PSXII-33 The Effect of Log Transformation on Carcass Data Measured by Ultrasound

Abstract

Abstract This study is to evaluate the effect of log transformation on ultrasound data records on the genetic evaluation of Hanwoo (Korean native cattle) proven bulls. Three different scenarios were established: genetic evaluations using (A) only yearling weights (YW; n = 15,665) and carcass traits (CT); (B) YW, CT and raw ultrasound data at 12 and 24 months of age; and (C) YW, CT and log transformed data of raw ultrasound data records in (B). Carcass traits include carcass weight (CW; n = 6,526), loin muscle area (LMA; n = 6,820), backfat thickness (BFT; n = 6,723), and intramuscular fat (IMF; n = 5,037). Ultrasound traits include LMA, BFT, and fat content (FC; %), which were measured with Aquila Vet (Pie Medical) between the 12th and 13th rib. REMLF90 was used to estimate genetic parameters such as heritability and genetic correlations. Rank correlations of breeding values were analyzed using SAS 9.2. The heritability of YW was the highest at (B) and reduced by 0.2% at (C). The heritability of CW was higher at (B) and (C) than at (A) by 0.6%. In the case of BFT and IMF, (B) and (C) was 0.5% and 0.6% higher than (A) and -1.0% and -0.8% lower than (A), respectively. The heritabilities regarding ultrasound traits at 12 months of age were higher for LMA and FC in (C) than (B), and higher for BFT in (B) than (C). In the case of 24 months of age, (C) was higher in all ultrasound traits than (B). The rank correlations of (B) and (C) at 12 months were 0.995 in ultrasound LMA and 0.991 in ultrasound BFT. For 24 months, the correlations were 0.989 and 0.986, respectively. In conclusion, the results didn’t provide us with evidence of a significant difference in genetic evaluations among different scenarios regarding log transformation on ultrasound data records of carcass traits.