a1 CSIRO Livestock Industries, Private Bag 5, Wembley, WA 6913, Australia
a2 CSIRO Food Futures Flagship, Riverside Corporate Park, 5 Julius Avenue, North Ryde, NSW 2113, Australia
α-Linolenic acid (ALA; 18 : 3n-3) and stearidonic acid (SDA; 18 : 4n-3) are on the biosynthetic pathway of EPA (20 : 5n-3) and DHA (22 : 6n-3). The n-3 fatty acid in rapeseed oil is ALA while Echium oil contains both ALA and SDA. To determine the comparative efficacy of ALA- and SDA-rich oils in enriching broiler meat with n-3 PUFA, we offered diets supplemented with rapeseed oil (rapeseed group) or Echium oil (Echium group) for 35 d to two groups of chicks (age 21 d). There were no differences in carcass weight (2·20 (sem 0·06) v. 2·23 (sem 0·05) kg), boned, skinless thigh muscle (494 (sem 20·5) v. 507 (sem 16·7) g), boned, skinless breast muscle (553 (sem 13·4) v. 546 (sem 11·6) g) or organ weights (heart, liver and gizzard) between the two groups. The total intramuscular fat (IMF) percentage of thigh (8·0 (sem 0·64) v. 8·1 (sem 0·62) %) and breast muscles (2·3 (sem 0·24) v. 2·0 (sem 0·19) %) were also similar between the groups. In contrast, the concentrations of most of the individual n-3 fatty acids (ALA, SDA, EPA and docosapentaenoic acid) were all higher in the Echium than the rapeseed group (P < 0·05). However, differences in DHA concentrations were significant in breast but not thigh muscle IMF. The total n-3 yields/100 g serve thigh muscle were 265 and 676 mg for the rapeseed and Echium groups, respectively (P < 0·0001). The corresponding values for equivalent breast muscles were 70 and 137 mg, respectively (P < 0·01). We conclude that Echium oil is a better lipid supplement than rapeseed oil in changing the concentration and yield of n-3 fatty acids, except DHA, in broiler meat.
(Received March 28 2008)
(Revised June 02 2008)
(Accepted June 03 2008)
(Online publication July 11 2008)
Abbreviations: ALA, α-linolenic acid; CSIRO, Commonwealth Scientific and Industrial Research Organisation; DPA, docosapentaenoic acid; n-3 LC-PUFA, n-3 long-chain PUFA; SDA, stearidonic acid