Animal Industry Report

Extension Number

ASL R2552



Summary and Implications

The objectives of this study were to determine the effect of selection for reduced residual feed intake (RFI) on lesion scores in gilts in their home pen. A total of 192 gilts were used; 96 were from a line that had been selected for low residual feed intake over 5 generations (LRFI) and 96 from a randomly bred control line (CRFI). Gilts were housed in 12 pens (16 gilts/pen; 0.82 m2 /gilt) containing 8 gilts from each line in a conventional grow-finish unit. Lesion scores were collected the day after placement and every 4 weeks for 3 subsequent periods. The gilt’s body was divided into 4 regions, with each region receiving a score of 0 (0 lesions) to 3 (5+ lesions). All analyses were done using Proc Mixed of SAS. The data were analyzed separately for the day after placement and the subsequent three rounds. Lesion scores for each region of the body were analyzed as repeated measures. Gilts from the LRFI line had lower (P < 0.045) lesion scores on the day after placement. However, over subsequent rounds there were no (P > 0.05) differences between the genetic lines. In conclusion, gilts from the line selected for low RFI had lower lesions scores on the day after placement into the grow-finish environment and this may be a useful tool to use in a selection program for more efficient gilts.

Copyright Holder

Iowa State University