Abstract :
The three experiments investigated the effects on physiology and production parameters
of Corriedale ewes shorn in mid pregnancy, either using the cover or “R13” combs or leaving
them unshorn. The experiments utilised both ewes and hoggets. In both experiments,
the R13 comb left a greater stubble depth than the cover comb (P < 0.05). The rectal post
shearing temperature of ewes shorn either by the traditional cover or by R13 comb was
lower than that of unshorn ewes (P < 0.05), but between combs did not differ from each
other (P > 0.05). Shearing treatment had no effect on ewe live weight (P > 0.05) and only a
transitory (P < 0.05) effect on ewe body condition score was observed on some occasions. In
general, mid-pregnancy shearing increased lamb birth weight (P < 0.05). In one out of three
experiments, birth weight was increased by the R13 compared to the cover comb (P > 0.05).
Therefore, under the extensive grazing situations of Uruguay, shearing Corriedale ewes in
mid-pregnancy, is a management tool that does not increase lamb birth weight and weaning
weight consistently.
