陕西省种公牛站秦川牛经济类型测定研究

对陕西省种公牛站全部8头种用秦川牛进行体尺体重测定,计算其肉用指数(活重kg/体高cm,Beef purpose index,BPI),通过该指数确定种公牛的经济类型.结果表明:种公牛站的6头成年种公牛平均BPI为5.80±0.30,大于5.60,初步到达了肉用型;2头青年牛校正为成年当量后平均BPI为5.05,大于4.5,小于5.6,处于肉役兼用类型.可将BPI较高的公牛作为系祖选配高BPI母牛,培育肉用品系,促使秦川牛向肉用方向发展.     

乌鲁木齐种牛场褐牛种公牛产奶性能的种用价值评定

选择新疆乌鲁木齐种牛场6头新疆褐牛种公牛及后代母牛为研究对象,运用DMU软件AIREML算法及动物模型BLUP法,估计该场后代母牛的遗传参数及种公牛的育种值,并进行排序,为该场褐牛种公牛及后代母牛的选种选配计划提供理论依据。结果表明:该场新疆褐牛后代母牛的产奶量、乳脂率、乳蛋白率、乳糖率及总固体的遗传力分别为0.35、0.06、0.19、0.06、0.04;00233号种公牛在所选公牛中的各项育种值最高,196318号种公牛各项育种值最低。通过研究结果,可对公牛各项育种值高的后代母牛进行选育选配,进一步扩大核心群体,为该场牛品种的改良提供决策。     

乌鲁木齐种牛场荷斯坦种公牛产奶性能的种用价值评定

目的:估计新疆乌鲁木齐种牛场荷斯坦牛产奶性状的遗传参数及育种值,为该场荷斯坦种公牛的选种选配计划提供理论依据。方法:以新疆乌鲁木齐种牛场2009~2015年间荷斯坦泌乳母牛的产奶性能记录资料为基础,运用DMUAI-REML算法及动物模型BLUP法,对荷斯坦牛产奶量及乳成分进行单性状方差组分及育种值估计。结果:牛场荷斯坦种公牛后代母牛的产奶量、乳脂率、乳蛋白率、乳糖率及非脂固形物的遗传力分别为0.14、0.13、0.14、0.09、0.11。6头种公牛里估计得到产奶量育种值最高的是65206012号种公牛,乳脂率、乳蛋白率、乳糖率、非脂固形物育种值最高的是11101917号种公牛。结论:使种公牛生产性能评定的更准确,需综合考虑产奶量和乳成分等性状,最终对种公牛进行选育选配。     

秦川牛部分体量性状的遗传参数估测

本研究选用陕西秦川牛原种场饲养的33头公牛及其603头女儿1978年至2005年的记录资料,采用父系半同胞相关法对秦川牛初生、断奶、周岁及18月龄体重、体高、体长、胸围及体重体高比(BPI)的遗传力进行了统计分析,同时分析了各年龄段体重与体尺的相关性。结果表明,秦川牛初生重、断奶重、周岁重及18月龄体重的遗传力分别为0．4150、0．6136、0．2008和0．6371。同期体重体高比(BPI)的遗传力值为0．6225、0．6464、0．1632和0．4839。各年龄段体重与其它体尺性状均呈较强的正相关。     

牛育种新技术

1 利用BLUP法个体动物模型评价种公牛 用BLUP法个体动物模型可望达到: (1)现在种牛评价的中心是公牛,动物个体模型也能对母牛育种值进行评价,所以可成为按计划选配母牛的手段。 (2)对没有能力的年青后备牛可利用血缘信息算出育种值,所以可进行早期选择。 (3)地域育种时可做为保留后备牛时的判断资料利用。问题是第一动物个体模型与公牛模型、外祖父模型相比计算量大,计算时间长,第二动物个体模型因为能最大限度地利用血缘关系信息算出育种值,所以血缘的误差对结果影响恐怕很大。现场测定饲养     

北京市奶牛遗传评定概况

本文介绍了北京奶牛中心奶用种公牛遗传评定的发展过程。应用最佳线性无偏预测(BLUP)法估计育种值,经历了从公畜模型向动物模型的转变;中心积累了20多年的育种资料,与中国农大合作编制并实施了动物模型BLUP育种值评定程式,提高了种公牛育种值预测的精确性,加快了奶牛的改良速度;每年出版两期“北京市优秀公牛概要”,逐步与国际奶牛界接轨;建立、实施了奶牛的性能测定体系,使之制度化,测定报告成为奶牛场可靠、科学的生产指导。     

