ABSTRACT: In spite of the diffi culties in delivering
PUFA to ruminants, studies have generally indicated
that the PUFA of the omega-6 (linoleic acid) and
omega-3 [α-linolenic acid; eicosapentaenoic (EPA),
C20:5 omega-3; docosahexaenoic (DHA), C22:6
omega-3] families are the most benefi cial to improving
reproduction in cows. The objectives were to determine
if a diet enriched in α-linolenic acid (omega-3) or linoleic
acid (omega-6) would infl uence milk production
and composition, metabolic status, and reproductive
performance in lactating dairy cows. High-yielding
multiparous Holstein dairy cows (n = 120) with no
overt clinical illnesses were blocked according to
calving date and parity