奶牛难产浅析

奶牛以其饲料转化率高、耐粗饲、产奶量多、奶中营养成分均衡全面、且易被人体消化吸收,已被人们所接受。但是在奶牛的生产过程中,难产占5％,给养殖户、养殖场带来极大的经济损失。为此,对奶牛的难产进行具体的分析、综合的防治、科学的管理、合理的利用,以期达到最大限度地预防难产的发生。     

牛的肉用指数及影响因素

牛的肉用指数(活重kg/体高cm,BP I)是一区分役用型牛与肉用型牛的易测指标,将役牛转化为肉用型牛,其成年公牛BP I应达5.6以上,成年母牛平均达到4以上,这即是“由役转肉”转化成功的“转折点”。黄牛品种内存在BP I类型的多样性,这为选优转化提供了依据。影响牛的BP I因素包括品种(类型)、饲养条件、年龄和性别等。根据实际情况本文提出了公母牛(黄牛)BP I的年龄校正系数,按BP I选牛,可以提早到1~2岁。     

254例奶牛难产及救治

奶牛难产是产科病中常见病，多年来接助难产牛254例，其中经临床病志统计危重症124例，从中可按胎次、难产性质区分：一胎发生62例，占52％；2－4胎次发生36例，占28％；5胎次以上的26例，占22％。产道性难产24例，占19.4%；产力性难产37例，占29.8%；胎儿性难产63例，占50.8%。     

影响牛胚胎移植效果的主要因素分析

胚胎移植技术自创立以来,经过不断发展和完善,已成为现代畜牧业尤其是高价值低繁殖力畜种繁育中不可或缺的技术手段.但由于胚胎移植是一个系统工程,其移植效果受供受体的选择、超排效果、胚胎质量、供受体的同期性、操作技术、营养及饲养管理水平等诸多因素的影响,移植效果也参差不齐.本文就影响牛胚胎移植效果的主要因素进行简要分析,以期...     

影响肉牛育肥效果的因素及其提升措施

文章叙述了肉牛育肥的原理以及影响肉牛育肥效果的因素,在此基础上分析了提高肉牛育肥效果的有效方法。     

Factors Affecting the Development of Somatic Cell Nuclear Transfer Embryos in Cattle

Nuclear transfer is a complex multistep procedure that includes oocyte maturation, cell cycle synchronization of donor cells, enucleation, cell fusion, oocyte activation and embryo culture. Therefore, many factors are believed to contribute to the success of embryo development following nuclear transfer. Numerous attempts to improve cloning efficiency have been conducted since the birth of the first sheep by somatic cell nuclear transfer. However, the efficiency of somatic cell cloning has remained low, and applications have been limited. In this review, we discuss some of the factors that affect the developmental ability of somatic cell nuclear transfer embryos in cattle.     

荷斯坦奶牛维持净能需要量的测定及影响因素

介绍2种评定奶牛维持净能需要(NEm)的方法及其优缺点;并分析了造成近20年荷斯坦奶牛NEm提高的原因。     

影响新疆褐牛产奶量的相关因素分析

对1997年至2003年之间,乌鲁木齐种牛场462头新疆褐牛成年母牛的产犊间隔、产犊月份、胎次、犊牛初生重、犊牛性别等基础资料进行统计分析,研究上述因素与产奶量之间的关系.结果表明:产犊间隔、产犊月份、胎次对产奶量有极显著的影响;犊牛性别对产奶量无显著影响(P＞0.05).     

Factors Affecting the Selling Price of Feeder Cattle Sold at Arkansas Livestock Auctions

Data were collected from 17 Arkansas livestock auctions to determine factors affecting selling price. Data included how calves were sold (single or groups), gender, breed or breed type, color, muscle thickness, horn status, frame score, fill, body condition, age, health, BW, price, and when during the sale the calf was sold. Data were randomly collected on 81,703 calves. The selling prices for steers ($99.70 ± $0.07), bulls ($95.07 ± $0.08), and heifers ($88.75 ± $0.06) were different from each other (P<0.001). Charolais x Limousin feeder cattle sold for the highest price $97.96 ± $0.22), and Longhorns sold for the lowest price ($74.52 ± $0.46). selling prices of Hereford x Charolais, Hereford x Brahman x Angus, Charolais, and Angus x Brahman feeder cattle were greater than the overall mean and were not different from each other. selling prices of 1/4 Brahman x other crosses, Simmental, Hereford, Brahman, and Longhorn were less than the overall mean and were different (P<0.01) from each other and all other breeds or breed types. Yellow feeder cattle received the highest selling price ($96.47 ± $0.12), and spotted or striped feeder cattle received the lowest ($83.84 ± $0.23). selling in groups, muscle score, horn status, frame score, fill, and body condition impacted selling price (P<0.001). Selling prices differed across livestock auctions (P < 0.001). A positive relationship existed between livestock auction volume and selling price (P < 0.05), and a quadratic relationship existed between the number of different buyers and selling price (P < 0.01). A number of management and genetic factors affected the selling price of feeder cattle.     

