Simianer, Henner

[["dc.bibliographiccitation.firstpage","382"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Journal of Dairy Science"],["dc.bibliographiccitation.lastpage","391"],["dc.bibliographiccitation.volume","92"],["dc.contributor.author","Koenig, S."],["dc.contributor.author","Simianer, Henner"],["dc.contributor.author","Willam, A."],["dc.date.accessioned","2018-11-07T08:34:49Z"],["dc.date.available","2018-11-07T08:34:49Z"],["dc.date.issued","2009"],["dc.description.abstract","The objective of this study was to compare a conventional dairy cattle breeding program characterized by a progeny testing scheme with different scenarios of genomic breeding programs. The ultimate economic evaluation criterion was discounted profit reflecting discounted returns minus discounted costs per cow in a balanced breeding goal of production and functionality. A deterministic approach mainly based on the gene flow method and selection index calculations was used to model a conventional progeny testing program and different scenarios of genomic breeding programs. As a novel idea, the modeling of the genomic breeding program accounted for the proportion of farmers waiting for daughter records of genotyped young bulls before using them for artificial insemination. Technical and biological coefficients for modeling were chosen to correspond to a German breeding organization. The conventional breeding program for 50 test bulls per year within a population of 100,000 cows served as a base scenario. Scenarios of genomic breeding programs considered the variation of costs for genotyping, selection intensity of cow sires, proportion of farmers waiting for daughter records of genotyped young bulls, and different accuracies of genomic indices for bulls and cows. Given that the accuracies of genomic indices are greater than 0.70, a distinct economic advantage was found for all scenarios of genomic breeding programs up to factor 2.59, mainly due to the reduction in generation intervals. Costs for genotyping were negligible when focusing on a population-wide perspective and considering additional costs for herdbook registration, milk recording, or keeping of bulls, especially if there is no need for yearly recalculation of effects of single nucleotide polymorphisms. Genomic breeding programs generated a higher discounted profit than a conventional progeny testing program for all scenarios where at least 20% of the inseminations were done by genotyped young bulls without daughter records. Evaluation of levels of annual genetic gain for individual traits revealed the same potential for low heritable traits (h(2) = 0.05) compared with moderate heritable traits (h(2) = 0.30), preconditioning highly accurate genomic indices of 0.90. The final economic success of genomic breeding programs strongly depends on the complete abdication of any forms of progeny testing to reduce costs and generation intervals, but such a strategy implies the willingness of the participating milk producers."],["dc.identifier.doi","10.3168/jds.2008-1310"],["dc.identifier.isi","000261948600039"],["dc.identifier.pmid","19109296"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/17911"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Amer Dairy Science Assoc-adsa"],["dc.relation.issn","0022-0302"],["dc.title","Economic evaluation of genomic breeding programs"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","6143"],["dc.bibliographiccitation.issue","12"],["dc.bibliographiccitation.journal","Journal of Dairy Science"],["dc.bibliographiccitation.lastpage","6152"],["dc.bibliographiccitation.volume","94"],["dc.contributor.author","Schierenbeck, S."],["dc.contributor.author","Pimentel, E. C. G."],["dc.contributor.author","Tietze, Manfred"],["dc.contributor.author","Koerte, J."],["dc.contributor.author","Reents, R."],["dc.contributor.author","Reinhardt, Friedrich"],["dc.contributor.author","Simianer, Henner"],["dc.contributor.author","Koenig, S."],["dc.date.accessioned","2018-11-07T08:49:32Z"],["dc.date.available","2018-11-07T08:49:32Z"],["dc.date.issued","2011"],["dc.description.abstract","Because of the relatively high levels of genetic relationships among potential bull sires and bull clams; innovative selection tools should consider both genetic gain and genetic relationships in a long-term perspective. Optimum genetic contribution theory using official estimated. breeding values for a moderately heritable trait (production index, Index-PROD), and a lowly heritable functional trait (index for somatic cell score, Index-SCS) was applied to find optimal allocations of bull dams and bull sires. In contrast to previous practical applications using optimizations based on Lagrange multipliers, we focused on semi-definite programming (SDP). The SDP methodology was combined with either pedigree (a(ij)) or genomic relationships (f(ij)) among selection candidates. Selection candidates were 484 genotyped bulls, and 499 preselected genotyped bull darns completing a central test on station. In different scenarios separately for PROD and SCS, constraints on the average pedigree relationships among future progeny were varied from a(ij) = 0.08 to a(ij) = 0.20 in increments of 0.01. Corresponding constraints for single nucleotide polymorphism-based kinship coefficients were derived from regression