Plasma Fatty Acid Profile of Gestating Ewes Supplemented with Fishmeal

Abstract

Problem statement: The very long chain n-3 polyunsaturated fatty acids (>18C) cannot be adequately synthesized by ruminant tissues to meet their requirements; therefore, their concentration in body depends on the supply through feed. It may be possible to improve the essential fatty acid status of ruminant animals, during gestation by manipulating the maternal diet with Fishmeal (FM). The objectives of this research were to (1) determine the effect of fishmeal supplementation on the plasma fatty acid profile of ewes during late gestation and (2) determine the status of the plasma docosahexaenoic acid (22:6n3) of lambs born to these ewes. Approach: Eight gestating ewes [Rideau-Arcott, 97±5 kg initial body weight, 100 days of gestation] were used in a completely randomized design. Ewes were individually-housed and fed either a control diet (supplemented with soybean meal) or a fishmeal supplemented diet. Blood samples were collected via jugular venipuncture for plasma fatty acids analysis on 100, 114, 128 and 142 days of gestation after morning feeding. Blood samples from the lambs were also collected via jugular venipuncture immediately after birth and before receiving their mothers’ colostrum. Plasma fatty acids were analyzed by gas-liquid chromatography. Results: The ewes from both groups, i.e., control and fishmeal supplemented, had a similar fatty acid profile prior to supplementation (at 100 days, p>0.05). Thereafter, there was an increase in eicosapentaenoic acid (20:5n3), docosahexaenoic acid, total n3-PUFA and total very long chain n3-PUFA (>C18) contents in plasma for the fishmeal supplemented ewes compared to the control (p<0.03). There were no differences (p>0.05) in total saturated fatty acids, total monounsaturated fatty acids, total conjugated linoleic acid, total trans-18:1, total cis-18:1, or total n6-PUFA contents in ewe plasma between control and fishmeal supplemented groups. Lambs born to ewes fed the fishmeal supplemented diet had greater (p<0.05) plasma concentrations of eicosapentaenoic acid (0.7 Vs 0.4, g/100 g FA), docosahexaenoic acid (1.6 Vs 0.9, g/100 g FA) and total very long chain n3-PUFA (3.3 vs. 2.0, g/100 g FA) than lambs born to ewes fed the control diet. Conclusion: The ewes supplemented with fishmeal supplementation showed a positive response with the enrichment of docosahexaenoic acid, eicosapentaenoic acid and total very long chain n3-PUFA in plasma during gestation and these fatty acids were transferred to the fetus as well.