0000000000133184
AUTHOR
Cristiano Boiti
Hormonal and metabolic adaptation to fasting: effects on the hypothalamic-pituitary-ovarianaxis and reproductive performance of rabbit does
To assess the impact of acute caloric shortage on reproduction, rabbit does were either fed ad libitum (control, AL), or fasted for 24 (STF) or 48 h (LTF) before induction of ovulation with GnRH injection. Blood samples were collected during the last 3 h of fasting, and the following 4 h after GnRH injection, when feed was provided again, to measure plasma concentrations of LH, estradiol-17β, leptin, insulin, T3, corticosterone, glucose, and NEFA. Before re-feeding, plasma leptin, insulin, and T3 concentrations were lower (P ≤ 0.01) in both fasted groups than in controls, but then gradually increased following realimentation to match those of controls. During fasting, corticoster…
Metabolic adaptations in neonatal mother-deprived rabbits
[EN] In order to study the metabolic adaptation in response to 48 h transient doe-litter separation (DLS) in young rabbits (5 rabbits/d group) between postnatal 9 and 11 d, plasma concentrations of thyroid hormones T3 and T4, insulin, leptin, glucose, triglycerides (TG), and free fatty acids (FFA) were examined before (6-8 d), during (9-11 d), and after separation (12-16 d). T3 concentrations in newborn control rabbits gradually increased from 0.6 ng/mL at postnatal 6 d to 1.0 ng/mL at postnatal 16 d, whereas those of T4 remained fairly constant (25 ng/mL) up to postnatal 14 d, when T4 gradually declined to 8 ng/mL. T3 values of DLS newborn rabbits did not differ from those of controls at p…
Parity and number of repeated doe-litter-separation treatments affect differently the reproductive performances of lactating does.
[EN] Using data from three different experiments, the effects of oestrus synchronisation by doe-litter separation (DLS), applied 48 hours befare artificial insemination from day 9 to day 11 post partum, on productive performance of free nursing rabbit does and their litters in relation to parity and number of successive DLS treatments were evaluated. lnitially, 200 New Zealand White does of different parity were homogeneously and definitively distributed in two groups (DLS and Control). On the whole, DLS improved fertility (+23.9%, Ps0.001 ), but reduced the growth of young rabbits from day 9 to weaning (-1.7 g/d, Ps0.01) and their weaning weight (-38 g, Ps0.01) at day 35. DLS also increase…
Neuroendocrine responses in neonatal mother-deprived rabbits.
To study both short- and long-term adaptation mechanisms activated by rabbits which were separated from their mothers (DLS) for 48 h between postnatal days 9 and 11, we examined plasma corticosterone concentrations before, during, and after DLS as well as the expression of glucocorticoid receptor (GR) in the hippocampus and the adrenal axis responses to a mild stress stimuli or exogenous ACTH injection. At postnatal day 10, plasma corticosterone concentration of DLS rabbits was similar to that of controls, but rose two-fold at day 11 (17.7 + or - 1.3 vs. 9.3 + or - 1.2 microg/dl, P0.01) and then decreased at day 12, when suckling was allowed again, to match those of controls with no differe…