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1.
Variance components (VC) were estimated for the semen production trait ejaculate volume, sperm concentration and sperm motility in the Swiss cattle breeds Brown Swiss (BS), Original Braunvieh (OB), Holstein (HO), Red‐Factor‐Carrier (RF), Red Holstein (RH), Swiss Fleckvieh (SF) and Simmental (SI). For this purpose, semen production traits from 2,617 bulls with 124,492 records were used. The data were collected in the years 2000–2012. The model for genetic parameter estimation across all breeds included the fixed effects age of bull at collection, year of collection, month of collection, number of collection per bull and day, interval between consecutive collections, semen collector, bull breed as well as a random additive genetic component and a permanent environmental effect. The same model without a fixed breed effect was used to estimate VC and repeatabilities separately for each of the breeds BS, HO, RH, SF and SI. Estimated heritabilities across all breeds were 0.42, 0.25 and 0.09 for ejaculate volume, sperm concentration and sperm motility, respectively. Different heritabilities were estimated for ejaculate volume (0.42; 0.45; 0.49; 0.40; 0.10), sperm concentration (0.34; 0.30; 0.20; 0.07; 0.23) and number of semen portions (0.18; 0.30; 0.04; 0.14; 0.04) in BS, HO, RH, SF and SI breed, respectively. The phenotypic and genetic correlations across all breeds between ejaculate volume and sperm concentration were negative (?0.28; ?0.56). The other correlations across all breeds were positive. The phenotypic and genetic correlations were 0.01 and 0.19 between sperm motility and ejaculate volume, respectively. Between sperm motility and sperm concentration, the phenotypic and genetic correlations were 0.20 and 0.36, respectively. The results are consistent with other analyses and show that genetic improvement through selection is possible in bull semen production traits.  相似文献   

2.
Genetic parameters were estimated for semen production traits collected in an Austrian AI centre in the years 2000-2004. In total, 12,746 ejaculates from 301 Austrian dual-purpose Simmental (Fleckvieh) AI bulls were examined considering different effects on ejaculate volume, sperm concentration, percentage of viable spermatozoa in the ejaculate, total spermatozoa per ejaculate and motility. The model for genetic parameter estimation included the fixed effects age of bull, collection interval, number of collections on collection day, bull handler, semen collector, year and month of collection, a random additive genetic component and a permanent environmental effect. Correlations between estimated breeding values for semen traits and male fertility from the routine evaluation were calculated. The fertility trait considered in the routine evaluation is non-return rate 90 for the first insemination. All semen production traits were moderately heritable. Heritabilities for volume, concentration, percentage of viable spermatozoa, total number of spermatozoa and motility were 0.18, 0.14, 0.10, 0.22 and 0.04, respectively. Correlations between breeding values for semen quality traits and routinely estimated breeding values for male fertility were low and ranged from 0.08 to 0.17 indicating that semen production traits are rather poor predictors of male fertility.  相似文献   

3.
Using pedigree data, the inbreeding coefficients of 715 Austrian dual‐purpose Simmental (Fleckvieh) bulls stationed in two artificial insemination (AI) centres in Upper and Lower Austria were calculated and incorporated in statistical models for the analysis of semen quality. Five semen quality parameters (volume, concentration, motility, number of spermatozoa per ejaculate and percentage of viable spermatozoa) of approximately 30 000 ejaculates, used in two separate data sets, were investigated. The mixed model included the fixed effects age class of the bull, bull handler, semen collector, month and year of collection, number of collection per bull and day, time interval since last collection, the linear continuous effect of the inbreeding coefficient of the bull, interactions between age class and month, and age class and interval since last collection, respectively, as well as the random effect of the bull and the random residual effect. Non‐linear effects of inbreeding were significant for motility only. Despite the quite low inbreeding coefficients (mean 1.3%), all semen quality traits showed inbreeding depression, in four of the five traits significantly in at least one of the data sets. The magnitude of inbreeding depression was small, which might partly be caused by the low inbreeding levels and a potential pre‐selection of the bulls in the AI centres. However, monitoring of inbreeding depression on fertility traits is recommended to avoid unrecognized deterioration of such traits.  相似文献   

