title: Blood and tissue fatty acid compositions, lipoprotein levels, performance and meat flavor of broilers fed fish oil: changes in the pre- and post-withdrawal design.
abstract: Administration of fish oil (FO) in broiler diets can elevate α-linolenic acid (ALA), eicosapentanoic acid (EPA) and docosahexanoic acid (DHA) levels, which are protective against cardiovascular disease. However, optimization based solely on n-3 polyunsaturated fatty acid (n-3 PUFA) enrichment in chicken meat could lead to lower meat quality, unless the withdrawal period (plan) is applied for 1 week. The present study investigated whether the incorporation of FO in the diet for 32 days followed by its withdrawal for 1 week affected blood lipid profiles, lipoprotein particles, performance and meat flavor in male broiler chickens. Two hundred and forty birds (1-day-old, Ross 308) were assigned to 1 of 4 dietary groups: 0%, 1%, 2% or 3% FO with four replicates. Broilers were fed for 49 days according to a 4-phase feeding program. The experimental phase comprised day 11 to 42, and FO was removed on day 42. Blood samples were collected during the pre- and post-withdrawal period after the recordings before slaughter. The FO groups demonstrated decreased low-density lipoprotein (LDL) and increased high-density lipoprotein levels on day 42 (P < 0.01); however, these values were not significant after design withdrawal. Diet supplementation with FO elevated the blood levels of palmitic acid (C16:0) and n-3 PUFAs, especially long-chain (LC) PUFAs (EPA, C20:5n-3 and DHA, C22:6n-3), and caused a decline in the level of arachidonic acid (AA, C20:4n-6; P < 0.05). Application of a one-week withdrawal period resulted in a decrease in (P < 0.05) linoleic acid (C18:2n-6) and an increase in the level of AA, unlike their amounts on day 42. Although blood and tissue LC n-3 PUFA levels on day 49 were significantly higher in the FO groups compared with the control, they demonstrated a substantial decrease on day 49 compared with day 42. The best results, mainly the lowest n-6/n-3 fatty acids (FAs) and feed conversion ratio (FCRs), were observed for 3% FO (group T4), even after institution of the withdrawal design. Degradation of total n-3 FAs deposited in tissues occurred after instituting the withdrawal plan diet, but deposited levels of EPA and DHA in tissues could ensure omega-3 enrichment of broiler meat in groups 3 and 4. On the basis of the dissatisfaction of the panelists toward group 4 meats (scored as near to acceptable) and their satisfaction with cooked samples of T3 (scored as good), group 3 meats were selected as good-quality n-3-enriched broiler meat.
authors.affiliation: Department of Animal Science, Maragheh Branch, Islamic Azad University, Maragheh, Iran. n.aghaei.n@gmail.com
authors.forename: N
authors.initials: N
authors.lastname: Aghaei
authors.forename: A
authors.initials: A
authors.lastname: Safamehr
authors.forename: Y
authors.initials: Y
authors.lastname: Mehmannavaz
authors.forename: S
authors.initials: S
authors.lastname: Chekaniazar
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000822:Animal Husbandry / Q000379:methods*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002645:Chickens / Q000502:physiology*; D002849:Chromatography, Gas / Q000662:veterinary; D004032:Diet / Q000662:veterinary; D004041:Dietary Fats / Q000008:administration & dosage; D019587:Dietary Supplements / Q000032:analysis; D005227:Fatty Acids / Q000097:blood / Q000378:metabolism*; D005395:Fish Oils / Q000008:administration & dosage*; D008074:Lipoproteins / Q000097:blood / Q000378:metabolism*; D008297:Male; D008460:Meat / Q000592:standards*; D018482:Muscle, Skeletal / Q000737:chemistry; D011897:Random Allocation; D013997:Time Factors
chemical_list: D004041:Dietary Fats; D005227:Fatty Acids; D005395:Fish Oils; D008074:Lipoproteins