Summary and Implications
The objectives of this study were to determine the effect of selection for reduced residual feed intake (RFI) on behavior and activity 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, containing 8 gilts from each line in a conventional grow-finish unit. Twelve hours of video footage was collected on the day of placement and then every 4 wk for 3 more observational periods. Video was scored using a 10-min instantaneous scan sampling technique. Four postures (standing, lying, sitting and locomotion) and one behavior (at drinker) were collected. Categories of active (standing, locomotion and at drinker) and inactive (sitting and lying) were also created. Analyses were done using Proc Mixed of SAS. There were no differences (P > 0.05) between genetic lines for all postures and the behavior at drinker on the day of placement. However, over subsequent rounds it was observed that LRFI gilts spent less (P = 0.03) time standing, more time sitting (P = 0.05) and were less active (P = 0.03) overall. In conclusion, on the day of placement there were no behavioral differences between genetic lines. Behavioral differences were observed between genetic lines over subsequent rounds, with LRFI gilts becoming less active. Therefore, overall behavioral repertoire of the gilt in their home pen may be beneficial for future RFI selection programs and may contribute to variation in efficiency of the grow-finish gilt.
Iowa State University
Sadler, Larry J.; Johnson, Anna K.; Lonergan, Steven M.; Dekkers, Jack C.M.; and Nettleton, Daniel S.
"The Effect of Selection for Residual Feed Intake on General
Behavioral Activity in Yorkshire Gilts,"
Animal Industry Report:
AS 656, ASL R2553.
Available at: https://lib.dr.iastate.edu/ans_air/vol656/iss1/74