Vitamin A content of cow's butter fat.

DURING the past two decades, a good deal of
work has been done on butter, particularly in
relation to its vitamin A content. It has been
reported that the vitamin A content of butter
varies considerably. The three most important
factors which influence the vitamin A content
of butter are the feed, the lactation period and
the breed of the animal. The first of these factors
has been extensively studied by a number of
workers (5, 12). Comparatively less amount of
systematic work has been done on the influence
of lactation period and the breed of the cow on
vitamin A content of the butter-fat (2, 6).
Indian workers (3, 9, 10) reported lower
values for vitamin A content of butter as
compared with those obtained in Western
countries (11). Since this work was done in
South India, it may be that the poor state of
nutrition of the mulch cattle in these regions
could be responsible for the low values. In
the West Punjab, the cattle are comparatively
better fed. It was therefore thought desirable
to have the corresponding figures from the
butter-fat of the Punjab cows.