analysis. Applying the coefficient of 0.52 with an intercept of 0.14 estimated for the regression pedigree relationship on genomic relationship, the corresponding range to alter genomic relationships varied from f(ij) = 0.18 to f(ij) = 0.24. Despite differences for some bulls in genomic and pedigree relationships, the same trends were observed for constraints on pedigree and corresponding genomic relationships regarding results in genetic gain and achieved coefficients of relationships. Generally, allowing higher values for relationships resulted in an increase of genetic gain for Index-PROD and Index-SCS and in a reduction in the number of selected sires. Interestingly, more sires were selected for all scenarios when restricting genomic relationships compared with restricting pedigree relationships. For example, at constraint of f(ij) = 0.185 and selection on Index-PROD, the number of selected sires was 35. In contrast, only 21 sires were selected at the comparable constraint on additive genetic relationship of a(ij) = 0.09. A further reduction in relationships is possible when using SDP output (i.e., suggested genetic contributions of selected parents) and applying a simulated annealing algorithm to define specific mating plans. However, the advantage of this strategy is limited to a short-term perspective and probably not successful in the period of genomic selection allowing a substantial reduction of generation intervals."],["dc.identifier.doi","10.3168/jds.2011-4574"],["dc.identifier.isi","000297229000039"],["dc.identifier.pmid","22118102"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/21482"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Inc"],["dc.relation.issn","0022-0302"],["dc.title","Controlling inbreeding and maximizing genetic gain using semi-definite programming with pedigree-based and genomic relationships"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","114"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","Züchtungskunde"],["dc.bibliographiccitation.lastpage","126"],["dc.bibliographiccitation.volume","80"],["dc.contributor.author","Koenig, S."],["dc.contributor.author","Bruegemann, Kerstin"],["dc.contributor.author","Simianer, Henner"],["dc.contributor.author","Swalve, H. H."],["dc.date.accessioned","2018-11-07T11:18:10Z"],["dc.date.available","2018-11-07T11:18:10Z"],["dc.date.issued","2008"],["dc.description.abstract","As outlined in the first communication, the implementation of test herds in dairy cattle breeding programmes offers a number of advantages. These range from very basic operational advantages like improved logistics arising from the concentration of progeny in a limited number of herds to advantages to be exploited when applying molecular diagnostics. Aim of the present study was the evaluation of strategies to find suitable test herds with respect to the goal of maximization of genetic differences among progeny groups. Results from the estimation of variance components within classes of herd level of production and herd size demonstrate increased heritabilities with increasing production level and herd size. These differences correspond to higher standard deviations of cow breeding values. Yield deviations of cow performance were stratified within sire and then related to herd parameters. More extreme yield deviations were found at increased production levels. A cluster analysis yet again revealed that herds with a higher genetic differentiation of cows (increased s.d. of cow ebv) exhibit increased levels of production. The present study thus demonstrates the feasibility of finding test herds applying scientific methods."],["dc.identifier.isi","000254541800003"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/54978"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Eugen Ulmer Gmbh Co"],["dc.relation.issn","0044-5401"],["dc.title","Test herds in dairy cattle breeding programmes 2nd communication: Strategies for finding test herds"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","3316"],["dc.bibliographiccitation.issue","9"],["dc.bibliographiccitation.journal","Journal of Dairy Science"],["dc.bibliographiccitation.lastpage","3325"],["dc.bibliographiccitation.volume","88"],["dc.contributor.author","Koenig, S."],["dc.contributor.author","Sharifi, Ahmad Reza"],["dc.contributor.author","Wentrot, H."],["dc.contributor.author","Landmann, D."],["dc.contributor.author","Eise, M."],["dc.contributor.author","Simianer, Henner"],["dc.date.accessioned","2018-11-07T10:56:15Z"],["dc.date.available","2018-11-07T10:56:15Z"],["dc.date.issued","2005"],["dc.description.abstract","The primary aim of this study was to estimate heritabilities for different types of claw and foot disorders and the genetic relationship of disorders with milk yield and selected conformation traits by applying logistic models in Holstein dairy cattle. The study included data from 5634 Holstein cows kept on large-scale dairy farms in Eastern Germany. Dichotomous response variables were the presence or absence of the disorder in 2003. Cows that were present in herds for <6 wk in 2003 were excluded from the analysis. Incidences, disregarding repeated measurements, for digital dermatitis (DD), sole ulceration (SU), wall disorder (WD), and interdigital hyperplasia (IH) in rear legs were 13.2, 16.1, 9.6, and 