4.
Shortening age at puberty of crossbred breeding bull is an important issue in the tropics. This study aimed at selecting crossbred bulls at earliest possible age with bigger scrotum and potential for donating quality semen. One hundred and 31 pre-joining crossbred bulls of Central Artificial Insemination Laboratory, Saver, Dhaka were examined. The bulls being trained by seeing semen collection from mature bulls were allowed ejaculation into the artificial vagina at homosexual mount during a 20 min time at three occasions, every three months. Eighty one of 131 bulls produced at least one ejaculate during the study and their mean +/- SD age and scrotal circumference (SC) were 20.3 +/- 4.7 months and 28.2 +/-2.7 cm, respectively. Bulls' body weight, body condition score (BCS) and SC influenced the attainment of their puberty (p < 0.05). Bull's body weight had positive effects on scrotal circumference and ejaculate volume (p < 0.05). Scrotal circumference positively influenced the percentages of normal spermatozoa (p < 0.05). Scrotal skin-fold thickness negatively influenced the proportion of spermatozoa with normal head (p < 0.05). Based on age at first ejaculate and SC, 29.6% bulls (n = 24) were selected by cluster analysis. Selected bulls had mean +/- SD age 17.9 +/- 2.2 months, body weight 287.3 +/-48.6 kg, SC 30.5 +/- 1.5 cm, ejaculate volume 3.4 +/- 1.3 ml, sperm motility 50.8 +/- 17.2%, total spermatozoa per ejaculate 2541.9 +/- 1699.2 million and normal spermatozoa 81.5 +/-14.5%. The selected pubertal bull group was different from the unselected pubertal bulls at MANOVA (p < 0.0001). About 30% of pubertal crossbred bulls can be selected with shorter age and larger scrotum at puberty under conditions prevailed in Bangladesh.  相似文献   

5.
为探讨荷斯坦牛和西门塔尔牛冻精的精液品质及体外受精后胚胎发育能力的差异,利用目测法、低渗膨胀法和考马斯亮蓝染色法评估了荷斯坦牛和西门塔尔牛冻精的活力、质膜完整率和顶体完整率,并比较了二者冻精体外受精后胚胎的卵裂率和囊胚率。结果表明,荷斯坦牛和西门塔尔牛冻精的活力(30.4%和27.2%)、质膜完整率(41.96%和36.22%)和顶体完整率(77.02%和73.02%)均无显著差异(P>0.05),但荷斯坦牛冻精体外受精后的卵裂率(57.5%和48.6%)和囊胚率(30.3%和23.2%)显著高于西门塔尔牛冻精(P<0.05)。提示,不同品种公牛精液体外受精后的发育能力有显著差异(P>0.05)。  相似文献   

6.
Subjective microscopic sperm motility results have recently been demonstrated to differ between Holstein-Friesian (HF) and Belgian Blue (BB) bulls. However, such assessments are rather imprecise. In the present study, sperm motility was assessed objectively by means of the Hamilton Thorne CEROS version 12.2c computer-assisted sperm motility analyser (CASA), and differences between the BB and HF breed could also be demonstrated. Higher percentages of both totally (p < 0.0001) and progressively (p < 0.0001) motile spermatozoa were encountered in the HF breed compared with the BB breed. Furthermore, a lower kinetic efficiency of the BB spermatozoa, evidenced by a lower beat cross-frequency (p = 0.0007) combined with a higher lateral head displacement (p = 0.0015), was the basis for the lower velocity of BB sperm cells. Additionally, BB spermatozoa move less straight forward, resulting in a lower straightness (p < 0.0001). No sperm motility differences were observed between age groups within the BB breed. The breed differences were observed in the examined bull populations residing at AI centres, in Belgium for the BB bulls and in the Netherlands for the HF bulls. However, these bull populations are selected for fertility. A similar pattern was observed in an unselected bull population of both breeds, although these differences were mostly non-significant for the different CASA parameters. Nevertheless, these data suggest that a genetic component might be responsible for the observed sperm motility breed differences.  相似文献   

