Long term dietary supplementation with microalgae increases plasma docosahexaenoic acid in milk and plasma but does not affect plasma 13,14-dihydro-15-keto PGF_2α concentration in dairy cows

Abstract

The aims of the study were to determine the long-term effects of dietary supplementation with microalgae (SCIM) on milk and blood fatty acid (FA) composition and reproductive hormones in early lactation dairy cows. Sixty Holstein–Friesian dairy cows (30 per treatment) were unsupplemented (Control) or supplemented with 100 g of SCIM (Schizochytrium limacinum sp.) per cow per day from 25 ± 0.5 d post-partum for 98 d. Intake and milk yield were recorded daily, with milk samples collected at weeks 0, 1, 2, 4, 8 and 14, and blood samples collected from 12 representative pairs per treatment at weeks 0, 2, 4, 8, and 14 for subsequent analysis of FA, β-hydroxybutyrate, non-esterified fatty acids and glucose. At 33 ± 0.9 d postpartum the oestrus cycle of 24 cows (12 per treatment) were synchronized and plasma 13,14-dihydro-15-keto PGF2α (PGFM) concentrations determined following an oxytocin challenge. Data were analysed by repeated measures analysis of variance. There was no effect of treatment on dry matter intake, milk yield or milk fat content, with mean values across treatments of 22.1 and 40.6, and 37.2 g/kg respectively. Milk fat concentration of C22:6 n-3 increased rapidly in cows receiving SCIM, reaching a maximum of 0.38 g/100 g FA by week 14. Similarly, blood concentration of C22:6 n-3 increased to 1.6 g/100 g FA by week 14 in cows fed SCIM. There was no effect of treatment on plasma metabolites, but plasma glucose was lower in cows fed SCIM compared to the Control at week 2, and higher in week 8. There was no effect of treatment on peak plasma PGFM concentration or area under the curve. It is concluded that feeding SCIM rapidly increases blood and milk concentrations of C22:6 n-3 which are maintained over time, but does not improve plasma PGFM in dairy cows.

Dietary strategies to enrich milk with healthy fatty acids – A review

“…However, Lum et al (2013), in their review, stated that feeding of defatted microalgae biomass to dairy cows increased the DHA and EPA and decreased the SFA concentrations in milk. Till et al (2020) noted that supplementation of dairy cow diet with Schizochytrium limacinum microalgae increased milk fat content of C22:6n-3, total PUFA, and total n-3 PUFA but reduced n-6/n-3 PUFA ratio.…”

“…Inclusion of full-fat, defatted, or microalgal oil to alter the profile of FA in milk has been investigated (Toral et al, 2010;Glover et al, 2012;Kholif et al, 2017b;Till et al, 2020).…”

Microalgae: Potential for Bioeconomy in Food Systems

“…In ruminants, food supplementation with meal or oil from some species of microalgae has been explored [51,61,62]. As a result, improved organoleptic properties and fatty acid composition of meat and milk were observed in bovines [63][64][65]. Microalgae, such as A. platensis, were shown to be a good replacement for plant supplements, and improving the quality of milk [66].…”

Transfer Rates of Docosahexaenoic and Eicosapentaenoic Acids into Cow's Milk in Pasture Based and Feed‐Lot Management Systems

“…Ruminant derived foods are major components of the diet of many consumers, thus there is on‐going research to increase the N‐3 and N‐6 fatty acid content of dairy and meat product(s). [ 1,6–15 ] Grazing ruminants ingest significant quantities of N‐3 C18:3 as this is the most abundant fatty acids in the lipid of pasture. This unsaturated fatty acid is hydrogenated by rumen micro‐organisms to stearic acid (C18:0) and oleic acid (C18:1) cis, trans isomers; likewise in lot‐fed animals the major fatty acids in grain is N‐6 C18:2 and it is also bio‐hydrogenated; [ 16,17 ] thus, ruminant derived foods have low levels of C18:2 and C18:3.…”

“…Many different forms of dietary inert marine fat supplements have been developed for dairy cows, including calcium salts, encapsulated oil‐protein supplements, extruded oil seeds, prilled‐fats, esters, and micro‐algae to increase the transfer of DHA/EPA into milk fat. [ 9–11 – 15,20–26 ] However, reduced milk fat% and increased trans fatty acids occur particularly when supplements containing C20 and C22 polyenoic fatty acids with a low level of inertness are fed to dairy cows. For example, feeding a micro‐alga (DHA Gold) and other marine algae [ 13,14,21,22 ] as the primary source of DHA, trans10 C18:1 increased from 1.4% to 4.6%; while milk fat was reduced from 3.6% to 1.8% and the transfer of DHA in algae varied from 3.0% to 18.0%.…”