QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Mowrey, R. A. Articles by Hershberger, T. V. Search for Related Content PubMed PubMed Citation Articles by Mowrey, R. A., Jr. Articles by Hershberger, T. V.

Effect of Age and Body Weight on the Maintenance Requirement of Lean and Obese Zucker Rats^1,2,

Department of Dairy and Animal Science, The Pennsylvania State University, University Park, PA 16802

The effect of age (34–215 days) and body weight (80–627 g) on the maintenance requirements of lean (n = 4) and obese (n = 4) Zucker rats was determined in 5 maintenance trials. The rats were fed a semipurified, 20% protein diet. The metabolizable energy intake (MEI) required for maintenance of body weight (BW) was determined in weekly intake-metabolism trials. Maintenance requirements [kilocalories MEI/(day·kilogram BW)] were lower (P < 0.01) for obese rats than for lean rats, and they decreased with age for both body types, respectively (Y = 206.23 - 0.3524 X; r = -0.547 and Y = 252.61 -0.4818 X; r = -0.649). Maintenance requirements (kilocalories MEI/day) of obese rats were lower (P < 0.01) than lean rats, respectively, when expressed in terms of grams body weight (Y = 7.03 + 0.1333 X; r = 0.994 and Y = 9.04 + 0.1441 X; r = 0.994), metabolic body size (kilogram^0.75) (Y = -4.52 + 132.33 X; r = 0.989 and Y = 0.05 + 130.52 X; r = 0.992) or least squares, type-specific exponent [Y = 119.03 (kilogram^0.77); r = 0.975 and Y = 120.87 (kilogram^0.71); r = 0.986]. The results indicate that obese Zucker rats have lower maintenance requirements than their lean littermates and that maintenance requirements are as closely related to body weight as to metabolic body size or type-specific exponent for each body type.

KEY WORDS: • maintenance requirement • Zucker rat • voluntary activity • metabolic body size

¹ Authorized for publication as paper no. 6019 in the journal series of the Pennsylvania Agricultural Experiment Station.

² Supported by National Institutes of Health Grant No. 7090.

³ Current address is Department of Animal Science, North Carolina State University, Raleigh, NC 27650.

⁴ To whom reprint requests should be addressed.

Manuscript received 3 May 1982.