西门塔尔与荷斯坦母牛胚胎生产及移植效果的分析

本试验对10头西门塔尔母牛与17头中国荷斯坦母牛进行超排处理。试验结果表明,处理后,分别采集76枚和148枚胚胎,可用胚分别为61枚和112枚,可用胚率分别达到80.20%和75.70%,西门塔尔牛可用胚率高于中国荷斯坦牛(P0.05);西门塔尔与中国荷斯坦母牛胚胎移植后的受胎率分别达到41.86%和52.75%,两者之间差异显著(P0.05)。     

广西西门塔尔青年母牛和荷斯坦母牛超数排卵及胚胎移植初报

本试验于 2 0 0 2年 1 2月 1 6日至 2 0 0 3年 2月 2 8日期间在广西畜牧研究所种牛场对 3头西门塔尔青年母牛和 5头荷斯坦母牛作了超排 ,同时做供体牛及受体牛的同期发情 ,杂种牛和本地牛的胚胎移植和胚胎冷冻试验 ,并获得较好的效果 ,现报告如下。1　材料与方法1 .1　供体牛与受体牛的选择供体牛 :选择本所种牛场引进的纯种西门塔尔青年母牛 3头 ,平均年龄 2 0个月 ,体重达3 50千克以上 ,已正常发情 3次以上 ,膘情中上等。荷斯坦母牛 5头 ,其中经产母牛 2头 ,年龄3 -5岁 ,产奶为 60 0 0千克以上 ,青年母牛 3头 ,平均年龄 2 0个月 ,体重达 3…     

娟姗牛与荷斯坦牛超排效果比较

本试验对56头青年娟姗牛和179头荷斯坦青年牛进行超排处理,平均获得可用胚胎数4.05±4.20枚/头次和7.06±3.72枚/头次;可用胚率分别为57.80%和70.65%,娟姗牛和荷斯坦牛超排黄体数无明显差异(P>0.05),但采胚数娟姗牛明显低于荷斯坦牛。共移植受体牛310头,怀孕157头(50.65%)。娟姗牛胚胎与荷斯坦牛胚胎的移植妊娠率分别为52.54%(31/59)和50.20%(126/251),无明显差异(P>0.05)。结果表明,青年荷斯坦牛和青年娟姗牛可用于胚胎生产,但娟姗牛的可用胚胎数低于荷斯坦牛。     

青海省荷斯坦牛胚胎移植

青海省民和县种畜场2001年引进了48头秦川牛,于2001年4月～2002年6月进行了荷斯坦奶牛胚胎移植,结果12头秦川牛移植成功,所产荷斯坦牛犊生长发育良好。1材料与方法1．1供体胚胎荷斯坦奶牛7日龄冷冻胚胎,由新疆生物科技研究所提供。     

胚胎移植在加拿大荷斯坦牛中的应用

序 言 胚胎移植(ET)作为繁育牛的较新方法已被公认和接受。ET是一项过程,通过它在相对短的时间里,从1头母牛能够获得更多的小牛。例如,仅在1年里从1头母牛获得的小牛可能比它整个一生自然生下的小牛还要多。因而,对1头遗传上优秀的母牛使用ET其优越性是十分明显的。 简单地说,这个过程涉及到用激素处理母牛(供体),以便使它在给定的发情周期排出多个卵来(超数排卵)。紧跟这种处理,用供体跟理想公牛配种;大约7天之后,通过一种叫做冲卵的过程从供     

新疆昌吉某牛场西门塔尔牛与荷斯坦牛淘汰原因分析

本文通过对2017-2019年共1681条成母牛淘汰记录进行淘汰原因分析,结果表明肢蹄疾病是现今牧场最主要的淘汰原因,西门塔尔牛因肢蹄疾病、乳房疾病等5种疾病而淘汰的比例低于荷斯坦牛,而自然淘汰牛比例高于荷斯坦牛,其中因无奶淘汰牛头数最多.本研究为牧场针对不同疾病、不同品种牛群制定合理的饲养管理措施提供了依据.     

德系西门塔尔牛与荷斯坦牛杂交初报

德系西门塔尔牛属乳肉兼用牛,经不断选育,其平均产奶量已达6 768kg.虽然弗莱维赫牛的产奶性能略逊于荷斯坦牛,但却具有诸多优点.本文介绍了浙江金华利用德系西门塔尔牛冻精与荷斯坦牛杂交的情况,结果显示,二者进行杂交具有很好的应用前景.     