7.
Evaluation of two seminal collection regimens for mature Holstein bulls   总被引：2，自引：0，他引：2  
Twenty mature Holstein bulls (3 to 10 yr old) were used to test the effect of two semen collection regimens on spermatozoal output, post-thaw percentage spermatozoal motility, and time needed to make the collections/week. For both regimens, six ejaculates/wk were collected using either three ejaculates/d, 2 d/wk, or two ejaculates/d, 3 d/wk. A three-period switchback experimental design was used. Each collection period for which measurements were taken was 3 wk and was preceded by a 2 wk period of acclimation. The total number of spermatozoa harvested per week was not significantly different (P greater than .05): 33.2 X 10(9) when the bulls were collected two ejaculates 3 d/wk, compared with 33.9 X 10(9) three ejaculates 2 d/wk. Post-thaw progressive spermatozoal motility was 50.3 and 52.1% (P greater than .05), respectively. The average time per week to collect each bull was 73.6 and 83.7 min (P less than .05), respectively.  相似文献   

8.
In the present study, the correlations among age, body weight, scrotal circumference (SC), semen quality and peripheral testosterone and estradiol-17beta (E(2)) concentrations were investigated in pubertal (n=5) and postpubertal (n=7) groups of Holstein bulls over a 6 week period. There were significant positive correlations (P<0.01) among age, body weight and SC in both groups, and similar significant correlations between sperm motility and SC in pubertal bulls (P<0.01) and between sperm concentration and SC in postpubertal bulls (P<0.05). The sperm motility after collection (P<0.05) and after freezing and thawing (P<0.01) of the postpubertal bulls correlated positively with the E(2) concentration. Estrogen may be important for the function of postpubertal bull testes, in which it may regulate spermatozoa motility in vivo.  相似文献   

9.
Decapitation of spermatozoa was recorded in a young boar as a consequence of epididymitis and in a young dog (mastiff) and a young bull (Brown Swiss breed) as a congenital cause of the subfertility and sterility of the affected animal. Decapitation of spermatozoa as a consequence of an inflammation led to the sterility of the breeding male and affected 52 to 68% of the spermatozoa. The motility of the spermatozoa was reduced considerably (10 to 20%) and the flagella were not observed to move without the heads. In cases of congenital decapitation of spermatozoa, sperm motility in the dog and bull was reduced, but the flagella were observed to move without the heads. Decapitation affected 15 to 42% of the spermatozoa and most frequently it was accompanied by a narrowing of head base and by the presence of a protoplasmic drop, located proximally. Further developmental changes, affecting the flagella of the sperms, were observed in the dog. The mentioned morphological changes led to infertility in the dog and to a substantial reduction of fertility in the bull. After natural mating of the bull with a superovulated cow, the ten eggs obtained included four blastocysts, two were degenerated, and four were unfertilized.  相似文献   

10.
Improvements in bull reproductive performance are necessary to optimize the efficiency of cattle production. Female fertility has been enhanced through assisted reproductive technologies as well as genetic selection; however, improving beef bull fertility has been largely ignored. Phenotypes routinely collected at bull semen collection facilities are believed to affect fertility and provide the phenotypes necessary for a genetic evaluation. The first objective of this study was to determine the significant fixed effects for modeling beef bull fertility using data from bull semen collection facilities. The second objective was to estimate variance components, heritabilities, repeatabilities, and correlations between beef bull semen attributes. Beef bull fertility phenotypes including volume (VOL), concentration (CONC), number of spermatozoa (NSP), initial motility (IMot), post-thaw motility (PTMot), 3-h post-thaw motility (3HRPTMot), percentage of normal spermatozoa (%NORM), primary abnormalities (PRIM), and secondary abnormalities (SEC) were obtained from two bull semen collection facilities. A total of 1,819 Angus bulls with 50,624 collection records were analyzed. Of the fixed class and covariate effects tested, the significant class effects were collection location and collection day within year and the significant covariate effects included age at collection, days since previous collection, and cumulative comprehensive climate index (CCI). For this study, the CCI was calculated for a 75-d period including the 61-d spermatogenesis cycle and 14-d epididymal transit time. The 75 d prior to collection accounted for the environmental stress a bull may have experienced over the course of development of the spermatozoa, which was more significant than the CCI calculated for collection day or spermatogenesis start date. Pre-thaw beef bull semen traits had low heritability estimates of 0.11 ± 0.02 (VOL), 0.09 ± 0.02 (CONC), 0.08 ± 0.02 (NSP), and 0.12 ± 0.03 (IMot). Heritabilities of post-thaw beef bull semen attributes were more variable at 0.10 ± 0.02 (PTMot), 0.05 ± 0.04 (3HRPTMot), 0.10 ± 0.04 (%NORM), 0.03 ± 0.03 (PRIM), and 0.18 ± 0.04 (SEC). Correlations of breeding values for these traits with scrotal circumference (SC) expected progeny difference (EPD) are low. The low to moderate heritability estimates indicate that genetic improvement can be made in beef bull semen quality traits if new tools are developed to augment the scrotal circumference EPD that are currently available within the industry.  相似文献   

