Cleal, J.K., Poore, K.R., Newman, J.P., Noakes, D., Hanson, M.A. and Green, L.R.
Sex and twinning influence early gestation undernutrition effects on sheep offspring growth
Early Human Development, 82, (8), . (doi:10.1016/j.earlhumdev.2006.06.003).
Full text not available from this repository.
Objectives: Multiple pregnancy affects size at birth and
growth pattern from as early as 8 weeks gestation (Iffy et
al., 1983. Am. J. Obstet. Gynecol. 146, 970—972). Male
embryos grow at a greater rate than females (Pedersen,
1980. Br. Med. J. 281, 1253). We hypothesised that
moderate maternal undernutrion in early gestation will
have a greater effect on male offspring growth, particularly
if combined with the increased constraint of being a twin.
Methods: Welsh Mountain ewes received 100% (C, n =41) or
50% nutrient requirements (U, n =47) from 1 to 31 days
gestation (dGA), and 100% thereafter. Ewes were weighed
weekly and blood samples were collected at 1, 30, and 65
dGA for cortisol analysis (Immulite analyser, DPC).
Results: At day 31, U ewes had gained less weight than C
ewes and had a lower plasma cortisol concentration
( p b0.05). During 1—31 dGA, twin bearing ewes gained less
weight than singleton bearing ewes. At birth, twins were
smaller than singleton lambs ( p b0.05). Weight gained
between birth and 12 weeks old and weight at 12 weeks
old were greater in U males compared to C males, an effect
that was predominantly in twins ( p b0.01). Data were
analysed by ANOVA.
Conclusion: The increased constraint of being a twin and a
male embryo in a nutrient-restricted intrauterine environment
induces a phenotype more likely to gain weight in a
good postnatal environment.
Supported by the British Heart Foundation.
Actions (login required)