BLUP和PD法在小群混合世代种牛育种值测定的对比

本文用10头西门塔尔公牛168个女儿的材料对比同期同龄法和布拉普(BLUP)法来估测育种值。两种方法的结果基本一致。在小样本的情况下布拉普法可验证同期同龄法的可靠性。引入亲缘矩阵和世代矩阵在混合世代的情况下,不以年度的表型值的进展为转移,可以估测各代的各自遗传效应。BLUP法可对无后裔的公牛进行育种值的预报。     

乳用种公牛后裔测定方法的比较

优良的种公牛是提高后代品质的关键,尤其是冷冻精液的推广使用,更加突出了种公牛的作用。如何选择种公牛,这在育种工作中是一个重要的课题。当前对奶用种公牛的选择,一是在犊牛阶段采用系谱,但准确度较低,可靠性只有6—30％左右、据《南方奶协》《种公牛早期选择》科研组报道,母牛表型值(产奶量)与其子代公牛育种值的相关系数(BAI)在0.27左右;后者准确度较高,当女儿数在40头以上可达80％以上,但需较长时间方可作出判断。近25年来国内外许多育种工作者,在血液蛋白、牛奶蛋白、酶、激素、血液代谢物及     

应用总性能指数(TPI)评定西门塔尔种公牛

<正> 前言应用正确的方法计算种公牛的育种值,对于准确地选择种公牛,改良牛群的遗传特性,提高牛群质量,获得更大的经济效益,无疑是十分重要的。过去对于种公牛的评定方法,只是根据单个性状育种值的高低作为唯一的标准,忽略其他一些重要的经济性状,无疑是一个很大缺点。目前应用最广泛的是总性能指数法(TPI),即多项性状估计的育种值综合为一个指数,根据指数大小选择种公牛。为消除畜群间、年季间和季度间的差异,在计算各性状育种值时,可用最佳线性无偏预期法(BLUP)或改进的同龄比较法(MCC)。本文重点以改进的同龄比较法(MCC)计算总性能指数(TPI),对我国西门塔尔种公牛评定作以研究。     

不同精粗比日粮对秦川肉牛甲烷产量和瘤胃发酵的影响

试验旨在研究不同精粗比日粮对秦川肉牛甲烷产量和瘤胃发酵的影响。选取秦川肉牛公牛、阉牛、母牛各3头,分为3个处理,每个处理3头牛。3种粗蛋白水平相同(16.44%)的日粮,精粗比分别为30∶70(低能组)、50∶50(中能组)、70∶30(高能组)。试验牛饲养在环境控制代谢仓实时测定甲烷气体排放量;采用瘤胃穿刺技术采取瘤胃液分析瘤胃发酵情况。结果表明:(1)日粮精粗比的提高显著降低了秦川肉牛公牛、阉牛和母牛的甲烷排放量(P0.05),且在高能组能量水平下,秦川肉牛阉牛的甲烷排放量显著低于母牛和公牛(P0.05);(2)在瘤胃发酵指标方面,日粮精粗比的提高显著降低了秦川肉牛公牛、阉牛和母牛的瘤胃pH(P0.05),同时显著降低了秦川肉牛公牛、阉牛和母牛瘤胃NH3-N浓度(P0.05);(3)日粮精粗比的提高显著提高了秦川肉牛公牛、阉牛和母牛的瘤胃总挥发性脂肪酸浓度(P0.05),并显著降低了乙酸丙酸比值(P0.05)。在中等能量日粮下,阉牛和母牛的乙酸丙酸比值显著高于公牛(P0.05)。日粮精粗比的提高显著提高了公牛、阉牛瘤胃发酵中的丁酸浓度(P0.05),母牛瘤胃发酵中丁酸浓度有上升趋势,但不显著(P0.05),在高能组下,阉牛的丁酸浓度最高(P0.05)。研究结果表明,在舍饲条件下,提高秦川肉牛日粮精粗比,可显著降低甲烷气体的排放,且阉牛甲烷排放量最低,其次为母牛、公牛;在舍饲育肥条件下,提高日粮的精粗比可以显著提高舍饲秦川肉牛瘤胃丙酸的浓度,且阉牛的乙酸丙酸比值最低。     

安秦F_1代、和秦F_1代与秦川牛生长性能比较

[目的]为探讨安秦F1代与和秦F1代与秦川牛的生长发育情况。[方法]选择安秦、和秦、秦川公牛各10头作为2个试验组和1个对照组,测定6、12、18、24月龄的空腹体重、体长、体高、胸围数据,并进行比较分析。[结果]表明,在集约化饲养条件下,6～24月龄的安秦F1代体重及各项体尺指标,均显著高于秦川牛（P〈0.05）,和...     

