Blank panels in sheep yards encourage sheep to jump

摘要

The lateral sides of two adjacent forcing pens and the sides of the races were clad with plywood to improve sheep flow in yards at AgResearch Lincoln farm. Following this, two flocks of yearling sheep were run through the yards every two weeks for drafting. One flock was exclusively male (n = 223), while the other was all female (n = 248). On the first occasion, a number of yearlings jumped out of the forcing pen. This had not been observed in previous years, so the number jumping was recorded. A non-parametric time-to-event analysis method, the Kaplan-Meier estimator, was used to obtain cumulative incidence functions of sheep jumping. If they were to jump out of the pen, the sheep had two choices, a pipe rail fence (or gate) or a blank plywood wall. During 14 handling events, 1% of yearlings jumped the pipe rails whereas 7% jumped the plywood wall (P < 0.001). These yearlings chose to jump a fence they could not see through. Clearly there are many variables that could be tested in this model.