Pregnancy shearing of mature ewes has been shown to influence lamb birthweight and sometimes lamb survival to weaning and wool follicle characteristics. However, the effects of shearing hoggets in mid- or late-pregnancy under New Zealand’s pastoral conditions have not been examined. This study was designed to determine the effects of mid- and late-pregnancy shearing on lambs born to Romney hoggets. Single-bearing hoggets were either shorn at average day 79 of pregnancy (n = 74), at average day 119 (n = 80), or left unshorn (n = 76) while their twin-bearing counterparts were either shorn at average day 79 of pregnancy (n = 18) or left unshorn (n = 12).

Mid-pregnancy shearing was found to increase the birthweights of singles (by 0.32 kg, P < 0.05) in comparison with unshorn ewes; however, this relationship was not observed in twins. Neither mid- nor late-pregnancy shearing affected lamb survival to weaning. Singles born to late-pregnancy shorn ewes had whiter wool (P < 0.05) in comparison with lambs born to unshorn dams. Dam treatment had no other effects on follicle or wool characteristics.

The results of this study indicate that mid-pregnancy shearing of hoggets can be used as a technique to increase birthweight in single lambs but not twin-born lambs. Pregnancy shearing had no effect on lamb survival rates to weaning, whereas shearing in late-pregnancy had minor effects on wool colour that would be unlikely to affect wool value in Romneys. Shearing in mid-pregnancy had no effect on either progeny follicle or wool characteristics.