Feeding soybeans to dairy cows has attracted the attention of dairy producers for decades. Jaylor's Ruminant Nutritionist, Janet Kleinschmidt, explores the best way to utilize soybeans in a dairy ration.

1. Soybeans in Dairy Rations: The
Whole Story

2. Soybeans in Dairy NutritionSoybeans in Dairy Nutrition
Feeding soybeans to dairy cows has garnered
the attention of dairy cattle producers for
decades.
As a field nutritionist the question that I get
asked most frequently from clients is: “What is
the best way to utilize soybeans in a dairy
ration, raw or heat treated?” The answer is
both ways.
Confused? Let’s take a closer look.
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3. Soybeans in Dairy NutritionSoybeans in Dairy Nutrition
Dry Matter % CP% UIP % NElcal/kg)
Raw Beans 87 41.4 20 2.11
Roasted Beans 92 41.3 49 2.17
48% SB Meal 90 53.3 28 1.99

4. Soybeans in Dairy Nutrition
“Full fat” beans as a protein for dairy cattle
makes a great deal of sense for two major
reasons: economics and the high-energy value
of full fat beans.
Roasting adds an additional cost but roasted
beans still break even economically compared
to commercial protein supplements.

5. Soybeans in Dairy Nutrition
On dairy farms with enough acreage to justify
growing beans, growing a protein/energy
supplement for the herd certainly looks more
attractive than other cropping options.

6. Soybeans in Dairy Nutrition
The high fat content of soybeans impacts on
the dairy ration in two positive ways: fat has
2.25 times the energy value of starch and
therefore has a higher energy density.
Because of this the cow requires slightly less
grain and supplement, allowing her to eat
slightly more forage; with more energy coming
from fat there is less starch in the diet.

7. Soybeans in Dairy Nutrition
With more fibre and less starch, diets that
contain soybeans usually result in a higher
butterfat test in early lactation.
With more energy available, many cows also
respond with a slight increase in milk
production or maintenance of body condition.

8. Soybeans in Dairy Nutrition
The decision to feed raw or roasted beans will
be dictated by the additional cost of heat-
treating and the quality of heat treatment
available.
Roasted beans should exit the roaster at 140 to
150 C and steep for 30 to 40 minutes.
Over cooking beans denatures the protein
making it unavailable and reduces specific
amino acid availability.

9. Soybeans in Dairy Nutrition
Heat-processed beans should be uniform in
colour, show no evidence of burning and have
a pleasant nutty taste; beans that taste bitter
have not been roasted properly.
Over the years I have seen far too many poorly
roasted beans that have resulted in on-farm
disasters.

10. Soybeans in Dairy Nutrition
Under-cooked beans have the same properties
as raw beans but are fed out as roasted,
presenting inherent problems. Burnt beans
render the protein unavailable.
Many “back yard” roasters have both “hot”
and “cold” spots in them resulting in both
burnt and under cooked beans. I would much
rather work with quality raw beans that
roasted beans of an unknown quality!

11. Soybeans in Dairy Nutrition
To use raw soybeans effectively, certain
precautions must be taken.
Raw beans contain the enzyme urease that
breaks down urea to ammonia making diets
that include raw beans and urea unpalatable
and potentially dangerous.
In hot weather ground or rolled beans become
rancid quickly and should not be stored after
processing.

12. Soybeans in Dairy Nutrition
Also in raw beans exists the anti-nutrient
“trypsin inhibitor” which interferes with
protein digestion.
Therefore, raw beans should not be fed to
animals less than 6 months of age; in mature
ruminant the toxin is destroyed in the rumen.

13. Nutritionally
When too much fat is introduced into the diet
or it is introduced too quickly both milk
production and butterfat can be depressed.
To avoid this situation all high fat feeds should
be introduced to the rumen slowly; in
addition extra calcium (1 – 1.1% DM) and
magnesium (0.35 – 0.4% DM) should be
added to the diets.

14. Nutritionally
These minerals, in combination with fat, form
soaps that do not coat the feed particles.
There is some research that also recommends
feeding higher levels of selenium and
vitamin E because unsaturated fats reduce
vitamin E activity.

15. Soybeans in Dairy NutritionSoybeans in Dairy Nutrition
Store raw and processed beans whole; crack or
roll them as you use them to avoid rancidity,
this is especially true in warm weather.
Ration fat level must not exceed 7 to 8%.
This includes 2-3% from natural sources, 2-3%
from vegetable oil or tallow, 2-3% from by-
pass fat.

16.
Quick tips for utilizing raw or heat-treated soybeans in
your herd:
Raw soybeans are an excellent feed
ingredient for lactating dairy cows.
Feed a maximum of 2.5 kg as fed/ head/day
of raw beans.
Feed a maximum of 3.0 kg as fed/ head/day
of heat-treated beans.
Raw soybeans should never be fed with urea
or supplements that contain non-protein
nitrogen.

17.
Quick tips for utilizing raw or heat-treated soybeans in
your herd:
Use only heat-treated beans in young
ruminants less than 6 months old.
Store beans whole to prevent rancidity.
Beans should be rolled or cracked before
including in a ration.
Heated treated beans are more palatable
and contain more bypass protein than raw
beans.

18.
Quick tips for utilizing raw or heat-treated soybeans in
your herd:
In addition, heat-treating destroys anti-
nutrient factors such as urease and trypsin
inhibitor. However, heat treatment MUST be
done properly and be cost effective.
Watch that the total fat levels in the diet do
not exceed 7 to 8% and unprotected, added
fat must not exceed 2% to 3% of the dry
matter intake.

19.
Quick tips for utilizing raw or heat-treated soybeans in
your herd:
Increase ration levels of calcium to 1% to
1.1% and magnesium to 0.35% to 0.40%
(total ration dry matter).
Added dietary fat can increase the risk of
oxidized milk; vitamin E levels in the total
ration DM should be between 1000 to 4000
IU/cow/day to help prevent oxidized milk.