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牛的肉用指数及影响因素 总被引:3,自引:5,他引:3
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。 相似文献
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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%。 相似文献
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Satoshi AKAGI Kazutsugu MATSUKAWA Seiya TAKAHASHI 《The Journal of reproduction and development》2014,60(5):329-335
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. 相似文献
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《The Professional Animal Scientist》2002,18(3):227-236
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. 相似文献
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[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。 相似文献
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影响内蒙古三河牛泌乳曲线参数的非遗传因素 总被引:1,自引:0,他引:1
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)。 相似文献
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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。 相似文献
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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。 相似文献
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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。 相似文献
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Incidence of Dystocia and Perinatal Calf Mortality Resulting from Reciprocal Crossing of Double-muscled and Normal Cattle 总被引:2,自引:0,他引:2 下载免费PDF全文
Arthur PF Makarechian M Price MA 《The Canadian veterinary journal. La revue veterinaire canadienne》1988,29(2):163-167
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. 相似文献