However,
transfer efficiencies (milk secretion response, treated
minus control, g/day, as a percentage of intake, g/day)
from FO to milk fat were 3.2% for EPA and 3.4% and
4.3% for DHA, respectively, for LFO and HFO
treatments. These low values can be explained by
the fact that EPA and DHA are in part hydrogenated in
the rumen and mostly concentrated in cholesterol ester
and phospholipid fractions of plasma (Offer et al.,
1999), which are only used in a low proportion by the
mammary gland. These results are supported by data
reviewed by Chilliard et al. (2001