Interplay between heritability, genetic correlation and economic weighting in a selection index with and without genomic information

2013 ◽  
Vol 130 (6) ◽  
pp. 456-467 ◽  
Author(s):  
A.M. Haberland ◽  
E.C.G. Pimentel ◽  
F. Ytournel ◽  
M. Erbe ◽  
H. Simianer
Keyword(s):  
Genetic Correlation ◽  
Selection Index ◽  
Genomic Information

scholarly journals Selection Response Due to Different Combination of Antagonistic Milk, Beef, and Morphological Traits in the Alpine Grey Cattle Breed

Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1340
Author(s):  
Enrico Mancin ◽  
Cristina Sartori ◽  
Nadia Guzzo ◽  
Beniamino Tuliozi ◽  
Roberto Mantovani
Keyword(s):  
Genetic Correlation ◽  
Functional Traits ◽  
Performance Test ◽  
Genetic Relationships ◽  
Selection Index ◽  
Milk Traits ◽  
Linear Type ◽  
Dual Purpose ◽  
Type Traits ◽  
Selection Indexes

Selection in local dual-purpose breeds requires great carefulness because of the need to preserve peculiar traits and also guarantee the positive genetic progress for milk and beef production to maintain economic competitiveness. A specific breeding plan accounting for milk, beef, and functional traits is required by breeders of the Alpine Grey cattle (AG), a local dual-purpose breed of the Italian Alps. Hereditability and genetic correlations among all traits have been analyzed for this purpose. After that, different selection indexes were proposed to identify the most suitable for this breed. Firstly, a genetic parameters analysis was carried out with different datasets. The milk dataset contained 406,918 test day records of milk, protein, and fat yields and somatic cells (expressed as SCS). The beef dataset included performance test data conducted on 749 young bulls. Average daily gain, in vivo estimated carcass yields, and carcass conformation (SEUROP) were the phenotypes obtained from the performance tests. The morphological dataset included 21 linear type evaluations of 11,320 first party cows. Linear type traits were aggregated through factor analysis and three factors were retained, while head typicality (HT) and rear muscularity (RM) were analyzed as single traits. Heritability estimates (h2) for milk traits ranged from 0.125 to 0.219. Analysis of beef traits showed h2 greater than milk traits, ranging from 0.282 to 0.501. Type traits showed a medium value of h2 ranging from 0.238 to 0.374. Regarding genetic correlation, SCS and milk traits were strongly positively correlated. Milk traits had a negative genetic correlation with the factor accounting for udder conformations (−0.40) and with all performance test traits and RM. These latter traits showed also a negative genetic correlation with udder volume (−0.28). The HT and the factor accounting for rear legs traits were not correlated with milk traits, but negatively correlated with beef traits (−0.32 with RM). We argue that the consequence of these results is that the use of the current selection index, which is mainly focused on milk attitude, will lead to a deterioration of all other traits. In this study, we propose more appropriate selection indexes that account for genetic relationships among traits, including functional traits.

scholarly journals 209 Genomic selection for multiple maternal and growth traits in large white pigs using Single-Step GBLUP

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 42-42
Author(s):  
Breno Fragomeni ◽  
Zulma Vitezica ◽  
Justine Liu ◽  
Yijian Huang ◽  
Kent Gray ◽  
...  
Keyword(s):  
Genetic Correlation ◽  
Growth Traits ◽  
Computing Time ◽  
Average Daily Gain ◽  
Genetic Correlations ◽  
Single Step ◽  
Genomic Information ◽  
Genomic Evaluation ◽  
Large White ◽  
Daily Gain

Abstract The objective of this study was to implement a multi-trait genomic evaluation for maternal and growth traits in a swine population. Phenotypes for preweaning mortality, litter size, weaning weight, and average daily gain were available for 282K Large White pigs. The pedigree included 314k individuals, of which 35,731 were genotyped for 45K SNPs. Variance components were estimated in a multi-trait animal model without genomic information by AIREMLF90. Genomic breeding values were estimated using the genomic information by single-step GBLUP. The algorithm for proven and young (APY) was used to reduce computing time. Genetic correlation between proportion and the total number of preweaning deaths was 0.95. A strong, positive genetic correlation was also observed between weaning weight and average daily gain (r = 0.94). Conversely, the genetic correlations between mortality and growth traits were negative, with an average of -0.7. To avoid computations by expensive threshold models, preweaning mortality was transformed from a binary trait to two linear dam traits: proportion and a total number of piglets dead before weaning. Because of the high genetic correlations within groups of traits, inclusion of only one growth and one mortality trait in the model decreases computing time and allows for the inclusion of other traits. Reduction in computing time for the evaluation using APY was up to 20x, and no differences in EPD ranking were observed. The algorithm for proven and young improves the efficiency of genomic evaluation in swine without harming the quality of predictions. For this population, a binary trait of mortality can be replaced by a linear trait of the dam, resulting in a similar ranking for the selection candidates.

