Characterization of the n-3 polyunsaturated fatty acid enrichment in laying hens fed an extruded flax enrichment source

Abstract

The time required to reach a plateau of n-3 polyunsaturated fatty acid (PUFA) concentration in plasma and egg yolk and dynamics of the enrichment process were examined in laying hens. A group of 75 Lohmann White Leghorn layers (65 wk) were fed one of 3 diets: control, moderate, or high n-3 PUFA-enriched diet for 18 d. Diets provided similar ME and CP and contained 0, 7.5%, or 15% LinPRO (source of n-3 PUFA), respectively. Prior to dietary treatment, baseline values were established for the BW, fatty acid composition in egg yolk on a whole-egg basis, and in plasma. These measurements were repeated at 6, 12, and 18 d of feeding. Enzymatic conversion rates of linolenic acid (LNA) to long-chain fatty acids were calculated. Data were analyzed with Proc Mixed of SAS, and broken stick analysis was used to determine n-3 PUFA plateau using the NLIN procedure of SAS (P < 0.05). The total egg yolk n-3 PUFA reached a plateau of 343.7 mg/egg and 272.9 mg/egg after 6.6 and 5.9 d on the high and moderate diets, respectively. In blood plasma, the n-3 PUFA concentrations reached saturation in 7.2 d with 0.93 mg/mL and 0.67 mg/mL on high and moderate diets, respectively. The transfer efficiency of total n-3 PUFA from the diet to the egg yolk was calculated as 55.6% in control birds, 30.5% in moderate birds, and 22.2% in high birds, demonstrating reduced transfer efficiency of n-3 PUFA as inclusion in the feed increases. Final egg yolk n-3 PUFA concentrations had a CV of 16.5% compared with 28.5% for plasma. After 12 d, the long-chain n-3 PUFA [eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA)] were significantly higher in egg yolk from hens on the moderate and high enriched diets compared with those from hens fed the control diet, whereas in plasma values did not differ. Broken stick analysis of egg enrichment indicated that high birds reached the target threshold of 300 mg of total n-3 PUFA/egg in 5 d. A significant increase in EPA, DPA, and DHA and reduction in arachidonic acid content in egg yolks from hens fed enriched diets compared with the control diet confirms competition for enzymes during postabsorptive modification of these fatty acids. This work contributes to the understanding of individual hen effects on n-3 PUFA absorption and the effect of level of dietary enrichment with an extruded flax product on final yolk n-3 PUFA concentration.

Dietary High‐Oleic Acid Soybean Oil Dose Dependently Attenuates Egg Yolk Content of n‐3 Polyunsaturated Fatty Acids in Laying Hens Fed Supplemental Flaxseed Oil

“…The reduced conversion/transfer efficiency of dietary ALA to yolk VLC n-3 PUFA (Fig. 4) with increasing levels of dietary FLAX confirmed a previous report (Nain, Renema, Korver, & Zuidhof, 2012) in laying hens fed an extruded flax product. The lower conversion of ALA to VLC n-3 PUFA with increased dietary ALA levels was hypothesized to be related to a saturation of activity of desaturase enzymes involved in ALA metabolism (Cachaldora et al, 2008).…”

Thymol feed supplementation in quail alters the percentages of nutritionally relevant egg yolk fatty acids: effects throughout incubation

“…Indeed, from the arachidonic/linoleic acid and docosahexaenoic/ -linolenic acid ratios in 0 day egg yolk, it is possible to roughly estimate the activity of desaturases and elongases. 42 As demonstrated by other authors, 20 supplementation with THY could allow greater bioavailability of the two precursors (linoleic and -linolenic acids) through increasing digestive enzyme activities and feed efficiency, leading to enhancements in docosahexaenoic and arachidonic acids as observed herein, without discarding the other hypothesis already mentioned.…”

Dynamics of omega‐3 long chain polyunsaturated fatty acid incorporation in egg yolk by autotrophic microalgal supplementation

“…A remarkable, somewhat unexpected observation was the slight decrease of the n‐3 LC‐PUFA content observed between days 14 and 25. The same reduction (in this case between days 12 and 18) was observed by Nain et al when supplementing extruded flaxseed in two doses (7.5 and 15%) to hens. The authors explained this little decrease of the n‐3 LC‐PUFA content in the eggs by a decrease of approximately 1 g of the yolk weight.…”