The average time taken for sheep to traverse the maze (Fig. 3) was significantly (P < 0.001) different over the three ages tested. Compared to 41 weeks of age (Layout 1), average traverse times at 83 and 95 weeks of age were 84 and 62% slower, respectively. A different maze layout was used at 83 weeks of age (Layout 2) to that used at 41 weeks of age, and comparison of these two ages only, indicated a tendency (P = 0.082) for average traverse times to be longer at 83 weeks of age; an effect that was seen equally in both groups (Controls: 2.92 ± 0.29 vs. 3.47 ± 0.30 min; GnRHa-Rec: 2.96 ± 0.38 vs. 3.49 ± 0.26 min).