Realized genetic parameters from an antagonistic selection index in Tribolium castaneum

1986 ◽  
Vol 28 (3) ◽  
pp. 358-364 ◽  
Author(s):  
J. L. Campo ◽  
L. G. Raya
Keyword(s):  
Genetic Correlation ◽  
Tribolium Castaneum ◽  
Selection Index ◽  
Selection Response ◽  
Pupal Weight ◽  
Base Population ◽  
Adult Weight ◽  
Antagonistic Selection ◽  
Individual Trait ◽  
Highly Correlated

Simultaneous selection of two highly correlated traits was practiced in Tribolium castaneum in a replicated experiment for six generations. Two lines were selected in each of three replicates: P+A− for an antagonistic selection index to increase pupal weight at 21 days and decrease adult weight at 31 days, and P−A+ for an antagonistic selection index to decrease pupal weight and increase adult weight. Genetic correlation between pupal and adult weights estimated in the base population was 0.95. Estimates of realized heritabilities and genetic correlation were obtained and compared with full-sib estimates. For the aggregate genotype, the P+A− line had a significant positive selection response, while the P−A+ line showed a significant negative response as would be expected. The response to divergent selection was asymmetrical, being less for the low pupal weight and high adult weight line than vice versa. Less asymmetry was found for the realized heritability, which agreed very well with the index heritability estimated in the base population. Both individual traits changed in the same direction, increasing for the P+A− line and decreasing for P−A+ line, even though a significant response was found only for pupal weight in the P+A− line. Therefore, the response to antagonistic selection for each individual trait seems to be heavily controlled by the strength of the genetic correlation between them. The realized genetic correlation between pupal weight and adult weight obtained from antagonistic selection index was in excellent agreement with full-sib estimates. Realized heritabilities for each trait were overestimated, especially for adult weight, even though there were essentially no differences between realized and estimated values.Key words: selection (artificial), antagonistic index, parameters (realized), Tribolium.

MOET breeding schemes for wool sheep 2. Selection for adult fleece traits

1994 ◽  
Vol 59 (1) ◽  
pp. 87-98
Author(s):  
N. R. Wray ◽  
M. E. Goddard
Keyword(s):  
Genetic Correlation ◽  
Embryo Transfer ◽  
Selection Index ◽  
Optimum Number ◽  
Genetic Response ◽  
Breeding Scheme ◽  
Merino Sheep ◽  
Individual Record ◽  
Breeding Programmes ◽  
Natural Mating

AbstractBenefits of collection of annual versus a single fleece record are investigated for breeding programmes of Australian Merino sheep. Breeding scheme alternatives are based on natural mating (N) or multiple ovulation and embryo transfer (MOET). The breeding objective is assumed to be an adult fleece trait which is expressed annually from a minimum of age 2 years, with a unity genetic correlation between annual records. Initial selection of parents can occur prior to the availability of their adult records, based on records collected at 6,12 or 18 months which have a maximum genetic correlation of 0·8 with the adult trait. Monte Carlo simulation is used to compare breeding programme alternatives, which allows overlapping generations and selection across age groups. MOET schemes select parents of minimum age 19 months in adult (A) schemes, 7 months in juvenile (J) schemes or 13 months when there are two breeding seasons per year. Natural mating results in an average of 1·09 lambs per ewe mated, whilst embryo transfer success rates follow realistic distributions (only 70% of donors giving live lambs) with an average of 3·45 lambs per donor flushed. Estimated breeding values, on which selection is based, are calculated by multiple trait selection index of an individual's own records or by multivariate best linear unbiased prediction (BLUP). In J schemes 7-month-old lambs may be selected on the basis of a pedigree index if no individual record has been collected at 6 months of age. Breeding scheme alternatives are compared on the basis of genetic response, rate of inbreeding and economic ‘income’ which is calculated as genetic response reduced for inbreeding depression, cumulated and discounted over a medium time horizon (14 years). The quantitative benefits of the collection of annual records are dependent on the choice of genetic and phenotypic parameters between traits, but these were chosen from the literature to be representative of annual fleece weight records in Merino sheep. Genetic response to selection and ‘income’ associated with the adult trait is increased by at least 15% in N, A and J schemes compared with when only a single record is collected at 18 months. The advantage of MOET over N schemes and the optimum number of sires to use is unchanged, but the average age of sires is increased. Both annual rate of inbreeding and average age of dams are unchanged. In N schemes, 80% of the benefits of collecting annual records on both sexes can be achieved by collecting records on males alone, whilst in MOET schemes measurement of dams contributes up to 50% of the benefit of the measurement of both sexes. Since MOET schemes have fewer dams to be recorded, the cost-effectiveness of collecting records on females is much higher than in natural mating schemes. Breeding programmes operating two mating seasons each year are found to be a viable alternative to J schemes: although genetic response is less, rate of inbreeding is also less, so that ‘income’ response is approximately equal.

