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Supplementing Grazing Dairy Ewes with Plant‐Derived Oil and Rumen‐Protected EPA+DHA Pellets Enhances Health‐Beneficial n−3 Long‐Chain Polyunsaturated Fatty Acids in Sheep Milk

Author:
Nguyen, Quang V., Le, Van H., Nguyen, Don V., Malau‐Aduli, Bunmi S., Nichols, Peter D., Malau‐Aduli, Aduli E. O.
Source:
European journal of lipid science and technology 2018 v.120 no.6 pp. e1700256
ISSN:
1438-7697
Subject:
Carthamus tinctorius, canola, canola oil, dairy sheep, diet, docosahexaenoic acid, eicosapentaenoic acid, ewe milk, ewes, fatty acid composition, grazing, lactation, linseed, milk fatty acids, omega-3 fatty acids, pellets, rice bran, rumen, sires
Abstract:
This study investigates the impact of supplementing dairy ewes in mid lactation with rumen‐protected (RPO) pellets containing eicosapentaenoic acid (EPA, 20:5n−3) and docosahexaenoic acid (DHA, 22:6n−3) or pellets infused with 50 mL kg⁻¹ DM of either canola (CO), rice bran (RBO), flaxseed (FSO), or safflower (SFO) oils on enhancing the concentration of n−3 long‐chain (≥C₂₀) polyunsaturated fatty acids (n−3 LC‐PUFA) in milk. It is hypothesized that including these oils in the diet of grazing dairy ewes will improve milk fatty acid (FA) composition by increasing levels of n−3 LC‐PUFA. Sixty grazing dairy ewes balanced by sire breed and parity are randomly allocated to one of 6 treatments: 1) Control: commercial pellets without oil inclusion; 2) pellets containing 50 mL kg⁻¹ DM of CO; 3) RBO; 4) FSO; 5) SFO; and 6) RPO at the rate of 1 kg day⁻¹ for each ewe for 8 weeks. Weekly bulked daily milk FA analysis shows RPO has the most efficiency at elevating n−3 LC‐PUFA content by twofold, threefold, and fivefold greater concentrations of EPA, DPA, and DHA, respectively, than the control (0.17 vs 0.08%, 0.23 vs 0.08%, 0.19 vs 0.04%) (P < 0.0001). FSO improves levels of EPA (0.11%) and DPA (0.15%), while CO increases DPA (0.13%) (P < 0.0001). FSO and RPO reached the “source” and good “source” of n−3 LC‐PUFA (ΣEPA + DHA + DPA) contents of 35.1 and 61.7 mg 250 mL⁻¹, respectively. These findings recommend that rumen protected pellets containing EPA + DHA, flaxseed, and potentially canola oil supplements, can be used to improve the content of n−3 LC‐PUFA in dairy ewe milk. Practical Applications: The results promote the potential for production of premium quality and health‐beneficial fresh milk through dietary supplementation of grazing dairy ewes with plant‐derived oil and rumen‐protected EPA + DHA. Interactions between supplemented diets and week of supplementation on the concentrations of LA (a), ALA (b), EPA (c), DHA (d), and DPA (e) in milk.
Agid:
5959286