不同品种肉牛与黄牛杂交屠宰试验效果分析

随机抽取西门塔尔、黑白花、利木赞与黄牛杂交二代优质牛各3头进行屠宰试验。测定并分析三个品种杂交肉牛的屠宰指标、分割部位所占比例、不同牛肉价格等指标。在屠宰指标上,西门塔尔×黄牛的屠宰率为54.48%,胴体出肉率为86.16%,分割后产品率为96.4%,肉骨比为6.22,黑白花×黄牛的屠宰率为53.31%,胴体出肉率为84.88%,分割后产品率为92.52%,肉骨比为5.61,利木赞×黄牛的屠宰率为54.63%,胴体出肉率为83.30%,分割后产品率为93.9%,肉骨比为7.54。结果表明利木赞×黄牛胴体最佳,其次是西门塔尔×黄牛,最后是黑白花×黄牛。在胴体出肉率这一指标上,西门塔尔×黄牛胴体最好,其次是利木赞×黄牛,最后是黑白花×黄牛。屠宰排酸后分割,分割产品中利木赞×黄牛的高档部位较西门塔尔×黄牛和黑白花×黄牛所占比例高0.1和0.9个百分点。牛前部肉利木赞×黄牛比西门塔尔×黄牛和黑白花×黄牛高2.4和4.8个百分点。而黑白花×黄牛的后部位比例较西门塔尔×黄牛和利木赞×黄牛高1.2和1.7个百分点。筋类黑白花×黄牛比西门塔尔×黄牛和利木赞×黄牛高0.3和1.7个百分点。     

牛胚胎移植及后代在高寒地区适应性观察试验

互助县在2001-2004年先后从新疆呼图壁种牛场胚胎工程中心引进不同品种牛冷冻胚胎172枚,进行了胚胎移植试验.结果表明：平均受胎率为41.86%,产犊成活率为91.67%.胚胎移植所产的黑白花、安格斯、西门塔尔、利木赞犊牛平均初生重、6月龄重、12月龄重显著高于同龄本地黄牛（P＜0.01）;周岁平均日增重显著高于同龄本地黄牛（P＜0.01）;且胚胎移植后代牛的体尺也相应高于本地黄牛.胚胎移植后代牛的生长发育良好,在青海高寒地区具有良好的适应性.     

不同品种肉牛育肥效果的比较试验报告

对21～23月龄的12头西门塔尔、夏洛来、利木赞、安格斯与黄牛级进杂交二代优质改良牛进行60d强度育肥,测定分析4个品种牛的生长指标、屠宰指标、肉的品质3个指标,并进行差异显著性分析。在生长指标上西门塔尔平均日增重1506g,夏洛来平均日增重为1390g,利木赞平均日增重为1054g,安格斯平均日增重为823g。结果表明,西门塔尔和夏洛来之间差异不显著,其他之间差异均极显著。在屠宰指标上,西门塔尔屠宰率为57.86%,净肉率为50.22%,肉骨比6.57,夏洛来屠宰率为60.28%,净肉率为51.47%,肉骨比5.41,利木赞屠宰率为57.80%,净肉率为50.48%,肉骨比为6.91,安格斯的屠宰率为57.48%,净肉率为48.81%,肉骨比为5.67。结果表明夏洛来的屠宰率与西门塔尔、利木赞、安格斯之间差异极显著,其他品种之间差异不显著。对净肉率而言,夏洛来、利木赞、西门塔尔与安格斯之间差异极显著;夏洛来与西门塔尔、利木赞之间差异显著;利木赞与西门塔尔之间差异不显著。各品种的肉骨比差异不显著。在肉品质这一指标上,嫩度、眼肌面积、优质肉的比例中西门塔尔最佳。     

平凉红牛生长性状及胴体性状育种值预计趋势研究

为开展平凉红牛生长性状与胴体性状育种值预计趋势研究，本实验以296头平凉红牛（274头母牛、22头公牛）的育种值预计趋势数据为基础，与美国主要肉牛品种育种值预计趋势进行对比，并开展生长性状与胴体性状间相关性分析，绘制生长性状与胴体性状标准化评分雷达图。研究结果显示，平凉红牛RFI、ADG、WWT、YWT育种值的遗传趋势较安格斯牛、利木赞牛及西门塔尔牛逊色，即各项生长性状的发育较其他品种肉牛慢；平凉红牛Marb、Fat育种值的预计趋势评分高于利木赞牛，但较安格斯与西门塔尔牛低；REA育种值的预计趋势评分较安格斯、西门塔尔及利木赞牛高；HCW育种值的预计趋势评分较安格斯、西门塔尔及利木赞牛低；生长性状中除RFI与胴体性状育种值预计趋势呈一定程度的负相关外，其余指标与胴体性状均呈正相关。本实验研究结果表明，平凉红牛与其他品种肉牛相比，在胴体性状特别是眼肌面积方面表现优秀，因此今后平凉红牛选育工作重点可放在高档肉培育方面。     

