title: Food resource allocation patterns in lactating females in a long-term selection experiment for litter size in mice.
abstract: Resource allocation patterns, as quantified by residual food intake (RFI), and the consequences for offspring development were investigated during lactation in 96 females of a mouse line selected for 104 generations for high litter size at birth (S-line) and in 87 females of a non-selected control line (C-line). Litters of 45 C-line dams (Cs) and 48 S-line dams (Ss) were standardised (s) at birth; other dams (ns) supported total number of pups born (Cns and Sns, respectively). RFI during lactation was significantly lower in Sns-dams than in C-line dams and Sns-dams. After weaning Sns-dams seemed to be able to restore the negative resource situation. Sns-pups were about 25% less mature than Cns-pups at all times. Maturity was similar for Cs- and Ss-pups from 2 d in lactation on, and about 18% and 53% higher than Cns- and Sns-pups. The pre-weaning mortality rate was significantly higher in Sns-litters (35.6 +/-2.76) than in Cns-litters (4.95 +/-2.23). The results suggest that S-line dams allocated considerably more resources to maintenance of offspring than C-line dams. This was insufficient to provide the offspring with an adequate amount of resources, resulting in reduced pup development and increased pre-weaning mortality rates.
authors.affiliation: Area de Producció Animal, Centre UdL-IRTA, Alcalde Rovira Roure 177, 25198 Lleida, Spain. wendy.rauw@irta.es
authors.forename: Wendy M
authors.initials: WM
authors.lastname: Rauw
authors.forename: Pieter W
authors.initials: PW
authors.lastname: Knap
authors.forename: Martinus W A
authors.initials: MW
authors.lastname: Verstegen
authors.forename: Petronella
authors.initials: P
authors.lastname: Luiting
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D004435:Eating; D005260:Female; D007774:Lactation; D008098:Litter Size / Q000235:genetics*; D051379:Mice / Q000235:genetics / Q000254:growth & development*; D008815:Mice, Inbred Strains; D010375:Pedigree; D011247:Pregnancy; D012641:Selection, Genetic; D016019:Survival Analysis; D013997:Time Factors; D014886:Weaning; D015430:Weight Gain