Effect of supplementation with fish oil or microalgae on fatty acid composition of milk from cows managed in confinement or pasture systems

Abstract

The objective of this study was to examine the interaction between lipid supplement (LS) and management system (MS) on fatty acid (FA) composition of milk that could affect its healthfulness as a human food. Forty-eight prepartal Holstein cows were blocked by parity and predicted calving date and deployed across pasture (PAS; n=23) or confinement (CONF; n=25) systems. Cows within each system were assigned randomly to a control (no marine oil supplement) or to 1 of 2 isolipidic (200 g/d) marine oil supplements: fish oil (FO) or microalgae (MA) for 125 ± 5 d starting 30 d precalving. The experiment was conducted as a split-plot design, with MS being the whole-plot treatment and LS as the subplot treatment. Cows were housed in a tie-stall barn from -30 until 28 ± 10 d in milk (DIM) and were fed total mixed rations with similar formulations. The PAS group was then adapted to pasture and rotationally grazed on a perennial sward until the end of the experiment (95 ± 5 DIM). Milk samples were collected at 60 and 90 DIM for major components and FA analyses. Milk yield (kg/d) was lower in PAS (34.0) compared with CONF (40.1) cows. Milk fat percentage was reduced with MA compared with FO (3.00 vs. 3.40) and the control (3.56) cows. However, milk fat yield (kg/d) was not affected by lipid supplements. Compared with CONF, PAS cows produced milk fat with a lower content of 12:0 (-38%), 14:0 (-28%), and 16:0 (-17%), and more cis-9 18:1 (+32%), 18:3 n-3 (+30%), conjugated linoleic acid (CLA; +70%) and trans 18:1 (+34%). Both supplements, regardless of MS, reduced similarly the milk fat content of 16:0 (-12%) and increased CLA (+28%) and n-3 long-chain polyunsaturated FA (n-3 LC-PUFA; +150%). Milk fat content of trans 18:1 (trans-6 to trans-16) was increased with FO or MA, although the effect was greater with MA (+81%) than with FO (+42%). The interaction between MS and LS was significant only for trans-11 18:1 (vaccenic acid, VA) and cis-9,trans-11 CLA (rumenic acid). In contrast to CONF, feeding FO or MA to PAS cows did not increase milk fat content of VA and rumenic acid. We concluded that compared with CONF, milk from PAS cows had a more healthful FA composition. Feeding either FO or MA improved n-3 long-chain polyunsaturated FA and reduced levels of 16:0 in milk fat, regardless of MS, but concurrently increased the trans 18:1 isomers other than VA, at the expense of VA, particularly in grazing cows.

Variability in nutrient composition and in vitro crude protein digestibility of 16 microalgae products

“…Accordingly, both genera are rich sources of omega‐3 fatty acids. As long‐chain PUFA from microalgae are enriched in milk (Glover et al., ; Vahmani, Fredeen, & Glover, ) or eggs (Bruneel et al., ; Fredriksson, Elwinger, & Pickova, ; Lemahieu et al., ), Phaeodactylum and Nannochloropsis may be direct or indirect sources for omeg‐3 fatty acids for human nutrition, when fed to cows and laying hens. C16:0 and C16:1 n‐7 were present in major concentrations (about 20% of the total fatty acids) in Nannochloropsis and Phaeodactylum products.…”

“…Accordingly, both genera are rich sources of omega-3 fatty acids. As long-chain PUFA from microalgae are enriched in milk (Glover et al, 2012;Vahmani, Fredeen, & Glover, 2013) or eggs Fredriksson, Elwinger, & Pickova, 2006;Lemahieu et al, 2013), Phaeodactylum and Nannochloropsis may be direct or indirect sources for omeg-3 fatty acids for human nutrition, when fed to cows and laying hens.…”

Effects of feeding steers extruded flaxseed on its own before hay or mixed with hay on animal performance, carcass quality, and meat and hamburger fatty acid composition

“…These fatty acids mainly originate from de novo fatty acid synthesis in adipose tissue (Nafikov & Beitz, 2007) and their synthesis might have been inhibited by ALA and its BHI (Vahmani, Fredeen, & Glover, 2013). Alternatively, the increased levels of ALA and its BHI (preformed fatty acids) in perirenal fat might have diluted the content of de novo synthesized fatty acids (i.e.…”

Lipid-Encapsulated Echium Oil (Echium plantagineum) Increases the Content of Stearidonic Acid in Plasma Lipid Fractions and Milk Fat of Dairy Cows

“…8,9 There are several challenges, however, when supplementing dairy cows with oils rich in polyunsaturated FA (PUFA). One is the extensive biohydrogenation of dietary unsaturated FA by rumen bacteria, which often exceeds 85%.…”