Reviewer Acknowledgment

Abstract

The present study was undertaken to analyze the maternal-offspring behavior during the neonatal period in St. Croix sheep and its possible effect on reproductive development. Two experiments were carried out. In experiment I, the behavior of 30 multiparous ewes and their single ram lambs was recorded from parturition until the lamb suckled for the first time. Lambs averaged 10.4 ± 1.1 minutes to stand and 13.1 ± 2.0 minutes to start suckling. In general, the perianal region was less licked than the head or trunk areas (1.5 ± 0.6 vs. 2.3 ± 0.4 and 3.2 ± 0.6 minutes; P < 0.05) in a nonrandom pattern. More (P < 0.05) ewes started licking the trunk of their lambs (67%) than the head 33%. In experiment II, 40 multiparous ewes and their single male lambs were randomly assigned to 1 of 4 groups: In the control group, ewes were allowed to interact with their lambs freely. In the NPAL group, the perianal area of the lamb was covered at the time of birth; in the NBL group, the trunk of the lamb was covered, and in the TMS group, licking was totally prevented by maternal separation. Licking activity was registered from parturition until the lamb suckled for the first time. These lambs were also evaluated for onset of puberty and sexual capacity. When one area of the lamb was covered, the time licking the uncovered areas increased, although the total licking time remained unaffected. Regardless of previous treatment, lambs reached puberty at 151.4 ± 5.0 days of age and had similar (P > 0.05) sexual capacities. It was concluded that (1) all areas of the lamb are licked before the first suckle; (2) if licking is prevented on some area of the body, the mother will compensate by increasing the licking of the other areas; (3) the partial or total prevention of licking activity before the first suckle has no effect on the age when puberty is reached and has no effect either in the sexual behavior displayed at the age of 1 year.