11.
Yearling bulls (n = 3,071) located at 18 stations in Missouri, Nebraska, Virginia, and Wisconsin were measured for pelvic area, in addition to standard performance traits. Linear adjustments for age and weight were determined using covariate regression analyses. Only bulls that were 300 to 452 d of age, 325 to 640 kg, and were in consignments offering more than nine bulls per breed were included in the analyses. Because the subsets of Angus, Polled Hereford, and Simmental bulls had large numbers of observations (817, 271, and 449, respectively), individual adjustment coefficients were determined for each breed. Angus, Polled Hereford, and Simmental bulls had pelvic area adjustment regressions on age of .20, .32, and .20 cm2/d, respectively, and regressions on body weight of .15, .22, and .18 cm2/kg, respectively. Homogeneous linear responses of all breeds (11 breeds including Angus, Polled Hereford, and Simmental) were combined to form all-breed coefficients for age and weight adjustments, which were .21 cm2/d and .15 cm2/kg, respectively. Weight or age adjustments can be used to compare contemporaries for relative pelvic area differences, but both should not be used on the same bull. Although many factors contribute to dystocia, high priority should be given to identifying sires of replacement heifers of low to moderate birth weight genotype and above average pelvic area genotype.  相似文献   

12.
[目的]本文旨在分析种公牛精液品质的影响因素,以便进一步提高种公牛冷冻精液质量。[方法] 对2010年至2020年采精记录种公牛的射精量、原精活力、精子密度、解冻活力进行统计分析。[结果] 笔者对影响牛精液质量的主要因素进行了研究。结果发现,不同种之间、不同品种之间、不同品系之间、不同年龄、不同季节之间、不同饲养和管理方法之间,公牛的精液质量存在显著差异。 [结论] 遗传、气候环境、饲养管理等因素影响种公精液质量。  相似文献   

13.
Contents
The value of routine evaluation of bull semen was analysed for 117 AI bulls placed in two studs. Data from semen analysis of a total of 1635 ejaculates was compared statistically with the nonreturn rates of the bulls. The semen parameters which were significantly correlated to nonreturn rates were the motility of the freshly collected ejaculates (p = 0.0140) and post-thaw motility (p = 0.0075). The total number of motile sperm in the inseminate ranged from 10.9 to 19.3 × 106 and according to previous reports the effects of low motility should be fully 'compensated' when doses above 10 × 106 sperm/dose are used for insemination. In conclusion, the motility of freshly collected semen does not appear to be 'compensation' and a low percentage of motile sperm in an ejaculate may indicate other dysfunctions of the population of motile cells. Furthermore, post-thaw motility appears to correlate significantly with nonreturn rates. The largest proportion of the variation was explained by the breed of the bull and stud (42.2% of the variation), whereas the two motility parameters explained 10% of the total variation in nonreturn rates. Objective and precise evaluation of sperm motility in combination with other semen traits are needed to improve breeding efficiency. Although microscopic evaluation of sperm motility correlates with nonreturn rates of bulls, the methods are subjectively assessed and inaccurate and therefore do not allow a satisfactory prediction of fertility.  相似文献   

14.
The aim of this study was to estimate the non‐additive genetic effects of the dominance component of heterosis as well as epistatic loss on semen traits in admixed Swiss Fleckvieh, a composite of Simmental (SI) and Red Holstein Friesian (RHF) cattle. Heterosis is the additional gain in productivity or fitness of cross‐bred progeny over the mid‐purebred parental populations. Intralocus gene interaction usually has a positive effect, while epistatic loss generally reduces productivity or fitness due to lack of evolutionarily established interactions of genes from different breeds. Genotypic data on 38,205 SNP of 818 admixed, as well as 148 RHF and 213 SI bulls as the parental breeds were used to predict breed origin of alleles. The genomewide locus‐specific breed ancestries of individuals were used to calculate effects of breed difference as well as the dominance component of heterosis, while proxies for two definitions of epistatic loss were derived from 100,000 random pairs of loci. The average Holstein Friesian ancestry in admixed bulls was estimated 0.82. Results of fitting different linear mixed models showed including the dominance component of heterosis considerably improved the model adequacy for three of the four traits. Inclusion of epistatic loss increased the accuracy of the models only for our new definition of the epistatic effect for two traits, while the other definition was so highly correlated with the dominance component that statistical separation was impossible.  相似文献   

