Genet. Sel. Evol.
Volume 34, Number 1, January-February 2002
|Page(s)||83 - 104|
Genet. Sel. Evol. 34 (2002) 83-104
Food resource allocation patterns in lactating females in a long-term selection experiment for litter size in miceWendy M. Rauwa, Pieter W. Knapb, Martinus W.A. Verstegenc and Petronella Luitingb
a rea de Producció Animal, Centre UdL-IRTA, Alcalde Rovira Roure, 177, 25198 Lleida, Spain
b PIC Deutschland GmbH, P.O. Box 1630, D-24826 Schleswig, Germany
c Animal Nutrition Group, Wageningen Institute of Animal Science, P.O. Box 338, 6700 AH Wageningen, The Netherlands
(Received 14 June 2000; accepted 25 July 2001)
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 ( ) than in Cns-litters ( ). 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.
Key words: mice / litter size / lactation / resource allocation / residual food intake
© INRA, EDP Sciences 2002