The objective of this study was to determine the effect of selection for reduced residual feed intake (RFI) on the general behavior and activity of Yorkshire gilts in their home pen. A total of 192 gilts were used, 96 from a line selected for low RFI over five generations (LRFI) and 96 from a randomly bred control line (CRFI).
Gilts were housed 16/pen (8.8 sq. ft./gilt), eight gilts from each line placed in 12 pens of a conventional grow-finish unit. Gilts had ad-libitum access to feed and water via a one-space electronic feeder and two nipple waterers.
Twelve hours of video footage was collected on the day gilts were placed, then every four weeks for three additional observation periods. Video was scored using a 10-minute, instantaneous scan sampling technique for four postures (standing, lying, sitting and locomotion) and one behavior (at drinker). Categories of active (standing, locomotion and at drinker) and inactive (sitting and lying) were also created.
The data were analyzed separately for the day of placement and the three subsequent rounds. General activity data were summarized on a percentage basis by each posture and behavior.
There were no differences between genetic lines for all postures and behavior at drinker on the day of placement. However, over subsequent rounds, it was observed that LRFI gilts spent less time standing (13.7 vs. 15.2%), more time sitting (2.5 vs. 2.1%) and were less active overall (16.9 vs. 18.5%).
Based on this study, it may be worthwhile for pork producers to consider overall behavior of the gilt, to help identify factors that may contribute to variation in the efficiency of grow-finish gilts in addition to their genetic potential.
This research was funded by grants from the National Pork Board and the Iowa Pork Producers Association.
Researchers: L. J. Sadler, A. K. Johnson, S. M. Lonergan, D. Nettleton, and J. C. M. Dekkers, Iowa State University. Contact Sadler by phone (515) 294-5275 or e-mail ljsadler@iastate.edu.