Incidence and frequency of intersucking were observed in heifers from a predominantly Simmental herd at the ages of 3, 9, 17 and 25 months, with samples of 48, 44, 45 and 30 heifers respectively. Except at the youngest age, the observations were made just before, and repeated not later than 24 hours after, transportation to another stall. There were 81% of heifers intersucking at 3 months, and from 53% to 57% at later ages. The transport had no effect on the incidence or frequency of intersucking. The intersucking heifers had no preferred target partners. With the exception of the oldest group, those heifers which performed intersucking were themselves more likely to be intersucked than those without intersucking activity. There was also a coincidence in time between acts of intersucking and being intersucked: from 25% to 57% of intersuckings were preceded or followed within 10 minutes by the animal which had performed the intersucking itself being intersucked. The results suggest that intersucking exists throughout ontogeny and that it is not influenced by disturbance. It is hypothesized that in intensively raised heifers, intersucking continues until adulthood because it is not stopped by the process of weaning, which in a natural situation would be accomplished by the mother's refusal to suckle. © 1992.
Špinka, M. (1992). Intersucking in dairy heifers during the first two years of life. Behavioural Processes, 28(1–2), 41–49. https://doi.org/10.1016/0376-6357(92)90047-H