Utilisation of fish oil in ruminants - II. Transfer of fish oil fatty acids into goats' milk

A study was conducted to determine the transfer of eicosapentaenoic acid (E PA, 20:5) and docosahexaenoic acid (DHA, 22:6) from fish oil into goats' mi lk. Goats were sequentially offered three diets: control(C) pellets (lucern e hay-oat grain: 60/40 w/w), C plus tuna oil protected against ruminal bioh ydrogenation (PTO pellets), and C plus unprotected tuna oil (UTO pellets), In supplemented diets, tuna oil constituted 3% of total dry matter (DM), an d each supplement was fed for 7 days, with 12 days allowed between the two fish oil feeding periods to minimise carry-over effects, Dry matter intake, milk yield, protein and fat yield were reduced by feeding UTO, but not PTO , pellets, Goats produced omega -3 enriched milk (0.3-0.5% EPA and 1.01-1.1 2% DHA) when fed either supplement, The rate of transfer of dietary EPA and DHA to milk ranged from 3.5 to 7.6%. Significant transfer of EPA and DHA f rom tuna oil into goat milk, without deleterious effects on intake or milk yield is possible, provided that the oil supplement is substantially protec ted against ruminal biohydrogenation. (C) 2001 Published by Elsevier Scienc e B.V.