RESUMEN
A comparison of conserving timothy/meadow fescue/meadow grass as silage or hay was conducted with Finnish Landrace ewes. Intake of hay (H), silage (S) and hay/silage (HS), and the performance of 30 Finnish Landrace ewes carrying twins, triplets and quadruplets and suckling either twin or triplet lambs was measured during the last 8 weeks of pregnancy and during the first 6 weeks of lactation. The dry matter (DM) intake of HS was lower (p<0.03) than H during lactation, whereas there was no difference in DM intake between pregnant and lactating ewes fed either H or S. The intake of metabolisable energy was on an average 12.8, 14.3 and 13.4MJperday in pregnancy, and 17.7, 20.2 and 18.1MJ in lactation for H, S and HS, respectively. Daily intakes of protein assessed in terms of amino acids absorbed in the small intestine (AAT) were on an average 92, 110 and 102g for H, S and HS during pregnancy and 157, 184 and 165g during lactation, respectively. Ewes in all treatments were, relative to calculated requirements, deficient in energy and protein during the last month of pregnancy and early lactation. Ewes performed consistently better when fed silage than hay. Lamb mortality was low for all treatments. The number of artificially reared lambs tended to be highest when ewes were fed both hay and silage ad libitum. Lamb growth was higher on S than H based diet (p<0.005). With respect to winter feeding of ewes, grass silage compared favourably with hay and indicated that hay could be replaced by well preserved grass silage. During late pregnancy and early lactation, there was no advantage of supplementing silage with hay, relative to entirely silage based diets.