Relationship Between Performance Test Traits and Subsequent Reproductive Performance of Yorkshire Females

摘要

The objective of this study was to examine relationships between performance test traits of Yorkshire females and their subsequent reproductive performance. Performance test records were collected in a commercial swine operation from 1992 to 1999. Allfemales in the breed were grown to 100 d of age (AGF100: n = 38,979). At this time pigs were weighed (WT100) and selected for performance testing based on a combination of maternal and performance indexes. Pigs were weighed at the end of the 77-d performance test (WT177) and ADO calculated. Backfat (BF), loin eye area (LEA), and body length (LEN) were measured. Reproductive traits were number born live (NBA) and weaning weight (WWL) of the first litter. Heritabilities and genetic correlations were estimated with multiple-trait DFREV1L procedures using an animal model with litter effects. Fixed effects for performance traits included contemporary group and appropriate age as a covariate. Estimates of heritability for NBA, WWL. WT100. WT177, ADG, BF, LEA. and LEN were 0.09 +- .03, 0.10 +- .03. 0.22 +- .01, 0.32 +- .02, 0.28 +- .02, 0.47 +- .02, 0.31 +- .02, and 0.23 +- .02, respectively. Genetic correlations for NBA with WT100, WTP7, ADG, BF, LEA, and LEN were -0.43, -0.20, 0.06, 0.01, -0.17, and -0.11, respectively. Genetic correlations for WWL with WT100, WT177, ADG. BF, LEA, and LEN were 0.55. 0.14. -0.04, -0.05, -0.05, and 0.13, respectively. These correlations indicated that 100-d weight of the mother was more related to NBA and WWL. than any performance trait measured. Females that weighed more at 100 d of age had smaller litter sizes, but greater weaning weight of the litter.