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Intermittent fasting during winter and spring affects body composition and reproduction of a migratory duck

Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology

6153_Barboza.pdf
By:
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DOI: 10.1007/s00360-002-0267-y

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Abstract

We compared food intake, body mass and body composition of male and female black ducks (Anas rubripes) during winter (January-March). Birds were fed the same complete diet ad libitum on consecutive days each week without fasting (control; nine male; nine female) or with either short fasts (2 day.week-1; nine male; nine female), or long fasts (4 day.week-1; eleven male; twelve female). We continued treatments through spring (March-May) to measure the effect of intermittent fasts on body mass and egg production. Daily food intake of fasted birds was up to four times that of unfasted birds. Weekly food intake of males was similar among treatments (364 g.kg-1.week-1) but fasted females consumed more than unfasted females in January (363 g.kg-1.week-1 vs. 225 g.kg-1.week-1). Although both sexes lost 10-14% body mass, fasted females lost less mass and lipid than unfasted females during winter. Total body nitrogen was conserved over winter in both sexes even though the heart and spleen lost mass while the reproductive tract and liver gained mass. Intermittent fasting increased liver, intestinal tissue and digesta mass of females but not of males. Fasting delayed egg production in spring but did not affect size, fertility or hatching of the clutch. Females on long fasts were still heavier than controls after laying eggs. Thus black ducks combine flexibility of food intake with plasticity of digestive tract, liver and adipose tissue when food supply is interrupted during winter. Females modulate body mass for survival and defer reproduction when food supply is interrupted in spring.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Intermittent fasting during winter and spring affects body composition and reproduction of a migratory duck
Series title:
Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology
DOI:
10.1007/s00360-002-0267-y
Volume
172
Issue:
5
Year Published:
2002
Language:
English
Contributing office(s):
Patuxent Wildlife Research Center
Description:
419-434
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology
First page:
419
Last page:
434
Number of Pages:
16