Testicular development, epididymal sperm reserves and seminal quality in two-year-old Hereford and Angus bulls: effects of two levels of dietary energy

The effect of high (HED) and medium energy diets (MED), fed to Hereford (H) and Angus (A) bulls from 6 through 24 mo of age, on scrotal circumference (SC), paired testes weight (PTW), epididymal sperm reserves (ESR) and seminal traits were examined. Over 3 yr, 120 bulls were involved. Angus exceeded H for both SC and PTW. Hereford bulls in yr 2 had smaller SC than in yr 1 or 3 but the response for A was consistent. Year affected PTW. In yr 2 Hereford bulls fed HED had 75% fewer ESR than MED-H bulls (9.3 vs 37.2 X 10(9]. Comparably treated A bulls had similar ESR numbers (29.2 vs 33.4 X 10(9]. In yr 3, epididymal sperm reserves of HED-H were depressed by 35% compared with MED-H (23.1 vs 35.7 X 10(9], whereas HED-A had 14% fewer ESR than did MED-A bulls (28.6 vs 33.1 X 10(9]. It was not obvious why H bulls were more susceptible to the effects of HED. Seminal quality of HED bulls was inferior to that of MED bulls, particularly with respect to progressive motility and the incidence of sperm in which a crater defect of the head was present at 2 yr of age. In yr 2 all seminal traits were severely depressed in 2-yr-old HED-H. Feeding HED to young H and A bulls reduced their reproductive potential.     

基于BLUP和GBLUP方法估计北京油鸡胴体和肉质性状遗传参数的差异

旨在比较不同方法对遗传参数估计的差异,为未来北京油鸡胴体和肉质性状选育方法的制定提供参考依据。本研究利用传统最佳线性无偏预测（best linear unbiased prediction,BLUP）和基因组最佳线性无偏预测（genomic best linear unbiased prediction,GBLUP）两种方法对北京油鸡的胴体和肉质等性状进行了遗传参数估计。从系谱较为完整的北京油鸡群体中,选择100日龄体重相近的公鸡615只,测定其100日龄体重（BW）、屠宰率（EP）、胸肌率（BMP）、腿肌率（LMP）、腹脂率（AFP）、嫩度（T,以剪切力值表示）和肌内脂肪（IMF）等性状,并用SNP芯片（Illumina,60K）进行个体基因分型。结果表明,除IMF和剪切力（SF）遗传力基于两种方法的估值存在较大差异外,其余性状利用两种方法得到的遗传力估值差异较小;除嫩度外,GBLUP方法估计的遗传力均低于BLUP方法。所有胴体相关性状中,除屠宰率遗传力为低遗传力外,其余性状均属于中等遗传力性状。嫩度呈现低遗传力,而IMF基于BLUP法和GBLUP法的估计遗传力分别为中等（h² =0.256）和低遗传力（h² =0.107）。基于BLUP方法,IMF与BW、BMP和SF 3个性状间均呈高度遗传负相关（-0.572、-0.420、-0.682）,与EP的遗传相关为中度负相关（-0.234）,与AFP的遗传相关为中度正相关（0.420）;基于GBLUP方法,IMF与BW、BMP和SF 3个性状间均呈高度遗传负相关（-0.808、-0.725、-0.784）,与EP的遗传相关为高度负相关（-0.626）,与AFP的遗传相关为低度正相关（0.097）。综上,对于某些性状,基于传统的BLUP方法与新的GBLUP方法得到的遗传力与遗传相关估值存在较大差异,实际育种工作中,为提高育种效率,需要综合考虑。     

Selection for weaning weight and postweaning gain in Hereford cattle. II. Response to selection