15.
This paper aimed at investigating the potential use of sperm DNA fragmentation (SDF) to improve the routine screening of infertility of Holstein bulls. Cryopreserved sperm samples from 201 Holstein bulls provided by an AI center were used in the analyses of SDF at 0 (SDF_0) and 6 (SDF_6) h of incubation at 37°C. A refinement of the sperm chromatin dispersion test implemented in the Sperm-Halomax kit was employed to measure SDF. Records on routinely collected semen traits (volume, concentration, mass and individual motility evaluated in the fresh ejaculate, and individual motility in post-thawed semen straws) were provided by the AI center. Artificial insemination bull fertility was obtained from official field recording as successful or failed insemination. The results show that the average SDF was low (around 3.5%) at 0 and 6 h of incubation. A moderate effect of inbreeding depression was found. Estimated heritability for SDF traits were moderately high (0.41 and 0.29 for SDF_0 and SDF_6, respectively) and estimated repeatability of SDF measures in the same animal were high (0.73 and 0.70 for SDF_0 and SDF_6, respectively). An overall estimated service bull value (ESBV) obtained through statistical modeling that allowed for adjustment of systematic environmental effects not specific to a bull and of the female contribution to fertility, and the estimated genetic values (EGV) were obtained from field-recorded AI information. The ESBV and EGV were also obtained for all semen traits. Moderately large and negative Pearson correlation coefficients were observed between SDF traits and male fertility ranging from (-0.43 to -0.50; P <0.001). Results of stepwise regression analyses showed that SDF_6 had the largest partial r(2) (0.15 to 0.26) among all semen characteristics. Overall, the selected semen traits explained 25% and 31% of the observed variability in bull fertility measured as EGV and ESBV, respectively. When looking at the predictive ability of bull fertility categories, the results of discriminant and logistic regression analyses showed that low-fertility bulls (those in the 10th or lower percentile in the fertility distribution) can be accurately identified by using measures of SDF alone or in combination with sperm motility. Values of SDF around 7% to 10% could be used as indicators of low AI success.  相似文献   

16.
This study investigated genomic predictions across Nordic Holstein and Nordic Red using various genomic relationship matrices. Different sources of information, such as consistencies of linkage disequilibrium (LD) phase and marker effects, were used to construct the genomic relationship matrices (G‐matrices) across these two breeds. Single‐trait genomic best linear unbiased prediction (GBLUP) model and two‐trait GBLUP model were used for single‐breed and two‐breed genomic predictions. The data included 5215 Nordic Holstein bulls and 4361 Nordic Red bulls, which was composed of three populations: Danish Red, Swedish Red and Finnish Ayrshire. The bulls were genotyped with 50 000 SNP chip. Using the two‐breed predictions with a joint Nordic Holstein and Nordic Red reference population, accuracies increased slightly for all traits in Nordic Red, but only for some traits in Nordic Holstein. Among the three subpopulations of Nordic Red, accuracies increased more for Danish Red than for Swedish Red and Finnish Ayrshire. This is because closer genetic relationships exist between Danish Red and Nordic Holstein. Among Danish Red, individuals with higher genomic relationship coefficients with Nordic Holstein showed more increased accuracies in the two‐breed predictions. Weighting the two‐breed G‐matrices by LD phase consistencies, marker effects or both did not further improve accuracies of the two‐breed predictions.  相似文献   