牛胚胎移植试验及其后代生长发育指标测定

为探讨牛胚胎移植受胎率、产犊成活率及后代生长发育情况,互助县先后从新疆呼图壁种牛场胚胎工程中心引进不同品种牛冷冻胚胎93枚,进行了胚胎移植试验.结果表明：平均受胎率为45.16%,产犊成活率为90.48%.黑白花、西门塔尔、利木赞、安格斯犊牛平均初生重为40.77,42.50,47.41,39.13,分别比同龄本地牛提高71.82%,79.10%,99.79%,64.90%;六月龄平均体重分别为116.74,123.36,134.15,120.49,分别比同龄本地牛提高64.80%,74.13%,89.37%,70.09%;12月龄体重分别为253.31,289.91,302.73,271.35,分别比同龄本地牛提高75.18%,100.51%,109.36%,87.66%;1周岁平均日增重分别为582.30g,677.84g,699.50g,636.22g.胚胎移植后代牛的生长发育较本地牛快.     

北京奶牛中心

北京奶牛中心种公牛站是农业部在国内建立的第一个种公牛性能测定中心，并被农业部命名为“国家重点种公”，目前饲养从美国、加拿大、澳大利亚进口和培育的优秀荷斯坦种公牛178头（可供选择的冻精超过200头），牛4头，瑞士褐牛5头，蒙贝利亚9头，西门塔尔、夏洛来、利木赞、安格斯及纯种和牛等肉用种公牛25头。     

北京奶牛中心

北京奶牛中心种公牛站是农业部在国内建立的第一个种公牛性能测定中心，并被农业部命名为“国家重点种公”，目前饲养从美国、加拿大、澳大利亚进口和培育的优秀荷斯坦种公牛178头（可供选择的冻精超过200头），牛4头，瑞士褐牛5头，蒙贝利亚9头，西门塔尔、夏洛来、利木赞、安格斯及纯种和牛等肉用种公牛25头。     

奶牛中心简介

北京奶牛中心种豁牛站是农业部在国内建立的一个种公牛性能测定中心,并被农业部命名为“国家重点种公牛站”，目前饲养从美国、加拿大、澳大利亚进口和培育的优秀荷斯坦种公牛178头，娟珊牛4头,瑞士褐牛5头，蒙贝利亚9头、西门塔尔、夏洛来、利木赞、安格斯及纯种和牛等肉用种公牛25头。     

北京奶牛中心

北京奶牛中心种公牛站是农业部在国内建立的第一种公牛性能测定中心，并被农业部命名为“国家重点种公牛站”，目前饲养从美国、加拿大、澳大利亚进口和培育的优秀荷斯坦种公牛140头（可供选择的冻精超过160头），娟珊牛4头，瑞士褐牛5头，西门塔尔、夏洛来、利木赞、安格斯及纯种和牛等肉用种公牛25头。     

不同季节与品种对种公牛精液品质的影响

试验旨在通过对新疆地区安格斯、和牛、利木赞、夏洛来和西门塔尔5个品种种公牛全年精液品质分析,探究不同季节与品种对种公牛精液品质的影响,为冻精生产提供理论依据。选择3～5岁的5个品种的种公牛106头,收集其2018—2019年采精量、原精活力和原精密度共2 211条数据,使用SAS 9.2软件进行分析。结果表明:季节及品种对种公牛精液品质均有极显著影响,其中夏洛来种公牛采精量高于和牛、利木赞及西门塔尔(P0.01),利木赞种公牛的原精活力高于安格斯、夏洛来(P0.01),和牛的原精密度高于安格斯和夏洛来(P0.01);春季的采精量、原精活力及原精密度均高于其他季节(P0.05或P0.01)。综上,就新疆地区种公牛精液品质而言,利木赞、夏洛来和西门塔尔种公牛的精液品质相对好于其他品种;春、秋两季种公牛的精液品质较好,建议将精液采集的工作集中在春、秋两季。     

