胎次对乳蛋白率没有显著影响(P0.05)。表型相关分析表明:SCC与产奶量呈显著负相关(r=-0.158,P0.05),SCS与产奶量相关性接近显著水平(r=-0.140,P=0.055)。SCC/SCS与乳脂率、乳蛋白率呈正相关,但未达到显著性水平(P0.05)。     

复合菌培养物对奶牛产奶性能及体细胞数的影响

试验旨在研究日粮中添加复合菌培养物对奶牛产奶量、乳品质和体细胞数的影响。选择30头荷斯坦奶牛,分为对照组和试验组,对照组饲喂基础日粮,试验组在基础日粮中添加复合菌培养物400 g/(头·d),试验期为37 d。测定指标包括产奶量、乳脂率、乳蛋白率及体细胞数。结果表明,试验组奶牛产奶量比对照组增加6.84%(P>0.05);乳汁体细胞数下降率比对照组提高29.78%(P<0.05);两组奶牛乳脂、乳蛋白之间无明显差异(P>0.05)。本试验结果表明,复合菌培养物在降低体细胞数和改善奶牛产奶性能方面具有良好的效果。     

奶牛乳房性状对泌乳性能的影响分析

为了发现有助于提高奶牛产奶量和乳房健康的关键乳房性状,为奶牛选种和管理提出建议,研究测定河北省定州某奶牛场一胎泌乳牛的乳头长度(859头牛的平均长度与均匀度)、乳房质地和乳房深度(1 630头),应用最小二乘法原理,配合线性固定效应模型,分析了乳头长度、乳房深度和乳房质地对产奶量和体细胞数的影响。结果表明:在头胎牛中,乳头长度对产奶量有极显著影响(P0.01),对体细胞评分有显著影响(P0.05),乳头越长、均匀度越高的个体,其产奶量越高,体细胞数越低;同时,乳房质地对产奶量有极显著影响(P0.01),乳房较充盈硬实的个体产奶量较高;乳房深度和乳房质地对体细胞评分的影响虽然没有达到显著水平,但有乳房越深、质地越硬体细胞数越高的趋势。说明在生产中关注奶牛乳房性状,加强对乳房性状的选择与管理对于提高奶牛产奶性能、提高经济效益有着重要的作用。     

乳房炎对奶牛产奶量的影响

为了研究乳房炎对奶牛产奶量的影响,收集了西安某奶牛场的620头荷斯坦奶牛完整记录的全年报告中体细胞数据、生产性能和兽医记录,对比分析不同体细胞数对奶牛胎次奶量﹑日产奶量的影响;结果表明,临床乳房炎极显著降低奶牛305d奶量,而在泌乳盛期患病的牛305d奶量减低可达32.5%。隐性乳房炎对奶牛产奶量的影响随患病程度加重而增大。平均体细胞数20万/mL,胎次奶量就会显著较少,而体细胞数50万/mL,胎次奶量极显著降低。奶牛泌乳盛期患隐性乳房炎比泌乳中后期患隐性乳房炎对产奶量影响更大。     

使用SCC差值法分析北方牛场中国荷斯坦牛生产状况

本研究对北方三个牛场中国荷斯坦牛泌乳牛的体细胞数变化规律和产奶量的关系进行分析,为有效指导牛场的生产提供科学依据和参考建议。通过数据筛选,统计分析在不同胎次、测定日情况下,中国荷斯坦牛体细胞数(somatic cell count,SCC)与产奶量之间的关系,并通过相邻两月SCC差值等级法进行分级和分析。结果表明:胎次对体细胞数评分(somatic cell score,SCS)和产奶量均有影响;测定日对SCS和产奶量均有影响;使用SCC差值等级法能够有效评价奶牛产奶量以及判定奶牛乳房炎的发病趋势。横向比较三个奶牛场产奶量情况及SCC控制情况,以二号牛场较好,其产奶量最高,SCC最低,且体现较好长寿性;而一号牛场则产奶量最低,SCC最高,第1胎后产奶量逐渐降低。     