17.
Beef production characteristics of 254 intensively fed young bulls are described. The results are part of a beef × dairy crossbreeding experiment, where sires of eight European beef and dual-purpose breeds were used on cows of RDM (Danish Red Cattle) and SDM (Black Pied Danish Cattle).Daily gain and feed conversion were influenced by the sire breeds. Charolais, Blonde d'Aquitaine and Simmental crosses showed the highest daily gain, followed by Romagnola, Danish Red and White, Chianina, Limousin and Hereford crosses.Carcass composition and carcass conformation were strongly influenced by sire breed with Blonde d'Aquitaine and Limousin crosses producing the most valuable carcasses followed by Chianina, Charolais, Romagnola, Simmental, Danish Red and White and Hereford crosses in descending order.The analysis showed a sire breed × weight/age interaction in carcass composition traits, due to sire breed differences in maturity. That demonstrates the importance of serial slaughtering in breed comparison experiments. Hereford and Limousin produced the earliest maturing crosses and Danish Red and White and Blonde d'Aquitaine the latest maturing crosses.  相似文献   

18.
种公牛阴囊周径与其体重、体高间的相关性研究   总被引：1，自引：0，他引：1  
测定了山东银香伟业集团中大种公牛站1998～2003年引进的西门塔尔(XM)、盖普威(德国黄牛GL)、利木赞(LM)、荷斯坦(HS)四个品种62头种公牛阴囊周径(SC)、体高,体重,并对SC与体重、体高、年龄进行相关性分析.结果表明:西门塔尔、盖普威(德国黄牛)、利木赞、荷斯坦这四个品种的SC与体重、体高呈正相关,并且同品种不同年龄阶段SC与体重、体高呈高度正相关,同品种不同年龄阶段以及不同品种的同一年龄阶段,SC表现为差异显著(P＜0.05).为引进牛品种的选育工作提供依据.  相似文献   

19.
Bull spermatozoa samples contain variable portion of motile and normal morphology spermatozoa along with spermatozoa incapable of fertilization due to their pathologic changes. As semen quality is influenced by biochemical and morphological characteristics of all spermatozoa, the aim of the study was to separate spermatozoa in discontinuous iodixanol density gradient solution and to determine their cholesterol, phospholipid, triacylglycerol and lipid peroxide concentrations and creatine kinase activity. The study was performed in winter and included seven Simmental bulls aged 1.5-3.5 years. Semen samples were collected by use of artificial vagina. Upon evaluation of semen quality (volume, concentration and progressive sperm motility), the samples were centrifuged in iodixanol density solution to obtain two sperm fractions. The two fractions included sperms with progressive motility greater than 90% and less than 20%, respectively. A statistically significantly higher lipid peroxide concentration was determined in sperm fraction with <20% progressive motility. Different sperm subpopulations can be obtained by separating bull spermatozoa in different iodixanol density gradient solutions, while monitoring their biochemical properties can help assess the sperm quality.  相似文献   

20.
基因芯片技术在晋南牛种公牛选育中的应用   总被引：1，自引：1，他引：0  
为了更好的保护开发利用晋南牛,确保晋南牛的遗传多样性,本研究应用基因芯片技术,对晋南牛进行群体遗传特性的检测及后备种公牛的遗传评估,为晋南牛的分子辅助选育与保种提供理论与技术支持。采集18月龄健康、体重相近（（350±20）kg）的荷斯坦牛、和顺肉牛、西门塔尔牛、延边牛及利木赞牛血样各10份,及晋南牛后备公牛血样25份,根据不同牛品种分为6组,其中前5组每组10个重复,晋南牛后备公牛25个重复。应用Illumina SNP 50K高密度牛SNP芯片进行基因型检测,分析比较晋南牛的群体遗传特征,运用亲缘矩阵计算晋南牛后备公牛的亲缘系数,同时用BLUP进行遗传评估。结果表明,晋南牛在遗传结构上与荷斯坦牛、和顺肉牛、西门塔尔牛及利木赞牛关系较远,与延边牛较近,为中国地方品种群体;对晋南牛后备公牛进行遗传评估,得出了牛的基因组胴体重方差育种值排名,JN23的胴体重倍数性状标准差最大,从基因组水平可选作肉用种公牛;应用亲缘分析对晋南牛后备公牛家系进行分类,避免群体间的近交。本研究对晋南牛后备公牛进行了遗传评估、近交家系分析、传统表型选择及遗传疾病检测,最终选留的种公牛为JN07、JN23、JN05、JN08、JN02、JN13、JN19、JN14,通过多种选育方法结合提高了公牛的选择准确性,为晋南牛的群体选育提高奠定了基础。  相似文献   

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