title: Conjugated linoleic acid and fish oil in laying hen diets: effects on egg fatty acids, thiobarbituric acid reactive substances, and tocopherols during storage.
abstract: The effects of incorporating conjugated linoleic acid (CLA) and fish oil in laying hen diets on egg CLA, n-3 fatty acid, tocopherol, and TBA reactive substances (TBARS) during 60 d of storage were investigated. Hens were fed corn-soybean meal-based diets containing 3% yellow grease (YG), 2.75% yellow grease + 0.25% CLA (YG-CLA), 2.5% yellow grease + 0.25% CLA + 0.25% fish oil (YG-CLA-FO), or 2.75% yellow grease + 0.25% fish oil (YG-FO). Eggs were collected and stored at 4 degrees C up to 60 d. On storage d 0, 20, 40, and 60, eggs (n = 8) from each treatment were selected randomly, and tocopherol and TBARS contents were measured. Egg total lipid and fatty acids were determined on d 0 and 60 of storage. Feeding YG-CLA-FO led to a 5.4 and 7.7% reduction in egg total lipids on d 0 and 60 (P < 0.05) when compared with YG eggs. The YG-CLA and YG-CLA-FO diets led to a 12% increase in egg saturated fatty acids compared with YG eggs. The content of monounsaturated fatty acids were lower ( > 19%) in YG-CLA and YG-CLA-FO compared with YG. Egg n-3 was highest in YG-FO eggs and lowest in YG eggs (P < 0.0001). Storage over 60 d led to a 20 and 67% depletion of CLA in the YG-CLA and YG-CLA-FO eggs (P < 0.0001). A 29% reduction was observed in the total n-3 fatty acid content of YG-CLA-FO eggs at d 60 of storage when compared with d 0 of storage (P < 0.0001). Diet and storage increased TBARS (P < 0.0001), which was highest in YG-CLA eggs at 60 d of storage. The YG-CLA and YG-CLA-FO diets reduced alpha and gamma-tocopherol contents at all days of storage compared with YG eggs (P < 0.05). Regardless of diet, egg storage for 40 d or longer depleted egg tocopherol contents (P < 0.05). These data demonstrate that healthy eggs with increased n-3 fatty acids and CLA can be generated by minor diet modifications, but added tocopherol supplementation may be needed to reduce lipid peroxidation when n-3 or CLA is included in the hen diet.
authors: Department of Animal Sciences, Oregon State University, Corvallis 97331, USA. Gita.Cherian@oregonstate.edu
authors: G
authors: G
authors: Cherian
authors: M G
authors: MG
authors: Traber
authors: M P
authors: MP
authors: Goeger
authors: S W
authors: SW
authors: Leonard
mesh_terms: D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002645:Chickens / Q000502:physiology*; D004032:Diet / Q000662:veterinary; D004531:Eggs / Q000032:analysis*; D005227:Fatty Acids / Q000032:analysis* / Q000737:chemistry; D005260:Female; D005395:Fish Oils / Q000494:pharmacology*; D044243:Linoleic Acids, Conjugated / Q000494:pharmacology*; D010058:Oviposition / Q000502:physiology*; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis*; D013997:Time Factors; D024505:Tocopherols / Q000032:analysis*
chemical_list: D005227:Fatty Acids; D005395:Fish Oils; D044243:Linoleic Acids, Conjugated; D017392:Thiobarbituric Acid Reactive Substances; D024505:Tocopherols