Glucose and insulin metabolism in ruminating and veal calves fed high and low fat diets.
Holstein male calves were maintained on conventional (milk to 6 wk of age, fed grain and hay after weaning) and veal (milk replacer only) diets to 16 wk of age. Within each of these 2 physiological states (ruminating or non-ruminating), calves were fed low or high fat diets (ruminating: 3 and 10%; veal: 10 and 18%). Glucose tolerance tests were undertaken at 8 and 16 wk of age in each group. Basal concentrations (4 hr postfeeding) and areas under the response curves for plasma glucose and insulin were higher in veal calves (P < .0001). Ruminating calves fed higher fat utilized glucose more readily (smaller areas under the curves for both glucose and insulin, P < .10) than those fed lower fat. Age did not influence basal glucose concentrations (P > .10), but older calves had higher basal insulin (P < .0001) and greater areas under the curves (P < .0005) for both glucose and insulin after a glucose challenge. Rate of clearance (k) was greater in ruminating calves (P < .001). Though rate of clearance in veal calves was slower, larger plasma pool size caused veal calves on average to utilize glucose at a 15% greater rate per kg body weight than ruminating calves. Whereas fat concentration in the diets did not influence glucose metabolism in veal calves, the high lactose content (> 50% of diet dry matter) of veal diets induced severe insulin resistance in these calves.
Palmquist
D L
DL
Ohio Agricultural Research and Development Center, Ohio State University, Wooster 44691.
Doppenberg
J
J
Roehrig
K L
KL
Kinsey
D J
DJ
D000818:Animals; D000833:Animals, Suckling / Q000378:metabolism*; D002417:Cattle / Q000378:metabolism*; D004041:Dietary Fats / Q000494:pharmacology*; D005947:Glucose / Q000378:metabolism*; D005951:Glucose Tolerance Test / Q000662:veterinary; D007328:Insulin / Q000378:metabolism*; D008297:Male; D014886:Weaning
D004041:Dietary Fats; D007328:Insulin; D005947:Glucose