利用非参数检验法分析热应激和胎次对奶牛生产性能的影响

为了解南方地区热应激和胎次对奶牛产奶量、乳脂率、乳蛋白率和体细胞数的影响,本文收集了南方某大型牧场一个生产年度的DHI数据、气候数据、生产数据,采用SPSS 25软件中的非参数检验法,分析了热应激和胎次对奶牛产奶量、乳成分和体细胞数的影响。结果表明:乳脂率随热应激程度加大而升高,产奶量反之,不同热应激程度之间存在明显差异(P<0.05);无热应激月份比有热应激月份的乳蛋白率和体细胞数低(P<0.05)。1胎奶牛产奶量最低(P<0.05),3胎产奶量最高(P<0.05);体细胞数随胎次增加呈上升趋势,1胎体细胞数最低(P<0.05);2胎、5胎乳脂率较高,2胎乳蛋白率显著高于1、3、4胎(P<0.05),但和5胎差异不明显(P>0.05)。     

Microbiologic investigation of an epizootic of mastitis caused by Serratia marcescens in a dairy herd.

An epizootic of subclinical and clinical mastitis caused by Serratia marcescens was investigated in a 1,000-cow dairy farm in California. Serratia marcescens was isolated from 13 to 18% of composite milk samples obtained from lactating dairy cows. During monthly milk sampling performed during a 4-month period, S marcescens was isolated from 38.8 to 62.3% of composite milk samples obtained from cows from which S marcescens was previously isolated. Few cows infected with S marcescens had evidence of clinical mastitis. Somatic cell count value was associated with isolation of S marcescens. Cows with somatic cell counts greater than 500,000 were 5.48 times as likely to have intramammary infections with S marcescens, compared with cows with somatic cell count less than or equal to 500,000. Lactation number also was associated with S marcescens intramammary infection. After adjusting for the effect of lactation number, cows with high somatic cell count values were 2.98 times as likely to have intramammary infection with S marcescens, compared with cows with low somatic cell counts. Infection with S marcescens was independent of days in lactation, production string, and daily milk production. Eleven months after the beginning of the epizootic, S marcescens was isolated from organic bedding samples obtained from the dairy. Despite numerous attempts, other sources of S marcescens could not be identified on this dairy.     

Somatic cell counts: associated factors and relationship to production.

Factors affecting somatic cell counts and the association between somatic cell counts and milk production were evaluated. Data were collected from 748 Ontario Dairy Herd Improvement Corporation supervised herds that were on production and somatic cell count programs between April 1981 and March 1983. Two data files were created; one, the lactation summary file, contained one record per cow on each of 9406 Holsteins and the other, the test day file, included results of all tests during the complete lactation on each of the above cows. The latter file contained 85,236 records. Multiple curvilinear least squares regression was used to create five separate models. The dependent variables used in the models were natural logarithms (Loge) of the geometric mean of the somatic cell count for the lactation, 305 day milk production and breed class average for milk from the lactation summary file, and loge of the 24 hour somatic cell count and 24 hour milk production from the test day file. The somatic cell count at both the lactation and test day level increased with age up to approximately ten years and thereafter slowly decreased. The variable "days in milk" was not significantly associated with the lactation average somatic cell count. A curvilinear relationship was found between days in lactation at the time of test and the somatic cell count of 24 hour milk production. The somatic cell count increased until approximately 250 days in lactation and thereafter slowly decreased. It was found that the highest cell counts occurred in summer and the lowest in winter.(ABSTRACT TRUNCATED AT 250 WORDS)     

Factors affecting the transfer of immunoglobulin G1 into the milk of Holstein cows

Immunoglobulin (Ig) G1 concentrations in milk from Holstein cows was measured to determine if transfer and concentration was influenced by production factors (lactation number, stage of lactation, daily milk production), milk composition (milk fat, protein, lactose, and total solids content) or by serum IgG1 concentration. Two hundred and ninety-nine Chinese Holstein cows were randomly selected from four herds containing a total of more than 1600 lactating animals. The concentration of IgG1 in the milk and serum was determined by ELISA.Milk IgG1 concentrations varied between 0.030 and 0.614 mg/mL and significantly correlated with lactation number, stage of lactation, daily milk production and somatic cell count. The IgG1 mass was found to highly correlate with lactation number, stage of lactation, daily milk production and milk protein content. Lactation number had the highest positive direct relationship with IgG1 concentration.     