母牛难产的风险病因--基于系列案例研究

[目的]难产是繁殖母牛的常见疾病,危害母牛和犊牛健康,进行难产牛原因分析有助于兽医或者牛场做好接产工作,提高生产力。 [方法]在万方数据服务平台、CNKI中国知网、Elsevier SD数据库和“SCI-科学引文索引”上,用关键词“难产”、“病例”、“牛”精确搜索我国相关的案例,统计筛除后的病例数,对牛难产原因进行统计和分析。 [结果]检索获得母牛难产的病例总数为753例,难产原因占比最大的是胎儿性难产有525例,占69.72%(95%CI 66.3-73.0);其次是产道异常（骨折造成骨盆畸形,子宫颈、阴道、阴门狭窄造成的产道异常）造成的难产89例,占11.82%(95%CI 9.6-14.3);阵缩及努责无力造成的难产41例,占5.44%(95%CI 3.9-7.3);子宫扭转造成的难产38例,占5.05%(95%CI 3.6-6.9);子宫颈开张不全造成的难产26例,占3.46%(95%CI 2.3-5.0);营养不良造成的难产18例,占2.39%(95%CI 1.4-3.8);双胎难产9例,占1.20%(95%CI 0.5-2.3);人为因素和其他因素造成的难产有7例,占0.93%（95%CI 0.4-1.9）。 [结论]引起母牛难产的最主要的因素是胎儿性难产、产道异常。兽医在实际临床中,应快速、准确确定母牛难产的病因,采取对应接产措施,减少经济损失。     

我国肉牛品种比较及影响品种选择的因素分析

近年来,我国肉牛产业的迅速发展提高了农牧民饲养肉牛的积极性,但我国地域辽阔,各地气候条件、饲料品质、肉牛产业体系存在较大差异,这也使得养牛者需要根据自己的实际情况来选择适宜的肉牛品种。我国现有的肉牛品种繁多,文章对选择肉牛品种的影响因素以及各个品种的主要特征进行了详细陈述,并结合前人的研究结果对引进的肉牛品种进行了比较。     

肉牛基础母牛难产综合防治技术

为了弄清张掖市百万头肉牛基地母牛难产发病情况和发病原因进一步制定,采取综合防控措施,减少母牛发病率、提高犊牛产活率.采取健全母牛电子档案,推行科学饲养管理,规范人工受精技术,及时准确诊断,合理有效治疗等方法.使该病的发病率由8.65％降低至2.5％.科学的饲养管理及防治方法,对难产发病率降低和犊牛产活率的提高有显著效果.     

影响内蒙古三河牛泌乳曲线参数的非遗传因素

为了解三河牛泌乳曲线形状及其影响因素,试验对三河牛的486个泌乳期记录,应用Wood模型进行泌乳曲线拟合,结果显示,Wood模型能够较好拟合三河牛泌乳曲线,平均拟合优度R2为0.93±0.004。应用方差分析进一步研究场效应、产犊年度、产犊季节及胎次对Wood模型各参数的影响情况,结果表明,场效应对参数c、tmax、per、Y305影响差异极显著;不同产犊年度间,参数b表现为差异显著(P0.05),参数c、ymax、Y305表现为差异极显著(P0.01);各产犊季节间,参数a、b、c、Y305均表现为差异极显著(P0.01),参数per表现为差异显著(P0.05);胎次对参数a、ymax、Y305影响差异极显著(P0.01);其它参数与效应间均表现为差异不显著(P0.05)。     

影响荷斯坦牛产犊难易的原因分析

通过研究不同胎次、产犊季节和犊牛初生重、犊牛性别、产犊方式等因素对荷斯坦牛难产程度的影响,旨在降低难产率,帮助牛场制定合理有效的繁殖管理措施。试验收集上海金山奶牛场2018年1~12月产犊难易记录共2 812条,采用GLM模型对影响奶牛难产程度的因素进行分析。结果表明,胎次、产犊季节、犊牛初生重、犊牛性别、产犊方式对难产程度有显著影响(P<0.05),且第二胎奶牛自然分娩比例最高;春季和夏季产犊低难产度所占比例较大;随着犊牛初生重的增加,难产程度逐渐增大;生公犊难产程度越大;双胎生产方式难产度增大。     

浅谈影响牛冻精受胎率的因素

文章从冻精质量和剂型、冻改技术水平、母畜三方面阐述了影响牛冻精改良受胎率的主要因素,旨在为牛冻精改良提高生产效率提供技术指导。     

影响饲料安全的因素

在日益关注动物食品安全和环保的情况下,探讨影响饲料安全的因素,对研究饲料安全的措施,无疑具有重要的现实意义。     

非水溶液滴定法的影响因素分析

以盐酸氨丙啉为例,分析了实验环境、试剂、器具、操作和样品等因素对非水溶液滴定法测定结果的影响及控制方法。实验中要保持适宜的温度和湿度,保证实验试剂的质量要求;严格控制试剂、实验器具、检测样品的水分,保证滴定和称量的精度;规范滴定操作,熟练掌握滴定终点的判断,使测得的盐酸氨丙啉准确可靠。     

Incidence of Dystocia and Perinatal Calf Mortality Resulting from Reciprocal Crossing of Double-muscled and Normal Cattle

In order to study the incidence and causes of dystocia and perinatal calf mortality in double-muscled cattle, straight and reciprocal matings between double-muscled and normal cattle were made in three breeding seasons. A total of 348 matings resulted in 247 calvings in the four mating types. The frequency of normal calvings or calvings requiring slight assistance was higher among normal cows mated to double-muscled or normal bulls compared with that of double-muscled cows mated to double-muscled bulls (94% vs 78%, P < 0.05). In general the incidence of dystocia was higher among the double-muscled than the normal cows (19% vs 6%, P < 0.05). Calf birth weight, dam weight at calving, and condition score were not shown to contribute significantly to the differences in the frequencies of dystocia. A higher incidence of dystocia was found in the mating type which frequently gave rise to phenotypically muscular calves (DM × DM). The height, width, and area of pelvic opening were significantly smaller (P < 0.05) in the double-muscled than in the normal cows, indicating that the higher incidence of dystocia and perinatal mortality in double-muscled cattle can be attributed, at least partially, to the smaller area of pelvic opening in the double-muscled cattle.