A diet supplemented with n-3 polyunsaturated fatty acids influences the metabolic and endocrine response of rabbit does and their offspring

Abstract

The aim of the present study was to evaluate the productive, endocrine, and metabolic responses as well as oxidative stress of rabbit does and their offspring when fed a diet supplemented with n-3 PUFA during their first productive cycle. To this aim, a total of 105 rabbit does were fed ad libitum from d 60 to 172 of age 2 isoenergetic and isoproteic diets differing in fatty acid composition. The control diet (n = 52 does) contained 45.9 g/kg of n-3 of the total fatty acids and the enriched diet (n = 53 does) contained 149.2 g/kg of n-3 of the total fatty acids. Both experimental groups had similar feed intake during rearing, pregnancy, and lactation. The enrichment of diet had no effect on ultrasonographic assessment of does on d 9 and 16 of pregnancy, with an embryonic vesicle number and fetus and placenta size similar between groups (P > 0.05). Even though there were no major effects (P > 0.05) on fertility, duration of gestation, and number born alive and stillborn kits at parturition, live kits from enriched does were longer (71.6 ± 2.42 vs. 79.5 ± 2.13 mm; P < 0.05) and tended to be heavier (42.5 ± 3.94 vs. 50.8 ± 3.47 g; P = 0.07) than those from control does (P < 0.05). The 2 groups had similar milk production and mortality values during lactation; consequently, there were no differences between diets in ADG, litter weight, and number of weaned kits (P > 0.05). In enriched does, higher plasma leptin and estradiol concentrations than in control does (P < 0.05) were observed. In addition, enriched females also had lower total and high-density lipoprotein cholesterol (HDL-c) than control females during lactation (P < 0.05). Regarding offspring, the enrichment of diet with PUFA caused a hyperlipidemic status (greater values of plasma triglycerides, total cholesterol, and HDL-c; P < 0.05) at 1 d postpartum (dpp), compared with the control group, that disappeared at 32 dpp. Supplemented does before parturition and their offspring at 1 dpp had greater oxidative stress than those in the control group. In conclusion, an increase of n-3 PUFA concentration in the diet of rabbit does and, consequently, of their offspring during a productive cycle alters their lipid profile and the indicators of oxidative stress, without major endocrine modifications or improvements in the productive variables.