Thirty-five non-gestating
multiparous Holstein cows averaging 571 kg of BW (SE = 8) were allotted at 9 wk postpartum to one of two dietary fat supplements
based on either Megalac® (Volac Ltd., Roston, Hertfordshire, UK) and solvent extracted flaxseed meal (MEGA) or whole
flaxseed treated with formaldehyde (FLAX) to determine the effects on milk production and composition, follicular development,
gestation rate, and fatty acid (FA) composition of blood.Cows were fed a total mixed diet based on ryegrass silage and fat supplements
for ad libitum intake. The experiment was carried out between weeks 9 and 19 of lactation. Dry matter (DM) intake and
change in body weight were similar for cows fed MEGA and FLAX.