Nannochloropsis oceanica, a novel natural source of rumen-protected eicosapentaenoic acid (EPA) for ruminants

Abstract

We hypothesize that whole microalga biomass is a natural rumen-protected source of eicosapentaenoic acid (EPA, 20:5n-3) for ruminants. To test our hypothesis, we studied the ruminal biohydrogenation of EPA from two microalgae, Nannochloropsis oceanica and Phaeodactylum tricornutum using in vitro incubations with rumen fluid. A total mixed ration was incubated with: no EPA (control), EPA as free-fatty acid, N. oceanica spray-dried (SD), N. oceanica freeze-dried (FD), or P. tricornutum FD. The kinetics of EPA disappearance and of products formed during the 24 hours of incubation were evaluated, and complemented by deuterated-EPA incubation. Results showed that EPA metabolism from the N. oceanica was remarkably reduced compared with the P. tricornutum and free-EPA, and this reduction was even more effective with the N. oceanica FD. Our data also indicates that neither feed dry matter disappearance nor rumen microbial markers (branched-chain fatty acids and dimethyl acetals) were affected by EPA-sources. We reported for the first time the kinetics of EPA biohydrogenation class products and the unequivocal formation of 20:0 from EPA. Overall, N. oceanica shows a strong potential to be used as a natural dietary source of EPA to ruminants, nevertheless further studies are needed to verify its protection in vivo.

Performance and Milk Composition of Nubian Goats as Affected by Increasing Level of Nannochloropsis oculata Microalgae

“…These results reveal that the two rates/doses of microalgae in the current assay fell within tolerable range, as previously noted with feed intake. Additionally, result of digestibility confirms the result of Alves et al [ 11 ] who reported that the UFA in N. oculata are in a protected form, which means that minimal ruminal biohydrogenation occurs to microalgae UFA and prevents their negative effects on ruminal microbiota. Otherwise, the increased nutrient digestibility indicates improved rumen microflora population/activity with the supplementation.…”

“…This makes them as options to improve ruminal fermentation and feed digestion [ 6 , 7 , 8 ], with high concentrations of docosahexaenoic acid (DHA) and conjugated linoleic acid (CLA) fatty acids in milk [ 6 , 9 ]. Moreover, some other microalgae are richly endowed with n-3 poly UFA, such as α-linolenic acid and eicosapentaenoic acid (EPA) [ 3 , 10 , 11 ]. Including microalgae in the diet of ruminants showed promising results [ 3 , 6 , 7 , 12 ].…”

“…Nannochloropsis is a rich source of rumen-protected EPA, DHA and CLA as well as all essential amino acids required for animal feed [ 6 , 10 , 13 ]. Alves et al [ 11 ] reported that Nannochloropsis is a natural dietary source of EPA for ruminants. Durmic et al [ 14 ] reported that Nannochloropsis contains EPA and DHA (21.5 and 3.2% fat, respectively).…”

Microalgae n-3 PUFAs Production and Use in Food and Feed Industries

“…As for humans, EPA and DHA have been credited with health benefits even when supplemented in small amounts, and can have positive effects on the improvement of the immune system, lipid metabolism, stress resistance, increase in appetite, enhancing reproductive performance, or even the reduction of cholesterol levels [ 231 ]. Nannochloropsis oceanica has been tested as a natural source of EPA for ruminants [ 232 ]. The algae’s thick cell walls protect the healthy compound from metabolization by rumen microbiota, inducing a full enrichment in the EPA for better ruminant development and health without inhibiting the growth and activity of rumen bacteria [ 232 ].…”

“…Nannochloropsis oceanica has been tested as a natural source of EPA for ruminants [ 232 ]. The algae’s thick cell walls protect the healthy compound from metabolization by rumen microbiota, inducing a full enrichment in the EPA for better ruminant development and health without inhibiting the growth and activity of rumen bacteria [ 232 ]. Providing n-3 PUFAs has a positively impact on atopic dermatitis, osteoarthritis, and the modulation of immunity indicators in dogs [ 233 ].…”