6.3%, respectively. The herd effect was highly significant for all disorders. Incidences increased with increasing parities for SU and WD, but were highest among heifers for DD. High milk yield at the first 2 test d after calving was associated with a greater risk for claw and foot disorders in the same lactation. Estimates of heritability were 0.073 for DD, 0.086 for SU, 0.104 for WD, and 0.115 for IH. Genetically, health problems appear to occur in clusters (i.e., a cow showing one disease has an increased genetic risk of showing another claw disease). This phenomenon was also observed between claw and foot disorders and the somatic cell score. Genetic correlations between milk yield in early lactation and disorders were 0.240 for DD, 0.057 for SU, 0.270 for WD, and 0.336 for IH, indicating a physiological antagonism. Correlations between breeding values for claw and foot disorders of bulls and official breeding values for functional type traits were mostly favorable. Routine recording of claw data will offer a new chance to improve claw health within the population as was elaborated by different scenarios applying selection index procedures."],["dc.identifier.isi","000231260300032"],["dc.identifier.pmid","16107422"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/49972"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Inc"],["dc.relation.issn","0022-0302"],["dc.title","Genetic parameters of claw and foot disorders estimated with logistic models"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","50"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Züchtungskunde"],["dc.bibliographiccitation.lastpage","60"],["dc.bibliographiccitation.volume","80"],["dc.contributor.author","Koenig, S."],["dc.contributor.author","Simianer, Henner"],["dc.date.accessioned","2018-11-07T11:20:59Z"],["dc.date.available","2018-11-07T11:20:59Z"],["dc.date.issued","2008"],["dc.description.abstract","Practical improvements of dairy cattle breeding programs through marker assisted selection were behind theoretical expectations. Genetic gain is still based on traditional recording systems and progeny testing programs, but the theoretical potential is limited due to long generation intervals. Genomic selection enables the opportunity for substantial modifications of genetic evaluations and breeding programs as well. Genomic selection is possible due to a multitude of so called SNPs, distributed more or less evenly over the whole genome, and costs for SNP-genotyping through microarray technology are relatively cheap compared to microsatellite markers. The genomic breeding value is the sum of all single SNP effects. Reliable genomic breeding values for both sexes (accuracy > 0.75) can be calculated in an early stage of an animal's life, e.g. even for embryos. This implies a shift from BLUP animal models including pedigree information towards SNP based BLUP, and putting less weight on information provided by relatives. Economic efficiency and an increase of selection response in dairy cattle breeding programs are due to the entire abdication of progeny testing. Such a strategy implies a substantial reduction in generation intervals. Model calculations for the Canadian Holstein population showed a doubling of selection response per year and a reduction of breeding costs by 90 percent when comparing genomic selection to the traditional selection scheme. However, unresolved problems related to the methodology for the estimation of SNP-effects have to be clarified in advance."],["dc.identifier.isi","000253914900009"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/55670"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Eugen Ulmer Gmbh Co"],["dc.publisher.place","Stuttgart"],["dc.relation.conference","Annual Meeting of the Deutsche-Gesellschaft-fur-Zuchtungskunde"],["dc.relation.eventlocation","Stuttgart, GERMANY"],["dc.relation.issn","0044-5401"],["dc.title","Genomic selection - basics and perspectives for dairy cattle breeding programs"],["dc.type","conference_paper"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","31"],["dc.bibliographiccitation.journal","Livestock Science"],["dc.bibliographiccitation.lastpage","41"],["dc.bibliographiccitation.volume","162"],["dc.contributor.author","Yin, T."],["dc.contributor.author","Bapst, Beat"],["dc.contributor.author","von Borstel, Uta Ulrike"],["dc.contributor.author","Simianer, Henner"],["dc.contributor.author","Koenig, S."],["dc.date.accessioned","2018-11-07T09:41:59Z"],["dc.date.available","2018-11-07T09:41:59Z"],["dc.date.issued","2014"],["dc.description.abstract","Genetic parameters were inferred for the health traits mastitis, metritis, retained placenta, ovarian cysts and acetonemia from 1247 Brown Swiss cows in first parity kept in 53 organic and low input farms in Switzerland. For genetic analyses, univariate animal and sire models, repeatability animal and sire models, and random regression sire models (RRM) in a \"generalized linear mixed model (GLMM) context\" were applied. The five health traits were defined as binary data, count data, and longitudinal binary data in the interval between -1 and 120 d in milk (DIM). Firstly, binary data were analyzed by applying linear animal and sire models, and threshold animal and sire models with a probit link function. Secondly, data of total number of disease