Simultaneous estimation of the covariance structure of traits from field test, station test and litter recording in pigs (original) (raw)
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Genetic parameters for a joint genetic evaluation of production and reproduction traits in pigs
Czech Journal of Animal Science, 2005
The covariance structure was estimated by REML for a joint genetic evaluation of production and reproduction traits for Czech Landrace (58 258 records) and Czech Large White (167 161 records) pigs using fourtrait animal models. The following traits were analysed: lean mean percentage at the end of the performance test in the field, estimated from ultrasonic measurements unadjusted for live weight (LM), average daily gain in field test (in g/day) calculated as weight at the end of the test divided by age at the end of the test (ADG), number of piglets born alive in parity 1 (NBA1) and number of piglets born alive in parity 2 and subsequent parities (NBA2+). The heritabilities were in the range from 0.30 to 0.37 for LM, from 0.13 to 0.18 for ADG, from 0.09 to 0.13 for NBA1 and from 0.10 to 0.14 for NBA2+, depending on the breed and on the model (herd-year-season random or fixed). Genetic correlations between production and reproduction traits were estimated to be non-zero. Correlations between traits caused by the herd-year-season effect were mostly positive. As a general conclusion, the joint genetic evaluation of production and reproduction traits is recommended. The herd-year-season effect should be preferably considered as random.
Contemporary Agriculture, 2018
Summary The share of variance components and correlations between the most important sow production traits (namely duration of fattening - DF, backfat thickness - BF and number of liveborn piglets - NBA) included in the pig breeding selection programme of the Republic of Serbia were estimated in this paper. The litter size at repeated farrowings (NBA1,..., NBA6) was treated as a separate trait (the multi-trait model), whereas the litter size at birth was treated as a trait repeated a number of times (the repeatability model)). The estimation of dispersion parameters was performed using the Restricted Maximum Likelihood (REML) method. The heritability of DF accounted for 23.5%, i.e. 23.3% depending on the model used, whereas BF accounted for 40.4% in both cases. The heritability of the litter size in consecutive farrowings (the multi-trait model) were in intervals ranging between 0.104 (NBA1) and 0.136 (NBA5). The heritability of NBA in the repeatability treatment accounted for 0.106...
Variance components estimation for farrowing traits in three purebred pigs
Asian-Australasian Journal of Animal Sciences, 2017
Objective: This study was conducted to estimate breed-specific variance components for total number born (TNB), number born alive (NBA) and mortality rate from birth through weaning including stillbirths (MORT) of three main swine breeds in Korea. In addition, the importance of including maternal genetic and service sire effects in estimation models was evaluated. Methods: Records of farrowing traits from 6,412 Duroc, 18,020 Landrace, and 54,254 Yorkshire sows collected from January 2001 to September 2016 from different farms in Korea were used in the analysis. Animal models and the restricted maximum likelihood method were used to estimate variances in animal genetic, permanent environmental, maternal genetic, service sire and residuals. Results: The heritability estimates ranged from 0.072 to 0.102, 0.090 to 0.099, and 0.109 to 0.121 for TNB; 0.087 to 0.110, 0.088 to 0.100, and 0.099 to 0.107 for NBA; and 0.027 to 0.031, 0.050 to 0.053, and 0.073 to 0.081 for MORT in the Duroc, Landrace and Yorkshire breeds, respectively. The proportion of the total variation due to permanent environmental effects, maternal genetic effects, and service sire effects ranged from 0.042 to 0.088, 0.001 to 0.031, and 0.001 to 0.021, respectively. Spearman rank correlations among models ranged from 0.98 to 0.99, demonstrating that the maternal genetic and service sire effects have small effects on the precision of the breeding value. Conclusion: Models that include additive genetic and permanent environmental effects are suitable for farrowing traits in Duroc, Landrace, and Yorkshire populations in Korea. This breedspecific variance components estimates for litter traits can be utilized for pig improvement programs in Korea. Open Access 1240 www.ajas.info Lopez et al (2017) Asian-Australas J Anim Sci 30:1239-1244
Genetics Selection Evolution, 1993
Genetic parameters of 7 traits measured in central test stationsaverage daily gain (ADG1), feed conversion ratio (FCR) and backfat thickness (ABT) measured on candidates for selection, and average daily gain (ADG2), dressing percentage (DP), estimated carcass lean content (ECLC) and meat quality index (MQI) measured in slaughtered relativeswere estimated for the Large White (LW) and French Landrace (LR) breeds using a derivative free restricted maximum likelihood (DF-REML) procedure applied to a multiple trait individual animal model. The data consisted of 2 sets of records (3 671 and 3 630 candidates, 3 039 and 2 695 slaughtered animals in, respectively, LW and LR breeds) collected at 3 different stations from [1985][1986][1987][1988][1989][1990] (LW) or 1980-1990 (LR). The models included additive genetic value, common environment of birth litter and residual random effects, a fixed year x station x batch or year x station x slaughter date effect and, for traits measured in slaughtered animals, a fixed sex effect and a covariable (weight at the beginning or at the end of the test period). Heritabilities of ADG1, ABT, FCR, ADG2, DP, ECLC and MQI were respectively 0.30, 0.64, 0.22, 0.52, 0.39, 0.60, 0.33 in the LW and 0.34, 0.56, 0.25, 0.46, 0.31, 0.68, 0.23 in the LR breed. Common litter effects ranged from 5% (ABT in LW breed) to 16% (ADG2 in LR breed) of phenotypic variance.
