Assessment of the effects of feed restriction and amino acid supplementation on glucose tolerance in llamas

Christopher K. Cebra, Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331-4802.

Search for other papers by Christopher K. Cebra, in
Current site
Google Scholar
PubMed
Close
 VMD, MA, MS
,
Susan J. Tornquist Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331-4802.

Search for other papers by Susan J. Tornquist in
Current site
Google Scholar
PubMed
Close
 DVM, PhD
,
Rebecca M Jester Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331-4802.

Search for other papers by Rebecca M Jester in
Current site
Google Scholar
PubMed
Close
 BS
, and
Calogero Stelletta Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331-4802.
Present address is the Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Padua, Viale dell'Università 16, 35020 Agripolis, Legnaro (PD), Italy.

Search for other papers by Calogero Stelletta in
Current site
Google Scholar
PubMed
Close
 DVM

Abstract

Objective—To assess the effects of prolonged feed deprivation on glucose tolerance, insulin secretion, and lipid homeostasis in llamas.

Animals—9 adult female llamas.

Procedure—On each of 2 consecutive days, food was withheld from the llamas for 8 hours. Blood samples were collected before and 5, 15, 30, 45, 60, 120, and 240 minutes after IV injection of dextrose (0.5 g/kg) for determination of plasma insulin and serum glucose, triglyceride, and nonesterified fatty acid concentrations. Between experimental periods, the llamas received supplemental amino acids IV (185 mg/kg in solution). The llamas were then fed a limited diet (grass hay, 0.25% of body weight daily) for 23 days, after which the experimental procedures were repeated.

Results—Feed restriction decreased glucose tolerance and had slight effects on insulin secretion in llamas. Basal lipid fractions were higher after feed restriction, but dextrose administration resulted in similar reductions in serum lipid concentrations with and without feed restriction. Insulin secretion was decreased on the second day of each study period, which lessened reduction of serum lipid concentrations but did not affect glucose tolerance.

Conclusions and Clinical Relevance—Despite having a comparatively competent pancreatic response, feed-restricted llamas assimilated dextrose via an IV bolus more slowly than did llamas on full rations. However, repeated administration of dextrose reduced insulin secretion and could promote hyperglycemia and fat mobilization. These findings suggested that veterinarians should use alternative methods of supplying energy to camelids with long-term reduced feed intake or consider administering agents to improve the assimilation of glucose. ( Am J Vet Res 2004;65:996–1001)

Abstract

Objective—To assess the effects of prolonged feed deprivation on glucose tolerance, insulin secretion, and lipid homeostasis in llamas.

Animals—9 adult female llamas.

Procedure—On each of 2 consecutive days, food was withheld from the llamas for 8 hours. Blood samples were collected before and 5, 15, 30, 45, 60, 120, and 240 minutes after IV injection of dextrose (0.5 g/kg) for determination of plasma insulin and serum glucose, triglyceride, and nonesterified fatty acid concentrations. Between experimental periods, the llamas received supplemental amino acids IV (185 mg/kg in solution). The llamas were then fed a limited diet (grass hay, 0.25% of body weight daily) for 23 days, after which the experimental procedures were repeated.

Results—Feed restriction decreased glucose tolerance and had slight effects on insulin secretion in llamas. Basal lipid fractions were higher after feed restriction, but dextrose administration resulted in similar reductions in serum lipid concentrations with and without feed restriction. Insulin secretion was decreased on the second day of each study period, which lessened reduction of serum lipid concentrations but did not affect glucose tolerance.

Conclusions and Clinical Relevance—Despite having a comparatively competent pancreatic response, feed-restricted llamas assimilated dextrose via an IV bolus more slowly than did llamas on full rations. However, repeated administration of dextrose reduced insulin secretion and could promote hyperglycemia and fat mobilization. These findings suggested that veterinarians should use alternative methods of supplying energy to camelids with long-term reduced feed intake or consider administering agents to improve the assimilation of glucose. ( Am J Vet Res 2004;65:996–1001)

Advertisement