Hot topic: Enhancing omega-3 fatty acids in milk fat of dairy cows by using stearidonic acid-enriched soybean oil from genetically modified soybeans

Abstract

Very long chain n-3 fatty acids such as eicosapentaenoic acid (EPA; 20:5n-3) are important in human cardiac health and the prevention of chronic diseases, but food sources are limited. Stearidonic acid (SDA; 18:4n-3) is an n-3 fatty acid that humans are able to convert to EPA. In utilizing SDA-enhanced soybean oil (SBO) derived from genetically modified soybeans, our objectives were to examine the potential to increase the n-3 fatty acid content of milk fat and to determine the efficiency of SDA uptake from the digestive tract and transfer to milk fat. Three multiparous, rumen-fistulated Holstein cows were assigned randomly in a 3 x 3 Latin square design to the following treatments: 1) control (no oil infusion); 2) abomasal infusion of SDA-enhanced SBO (SDA-abo); and 3) ruminal infusion of SDA-enhanced SBO (SDA-rum). The SDA-enhanced SBO contained 27.1% SDA, 10.4% alpha-linolenic acid, and 7.2% gamma-linolenic acid. Oil infusions provided 57 g/d of SDA with equal amounts of oil infused into either the rumen or abomasum at 6-h intervals over a 7-d infusion period. Cow numbers were limited and no treatment differences were detected for DMI or milk production (22.9+/-0.5 kg/d and 32.3+/-0.9 kg/d, respectively; least squares means +/- SE), milk protein percentage and yield (3.24+/-0.04% and 1.03+/-0.02 kg/d), or lactose percentage and yield (4.88+/-0.05% and 1.55+/-0.05 kg/d). Treatment also had no effect on milk fat yield (1.36+/-0.03 kg/d), but milk fat percentage was lower for the SDA-rum treatment (4.04+/-0.04% vs. 4.30+/-0.04% for control and 4.41+/-0.05% for SDA-abo). The SDA-abo treatment increased n-3 fatty acids to 3.9% of total milk fatty acids, a value more than 5-fold greater than that for the control. Expressed as a percentage of total milk fatty acids, values (least squares means +/- SE) for the SDA-abo treatment were 1.55+/-0.03% for alpha-linolenic acid (18:3n-3), 1.86+/-0.02 for SDA, 0.23 +/- <0.01 for eicosatetraenoic acid (20:4n-3), and 0.18+/-0.01 for EPA. Transfer efficiency of SDA to milk fat represented 39.3% (range=36.8 to 41.9%) of the abomasally infused SDA and 47.3% (range=45.0 to 49.6%) when the n-3 fatty acids downstream from SDA were included. In contrast, transfer of ruminally infused SDA to milk fat averaged only 1.7% (range=1.3 to 2.1%), indicating extensive rumen biohydrogenation. Overall, results demonstrate the potential to use SDA-enhanced SBO from genetically modified soybeans combined with proper ruminal protection to achieve impressive increases in the milk fat content of SDA and other n-3 fatty acids that are beneficial for human health.

Browsing ratio, species intake, and milk fatty acid composition of goats foraging on alpine open grassland and grazable forestland

“…Comparable results have been repeatedly reported in the literature (among others, Kälber et al, 2011;Mancilla-Leytón et al, 2013) and may be ascribed to the low and step-decreasing efficiency of ALA metabolism to more unsaturated and long-chain members of the omega-3 FA family (Bernal-Santos et al, 2010). According to the lack of significant difference in LA concentration between OG and GF milk samples, long-chain omega-6 PUFA deriving from LA metabolism were also unaffected by the vegetation type fed by the goats.…”

Technical note: Stearidonic acid metabolism by mixed ruminal microorganisms in vitro1

“…Indeed, apparent biohydrogenation of SDA was extensive (Table 2), with more than 98.6% of incubated SDA being hydrogenated, yet it was not affected by its supplementation amounts (P > 0.05). Similarly, Bernal-Santos et al (2010) reported a very low SDA transfer to milk fat when SDA-rich soybean oil was infused in the rumen of multiparous Holstein cows to 2.50 g of SDA/kg of DM. Conversely, another study with lactating cows fed grass silage and cereal-based concentrate (60:40 forage-to-concentrate ratio) supplemented with fish oil was reported to reduce SDA biohydrogenation (58%; Shingfield et al, 2003).…”

“…Stearidonic acid (SDA; 18:4n-3) is a highly polyunsaturated n-3 fatty acid found in a small number of families of higher plants (mainly Boraginaceae and Primulaceae), with the richest sources known being echium oil (up to 15% SDA; Guil-Guerrero, 2007) and genetically modified oilseeds, such as SDA-enriched soybean oil (Bernal-Santos et al, 2010).…”

The effect of genetically modified maize (MON 810) and soyabean meal (Roundup Ready) on rearing performance and transfer of transgenic DNA to calf tissues

“…Flachowsky et al (2012) reported that changed fatty-acids patterns for soyabeans and derived feed can enrich soyabean oil in stearidonic acid (SDA-oil). It can be transferred into the body fat of lactating cows after duodenal infusion of SDA-soyabean oil (Bernal-Santos et al, 2010), or after feeding ruminal protected SDA-oil to dairy cows (Kitessa and Young, 2011).…”