胚胎移植荷斯坦牛泌乳性能测定

[目的]胚胎移植是荷斯坦牛繁育新技术之一,可缩短育种年限、迅速提高生产性能.[方法]本试验通过对胚胎移植荷斯坦牛泌乳性能的测定,真实表达了实施胚胎移植技术的作用和意义.[结果]表明,在完全相同的饲养管理条件下,试验组7头胚移荷斯坦牛305 d的泌乳量为5593.47 kg,对照组31头非胚移荷斯坦牛305 d的泌乳量为3 599.88 kg,前者泌乳量比后者高1 993.59 kg,提高55.38%(P<0.01).[结论]胚移荷斯坦牛的泌乳性能显著高于非胚移荷斯坦牛.     

荷斯坦母牛超数排卵及胚胎移植试验初报

应用FSH对3头荷斯坦母牛进行超数排卵处理，在母牛发情后第7天，2头共冲出11枚卵子，其中受精卵2枚（1枚桑椹胚，另1枚退化）。将回收的胚胎移植给1头受体牛，2个月后直检怀孕。     

一头荷斯坦牛多次超数排卵及胚胎使用效果分析

本试验选择一头荷斯坦牛,从2003年12月到2007年5月间,共超排处理15次,共获得胚胎(包括未受精卵)298枚,可用胚胎169枚;每次超排平均获得19.9枚胚胎,可用胚胎11.3枚;可用胚胎率56.71%。试验结果表明:进口FSH比国产FSH的效果好,重复超排FSH每次增加10%左右的使用量效果会增加,但FSH的量维持不变效果会下降;供体牛的子宫内环境和技术人员的操作水平是影响效果的主要因素之一;连续超排间隔时间在90 d以上的效果较好;连续超排15次或更多是可行的;并且表明经多次和长期超排生产的胚胎,使用效果仍然较好。同时也作了性控X-精子冷冻精液在供体牛超排发情后输精的对比试验。     

An analysis of age and body weight at first calving for Holsteins in the United States

In a national survey of US dairy producers, only 2.7 ± 0.5% of Holstein dairy operations reported achieving recommended target ranges of age ≤ 24 months and body weight (BW) ≥ 550 kg at first calving. Allowing for wider target ranges, still only 14.6 ± 1.3% of Holstein dairy operations reported achieving age ≤ 25 months and BW ≥ 544.3 kg at first calving. Ages of individual first-calf heifers observed at calving were heavily skewed toward older individuals. Dairy producers reported an average age at first calving that was 1.3 months lower than the mean and 1.0 months lower than median age of first-calf heifers' observed calving on the operations. Stepwise logistic regression was used to identify the herd characteristics associated with producers reporting first calvings within the wider age and BW target ranges for Holsteins. Rolling herd average milk production ≥ 7711 kg/yr, using a computer for recordkeeping, and not tying preweaned heifers in a barn with cows, were associated with achieving the target BW and age at first calving.     

Effects of heat stress on production,somatic cell score and conception rate in Holsteins

We examined the effects of heat stress (HS) on production traits, somatic cell score (SCS) and conception rate at first insemination (CR) in Holsteins in Japan. We used a total of 228 242 records of milk, fat and protein yields, and SCS for the first three lactations, as well as of CR in heifers and in first‐ and second‐lactation cows that had calved for the first time between 2000 and 2012. Records from 47 prefectural weather stations throughout Japan were used to calculate the temperature–humidity index (THI); areas were categorized into three regional groups: no HS (THI < 72), mild HS (72 ≤ THI < 79), and moderate HS (THI ≥ 79). Trait records from the three HS‐region groups were treated as three different traits and trivariate animal models were used. The genetic correlations between milk yields from different HS groups were very high (0.91 to 0.99). Summer calving caused the greatest increase in SCS, and in the first and second lactations this increase became greater as THI increased. In cows, CR was affected by the interaction between HS group and insemination month: with summer and early autumn insemination, there was a reduction in CR, and it was much larger in the mild‐ and moderate‐HS groups than in the no‐HS group.     

夏洛莱牛和西门塔尔牛育肥及屠宰性能对比试验研究

[目的]试验旨在研究青海省引进夏洛莱牛的育肥效果、屠宰性状和肉质品质,评估夏洛莱牛在青海省推广及杂交利用的可行性,[方法]在青海锦绣农业发展有限公司开展了引进6月龄夏洛莱牛与本地自繁6月龄西门塔尔牛的育肥对比试验,最后对15月龄夏洛莱牛和本地西门塔尔牛进行屠宰性能测定,分析其屠宰性能、胴体和肉质品质的差异。[结果]结果表明,夏洛莱牛在青海西宁育肥后可达到屠宰率57.80%,净肉率46.40%,胴体产肉率80.30%,肉骨比4.23,各项指标均优于本地西门塔尔牛;夏洛莱牛肉中必需氨基酸含量及必需脂肪酸含量分别为7.96%和3.29%,与本地西门塔尔牛无显著差异。[结论]综上所述,夏洛莱牛具有良好的生长性能和屠宰性能,其肉质营养水平与本地西门塔尔牛接近,因此,夏洛莱牛适合在本地育肥并推广。     

