Respuesta hipofisaria y ovulatoria de conejas nulíparas alimentadas con dietas suplementadas con ácidos grasos poliinsaturados n-3

Abstract

Twenty rabbit does were fed ad libitum from 10 to 16 weeks of age two isofibrous, isoenergetic and isoproteic diets (n=10) supplemented with two different fat sources: 0.75% lard for diet C (control) or 1.5% of a supplement (Optomega-50; Optivite International Ltd., Spain) containing a 50% of EE and 38% of n-3 polyunsaturated fatty acids for diet P (PUFA n-3). Does feed intake, ovulation rate and plasma progesterone and LH concentrations at 0, 60 min, 5, 7 and 9 days post-induction of ovulation with 20 μg of Gonadorelina (Inducel-GnRH, Lab. Ovejero) at 16 weeks of age were assessed. Average daily intake (150.5 g/d), ovulation rate (95%), preovulatory peak of plasma LH (149.7±10.9 ng/ml ng/ml) and number of corpora lutea (9.8±0.7) were similar between dietary treatments. Plasma progesterone concentrations increased at 60 minutes (7.13±1.9 ng/ml) and 5 days (13.3±1.9 ng/ml) after induction with respect to day 0 (0.7±1.9 ng/ml; P<0.05), remaining constant afterward in both groups (19.4±1.9 ng/ml). Moreover, plasma progesterone of does fed diet P tended to be higher than for diet C on day 5 and 7 post-induction (16.6±1.9 vs.12.6±1.8 and 19.0±1.8 vs. 15.5±2.1 ng/ml, P=0.068 and P=0.082; respectively). Therefore, PUFA n-3 supplementation in does rabbit diets might be related with high progesterone levels and reduced early embryo mortality.