Litter size influences milk composition and energy expenditure of rat pups

Conference · Mon Feb 26 04:00:00 EST 1990 · FASEB Journal (Federation of American Societies for Experimental Biology); (United States)

OSTI ID:5686693

Fiorotto, M L; Burrin, D G; Perez, M; Reeds, P J ^[1]

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1. Baylor College of Medicine, Houston, TX (United States)

The authors wished to determine whether differences in milk intake were solely responsible for differences in the weight gain of rat pups suckled in litters of varying sizes (S = 4, C = 10, L = 16 pups/litter; 9 litters/group). Milk intake was measured (by {sup 3}H{sub 2}O dilution) at 4-6, 8-10, and 14-16 d of age (3 litters of each size/time point). Pup (water, protein, and fat) and milk composition (water, fat, protein and lactose) were analyzed at 6, 10, and 16 d. Dam milk output was positively correlated with litter size and duration of lactation. Milk fat concentration was inversely related to dam milk output (r{sup 2} = 0.79). Weight gain was highest in S litters and lowest in L litters. Weight gain was highly correlated to the volume of milk consumed in S and C pups (r{sup 2} = 81%), but was poorly correlated among L pups (r{sup 2} = 23%). The different correlations may have resulted from (1) the disparate relationship between volume and energy intake of L pups compared to S and C pups, or (2) a higher maintenance energy expenditure in L pups up to 10 d of age determined by a comparison of the composition of weight gain and energy intake. Thus, the reduced weight gain of pups suckled in large litters resulted from changes in both milk energy intake and the efficiency of its utilization.

• OSTI ID: 5686693
• Report Number(s): CONF-9004153--
• Conference Information: Journal Name: FASEB Journal (Federation of American Societies for Experimental Biology); (United States) Journal Volume: 4:3
• Country of Publication: United States
• Language: English

Related Subjects

550501* -- Metabolism-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMAL GROWTH
ANIMALS
BIOLOGICAL MATERIALS
BODY FLUIDS
CHEMICAL COMPOSITION
CORRELATIONS
DIET
FOOD
GROWTH
HYDROGEN COMPOUNDS
ISOTOPE APPLICATIONS
MAMMALS
MATERIALS
METABOLISM
MILK
NUTRITION
RATS
RODENTS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES
WEIGHT