波尔山羊连续超排及移植试验

对20只波尔山羊间隔1.5～2个月进行3次连续超排、采胚和移植试验.结果表明:①3次超排获得的可用胚胎分别为13.1、12.8和13.2枚,差异不显著(P>O.05).②连续超排采胚获得的胚胎中,A级胚胎占可用胚胎的比例分别为67.5%、71.4%、64.4%,差异不显著(P>O.05).③获得的可用胚胎移植妊娠率分别为58.7%、58.8%、57.4%,胚胎产羔率分别为54.5%、51.2%、51.1%,其妊娠率和胚胎产羔率问差异不显著(P>O.05).④羔羊的出生重分别为4.2、4.0和3.9 kg,断奶时羔羊的体重分别为21.4、20.3和21.O kg,6月龄体重分别为40.9、41.2和39.3 kg,差异不显著(P>O-05).     

Effect of Mycobacterium paratuberculosis infection on production, reproduction, and health traits in US Holsteins

Our objective was to estimate the effect of Mycobacterium paratuberculosis infection on milk, fat, and protein yield deviations, pregnancy rate, lactation somatic cell score, and projected total months in milk (productive life). A serum ELISA and fecal culture for M. paratuberculosis were performed on 4375 Holsteins in 232 DHIA herds throughout the US. Primarily first through third lactation cows (99% of total) were assayed for infection. Trait information (except productive life) was obtained for the lactation concurrent with disease tests. Productive life was total months in milk through a cow's life, which was projected if a cow was still milking. For most analyses, case definition for M. paratuberculosis infection was defined as either an ELISA S/P ratio>or=0.25 or a positive fecal culture for M. paratuberculosis or both. To determine if diagnostic test affected estimates, case definition was redefined to include only cows with ELISA S/P ratios>or=0.25 or only fecal culture-positive cows. Linear models were used to estimate effect of M. paratuberculosis infection on traits. M. paratuberculosis-infected cows (7.89% of cows) produced 303.9 kg less milk/lactation, 11.46 kg less fat/lactation, and 9.49 kg less protein/lactation (P相似文献   

Development of genetic evaluation for milk production traits of Holsteins in Japan

The procedure used for the genetic evaluation of dairy cattle in Japan has developed from a lactation sire–MGS model to a multiple‐lactation random regression test‐day animal model. Genetic evaluation of Holstein bulls in Japan began in 1989 with the use of field‐style progeny testing; dairy herd improvement program data from all over Japan were used, along with a sire and maternal grandsire model. In 1993, an animal model was introduced to estimate breeding values for yield and type traits. A random regression test‐day model was first applied in 2010. In the business of breeding dairy cattle, it is very important to users that estimated breeding values are reliable and stable among subsequent routine evaluations. With experience in the genetic evaluation of dairy cattle in Japan, Japanese researchers have found ways to improve the stability of estimated breeding values. These modifications involve changes in data editing, development of evaluation models, changes to the structures of unknown‐parent groups, awareness of the problems of predicting lactation yield from partial test‐day records, and adjustment for heterogeneity within herd variances. Here, I introduce developments in, and our experiences with, the genetic evaluation of yield traits of Holstein cattle in Japan.     

An Approximate Bayesian Analysis of Somatic Cell Score Curves in Holsteins

Somatic cell score (SCS) decreases to a minimum at around 60 days postpartum and then increases until the end of lactation. This pattern was described with three non-linear mixed effects models. Parameters of the models were linear in fixed and random (cow) effects. Data were 1705 SCS test-day records (155 primiparous Holsteins) taken from 14 to 300 days in milk. Point estimates were the mode of the joint posterior distribution of fixed and random effects (given dispersion parameters) and approximate marginal maximum likelihood estimates of covariance components. Intramammary infection during lactation, season and period of calving affected SCS patterns. Estimates were similar with or without a relationship matrix. There was between-cow variation of trajectories, suggesting that SCS curve parameters can be modified by selection in some advantageous manner.     

猪胚胎移植技术研究进展及其在生产中的应用

综述了猪胚胎移植技术在国内外的研究进展及应用情况，提出了目前的技术水平在良种猪的快速扩繁和引进种猪方面应用的可行性及具体操作方案，供种猪的生产经营者和育种工作者参考。