Single trait selection was practiced in three lines of Hereford cattle at two locations. Bulls were selected within sire families for increased weaning weight (WW) in the WW line (WWL), for postweaning gain (PG) in the PG line (PGL) and at random in the control line (CTL). Data include the performance of 2,467 calves produced from 1967 to 1981. Environmental effects were estimated from CTL (method I) and from multiple regression procedures (method II). Phenotypic and environmental time trends were negative for WW and generally were positive for PG. Estimated genetic gains for WW in WWL were 1.07 +/- .51 kg/yr in bulls and .62 +/- .36 kg/yr in heifers using method I and .50 +/- .31 kg/yr in bulls and .10 +/- .17 kg/yr in heifers using method II. Corresponding values for PG in PGL were .85 +/- .40 and 1.03 +/- .24 kg/yr in bulls and .30 +/- .28 and .37 +/- .12 kg in heifers. Correlated genetic gains for WW in PGL were larger than direct WW gains, whereas genetic gains for PG in WWL were smaller than direct PG gains. From method I, estimates of realized heritability (h2R) for WW were .31 +/- .18 in bulls and .22 +/- .13 in heifers. For PG, h2R was .31 +/- .13 in bulls and .06 +/- .12 in heifers. Using method II, h2R for WW was .09 +/- .08 in bulls and .02 +/- .07 in heifers. Corresponding values for PG were .29 +/- .10 and .11 +/- .08. Joint estimates of the realized genetic correlation between WW and PG were .69 +/- .18 and .46 +/- .31 for methods I and II, respectively. Variation in selection response was evaluated using quasi-replicates. Results of this study indicate that selection for PG improved both WW and PG faster than selection for WW.     

Genomic and single-step evaluations of carcass traits of young bulls in dual-purpose cattle

Genetic evaluations for carcass traits of young bulls in Normande and Montbeliarde breeds are currently being developed in France. In order to determine a suitable genomic evaluation for three carcass traits of young bulls, genomic breeding values were estimated for young candidates to selection using different approaches. Records of 111,789 Normande and 118,183 Montbeliarde were used. Average progeny pre-adjusted performances (DYD) were calculated for sires. Evaluation approaches were compared based on an assessment of their accuracy (correlation between DYD and estimated breeding values [EBVs]) and bias (regression coefficient of DYD on EBVs) on the 20% youngest AI sires. All genomic approaches were generally more accurate than BLUP (+.045 to +.116 correlation points), except for age at slaughter where single-step GBLUP (SSGBLUP) was the only genomic method leading to a greater accuracy (+.038 to +.126 points). The best setting of the SSGBLUP relationship matrix was characterized by a weight of 30% for pedigree information in the genomic relationship matrix. SSGBLUP was the most valuable evaluation approach for the evaluation of carcass traits of Normande and Montbeliarde young bulls.     

Age adjustment factors, heritabilities and genetic correlations for scrotal circumference and related growth traits in Hereford and Brangus bulls

Field data records on 10,511 Hereford and 2,522 Brangus bulls between 330 and 430 d of age were analyzed to find age of calf and age of dam adjustment factors for yearling scrotal circumference. Age of calf adjustment factors were .024 cm/d for Hereford bulls and .041 cm/d for Brangus bulls. Sons of Hereford dams were adjusted to a 6- to 8-yr dam age basis by adding .7, .3, .2, .2 or .3 cm for dams 2, 3, 4, 5 or 8 or more years old, respectively. Age of dam adjustment factors for Brangus bulls were .8, .4, .3 and .2 for dams 2, 3, 4 or 8 or more years old, respectively. Variance and covariance components for yearling scrotal circumference and several growth traits were estimated within breed using multiple-trait models and pseudo expectations involving the solutions and the right-hand sides of the mixed-model equations. Additive heritability estimates for yearling scrotal circumference of .53 and .16 were found for Hereford and Brangus bulls, respectively. Maternal heritability estimates of .12 and .10 were found for Hereford and Brangus bulls, respectively. Genetic correlations between yearling scrotal circumference and other growth traits were positive for both sets of data indicating that selection for yearling scrotal circumference should not adversely affect other growth traits in either breed. Environmental correlation estimates between yearling scrotal circumference and adjusted birth weight and between yearling scrotal circumference and adjusted 205-d weight and adjusted 365-d height were positive and moderate in magnitude for both breeds.     

