Summary and Implications
The objective of this study was to determine if Yorkshire gilts become habituated to the process of weighing. A total of 192 pure bred Yorkshire gilts were used. The gilts were housed in 12 pens, 16 gilts/pen providing a space allowance of 0.82 m2/gilt. Gilts were weighed every 2-wks for a maximum of eight scores/ gilt. Gilts were scored while on the weigh scale for activity using a whole number scale of one to five (1 = calm, minimal movement; 5 = continuous rapid movement and an escape attempt) at two different time points, T = 0 (as soon as the back gate was closed and T = 15, 15 sec after the back gate was closed. Analyses were done using Proc Mixed of SAS. The differences during round one between T = 0 and T = 15 was 1 point on the 5 point scale. By round eight this had dropped down to a difference of 0.2. During the first round over both time points the gilts scored on average 2.5, by round 5 this had dropped down to around 1.5 at which point it stabilized. In conclusion, Yorkshire gilts appear to become habituated to the process of weighing over the course of a trial, and as such do not seem to find the process highly aversive.
Iowa State University
Sadler, Larry J.; Johnson, Anna K.; Young, Jennifer; Lonergan, Steven M.; Dekkers, Jack C.M.; and Nettleton, Daniel S.
"Do Yorkshire Gilts Become Habituated to Repeated Weighing
Over a Trial? ,"
Animal Industry Report:
AS 657, ASL R2635.
Available at: http://lib.dr.iastate.edu/ans_air/vol657/iss1/59