Fat contains over two times the amount of energy found in grain. This makes it
a very good energy supplement for early lactation cows.
The intake of supplemental fat should not exceed 5% of the ration. This corresponds
to approximately 0.7 to 0.9 kg fat/day (1.5 - 2 lbs). If this is exceeded, rumen
fermentation can be affected and milk fat depression, reduced feed intake and
off-feed problems may occur. There are three sources of supplemental fat.
Whole Oilseeds
The most common oilseeds grown in Manitoba are canola and sunflowers. Both
contain approximately 40% fat and 20% protein. Soybeans contain 20% oil and
about 40% protein. The seed coat protects the rumen from rapid exposure to the
fat and prevents rumen fermentation from being adversely affected. Some of the
benefit from the seed coat will be lost if seeds are processed prior to feeding.
Sunflower seeds are a popular fat source. Whole canola seeds are less digestible
because of their small size and hard seed coat. The digestibility can be increased
by processing but the small size and high oil content of the seed makes on-farm
processing difficult. Some form of commercial processing may be necessary to
maximize fat utilization. The University of Manitoba has fed up to 2 kg of whole
canola seed with no detrimental effects.
Commodity Fats
Commodity fats include animal fats (tallow, lard) and vegetable oils. Vegetable
oils are unsaturated fats and will likely cause changes in rumen fermentation.
Animal fats are saturated fats and are less likely to cause milkfat depression.
Special equipment is necessary to keep tallow in a liquid state. Feed intake
will be reduced if rancid tallow is fed.
Commercial Fats
A number of commercial products are available (eg. Booster Fat, Golden Flake,
Megalac). These fats are "protected" so they have the advantage of
being inactive in the rumen. They are easy to handle but are a more expensive
form of fat.
Product
% Fat
Price (1997 Figures)
Kg Required to
Provide 0.7 Kg Fat
Price/0.7 Kg Fat
Canola Seed
40
$200/tonne
1.75
$0.35
Sunflower Seed
40
$320/tonne
1.75
$0.56
Tallow
100
$600/tonne
0.7
$0.42
Commercial Product A
80
$1.05/kg
0.9
$0.95
Commercial Product B
100
$1.50/kg
0.7
$1.05
Karen Dupchak
Animal Nutritionist, Animal Industry Branch
Manitoba Agriculture & Food
204-545 University Crescent
Winnipeg, Manitoba, Canada R3T 5S6