cases recorded within the defined time span were analyzed by using GLMM animal and sire models with a log link function for Poisson distributed count data. Thirdly, for longitudinal health data, linear repeatability animal and sire models, linear sire RRM, threshold animal and sire repeatability models, and threshold sire RRM with a probit link function were applied. Disease incidences of the five health disorders in organic farms were on a generally low level, with a highest incidence of 5.78% for mastitis within the time span of 120 d. With regard to mastitis, moderate heritabilities with an average value of 0.15 were realized from univariate models and binary data, and from GLMM with the log link function and count data. Heritabilities for mastitis were smaller ( < 0.10) when using the longitudinal data structure in combination with repeatability models and RRM. Repeatabilities and heritabilities for longitudinal data as realized from repeatability models were on a quite similar level. Only for longitudinal ovarian cysts, heritabilities substantially differed from repeatabilities. Heritability was 0.02 from the animal model and 0.01 from the sire model, but repeatabilities were 0.14, which indicates a substantial permanent environmental effect. Daily heritabilities for all health traits from linear and threshold RRM at the beginning of lactation and at the end of the defined interval were three times higher than corresponding heritabilities in the middle of lactation. Bayesian information criterion (BIC) and heritabilities themselves favored threshold models over linear models. However, linear models converged more easily than threshold models, and genetic parameter estimates had smaller standard errors. Similar BIC values were found when comparing animal with sire models, although generally higher heritabilities were realized from sire models. For RRIVI applications, BIC was smaller and heritabilities were higher for linear sire compared to threshold sire models. (C) 2014 Elsevier B.V. All rights reserved."],["dc.description.sponsorship","European Commission [222623]"],["dc.identifier.doi","10.1016/j.livsci.2014.01.021"],["dc.identifier.isi","000333780100005"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/33851"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Bv"],["dc.relation.issn","1878-0490"],["dc.relation.issn","1871-1413"],["dc.title","Genetic analyses of binary longitudinal health data in small low input dairy cattle herds using generalized linear mixed models"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","3945"],["dc.bibliographiccitation.issue","8"],["dc.bibliographiccitation.journal","Journal of Dairy Science"],["dc.bibliographiccitation.lastpage","3954"],["dc.bibliographiccitation.volume","90"],["dc.contributor.author","Koenig, S."],["dc.contributor.author","Bosselmann, F."],["dc.contributor.author","von Borstel, Uta Ulrike"],["dc.contributor.author","Simianer, Henner"],["dc.date.accessioned","2018-11-07T11:00:09Z"],["dc.date.available","2018-11-07T11:00:09Z"],["dc.date.issued","2007"],["dc.description.abstract","The primary aim of this study was to estimate variance components for traits related to embryo transfer (ET) by applying generalized linear mixed models (GLMM) for different distributions of traits (normal, binomial, and Poisson) in a synergistic context. Synergistic models were originally developed for traits affected by several genotypes, denoted as maternal, paternal, and direct effects. In the case of ET, the number of flushed ova (FO) only depends on a donor's maternal genetic effect, whereas paternal fertility must be considered for other embryo survival traits, such as the number of transferable embryos (TE), the number of degenerated embryos (DE), the number of unfertilized oocytes (UO), and the percentage of transferable embryos (PTE). Data for these traits were obtained from 4,196 flushes of 2,489 Holstein cows within 4 regions of northwest Germany from January 1998 through October 2004. Estimates of maternal heritability were 0.231 for FO, 0.096 for TE, 0.021 for DE, 0.135 for UO, and 0.099 for PTE, whereas the relative genetic impact of the paternal component was near zero. Estimates of the genetic correlations between the maternal and the paternal component were slightly negative, indicating a genetic antagonism. For the analysis of pregnancy after ET, 8,239 transfers to 6,819 different Holstein-Friesian recipients were considered by applying threshold methodology. The direct heritability for pregnancy in the recipient after ET was 0.056. The relative genetic impact of maternal and paternal components on pregnancy of recipients describing a donor's and a sire's ability to produce viable embryos was below 1%. The genetic correlations of the direct effect of the recipient with the sire of embryos (paternal effect) and the donor cow (maternal effect) for pregnancy after ET were -0.32 and -0.14, respectively. With the exception of FO and PTE (- 0.17), estimates of genetic correlations among traits for the maternal site were distinctly positive, especially between FO and TE (0.74). Based on this high genetic correlation and due to the higher heritability for FO, indirect selection on FO will increase selection response in TE by about 22% compared with direct selection on TE. The negative