Based on the data collected from two feeding trials conducted with Ay-cows fed with linseeds as a principal source of unsaturated fatty acids in the ration, the following formula was computed showing the effect of the diet on the iodine number (I.N.) Girls Spring Dressy Set of the milk fat in these experiments: I.N.
= 6.7 + 38.5 * (U.F.
A.consumed, g/day + 200 x Sc.fuu + 2xL.W.
)/(M.F.secreted, g/day + 60 x Sc.fuo + 3 x L.
W.) where unsaturated fatty acids (U.F.A.
) in feed are expressed as sunglass case an oleic acid equivalent, M.F.= milk fat (g./day), Sc.
fuu=Scandinavian feed units underfed, Sc.fuo= Sc.feed units overfed, and L.W.
= live weight in kilograms.