Udder Management
Edema
Udder edema refers to the excessive
accumulation of body fluids outside the body cells and vascular
pathways of the udder. It occurs when blood is carried to the udder
faster than it is removed and some of the fluid settles into the
tissue causing the swelling or edema.
Edema may be associated with mastitis (see description below) but
more often it is not. Udder edema or "caked bag" is a physiological
condition usually found immediately before and/or after freshening
and is particularly common in cows lactating for the first time. It
generally disappears in a few days, but in some instances may lead
to a severe and persistent edema. Left unchecked, udder edema can
cause udder attachments to break down and lead to pendulous udder
and its associated problems. In the most serious cases, a complete
cut off of blood supply to the udder may occur.
Udder edema may be distinguished from the swelling associated with
mastitis in a number of ways. Edema usually involves the lower third
of the udder, feels doughy to the touch, and appears symmetrically
or equally on both sides of the udder - extending forward almost to
the belly wall. The swelling associated with mastitis, on the other
hand, typically occurs in one or two quarters of the udder. Edema
also does not produce heat to the same degree as an infection.
Another common test for udder edema involves pressing a fingertip
into the swollen area. Here, extra-cellular fluid will be forced
from the depression leaving a "dent" in the udder that will last for
several minutes. A
hereditary pre-disposition to edema as well as a
lack of exercise just prior to parturition (calving) are believed to
be the more common contributors to udder edema.
While udder edema will often gradually subside without intervention,
the dairyman's objective should be to get excess fluid absorbed back
into general circulation as quickly as possible.
The best way to do this is to increase the animal's overall blood flow.
This can be accomplished, in part, by walking the cow for exercise and
regularly massaging the affected areas of the udder. Blood flow can be
further increased when lotion is used in the massage process that also
contains ingredients known to increase blood flow to capillaries.
Udder lotions that combine lanolin for its massage characteristics;
peppermint and menthol for their properties of soothing and enhancement
of circulation; and tea tree oil for its naturally protective properties,
will enhance the massage process for best results.
Blood flow can be further increased if the lotion used in the
massage process also contains ingredients known to increase blood
flow to capillaries. Udder lotions that combine lanolin for its
message characteristics, peppermint and menthol for their soothing
analgesic effects while increasing blood circulation, and a
naturally occurring antiseptic such as tea tree oil for added
protection against infection, will maximize desired outcomes.
Mastitis
Mastitis, an inflammation of the
udder (mammary gland), is likely the most prevalent disease
afflicting dairy cows. A variety of bacteria can cause mastitis with
several species of streptococci, staphylococci, and Escherichia coli
being the most common. The presence of acute mastitis is usually
accompanied by a change in the physical properties of the afflicted
cow’s milk. It may contain flakes or lumps and appear watery,
bloody, stringy, or otherwise abnormal. Other symptoms may include a
hot, swollen, and often painful udder; significantly reduced milk
flow; fever; and a lack of appetite.
Abnormal milk and udder swelling are not, however, sure signs of mastitis.
Udders will often swell and feel harder after freshening. Similarly, it is
commonplace for the cow to pass a few plugs or strings both after freshening
and also near the end of lactation.
If not adequately treated, acute mastitis may subside into a chronic
form with afflicted cows experiencing periodic and repeated
flare-ups of mastitis. Because a cow with chronic mastitis may not
appear as sick as one with acute mastitis, the disease is not as
easy to diagnose. Low-grade infections caused by some bacteria, if
undetected, will nonetheless lead to a gradual deterioration of the
udder’s secretory tissue and a loss of production will result.
Whether acute or chronic, lost milk production and milk that must be
discarded are the most costly consequences of mastitis.
When mastitis is suspected, dairymen usually rely on a leukocyte-screening
test to confirm the presence of the disease. Tests like the
economical and easy to use California Mastitis Test (CMT)provide an
estimate of the number of somatic cells in milk. Since mastitis is
the leading cause of high somatic cell counts, it follows that a low
somatic cell count is a reasonably good indicator of udder health.
It is possible for many potential pathogens to infect the udder, yet
not result in mastitis. Mastitis usually occurs when these pathogens
are present in overwhelming numbers and when resistance to the
infection is lowered due to udder injury. Cows with large pendulous
udders, for example, may give more milk but are also much more
likely to injure their udders – even as they walk. Malfunctions of
the milking system can be another source of udder irritation that
can lead to injury and mastitis.
Of course the best strategy in avoiding mastitis is to apply good
sanitary practices with the dairy herd, the facilities, and the
equipment. This includes the use of germicides after each milking.
Equally important is ensuring that milking equipment is both
properly operated and operating properly. . Finally, should signs
of potential mastitis occur, massaging the quarter with a lotion
that contains naturally beneficial characteristics is highly recommended.
Massaging with the lotion after each milking, helps reduce swelling and
the potential for tissue destruction that is associated with such swelling.
Rather than resorting immediately to antibiotics and their inherent risks
and associated costs, massaging the area with the lotion is an excellent,
proactive, natural management tool, which can reduce the need for antibiotic
treatment.
Somatic Cells
Somatic cells are found in the milk
of virtually all dairy cows with the number of cells per ml. of milk
varying dramatically from one animal to the next. The lower the
somatic cell count, the healthier the udder is perceived to be.
Fresh heifers, cows recently fresh, and those drying off, will
typically give high somatic cell counts, even in the absence of any
infection. The leading cause of high somatic cell counts, however,
remains mastitis.
Dairymen usually rely on a leukocyte-screening test like the
California Mastitis Test (CMT) to confirm the presence of mastitis,
and to gain a rough estimate of the number of somatic cells in any
suspect milk. DHIA reports also provide somatic cell counts for individual
animals. If the cell count appears too high, the milk may need to be
discarded until the problem is brought under control. For information on
somatic cell count control, please refer to the preceding descriptions
of Edema and Mastitis.
Over the years, public health departments in countries around the globe
have placed increasingly stringent standards on the quality of milk
produced by commercial dairy farmers. In Canada and the USA, and
perhaps many other countries, the somatic cell count has been adopted
as an important measure of milk quality. Notwithstanding, these cell
count standards do vary widely between countries and regions, resulting
in very different qualities of milk even within the same country. Cell
count screening for milk shipments is done on a pooled sample basis
representing all cows in the herd. In other words, if only one cow in a
large herd has a high somatic cell count, the pooled milk will very
likely still meet a given standard. However, if just a few cows have
recently freshened, or have sub-clinical mastitis that goes undetected,
their collective high cell counts could lead to the costly consequences
of an entire shipment of milk being rejected. This is just one reason
why measuring and managing somatic cell count is so important.
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