8个牛品种的大理石花纹评分相关基因变异的微卫星DNA池分析

本研究以8个牛品种为研究对象,利用与大理石花纹评分基因相关的7个微卫星位点结合DNA池分析技术,探讨微卫星DNA多态性与8个牛品种大理石花纹评分间的关系,并根据性状同质性原理预测品种组合,以加快生产出高端"雪花"牛肉。结果表明:日本和牛与荷斯坦牛、安格斯牛、渤海黑牛的相似性系数均超过0.8,而日本和牛与其他牛品种的的相似性系数均小于0.8。利用MEGA4软件采用邻接法进行聚类,利木赞牛与西门塔尔牛先聚合在一起,再与草原红牛聚合;渤海黑牛与鲁西黄牛2个地方良种聚合在一起,以上5个品种聚为第1大类。荷斯坦牛与日本和牛聚合,再与安格斯牛聚在一起,它们聚为第2大类。根据本研究结果和国外肉牛杂交生产实践,从牛肉大理石花纹性状的同质性出发,建议利用日本和牛、荷斯坦牛为亲本,杂交生产高档"雪花"牛肉,以解决我国的肉牛牛源短缺问题。     

Effect of flunixin meglumine treatment during and after embryo transfer on the pregnancy rate in cattle

This study aimed to determine the effect of flunixin meglumine treatment during and after the transfer of in vivo produced embryos to Angus (cows) and Holstein (cows and heifers) breeds of cattle on pregnancy rate. Holstein cows were used as donors in the study. A double dose of prostaglandin F2α was administered to the recipient animals for synchronization. Uterine flushing was performed in donors on day 7 after artificial insemination. A total of 295 transferable embryos were obtained. These embryos were transferred to Angus cows (n = 85), Holstein heifers (n = 80) and Holstein cows (n = 130). After the transfer, these animals were divided into three subgroups. The first subgroup (TI) was administered flunixin meglumine during embryo transfer, and the second subgroup (TII) was administered flunixin meglumine both during embryo transfer and on days 8 and 9 after the transfer. The third subgroup (TIII) was not administered anything and it was considered the control group. Pregnancy examination of the recipients was performed on days 30–35 after the transfer using real-time ultrasonography. The pregnancy rates after embryo transfer were found to be 43.52% in Angus cows, 42.5% in Holstein heifers, and 24.61% in Holstein cows (p < .05). When the animals were not classified according to breed, the pregnancy rates in subgroups TI, TII and TIII were found to be 29.29%, 45.10% and 29.79%, respectively (p < .05). In addition, the pregnancy rates were higher in TII and TIII subgroups of Angus cows and Holstein heifers compared to that of Holstein cows (p < .05). As a result, the pregnancy rates obtained after embryo transfer in Angus cows and Holstein heifers were found to be higher than that in Holstein cows. In addition, it was concluded that the administration of flunixin meglumine during and during/after embryo transfer has a positive effect on pregnancy rates in Angus cows and Holstein heifers.     

Influence of genotype and yield and composition of milk on interval to first postpartum ovulation in milked beef and dairy cows.

Our objectives were to investigate the effects of genotype, yield and composition of milk, and changes in BW and body condition on the initiation of cyclic ovarian activity in nonsuckled beef and dairy cows milked twice daily. Nulliparous heifers were selected from three breeds, 12 Angus, 13 Simmentals, and 26 Holsteins, based on their EBV for milk yield. Cows were machine-milked twice daily, and daily milk yield was recorded; composite samples of milk were collected twice weekly for analyses of milk components. Blood was collected from all cows thrice weekly for 75 d postpartum, and concentrations of progesterone in serum measured by RIA were used to estimate day of first postpartum ovulation. Holstein cows produced more (P less than .05) milk (unadjusted or 3.5% fat-corrected) than Angus or Simmental cows during the first 30 d of lactation. Holstein cows had higher (P less than .01) peak yield of milk than Simmental and Angus cows. Days to peak milk yield were similar for Simmental and Holstein cows, and both were more (P less than .05) than those for Angus cows. Percentages of fat, protein, and total solids in milk were highest (P less than .05) for Simmental cows, whereas milk of Holstein cows had the highest (P less than .05) percentage of lactose and lowest (P less than .05) concentration of somatic cells. Average BW at ovulation differed (P less than .05) among breeds. Estimated daily changes in BW from calving to first ovulation were different (P less than .05) for Holstein and Simmental cows but were similar to those of Angus cows.(ABSTRACT TRUNCATED AT 250 WORDS)     

Bovine embryo transfer pregnancies. II. Lengths of gestation

Lengths of gestation were determined from 1,484 pregnancies resulting from embryo transfer procedures. Least-square means of lengths of gestation by breed of embryos (P less than .005) were: Holstein, 278.7; Angus, 281.0; Hereford, 285.7; Simmental, 287.6 and Limousin, 289.7 d. Recipient breed had a small effect on length of gestation (P less than .005). The length of gestation for recipients less than 4 yr old was 2.7 d shorter (P less than .005) than for older recipients. As asynchrony of recipient and donor estrus changed by 1 d, length of gestation changed linearly by .78 d (P less than .005). Male calves were carried 1.4 d longer than females (P less than .005). Embryo age at time of transfer, embryo quality, length of embryo storage between collection and transfer, and donor age did not affect length of gestation significantly. Lengths of gestation of 185 embryo transfer pregnancies were 1.5 d longer (P greater than .1) than those of 305 matched control pregnancies from the same farms. We conclude that length of gestation of embryo transfer calves and length of gestation of non-embryo transfer calves are influenced by similar factors.     

