The accuracy of genomic estimated breeding values (GEBV) was evaluated for sixteen meat quality traits in a Berkshire population (n = 1,191) that was collected from Dasan breeding farm, Namwon, Korea. The animals were genotyped with the Illumina porcine 62 K single nucleotide polymorphism (SNP) bead chips, in which a set of 36,605 SNPs were available after quality control tests. Two methods were applied to evaluate GEBV accuracies, i.e. genome based linear unbiased prediction method (GBLUP) and Bayes B, using ASREML 3.0 and Gensel 4.0 software, respectively. The traits composed different sets of training (both genotypes and phenotypes) and testing (genotypes only) data. Under the GBLUP model, the GEBV accuracies for the training data ranged from 0.42±0.08 for collagen to 0.75±0.02 for water holding capacity with an average of 0.65±0.04 across all the traits. Under the Bayes B model, the GEBV accuracy ranged from 0.10±0.14 for National Pork Producers Council (NPCC) marbling score to 0.76±0.04 for drip loss, with an average of 0.49±0.10. For the testing samples, the GEBV accuracy had an average of 0.46±0.10 under the GBLUP model, ranging from 0.20±0.18 for protein to 0.65±0.06 for drip loss. Under the Bayes B model, the GEBV accuracy ranged from 0.04±0.09 for NPCC marbling score to 0.72±0.05 for drip loss with an average of 0.38±0.13. The GEBV accuracy increased with the size of the training data and heritability. In general, the GEBV accuracies under the Bayes B model were lower than under the GBLUP model, especially when the training sample size was small. Our results suggest that a much greater training sample size is needed to get better GEBV accuracies for the testing samples.

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SUMMARYSince the racehorses with excellent performance have a heavy carried weight (CW) in the current system, their finishing time does not increase along with heavier CW. As the CW increases, the finishing time decreases. Moreover, the percentage of victories also gets higher as the CW increases. Therefore, the effect of ratio CW/ BW as the ratio of carried weight to the body weight on finishing time was analyzed in order to suggest the problems of current CW system. The objective of this study is to examine the influence of CW/BW ratio on finishing time, using a total of 155 656 racing records belong to 8197 racehorses. Generally, the BW of racehorse is heavier, the potentiality as a good racehorse is higher. The fact that the ratio CW/BW is high means that most of racehorses have lighter BW. As the ratio CW/BW increases in the racing distance of 1000 m, the actual finishing time tends to increase in general. The finishing time that has run while bearing the ratio of 12.0-12.7%, has demonstrated a good racing record. When the ratio CW/BW is about 13.1% or more, it has begun to influence on the finishing time gradually. Also, the racehorse tends to have a growth potential in a long distance race when the BW is no less than 475-480 kg. Consequently, when setting a handicap, it is desirable to consider the just before raced BW of racehorse to a certain degree. RESUMENDado que los caballos de carrera con excelentes prestaciones transportan un handicap pesado (CW) en el sistema actual, su tiempo a la finalización no aumenta con handicaps (CW) aún mayores. Cuando el CW aumenta, el tiempo de carrera disminuye. Por otra parte, el porcentaje de victorias se hace mayor a medida que aumenta el CW. Por ello, el efecto de la relación CW/BW, como relación entre peso transportado y peso corporal, sobre el tiempo de la carrera fue analizado al objeto de detectar los problemas en el sistema actual de handicap. El objetivo de este estudio fue examinar la influencia de la relación CW/BW, sobre el tiempo de carrera, empleando un total de 155 656 registros pertenecientes a 8197 carreras. Generalmente si el peso corporal del caballo es más pesado, su potencial como buen caballo de carrera es mayor. El hecho de que la relación CW/BW sea alta, significa que el peso de los caballos es menor. Cuando la relación CW/BW aumenta en la distancia de 1000 m el tiempo de la carrera tiende a aumentar. Cuando la relación está entre 12,0-12,7%, se ha demostrado conseguir un buen tiempo de carrera. Cuando la relación CW/BW es de 13,1 o más, comienza a influir gradualmente sobre el tiempo de carrera. También el caballo tiende a tener un buen potencial de recuperación en una distancia larga cuando el BW no es inferior a 475-480 kg. Consecuentemente cuando se asigna un handicap, es deseable tener en cuenta el peso del caballo antes de la carrera.