title: Effect of flaxseed oil and microalgae DHA on the production performance, fatty acids and total lipids of egg yolk and plasma in laying hens.
abstract: The incorporation of omega-3 polyunsaturated fatty acids (PUFA) in the egg is dependent on both the transfer efficiency of preformed dietary omega-3 fatty acids to the eggs as well as endogenous PUFA metabolism and deposition. Employing an experimental design consisting of 70 Lohmann LSL-Classic hens (n=10/treatment) in a 6-week feeding trial, we examined the impact of graded levels of either flaxseed oil (alpha-linolenic acid, ALA) or algal DHA (preformed docosahexaenoic acid, DHA), each supplying 0.20%, 0.40% and 0.60% total omega-3s. The control diet was practically low in omega-3s. Study parameters included monitoring the changes of fatty acid contents in yolk, measures of hen performance, eggshell quality, total lipids and fatty acid contents of plasma. Data were analysed as a complete randomized design using Proc Mixed procedure of SAS. No significant differences were observed between treatments with respect to hen performance, eggshell quality and cholesterol content in plasma and egg yolk. Individual and total omega-3 PUFA in the yolk and plasma increased (P<0.0001) linearly as a function of total omega-3 PUFA intake. At the highest inclusion levels, DHA-fed hens incorporated 3-fold more DHA in eggs compared with ALA-fed hens (179±5.55 vs. 66.7±2.25mg/yolk, respectively). In both treatment groups, maximal enrichment of total n-3 PUFA was observed by week-2, declined by week-4 and leveled thereafter. In addition, accumulation of DHA in egg yolk showed linear (P<0.0001) and quadratic (P<0.05) effects for flaxseed oil (R2=0.89) and algal DHA (R2=0.95). The current data, based on defined level of total omega-3s in the background diet, provides evidence to suggest that exogenous as well as endogenous synthesis of DHA may be subject to a similar basis of regulation, and serve to highlight potential regulatory aspects explaining the limitations in the deposition of endogenously produced omega-3 LCPUFA.
authors.affiliation: Department of Animal Science, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Neijat
authors.affiliation: Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada.
authors.forename: O
authors.initials: O
authors.lastname: Ojekudo
authors.affiliation: Department of Animal Science, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada; Department of Human Nutritional Sciences, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada; Richardson Centre for Functional Foods and Nutraceuticals, University of Manitoba, Winnipeg, Manitoba R3T 2E1, Canada; Canadian Centre for Agri-Food Research in Health and Medicine, St. Boniface Research Centre, Winnipeg MB R2H 2A6, Canada. Electronic address: j_house@umanitoba.ca.
authors.forename: J D
authors.initials: JD
authors.lastname: House
mesh_terms: D000821:Animal Feed; D000818:Animals; D002645:Chickens; D019587:Dietary Supplements; D004281:Docosahexaenoic Acids / Q000008:administration & dosage*; D004530:Egg Yolk / Q000378:metabolism*; D015525:Fatty Acids, Omega-3 / Q000097:blood* / Q000378:metabolism; D005260:Female; D008043:Linseed Oil / Q000737:chemistry*; D050356:Lipid Metabolism; D058086:Microalgae / Q000737:chemistry*; D011897:Random Allocation; D017962:alpha-Linolenic Acid / Q000008:administration & dosage*
chemical_list: D015525:Fatty Acids, Omega-3; D017962:alpha-Linolenic Acid; D004281:Docosahexaenoic Acids; D008043:Linseed Oil
keywords: Egg yolk; Fatty acid profile; Flaxseed oil and algal DHA