Correlated responses to selection for yearling or18-month weight in Angus and Hereford cattle

Correlated responses to selection for yearling (AS1 herd) or 18-month weight (AS2 herd) wereevaluated against a control (AC0 herd) in a progeny test herd using 2294 calves born in 1975–1988. A sample of privately-owned Angus bulls, available by artificial insemination (AI), were compared with them for eight liveweight or gain traits up to 18 months, with four carcass traits on steers. Cows of known pedigree in the progeny test herd were also evaluated for seven maternal traits. Other correlated responses were evaluated directly in the ACO and selection herds (three puberty traits, daily food intake, cow weight, and survival and reproduction traits).Realised genetic correlations to selection for yearling weight (AS1 herd) averaged 6% higher (forgrowth and carcass traits) than published paternal half-sib estimates, whilst those with 18-month weight (AS2 herd) were about 10% lower than with yearling weight. The sign of maternal genetic effects for live weights up to weaning varied among selection herds. Realised genetic correlations with selection weight averaged 0.51 (carcass fat depth), 0.93 (food intake), 0.16 (scrotal circumference in bulls), 0. 18 (age at puberty) and 0.37 (weight at puberty in heifers), 0.38 (cow weight, AS I herd) and 0.92 (cow weight, AS2 herd). The selection herd differences from control were not significant for cow or calf mortality or reproductive traits (6501 mating records), but tended to be negative for cow and calf death rates, and variable for overall reproductive rate.     

宁夏几个肉牛杂交群体与秦川牛的BPI比较研究

[目的]为了分析宁夏地区各品种改良牛群的改良情况,本研究对宁夏中卫山羊场、夏华育肥场、王强养殖场等6个养殖场的杂交肉牛群体的152头成年公牛进行了体尺、背膘厚及眼肌面积的测量。[方法]利用肉牛选择指数（Beef Purpose Index,BPI）分析了牛群的经济类型。[结果]显示,50头秦川牛成年公牛的平均背膘厚及其眼肌面积分别为1.98 mm和28.25cm2,平均BPI为4.04,属役肉兼用用型;102头各品种杂交成年公牛的平均背膘厚及其眼肌面积分别为2.67 mm~4.09 mm和35.44 cm2~55.16 cm2,平均BPI为5.33~6.21,属肉役兼用型。[结论]各品种改良牛群在经济类型上有别于秦川牛,且在体尺、背膘厚和眼肌面积等方面也比秦川牛有明显的改善和提高。     

Experimental selection for calving ease and postnatal growth in seven cattle populations. I. Changes in estimated breeding values

Selection was used to create select and control lines within 4 purebred and 3 composite cattle populations. Both lines were selected for similar direct yearling weight and maternal weaning weight EBV. Select lines were selected for lower 2-yr-old heifer calving difficulty score EBV and control lines were selected for average birth weight EBV. Select (n = 6,926) and control (n = 2,043) line calves were born from 1993 through 1999 and selection began with the 1992 mating. High replacement rates resulted in 2,188 births to select line and 598 births to control line heifers. Data used to calculate EBV came from these populations and from 15 yr of data preceding the experiment. Calving difficulty was scored from 1 (no assistance) to 7 (cesarean). Calving difficulty scores from all twins, malpresentations, and cows 3 yr old and older were eliminated. Except for the first year, when a single-trait BLUP was used, a multiple-trait BLUP was used to calculate direct and maternal EBV for calving difficulty score, birth weight, and weaning weight, and direct EBV for postweaning gain. Sires (n = 498) were selected from those born in both the preceding populations and the select and control lines. In purebred populations, some industry sires (n = 88) were introduced based on their EPD. Tests of mean select and control line EBV differences of calves born in the final 2 yr were based on population variation. Select line direct EBV were 1.06 lower for heifer calving difficulty score (P < 0.001) and 3.5 kg lower (P < 0.001) for birth weight than controls. Average differences for other EBV were small and not significant. Yearling weight EBV was intentionally increased in both select and control lines of purebred populations. Angus, Hereford, Charolais, and Gelbvieh yearling weight EBV in control lines increased by 32.4, 27.2, 21.0, and 10.5 kg, respectively, from 1991 and 1992 to 1998 and 1999 compared with an average increase of 2.7 kg in composite populations. Birth weight direct EBV in purebred control lines increased by approximately 8% of yearling weight EBV increases. Selection based on a multiple-trait BLUP was able to create lines differing in calving difficulty score and birth weight EBV, but not in weaning weight and postweaning gain EBV. Differences between lines should be useful for evaluating BLUP and other traits and for identifying potential limitations of genetically decreasing calving difficulty score and birth weight.