基于灰色关联模型的奶牛牛群改良测定报告分析及其应用

Dairy herd improvement （DHI） could provide accurate and reliable information for pasture，which could be helpful for the management of herds.This paper analyzed the indicators of DHI，and based on DHI data from February 2012 to December 2012 of a dairy farm in South China， this paper performed trend analysis for milk fat rate，milk protein rate，milk lactose rate，the number of somatic cell and daily milk yield and make correlation analysis of factors of daily milk yield by gray relational model.The results showed that the milk production from February to October was declined，which showed that the rearing environment of herds was poor.The milk lactose rate，milk protein rate and milk fat rate were increased，which showed that the diet structure was reasonable and the dietary dry matter was adequate.The somatic cell count was less than 500000/mL，which showed that the incidence of mastitis was lower and the herds were in good health. The number of somatic cell was also the most influential factor of the daily milk yield，and there was a very strong negative correlation among them.Therefore，strengthening the management of cattle rearing environment，improving the level of breeding cattle breeding，adjusting the dietary nutrition structure and doing mastitis detection and prevention were very important for dairy managers.     

Somatic cell counts in bovine milk

Factors which influence somatic cell counts in bovine milk are reviewed and guidelines for their interpretation are presented. It is suggested that the thresholds of 300 000 and 250 000 cells/mL be used to identify infected quarters and cows respectively. However, it is stressed that somatic cell counts are general indicators of udder health which are subject to the influence of many factors. Therefore the evaluation of several successive counts is preferable to the interpretation of an individual count.

Relationships between somatic cell counts and both milk production and milk composition are discussed. Subclinical mastitis reduces milk quality and decreases yield although the relationship between production loss and somatic cell count requires clarification. Finally the availability of somatic cell counting programs in Canada is presented.

     

奶牛性控和常规冻精生产的F1代母牛产奶量和乳品质对比试验

从试验牛母亲人工授精开始,到试验牛第一个泌乳期结束,在所有条件相同的情况下,对性控和常规冻精生产的F1代母牛的泌乳量、乳脂率、乳蛋白率和体细胞数进行了比较,结果表明,性控冻精生产F1代母牛与同期常规冻精生产的F1代月产奶量和305d的产奶量,以及月平均和305d的平均乳脂率、乳蛋白率和体细胞数差异不显著(P>0.05);305d产奶量、平均乳脂率、乳蛋白率和体细胞数分别为9 419.64和9 494.44、3.62和3.62、3.15和3.18、40.64和41.70。说明性控冻精生产的F1代母牛与常规冻精生产的后代相比,泌乳性能未见异常。     

影响江苏某牛场荷斯坦牛日产奶量和乳成分因素分析

[目的]探究江苏某牛场荷斯坦牛日产奶量和乳成分的影响因素。[方法]试验采集了该规模化牛场2018—2020年139 703条测定数据,并利用多因素方差模型对其进行系统的分析。[结果]不同胎次、测定季节、产犊季节、泌乳月对荷斯坦牛日产奶量、乳脂率、乳蛋白率、体细胞评分、乳尿素氮均有极显著影响(P<0.01)。产奶量与乳脂率、乳蛋白率、体细胞评分均存在极显著负相关。[结论]综上结果,在生产中,应结合胎次、季节、产犊时间、泌乳等多种因素,灵活调整牛群结构、生产规划和饲养管理,以实现提高产奶量和乳品质的目的。     

Relationship between test-day measures of somatic cell count and milk production in California dairy cows.

The relationship between test-day measures of milk somatic cell count and milk yield was evaluated using the November 1985 test data from 8352 Holstein cattle (2923 primiparous and 5429 multiparous cows) located in ten Tulare County, California dairies. Following correction for herd and stage of lactation effects, design variable regression was used to create separate models for primiparous and multiparous cows predicting the changes in milk production associated with milk somatic cell count class. Cell counts were stratified by 1/2 loge cell count (x1000 cells/mL) units, permitting comparisons with previous studies. Cell counts less than 148,000/mL were not found to be associated with significant reductions in milk yield when compared to the reference class (cell counts less than 20,000/mL). Consistent incremental decreases in milk production were not noted with increasing cell count strata, even following the natural log transformation. The most dramatic production losses were noted in the range of 148,000 to 665,000 cells/mL. Primiparous cattle in the 403,000 to 665,000 cell count strata experienced a 5.22 kg (19.72%) decrease in test-day milk yield. Multiparous cattle in the same class experienced 3.01 kg (7.82%) reductions in milk production. Primiparous and multiparous cows had similar production losses. The study population differed from previous studies on the basis of herd size, milk production and the level of udder health, measured by milk somatic cell count. These differences and the choice of experimental design may in part explain differences in study results and conclusions.