Evaluation of genetic parameters on crossing in pigs bred (original) (raw)
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Estimation of genetic parameters and genotype effects for crossing constructions of Hungarian Pigs
Acta Agraria Debreceniensis, 2013
Authors estimated the genetic parameters and genotype effects of average daily gain (ADG), age (AGE) and lean meat percentage (LMP) using the field test data of Pietrain (Pi), Duroc (Du), Hampshire (Ha) pigs and their crosses. Data was collected by the Agricultural Agency of Administration between 1998 and 2010 originating from 68 herds. Datasets of the different crossing combinations (Pi, Du, Pi × Du; Pi, Ha Pi × Ha) were evaluated separately using bivariate animal models. The estimated heritabilities were moderately low: 0.24–0.29, 0.22–0.26 and 0.18–0.19 for average daily gain (ADG), age (AGE) and lean meat percentage (LMP), respectively. The estimated genetic correlation coefficients were negligible: -0.07–0.01 (ADG-LMP), -0.01–0.04 (AGE-LMP). The Pi × Ha and Pi × Du crosses showed 6.76% and 4.96%; 6.74% and 4,17% and 0.08% and 0.44% heterosis for ADG, AGE and LMP, respectively. Among the environmental factors the herd effects were substantial: 41.17%, 53.67% and 14.16% for AGD,...
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.
Revista Brasileira de Zootecnia, 2019
The objective of this study was to evaluate the impact of farrowing and mortality rates on inbreeding levels and genetic gain through data simulation. Data came from two real populations A and B, composed of Pietrain and Landrace breed pigs, respectively. To generate the simulated populations, a Fortran-language simulator was developed using the (co)variances of the breeding values and productive and reproductive information obtained from populations A and B, as well as restrictions on mating and animals selected per generation. Two data files were created. The first contained the pedigree of the previous 10 years, with 21,906 and 251,343 animals in populations A and B, respectively. The second included the breeding values for age, backfat thickness, and feed conversion, all of which were adjusted for 110 kg live weight, for both populations; longissimus dorsi muscle depth adjusted for 110 kg live weight, for population A only; and number of live piglets at the fifth day of life per farrowing, for population B only. Three scenarios were simulated by varying the farrowing and mortality rates during the lactation period. Ten generations were simulated, with 30 replicates for each generation and scenario. Inbreeding levels in closed production units increase with productive and reproductive losses, and these reduce the variances of breeding values, selection intensity, and genetic gains by reducing the number of animals available for selection. Actions that maximize farrowing rates are more important than those that minimize mortality rates during the lactation period, since a reduction in simulated farrowing resulted in greater losses of genetic gains.
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...
Breeding for reproduction traits in context of multiplication herds efficiency in swine
Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis, 2013
Presented study is a follow-up to the studies focused on eff ect of diff erent selection pressure applied on two subpopulations of purebred Czech Large White sows on performance in multiplication herds. Higher selection pressure particularly on litter size and number of function nipples, while lower pressure on growth performance was applied in one population. About 1214 farrows of 393 F1 Czech Large White sows were included into statistical evaluation. The mixed linear models using the procedure REML in SAS for Windows 9.1.2. was used. The hypothesis that progeny of sows from hyper-prolifi c subpopulation breed in multiplier herds have diff erent performance was not confi rmed which is in contrast to previous studies. This non-homogeneity can be related to non-additive genetic eff ects which are caused by crossbreeding while selection methods are based on additive models.
Factors influencing growth performance and estimation of genetic parameters in crossbred pigs
Growth is an important trait of interest in any meat producing animal and body weight (BW) measurements are good indicators of growth rate. The present study focuses on identifying the factors influencing pre and post weaning BW and average daily gains (ADG) in Large White Yorkshire-Desi crossbred pigs (50% and 75%) using weekly BW measurements from birth to 8 weeks of age and monthly BW from 3 rd to 9 th month from 1,405 piglets born during the years , 0.272 and 0.255 respectively. Heritability estimated using full-sib analysis for BW at various ages varied from 0.577 to 0.966. Estimated genetic correlations among pre-weaning BW were positive and low in magnitude whilst among post-weaning BW, genetic correlations were high positive. The findings suggest that 12 th week BW can be used for selecting increased BW at 36 th week. The findings indicate scope for improvement through selection.
Estimation and decomposition of genetic trends in a two-way cross using Hungarian pig breeds
2014
Authors analyzed the estimation and partition of the genetic trends of lean meat percentage and average daily gain of the two-way cross Duroc (Du), Pietrain (Pi) pigs and their cross. The analysis was based on the data collected by the Agricultural Agency of Administration in course of field test between 1998 and 2010 from 68 herds. Total number of animals in the pedigree file was 60926. Genetic parameters and breeding values of average daily gain (ADG) and the lean meat percentage (LMP) were estimated separately by REML and BLUP methods using the VCE6 and PEST software applying a two-trait animal model. For the observed period the authors received a small genetic trend for ADG while it was negligible for LMP. Decomposing these trends to genotypes the highest contributions to the trends were observed for Duroc (ADG) and Pietrain (LMP), respectively
Livestock Science, 2017
The objective of this work was to develop a bioeconomic model and a computer program to calculate marginal economic values and relative economic weights of traits in pig breeds within various breeding systems. Using this program, economic values for up to 30 production and functional traits can be estimated. The bioeconomic model includes the calculation of the stationary state of sow herds using Markov chain methodology; calculation of progeny structure; modeling growth of protein and fat tissue of all animal groups; calculation of metabolizable energy, feed and water requirements, and feeding costs for all growth phases of young animals with different feeding diets and for sows in different reproductive statuses (open, lactating, and pregnant sows); calculation of non-feed costs and revenues for all production units; calculation of the total profit per sow and year in all links (breeds and crossbreeds) of the given breeding system; and calculation of marginal economic values of traits for all breeds involved in this breeding system. The complete profit functions of the integrated production systems of all involved breeds and crossbreeds are modeled, and therefore, the program can be used for further economic and sensitivity analyses within pig production systems.
Genetic and phenotypic correlations among reproductive traits in crossbred pigs
International Journal of Chemical Studies, 2017
Records on various reproductive traits belonging to a total of 541 crossbred pigs out of which 308 were half-bred inter se (½ Hampshire × ½ Local) pigs and 233 were graded inter se (¾ Hampshire × ¼ Local) pigs from the year 2002 to 2013 constituted the material for study. Pigs were born, maintained and bred at ICAR- Mega Seed Project (MSP) and All India Coordinated Research Project (AICRP) on pigs, Assam Agricultural University, Khanapara, Guwahati- 781022, Assam, India. Phenotypic and genetic correlation coefficients among the reproductive traits were estimated from the data by paternal half sib method (Becker 1975) [1]. The phenotypic correlation coefficient in both the genetic group was found to be positive for all reproductive traits and highly significant in among some traits. The genetic correlation coefficient among reproductive traits are positive and ranged from low to high and in desired direction in most of the case for both the genetic groups.