The influence of extruding corn grain on glucose metabolism in pregnant ewes

Glucose metabolism was studied in 31 pregnant ewes fed mixtures (50:50) of chopped alfalfa hay and corn grain given in whole (HWC) or extruded form (HEC). Number of fetuses was 1 (n = 10), 2 (n = 11) or 3 (n = 10). Diets were supplied at three dietary levels: maintenance (1.0 M), 1.25 x maintenance (1.25 M) or twice maintenance (2.0 M). Glucose metabolism was estimated by a double isotope dilution procedure at days 97-121 of pregnancy. Glucose entry rate (GER) was higher (P < 0.04), and glucose irreversible loss rate (GILR) tended to be higher (P < 0.07) in ewes given HEC than HWC. Dietary level (P < 0.001) and the number of fetuses (P < 0.005) affected GER and GILR positively. These results provide a probable explanation for higher birth weights previously found in lambs born to HEC-, compared with HWC-fed dams.