Les acides polyinsatures du beurre. Influence de la saison

Abstract - The polyunsatured fatty acids of butterfat. Seasonal variations
From April 1959 to April 1960 a study was made of the content of various polyunsatured fatty acids in the butterfat.
The experimental herd was composed of about twenty cows. They were turned out to grass at the end of April 1959 and brought back to stall at the beginning of November 1959.
Butter made from evening and morning milkings was analyzed separately.
During the stall period, conjugated diene content was about 0,5 (in g per cent g of fat) and increased during the pasture period to 1,6 at the end of the summer.
Non conjugated diene and tetraene acids contents were relatively uniform (mean values: 1,1 and 0,34 respectively), but a little higher during November and December. The non conjugated triene or linolenic acid content was higher during pasture (0,6) than during the stall period. Important variations of the linolenic acid content were noted throughout the year.
The exceptionally dry weather during the summer of 1959 was taken into account