Published online by Cambridge University Press: 22 November 2017
On the basis of experimental results, Forbes, Rees and Boas (1967) recommended that silage for pregnant ewes should have a DM content of at least 200 g/kg. Higher silage intakes and improved animal performance may be achieved by feeding silage of DM content in excess of this level.
Increases in lamb birth weight have been achieved with additional protein supplementation to ewes on hay based rations in late pregnancy (Clark and Speedy, 1981). The response to protein supplementation on silage based diets is less well documented.
In a 3 x 2 factorial experiment, 23A Border Leicester x Welsh Mountain in-lamb ewes, penned in groups of 18 or 21,were offered either an unwilted silage 199 g DM/kg) made with a formalin/formic acid additive (UA); a wilted, silage (287 g DM/kg) made with additive (WA) or a wilted silage (272 g DM/kg) made without additive (WO). The silages were offered ad-libitum from housing in January until lambing in mid-March.