genetic correlation of -0.27 between TE and lactation milk yield indicates the need for development of an index for bull dams in multiple ovulation and embryo transfer (MOET) breeding schemes combining production as well as traits related to ET."],["dc.identifier.doi","10.3168/jds.2007-0089"],["dc.identifier.isi","000248085500044"],["dc.identifier.pmid","17639006"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/50865"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Amer Dairy Science Assoc"],["dc.relation.issn","0022-0302"],["dc.title","Genetic analysis of traits affecting the success of embryo transfer in dairy cattle"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","2071"],["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","Journal of Dairy Science"],["dc.bibliographiccitation.lastpage","2082"],["dc.bibliographiccitation.volume","94"],["dc.contributor.author","Schierenbeck, S."],["dc.contributor.author","Reinhardt, Friedrich"],["dc.contributor.author","Reents, R."],["dc.contributor.author","Simianer, Henner"],["dc.contributor.author","Koenig, S."],["dc.date.accessioned","2018-11-07T08:57:42Z"],["dc.date.available","2018-11-07T08:57:42Z"],["dc.date.issued","2011"],["dc.description.abstract","Several arguments exist for breeding organizations to focus on cooperative herds for progeny testing, but an efficient methodology addressing herd selection strategies is lacking. In this study, a new approach based on yield deviations (YD) to identify the most informative cooperator herds in terms of genetic differentiation was evaluated. Data comprised YD from 717,377 first-lactation cows from 2 regions in East and West Germany calving between January 2003 and January 2008. Daughters were ranked and. classified within sire according to their YD for protein yield, fat yield, milk yield, and somatic cell score. Cows in created YD classes were merged with respective herd-calving year (HCY) characteristics. Cows of extreme YD classes (i.e., such classes including the most extreme daughter contributions); belonged to herds characterized by a high HCY production level, a low value for HCY somatic cell count, and a low HCY age at first calving (AFC). Cows with low extremes for YD in protein yield were associated with the lowest HCY production level, a high value for HCY somatic cell count, and a late HCY AFC. Ranks of HCY and ranks of herds considering HCY over the whole analyzed period were calculated by averaging YD percentages within HCY, and within herds, respectively. The YD percentages (in absolute values so that negative and positive daughter contributions were treated equally) were derived from the rank of the YD of a daughter within sire in relation to all daughters of a sire. A further partitioning of ranks of herds into quartiles revealed the following results: herds in the first quartile had the highest average protein yield, the highest intra-herd standard deviation for the national production index, and the lowest AFC. Correlations between herd rankings for different production traits ranged between 0.64 and 0.86, and were 0.65 for West Germany and 0.62 for East Germany between HCY 2006 and the average herd rank of all calving years. Correlations between daughter yield deviations for the highest and the lowest herd quartile of 0.87 for protein yield disproved concerns regarding genotype by environment interaction between test and production environment. The suggested methodology to identify informative cooperator herds is easy to implement, holds for regions with small herd sizes, and thus, may help in implementing sustainable and competitive dairy cattle breeding programs."],["dc.identifier.doi","10.3168/jds.2010-3466"],["dc.identifier.isi","000288641800048"],["dc.identifier.pmid","21426998"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/23460"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Inc"],["dc.relation.issn","0022-0302"],["dc.title","Identification of informative cooperator herds for progeny testing based on yield deviations"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","658"],["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","Poultry Science"],["dc.bibliographiccitation.lastpage","667"],["dc.bibliographiccitation.volume","89"],["dc.contributor.author","Koenig, S."],["dc.contributor.author","Tsehay, F."],["dc.contributor.author","Sitzenstock, Florian"],["dc.contributor.author","von Borstel, Uta Ulrike"],["dc.contributor.author","Schmutz, Matthias"],["dc.contributor.author","Preisinger, R."],["dc.contributor.author","Simianer, Henner"],["dc.date.accessioned","2018-11-07T08:44:50Z"],["dc.date.available","2018-11-07T08:44:50Z"],["dc.date.issued","2010"],["dc.description.abstract","Due to consistent increases of inbreeding of on average 0.95% per generation in layer populations, selection tools should consider both genetic gain and genetic relationships in the long term. The optimum genetic contribution theory using official estimated breeding values for egg production was applied for 3 different lines of a layer breeding program to find the optimal allocations of hens and sires. Constraints in different scenarios encompassed restrictions related to additive genetic relationships, the increase of inbreeding, the number of selected sires and hens, and the number of selected offspring per