Incorporation of dietary n-3 fatty acids into ovarian compartments in dairy cows and the effects on hormonal and behavioral patterns around estrus

摘要

The objective of this study was to examine the incorporation of dietary n-3 fatty acids (FAs) into ovarian compartments and the effects on hormonal and behavioral patterns around estrus. Multiparous 256-day pregnant cows were fed either a standard diet both prepartum and postpartum (PP) (control; n=22) or supplemented with extruded flaxseed (E-FLAX) providing C18:3n-3 at 172.2 and 402.5?g/day per cow prepartum and PP respectively (n=22). The estrous cycle was synchronized, and at day 7 of the cycle, the cows were injected with prostaglandin F2α (PGF2α) and then subjected to 5 days of intensive examination. Compared with those in the control, in the E-FLAX group, the interval from PGF2α injection to behavioral estrus peak tended to be longer (3.6?h; P<0.1), that to estradiol (E2) peak was 6.5?h longer (P<0.03), and that to LH peak tended to be longer (5.3?h; P 7?mm follicles were aspirated. The proportions of n-3 FA increased in plasma, FF, and granulosa cells in the E-FLAX group. The concentrations of PGE2 in the E2-active follicles tended to be lower in the E-FLAX cows (P<0.06). In conclusion, several modifications in hormonal and behavioral estrus patterns were demonstrated in cows fed n-3 FA, which might be attributed to alterations in membrane FA composition and partly mediated by lower PGE2 synthesis.