scholarly journals Study of relations among age at first calving, average weight gains and weights from weaning to maturity in Nellore cattle

2010 ◽  
Vol 39 (4) ◽  
pp. 746-751 ◽  
Author(s):  
Arione Augusti Boligon ◽  
Lucia Galvão de Albuquerque ◽  
Maria Eugênia Zerlotti Mercadante ◽  
Raysildo Barbosa Lôbo
Keyword(s):  
Weight Gain ◽  
Genetic Correlation ◽  
Maximum Likelihood Method ◽  
Selection Index ◽  
Likelihood Method ◽  
Average Weight ◽  
Age At First Calving ◽  
Nellore Cattle ◽  
Estimate Heritability ◽  
Selection For

Data from 23,120 Nellore animals were used to estimate genetic parameters for age at first calving, average gains from weaning to yearling and from yearling to after yearling, weaning weight, yearling weight, after yearling weight and weight at 2 and 5 years of age. Animal models were fitted by Restricted Maximum likelihood Method. Estimate heritability for age at first calving, weaning to yearling weight gain, yearling to after yearling weight gain, weight at weaning, yearling weight, after yearling weight and weight from 2 to 5 years of age were 0.17 ± 0.01; 0.23 ± 0.03; 0.25 ± 0.03; 0.28 ± 0.02; 0.26 ± 0.03; 0.30 ± 0.03; 0.32 ± 0.02 and 0.36 ± 0.04, respectively. The genetic correlation estimates between age at first calving and weight traits ranged from -0.26 to -0.14. The genetic correlation estimates between age at first calving and average gains were also negative, but higher (-0.29 and -0.32). In general, these results indicate that selection for average gains will promote changes in age at first calving and female mature weight. Improvement in reproductive performance could be obtained with the inclusion of the age at first calving in the selection index.

scholarly journals Association Between Backfat Thickness at 28 Weeks Old and Production Traits of Primiparous Landrace Sows Raised Under Tropical Conditions

2021 ◽  
Author(s):  
Praew Thiengpimol ◽  
Skorn Koonawootrittriron ◽  
Thanathip Suwanasopee
Keyword(s):  
Genetic Correlation ◽  
Selection Index ◽  
Genetic Correlations ◽  
High Standard ◽  
Backfat Thickness ◽  
Pedigree Information ◽  
Production Traits ◽  
Population Means ◽  
Maximum Likelihood Procedure ◽  
Tropical Conditions

Abstract Backfat thickness could reflex energy reserve of the female pigs that is required for their productivity, especially gilts that might be selected for the replacements. Therefore, phenotypic and genetic correlations between backfat thickness (BF) and production traits were estimated and considered for the possibility of using BF at pre-selective stage as an early indicator for productivity of the sow. Pedigree information, BF and body weight (BW) at 28 weeks old, age at first farrowing (AFF), transformed proportion of piglet loss at birth (tPL) and transformed weaning to first service interval (tWSI) of 806 primiparous Landrace sows were used to estimate the variance components by restricted maximum likelihood procedure with an average information algorithm for multivariate analysis. Genetic correlation between BF and BW was 0.70 ± 0.13. Both BF and BW had negative genetic correlation with AFF, but not tWSI. Unfortunately, genetic correlation estimates between tPL and other traits was unclear due to high standard error. The genetic correlation between AFF and tWSI was 0.78 ± 0.36. Besides 19.35% of sires, 26.34% of dams and 25.81% of sows had genetic ability for BF, BW, AFF and WSI above the population means. The genetic association between BF, BW, AFF and tWSI indicated the feasibility of using selection index to improve BF and BW at pre-selective stage and reduce AFF and tWSI of replacement gilt simultaneously. However, the estimation of genetic correlation between PL and other traits should be repeated in a larger population.

