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November 10, 2005: Managing the dry cow
starts during the last trimester of lactation. This is the
period when the bovine should be gaining back her body condition
after coming off her lactation curve. The last thing anyone
wants in a dry-off is an animal that is skin and bone. On
the flip side, you do not want an animal that is hog-fat going
into her dry period. The last trimester is when you want to
control the grain so you can get her body condition where
you want it.
A key factor the dairyman must know and be very aware of
during the dry period is the two dips in immune function that
all female herbivores experience. Immunologists uncovered
this in the 1980s, and it has been a well-kept secret in the
dairy industry. The two dips take place as follows. At dry-off,
the immune function is lowered by the endocrine system. A
tight udder triggers the endocrine system to hormonally switch
from a lactating animal. The second, bigger and longer drop
starts about two weeks before calving and bottoms out at calving.
It will take two to three weeks to return to normal. Experts
say that in some cows 75 percent of immune function is shut
down.
If possible any stress should be avoided during these two
times of lowered immune function. Vaccinations should be avoided
during dry-off and around freshening. Unfortunately, these
two time frames have been widely adopted as times to vaccinate
for everything and anything in the dairy world.
Avoid these windows at all costs.
The dry cow should have a high-forage diet with at least
10 pounds of dry hay for good rumen function. The potassium
level in the forage should be monitored. A correct balance
is to approach a one-to-one ratio with calcium and potassium.
This may be hard to do. If one can get the calcium levels
above 1 percent to 1.4 percent on a dry matter basis and the
potassium in the low 2 percent range this is acceptable.
Minerals, calcium and phosphorus should always be available
free choice. The ratios will be determined by the forages
fed. A good level of selenium and traces should be available
also. In the winter, a good level of vitamins should be supplemented.
A target figure would be to have your animals on 100,000 to
200,000 IU (international units) of vitamin A per head per
day. The vitamins D and E should be supplemented as well.
Because of the natural dips in the immune system, if you
want to upgrade immune function follow these tips:
If you are ever going to want to kick up the cow’s
immune system for one month to affect the next 11 months,
the time to do it is the four weeks just before calving.
I prefer 2 ounces of kelp meal mixed 50% with Redmond Natural
Salt. You can also put this in the TMR or some have chosen
to just free choice it. Salt in the loose form should also
be provided. I like the unrefined natural products.
A second way to put the immune system in high gear is to
add some aloe vera pellets to the ration. Levels of two
to four ounces are commonly used. More and more organic
dairymen are using this during the big immune function dip.
They typically start about two weeks before calving. The
window starting one week after dry-off is the time to do
your mastitis, somatic cell and dry-cow mastitis clean up.
This is when you become proactive. Any high cell count or
mastitis problem cow is attacked at this time.
I like to go on a regimen of a whey product SQ (subcutaneous)
of about 30 cc by the tail head. Hit them with 300 cc oral
drench of antioxidant tincture for three days. They should
also go on a garlic tincture either orally or vaginally for
three days. During this three-day time period, strip them
out two to four times a day to flush and clean the udder.
If a few more days are required, continue with this regimen.
This may be repeated in a few weeks when the udder has shrunk
down.
Any animal that has had a history of udder trouble or has
excessive udder swelling in the immediate pre-fresh state
should be considered for pre-milking. Start 10 to 20 days
before freshening if you suspect mastitis or just lots of
edema. Bring her into the milking line, wash her up and spend
some time massaging and washing her at first to stimulate
oxytocin let-down. The first two or three times you may get
nothing, but usually they will let down. Milk her to see what
you have; if it is bad, keep milking and treating her. Go
right up to and through calving. Colostrum will be there,
as it’s formed at calving and not before.
You are doing three things:
- Cleaning up the colostrum by getting the dead cells and
debris (pus) out of the system.
- Cleaning out the mastitis and treating her at the same
time.
- Reducing udder edema.
Do not use any whey products two weeks before calving as
you may precipitate calving--whey can do this. Grain feeding
to the dry cow is based on body conditioning as said previously,
this is not the time to get them hog-fat. Introduction of
a little grain before calving is fine for a thin cow or to
get her slowly up to speed before calving. The less you disturb
a cow during her four-week immune dip the better off you are.
When I am consulting and encounter a high-production, high-grain,
highly acidic, overly vaccinated BGH herd I will focus on
the three weeks after calving to evaluate what level their
immune function is at, and invariably their sick cows and
death loss will be highest shortly after calving. Organic
graziers and high-forage feeders may not realize the many
long-term benefits you get by raising your cows' immune function.
Prevention is a key strategy and reducing stress during this
critical time will go a long way towards improving the overall
health of the herd. 
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