Diversity
Genetic parameters, breeding values, and aggregate breeding values of number of piglets born alive (NBA), number of weaned piglets (NWE), and litter weight at weaning (LWWE) were predicted in the Hungarian Large White, Hungarian Landrace breeds, and in their cross (F1). Seven repeatability animal models were used. BLUP and REML methodology were used to estimate breeding values and variance–covariance components. PEST and VCE 6 software were used for estimating breeding values and variance components. Heritability for NBA and NWE was the same for all seven models. On the contrary, heritability estimates for LWWE were higher in comparison with NBA and NWE. The permanent environmental variance component was small for all traits. The large White breed had positive and significant genetic trends for all seven models and for all three traits. Landrace breed had significant trends for NBA, which was negative, and for NWE, the results were positive. The constructed indices result in one num...
Livestock Science, 2012
The purpose of this study was to determine the genetic and phenotypic relationships between litters per sow per year (LSY) and other economically important reproductive and postweaning traits from data collected in a commercial swine breeding company. Determining the genetic and phenotypic correlations among traits can help breeders evaluate the expected impacts their selection decisions have on other economically important production traits when they are included in a selection index. This is particularly important when considering reproductive and post-weaning traits due to possible undesirable genetic relationships. A total of 32,653 litter records from 7674 sows from 4 herds within a single production system (same genetics, same animal feeding specifications, same management procedures, etc.) were used in this study. The sows were born between 1992 and 2009. Post-weaning traits were recorded on male and female pigs (44,040 records), including sows and their progeny. The reproductive traits collected included number born alive (NBA), and wean to estrus (W2E). Number born alive and wean to estrus interval were recorded for every litter. Back fat between the 3rd and 4th last lumbar vertebrae and back fat and muscle thickness between the 3rd and 4th last rib were measured. Adjusted back fat (BF), percent lean (PCL), days to 100 kg (D100), and litters per sow per year (LSY) were calculated based on recorded information. Genetic parameters were estimated using ASREML. The heritability estimates for NBA, LSY, W2E, BF, D100, and PCL were 0.15, 0.03, 0.03, 0.41, 0.28, and 0.36, respectively. The genetic correlation between LSY and W2E was large, numerically negative, and favorable. The genetic correlations between LSY and the three post-weaning traits (BF, D100, and PCL) had large standard errors and were unclear in direction. Some economically important traits can be improved indirectly with selection on LSY; however, a selection index will be needed to ensure that post-weaning traits are not adversely affected by selection for LSY in a maternal line breeding program.
2015
Authors analysed genetic parameters and breeding value stability in Hungarian Large White (HLW), Hungarian Landrace (HL) pigs and their reciprocal cross (F1) for litter weight at weaning adjusted to 28 days of age. Data was collected by the legal predecessor of the National Food Chain Safety Office between 2001 and 2010. Data preparation was carried out using SAS 9.1.3 software. The litter weight records of the purebred and crossbred pigs were considered as separate traits. Genetic parameters were estimated by REML method using the VCE 6 software applying two-trait repeatability model. The total number of animal in the pedigree was 138 969. Heritability estimates were low for each breed and the cross. Corresponding values are 0.13 (0.004), 0.10 (0.004) and 0.13 (0.003) and 0.12 (0.002) for HLW, HL and F1 from the two datasets, respectively. Magnitudes of permanent environmental effect were 0.008 for HLW and less than 0.001 for HL and F1. Genetic correlations between purebred and cro...