Genetic correlations for foal and studbook traits with racing traits and implications for selection strategies in the Finnhorse and Standardbred trotter

Wool production of the Spanish Merino breed was analysed after several decades of genetic selection to improve meat production. Genetic parameters (heritability and correlations) were estimated for greasy fleece weight, staple length, crimp frequency and fibre diameter of 1869 Spanish Merino purebred sheep. Heritabilities ranged from 0.08 ± 0.050 (fibre diameter) to 0.22 ± 0.060 (staple length), and the genetic correlations ranged from –0.63 ± 0.159 (crimp frequency – staple length) to 0.75 ± 0.222 (fibre diameter – staple length). Genetic simulations were developed to show the consequences of eight selection strategies, which included single trait selection on wool traits and liveweight (the current selection criteria) and index selection combining traits. The results show that it is possible to improve wool and growth traits at the same time. Also, our results show there is indirect genetic progress for wool characteristics using the current liveweight selection criterion.

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Multivariate selection under adverse genetic correlations: impacts of population sizes and selection strategies on gains and coancestry in forest tree breeding

Tree Genetics & Genomes ◽

10.1007/s11295-011-0404-4 ◽

2011 ◽

Vol 7 (6) ◽

pp. 1169-1183 ◽

Cited By ~ 10

Author(s):

Alvin D. Yanchuk ◽

Leopoldo Sanchez

Keyword(s):

Genetic Correlations ◽

Tree Breeding ◽

Forest Tree ◽

Forest Tree Breeding ◽

Selection Strategies ◽

Population Sizes

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Genetic gain of pure line selection and combined crossbred purebred selection with constrained inbreeding

Animal Science ◽

10.1017/s1357729800055715 ◽

2001 ◽

Vol 72 (2) ◽

pp. 225-232 ◽

Cited By ~ 15

Author(s):

P. Bijma ◽

J.A. Woolliams ◽

J.A.M. van Arendonk

Keyword(s):

Genetic Gain ◽

Selection Index ◽

Computing Time ◽

Genetic Correlations ◽

Pure Line ◽

Selection Strategies ◽

Line Selection ◽

Breeding Schemes ◽

Estimated Breeding Values ◽

Genetic Contributions

AbstractUsing deterministic methods, rates of genetic gain (Δ G) and inbreeding (Δ F) were compared between pure line selection (PLS) and combined crossbred purebred selection (CCPS), for the sire line of a three-way crossbreeding scheme. Purebred performance and crossbred performance were treated as genetically correlated traits assuming the infinitesimal model. Breeding schemes were compared at a fixed total number of purebred selection candidates, i.e. including crossbred information did not affect the size of the purebred nucleus. Selection was by truncation on estimated breeding values for crossbred performance. Rates of genetic gain were predicted using a pseudo-BLUP selection index. Rates of inbreeding were predicted using recently developed methods based on long-term genetic contributions. Results showed that changing from PLS to CCPS may increase ΔF by a factor of 2·14. In particular with high heritabilities and low purebred-crossbred genetic correlations, CCPS requires a larger number of parents than PLS, to avoid excessive ΔF. The superiority of CCPS over PLS was judged by comparing ΔG from both selection strategies at the same ΔF. At the same ΔF, CCPS was superior to PLS and the superiority of CCPS was only moderately reduced compared with the situation without a restriction on ΔF. This paper shows that the longterm genetic contribution theory can be used to balance ΔF and ΔG in animal breeding schemes within very limited computing time.

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Stability and adaptability for wood volume in the selection of Eucalyptus saligna in three environments

Pesquisa Agropecuária Brasileira ◽

10.1590/s0100-204x2018000500010 ◽

2018 ◽

Vol 53 (5) ◽

pp. 611-619 ◽

Cited By ~ 5

Author(s):

Thiago Wendling Gonçalves de Oliveira ◽

Rinaldo Cesar de Paula ◽

Mario Luiz Teixeira de Moraes ◽

Clayton Alcarde Alvares ◽

Aline Cristina Miranda ◽

...

Keyword(s):

Survival Rate ◽

Block Design ◽

Genetic Correlations ◽

Eucalyptus Saligna ◽

Wood Volume ◽

Selection Strategies ◽

Gxe Interaction ◽

Restricted Likelihood ◽

Analysis Of Stability ◽

The Stability

Abstract: The objective of this work was to evaluate the genotype x environment (GxE) interaction in open-pollinated Eucalyptus saligna progenies for simultaneous selection for greater stability and adaptability for wood volume, as well as to compare the selection strategies through combined and individual analyses in three environments. Three experiments were conducted in a randomized complete block design, with four replicates and six plants per plot, with 102 to 122 progenies. Three years after planting, survival rate and wood volume were evaluated. The genetic parameters were estimated by the maximum restricted likelihood and best linear unbiased prediction (REML/Blup) methods, and the stability and adaptability analysis was conducted using the harmonic mean of the relative performance of genetic values (HMRPGV). The highest survival rate (82%) was observed in Sabinópolis and the highest volume (120 m³ ha-1) in Lençóis Paulista. The mean heritability of progenies for the two analyzed variables was considered high, and the genetic correlations between survival rate and volume were weak for all sites. The G×E interaction was significant and of the complex type, with genotype correlation between sites of 47%, indicating that the ranking of the best progenies differed in each studied environment. The analysis of stability and adaptability indicated the possibility of selecting progenies with good performance in the three environments; however, to improve the quality of the evaluated characteristics, it is necessary to select specific progenies for each environment.

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Within- and across-flock genetic relationships for breech flystrike resistance indicator traits

Animal Production Science ◽

10.1071/an10102 ◽

2010 ◽

Vol 50 (12) ◽

pp. 1060 ◽

Cited By ~ 18

Author(s):

D. J. Brown ◽

A. A. Swan ◽

J. S. Gill

Keyword(s):

Genetic Relationships ◽

Genetic Correlations ◽

Fibre Diameter ◽

The Body ◽

Production Traits ◽

Sheep Industry ◽

Selection Strategies ◽

Australian Sheep ◽

Fleece Weight ◽

Indicator Traits

Flystrike is a major cost for the Australian sheep industry. The industry is currently implementing selection strategies for flystrike resistance to reduce the need for breech flystrike prevention. The following indicator traits are used to select for breech flystrike resistance: wool cover, skin wrinkle on the body and breech, scouring (dags) and wool colour. The aims of this study were to estimate genetic correlations between these indicator traits and production traits using the Sheep Genetics database, to distinguish between within- and across-flock genetic relationships, and to quantify responses to selection using indexes that include breech wrinkle as a proxy trait for flystrike resistance. Breech flystrike indicator traits are all heritable; however, there are significant antagonisms between wrinkle score and some production traits, primarily fleece weight and fibre diameter. Thus, simultaneous improvement in both flystrike resistance and production will be most efficient when index selection is used. Our results show that, depending on the level of emphasis placed on breech wrinkle in the index, reductions in breech wrinkle score of 0.4–0.9 units can be achieved over a 10-year period. As across-flock relationships are generally stronger than within-flock relationships, breeders will be able to take advantage of this additional variation, depending on the relative merit of their flocks. Therefore, ram breeders should combine within-flock selection with across-flock selection where possible. Sheep Genetics released early breech wrinkle Australian Sheep Breeding Values in September 2009 to assist Merino breeders in making faster progress towards reducing breech wrinkle by using flock selection.

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