The nutritive value of frosted wheat for sheep

The effect of frosting on the nutritive value of wheat grain was determined in a digestibility experiment with sheep. Thirty-six Merino wethers were m aintained on diets of lucerne chaff (30%) and whole wheat grain (70%) which was sourced from either severely frosted (SF), lightly frosted (LF) or unf rosted (UF) crops. The experiment was conducted in a repeated balance study with 8 replications per treatment diet for each of the 7 treatment diets, new animals were assigned to the chaff control (treatment diet 8). The diet s were offered at the liveweight maintenance level of feeding and the diges tibility of the wheat component was calculated by adjusting for the digesti bility of the lucerne component. Frosting had a relatively small effect on the nutritive value of wheat grain for sheep. Dry matter digestibility for UF, LF and SF wheats did not differ significantly (0.886, 0.854 and 0.839, respectively), although the SF wheat had a lower digestibility than the UF wheat at P< 0.10. The organic matter digestibility, digestible organic matt er in the dry matter and estimated metabolisable energy (ME) content were a ll significantly (P< 0.05) lower for SF compared with UF wheat grain (0.856 v. 0.908, 0.859 v. 0.915 and 13.5 v. 14.3 MJ/kg DM respectively). This stu dy demonstrated that wheat from the severely frosted wheat crop had a lower estimated ME content of about 1 MJ/kg DM (equivalent to about 6% less ME) than wheat from the unfrosted crop fed in this study. However, the resultan t ME of all samples fed fell within the normal observed ME range for wheat.