Effect of perinatal undernutrition in Merinos d’Arles ewes on physiology and reproductive function

Abstract : Maternal nutrition can affect postnatal growth and develop- ment of offspring. The aim of this study was to evaluate the long-term effects of maternal periconceptional undernutrition S12 Journal of Developmental Origins of Health and Disease, Volume 4, Supplement 1 (PCUN) in ewes on postnatal development of male lambs. A total of 52 Merinos d’Arles ewes were fed to requirements (control group, C), whereas 64 restricted (R) ewes received 50% of their dietary needs from 215 days to 130 days post conception. Thereafter, both groups were fed according to needs. Male offspring were weighed at birth and then weekly. They were weaned at 22 kg body weight (BW). Male lambs were raised until about 35 kg BW at commercial slaughter. Plasma leptin and cortisol concentrations were determined monthly. Organ weights were recorded at slaughter, and histological analysis was performed on testicles and adrenals. A total of 22 C and 34 R male lambs were obtained at lambing. Gestation was significantly longer in the nutrient- restricted group (P , 0.01).1 Birth weight and growth rate in all lambs was not significantly different between groups.1 Plasma leptin concentrations were significantly lower in R male lambs at birth (P , 0.001), increased gradually in both groups until 3 months and tended to be higher at 4 months in R group. There was a significant interaction between groups, age and litter size for basal cortisol concentrations: in singletons, cortisol was significantly lower in R at 3 months (P , 0.05) and tended to be higher at 4 months, whereas in twins, cortisol was significantly lower at birth (P , 0.05) but not thereafter. The ratios of carcass weight/BW and perirenal fat/BW were increased in R lambs. Adrenal on BW ratio tended to be higher in R lambs but adrenal corticomedullary ratio was not different between groups. There was no significant difference for adrenal and testicular tissue analyses. These results obtained in a hardy breed confirm the effects of PCUN on metabolic function but not on male reproductive development.