Studies in flock mating of sheep. 4. The relation of libido tests to subsequent service activity of young rams

Abstract

Seventy-five Merino rams, l 1/2 years old, were tested for libido in pens and were later observed while mating in flocks. The total number of services performed in three pen libido tests was the parameter most highly correlated with service frequency during flock mating. For the 58 rams that mounted ewes in the libido tests, the total number of services in the three tests was highly correlated with the number of services performed during the first three hours in flocks of 40 ewes containing only one ram (r56 = 0.853, P<0.001). Subsequently, pairs of rams were joined with flocks of 66 or 125 ewes. With these rams, the number of services in the pen libido tests was highly correlated with the number of services performed in three hours immediately after introduction of the rams (r20 = 0.717, P<0.001) or seven days later (r14 = 0.709). It is concluded that the number of services performed by young rams during a simple form of libido test could provide an indication of their subsequent service activity during flock mating.