The effects of offering a concentrate or grass silage based diet to single, twin and triplet-bearing ewes in late pregnancy on ewe performance

Abstract

The nutrient requirements of ewes increase greatly during the final two months of gestation as a result of the rapid foetal growth (Robinson, 1990). Traditionally these nutritional requirements were met by feeding grass silage supplemented with concentrates (Sheehan et al., 1979). Intakes of silage by sheep are variable, dependant on a range of factors with silage digestibility of major importance (Sheehan, 1975). However, voluntary silage intakes have been reported to vary irrespective of quality (Sheehan and Fitzgerald, 1977). Alternatively, the energy requirements of the ewe during late pregnancy can be supplied by offering a complete concentrate diet (Sheehan, 1975). The objectives of this experiment were to compare the performance of single, twin and triplet-bearing ewes when offered either a concentrate diet or a silage based diet supplemented with concentrates, each offered at 90% of metabolizable energy requirements for maintenance and conceptus growth.