Effect of specific weight on the metabolizable energy content of four cultivars of wheat grain in ewes

To determine the effect of specific weight on the metabolizable energy value of wheat grain for ruminants, 16 samples of winter wheat grain, comprising four cultivars (Riband, Buster, Consort and Haven) each at four specific weights ranging from 60 to 78 kg/hl were fed in a pelleted concentrate (wheat=0.7 of total fresh weight) to housed mature sheep at the maintenance level of feeding. The concentrate comprised 0.6 of total daily dry matter (DM) intake, and chopped winter wheat straw comprised 0.4 of total daily DM intake. There was no effect of specific weight on apparent digestibility of whole-diet DM or on whole-diet estimated metabolizable energy (ME) concentration. There were no interactions between specific weight and cultivar in terms of apparent digestibility of whole-diet DM. Apparent digestibility of DM was lower (P<0.05) for Buster and Consort than for Riband and Haven. Estimated concentration of ME was lower (P<0.05) for Buster than for Riband and Haven. There is energetic flexibility in the use of winter wheat of different specific weights in diets for ruminants, since there is no relationship between specific weight and metabolizable energy content.