mating. All these constraints enabled higher genetic gain up to 10.9% at the same level of additive genetic relationships or in lower relationships at the same gain when compared with conventional selection schemes ignoring relationships. Increases of inbreeding and genetic gain were associated with the number of selected sires. For the lowest level of the allowed average relationship at 10%, the optimal number of sires was 70 and the estimated breeding value for egg production of the selected group was 127.9. At the highest relationship constraint (16%), the optimal number of sires decreased to 15, and the average genetic value increased to 139.7. Contributions from selected sires and hens were used to develop specific mating plans to minimize inbreeding in the following generation by applying a simulated annealing algorithm. The additional reduction of average additive genetic relationships for matings was up to 44.9%. An innovative deterministic approach to estimate kinship coefficients between and within defined selection groups based on gene flow theory was applied to compare increases of inbreeding from random matings with layer populations undergoing selection. Large differences in rates of inbreeding were found, and they underline the necessity to establish selection tools controlling long-term relationships. Furthermore, it was suggested to use optimum genetic contribution theory for conservation schemes or, for example, the experimental line in our study."],["dc.description.sponsorship","German Ministry of Education and Research (BMBF); Lohmann Tierzucht GmbH"],["dc.identifier.doi","10.3382/ps.2009-00543"],["dc.identifier.isi","000276023400006"],["dc.identifier.pmid","20308397"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/20287"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Poultry Science Assoc Inc"],["dc.relation.issn","0032-5791"],["dc.title","Evaluation of inbreeding in laying hens by applying optimum genetic contribution and gene flow theory"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","327"],["dc.bibliographiccitation.issue","2-3"],["dc.bibliographiccitation.journal","Livestock Science"],["dc.bibliographiccitation.lastpage","334"],["dc.bibliographiccitation.volume","121"],["dc.contributor.author","Schierenbeck, S."],["dc.contributor.author","Koenig, S."],["dc.contributor.author","Simianer, Henner"],["dc.date.accessioned","2018-11-07T08:31:13Z"],["dc.date.available","2018-11-07T08:31:13Z"],["dc.date.issued","2009"],["dc.description.abstract","The aim of the present analysis was to determine the impact of a variety of traits and effects (i.e. production, type, health, management effects, pedigree information) on prices of Holstein cows sold at auction, and to estimate genetic (co)variance components between type traits and auction price. Results were used to derive economic weights for type traits. Data of 1565 cows in first parity were collected at six monthly auction sales from August 2005 through January 2006. Seventeen linear type traits and body condition (scale I to 9), and four type composites (dairy character, body, feet and legs, and udder: scale 65 to 88) were scored by two classifiers in the auction hall before cows were sold. Analysis of variance revealed a highly significant impact (P<0.001) Of auction date, test day milk yield, stage of lactation, origin of sire. and miscellaneous defects on auction price. The most expensive cows were sold in August, they were from foreign proven sires, they had a high level of test day milk yield, and they were free from defects related to udder, feet and legs, or milkability. The feet and leg, udder. and body composite also had a significant effect on the price (P<0.001), with higher scores being associated with higher prices. The opposite association was found for dairy character (P<0.01). Utilizing results from regression analysis, economic weights per genetic standard deviation were highest for linear scored rear udder height (1.23 (sic)). front teat placement (0.97 (sic)), and strength (0.80 (sic)), but were negative for dairy character (-0.69 (sic)). Genetic parameters for linear type traits scored at the auction date were consistent with literature reports. Heritability for auction price was 0.27, and auction price was genetically positively related to the feet and leg (0.55), udder (0.55), and body composite (0.21). A relative breeding value for auction price was estimated for 27 influential sires, and correlated with official indices for production, conformation, somatic cell count, functional herd life, fertility. and the total net merit index. Correlations were 0.15, 0.21, 0.11, 0.03, 0.05, and 0.19, respectively. Auction price in combination with type scores and information related to farm management provide valuable information for genetic analysis in dairy cattle, and results can be used to increase dairy cow profitability. (C) 2008 Elsevier B.V. All rights reserved."],["dc.identifier.doi","10.1016/j.livsci.2008.07.008"],["dc.identifier.isi","000265007600024"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/17075"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Bv"],["dc.relation.issn","1871-1413"],["dc.title","Genetic and environmental impact on auction prices for Holstein cows"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]