利用西杂牛和秦川牛做受体进行奶牛胚胎移植的对比试验

[目的]为了选择奶牛胚胎移植的理想受体。[方法]通过利用不同品种的本地黄牛～西杂牛84头和秦川牛77头做受体,进行荷斯坦奶牛胚胎移植效果的对比试验。[结果]西杂牛的同期发情率、受体可用率、受胎率都显著高于秦川牛（P〈0．05）,而且难产率低,奶水充足。[结论]表明西杂牛是奶牛胚胎移植的理想受体。     

母牛难产的原因及解决方法

[目的]为了寻求本地黄牛母牛难产的原因和解决方法。[方法]2013年对5081头母牛的产犊情况进行统计分析。[结果]在统计产犊的母牛中,本地母牛为4018头,西本杂母牛为1063头,难产率最高的是本地母牛×西门塔尔,难产率为7.98%,其后依次为本地母牛×利木赞（6.55%）,西本杂母牛×西门塔尔（4.65%）,本地牛×安格斯（3.1%）,难产率最低的是本地母牛×本地公牛,难产率为0.85%。[结论]可采取科学选配、控制营养等方法来减少难产的发生率;采取科学的接产方法,能有效解决难产问题。     

牛胚胎移植试验报告

2000年9月至2003年9月,在大通县青林、多林、逊让、向化等9个乡镇开展了安格斯牛、荷斯坦、皮埃蒙特牛冷冻胚胎移植工作。经过对298头当地黄牛母牛及杂交母牛进行了诱导同期发情,结果获得93.29%的同期发情率和38.13%的黄体合格率。对于黄体合格的106头母牛进行了安格斯、荷斯坦、皮埃蒙特牛冷冻胚胎移植,获得移植妊娠率42.5%。     

Lactation characteristics of nine breeds of cattle fed various quantities of dietary energy.

Milk yield data were collected by weigh-suckle-weigh procedures at approximately 14, 28, 56, 84, 112, 138, 156, 184, and 212 d postpartum for mature Angus, Braunvieh, Charolais, Gelbvieh, Hereford, Limousin, Red Poll, Pinzgauer, and Simmental cows over a 4-yr period. Individual cows were fed at one of four energy intake levels. Parameters characterizing lactation curves for 431 lactations from 179 cows were estimated by nonlinear regression. Differences due to breed, level of energy intake, and the two-factor interaction between breed and level of ME allowance for scale and shape parameters of lactation curves and derived estimates for time of peak lactation, yield at time of peak lactation, and for total yield for a 210-d lactation period were evaluated. Breed and energy intake level were significant sources of variation for all traits. Pooled over energy levels, daily yields at time of peak lactation of Braunvieh, Gelbvieh, and Pinzgauer were greater (P less than .05) than those of Angus, Charolais, Hereford, and Limousin. Simmental and Red Poll were intermediate. Total lactation yield of the Braunvieh exceeded (P less than .05) that of all other breeds with the exception of Gelbvieh. Hereford produced less milk than (P less than .05) the other breeds. The response in yields at time of peak lactation as energy allowances increased for Braunvieh, Charolis, Gelbvieh, Limousin, and Pinzgauer cows were linear and resulted in higher yields at this time. Linear increases in total 210-d yield and times of peak lactation were observed for all breeds with the exception of Hereford.     

和牛母牛超数排卵及胚胎移植试验研究效果初报

[目的]研究和牛母牛超数排卵及胚胎移植效果。[方法]利用纯种和牛母牛作为供体,荷斯坦母牛及西杂母牛作为受体,通过供体牛的超数排卵、人工授精、采胚、胚胎冷冻及受体牛的同期发情和鲜胚移植,快速获得纯种和牛及和牛胚胎。[结果]对4头青年纯种和牛母牛进行超排,重复冲卵13头次,共采卵数122枚,其中75枚可用胚胎,可用胚率为61.5%,平均5.76枚/头次。对75头荷斯坦牛及西杂母牛同期发情,结果获得89.2%的同期发情率。67头受体牛移植了鲜胚,2个月后妊娠检查有35头怀孕,移植妊娠率为52.23%。[结论]可以利用超数排卵及胚胎移植增加和牛母牛利用效率。