The effect of shearing pregnant ewes on lamb birth weights.

Shearing housed pregnant ewes at about the 11th week of pregnancy resulted in increased ewe liveweight gain (P greater than 0-01) and heavier twin litter weights (P greater than 0-01). The lambs from the shorn ewes also grew faster when put out to pasture. Unshorn pregnant ewes had a faster and more variable respiration rate, probably due to their being too hot in the prevailing conditions. The effect of this apparent heat stress on fetal nutrition is discussed.