Genetic correlations between female fertility and postweaning growth and feed efficiency traits in multibreed beef cattle

2016 ◽  
Vol 96 (3) ◽  
pp. 448-455 ◽  
Author(s):  
Y. Mu ◽  
G. Vander Voort ◽  
M.K. Abo-Ismail ◽  
R. Ventura ◽  
J. Jamrozik ◽  
...  
Keyword(s):  
Beef Cattle ◽  
Genetic Correlation ◽  
Feed Intake ◽  
Feed Efficiency ◽  
Genetic Relationships ◽  
Selection Index ◽  
Genetic Correlations ◽  
Residual Feed Intake ◽  
Gestation Length ◽  
Fertility Traits

With selection in beef cattle now incorporating feed efficiency, knowing the relationship with other traits is needed. Genetic relationships were estimated with an animal model in ASReml with a three-generation pedigree inclusive of 2882 animals. Multibreed data from two Ontario beef research farms with fertility traits were available on 1366 females and postweaning traits, including feed efficiency on 1297 individuals. Estimates of heritability for fertility traits were low to moderate ranging from 0.03 ± 0.01 for pregnancy rate to 0.21 ± 0.02 for gestation length, and postweaning traits were moderate to high with feed conversion ratio at 0.22 ± 0.06 to mid-metabolic weight at 0.89 ± 0.01. Both dry matter intake and mid-metabolic weight were genetically correlated with most fertility traits from −0.52 to 0.34. The genetic correlation between average daily gain and days to calving was moderately negative (–0.33 ± 0.16) as was residual feed intake with days to calving (–0.34 ± 0.17). Bigger cows with more feed intake and faster growth were more fertile, and residual feed intake had an unfavorable genetic correlation with days to calving, indicating that programs to select for feed efficiency should include fertility simultaneously in a selection index.

scholarly journals Nutzung des Ultraschalls in der Schlachtleistungsprüfung und Zuchtwertschätzung für Schafe

2005 ◽  
Vol 48 (2) ◽  
pp. 174-184
Author(s):  
E. Gernand ◽  
H. Lenz
Keyword(s):  
Genetic Correlation ◽  
Selection Index ◽  
Genetic Correlations ◽  
Carcass Composition ◽  
The Other ◽  
Breeding Value ◽  
Other Hand ◽  
Kidney Fat ◽  
Increase Efficiency

Abstract. Title of the paper: Using of Ultrasound for estimation of carcass composition and prediction of breeding value for sheep’s In Thuringia the subjective visual conformation scores of carcasses for blade (BL), leg (K), back (R), fat overlay (OF) and kidney fat (NF) were added by ultrasonic muscle (USK) and fat (USF) depths of living lambs. Heritabilitity estimates were carried out on 2654 slaughtered and 3228 living and ultrasonic-tested Merinolongwool lambs. Estimates of the subjective conformation scores were very low with 0.178 (BL); 0.143 (K); 0.165 (R) and 0.118 (OF). Slightly higher heritabilities could be estimated for NF (0.234), USK (0.26) and USF (0.174). The genetic correlations between conformation scores for muscle on one hand and OF and USF on the other hand were between 0.313 and 0.848. In contrast, the genetic correlation between USK on one hand and OF and USF on the other hand was rA = 0.022 and rA = −0.110, respectively). This may increase efficiency of breeding . By means of selection differences, it is recommended to use USK instead of blade and back, and USF instead of fat overlay in selection index.

Genomic Information Retrieval

2007 ◽  
Vol 2 (3) ◽  
pp. 9-14
Author(s):  
Jacinth Salome ◽  
◽  
Ramya Ravishankar ◽  
Keyword(s):  
Information Retrieval ◽  
Genomic Information
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