ArticlePDF Available

Review: How well have United States dairy producers adopted mastitis-control technologies for reducing herd somatic cell counts and improving milk quality?

Authors:

Abstract and Figures

Mastitis continues to be a major livestock disease affecting the dairy industry. In the United States, this disease results in economic losses approaching $2 billion annually due to reduced milk production, milk discard, veterinary services, antibiotic use, increased labor, and reduced cow sale value. As the industry strives to improve milk quality to meet consumer as well as exportation demands, the legal limit for bulk-tank SCC will likely be reduced from 750,000/mL to 400,000/mL in the near future. It is estimated that between 10 and 20% of United States dairy farms, mostly located in the Southeast, are currently at or above the 400,000/mL SCC limit and will have to adopt stricter methods for controlling mastitis in their milking herds, dry cows, and heifers. The 5-point plan of mastitis control has provided the basics of managing this disease for more than 4 decades and includes 1) teat disinfection, 2) dry-cow therapy, 3) use of functionally adequate milking machines, 4) therapy of clinical infections, and 5) culling of chronically infected cows. However, additional measures of control will have to be implemented to reduce mastitis prevalence and the associated elevation in SCC. Such management practices include maintenance of a clean and dry environment, vaccination, dietary supplementation, and mastitis control in heifers. The adoption of both the proven traditional methods and the more novel technological approaches toward mastitis management by dairy producers will have to be implemented by those with herd bulk-tank SCC exceeding 400,000/mL. In addition, extension and outreach personnel associated with agricultural universities should play a major role in disseminating mastitis-management programs to assist dairy producers in attaining maximum production of the highest-quality product.
Content may be subject to copyright.
© 2014 American Registry of Professional Animal Scientists
ABSTRACT
Mastitis continues to be a major live-
stock disease affecting the dairy industry.
In the United States, this disease results
in economic losses approaching $2 billion
annually due to reduced milk production,
milk discard, veterinary services, anti-
biotic use, increased labor, and reduced
cow sale value. As the industry strives to
improve milk quality to meet consumer
as well as exportation demands, the legal
limit for bulk-tank SCC will likely be
reduced from 750,000/mL to 400,000/
mL in the near future. It is estimated
that between 10 and 20% of United
States dairy farms, mostly located in the
Southeast, are currently at or above the
400,000/mL SCC limit and will have
to adopt stricter methods for control-
ling mastitis in their milking herds, dry
cows, and heifers. The 5-point plan of
mastitis control has provided the basics
of managing this disease for more than 4
decades and includes 1) teat disinfection,
2) dry-cow therapy, 3) use of functionally
adequate milking machines, 4) therapy
of clinical infections, and 5) culling of
chronically infected cows. However, ad-
ditional measures of control will have
to be implemented to reduce mastitis
prevalence and the associated elevation
in SCC. Such management practices
include maintenance of a clean and
dry environment, vaccination, dietary
supplementation, and mastitis control in
heifers. The adoption of both the proven
traditional methods and the more novel
technological approaches toward masti-
tis management by dairy producers will
have to be implemented by those with
herd bulk-tank SCC exceeding 400,000/
mL. In addition, extension and outreach
personnel associated with agricultural
universities should play a major role
in disseminating mastitis-management
programs to assist dairy producers in
attaining maximum production of the
highest-quality product.
Key words: milk quality , mastitis ,
somatic cell count
INTRODUCTION
Mastitis remains a major livestock
disease for United States dairy pro-
ducers, with losses of approximately
$2 billion per year (National Mastitis
Council, 1996). This disease is associ-
ated with elevated herd bulk-tank
SCC, and although the legal limit
for bulk-tank SCC sold as grade A
milk in the United States is currently
750,000/mL, other countries have
much lower limits [European Union
(EU): 400,000; Australia and New
Zealand: 400,000; Canada: 500,000;
as reviewed by Lombard et al., 2011].
To comply with global milk-quality
standards, consumer demand, and
exportation requirements promulgated
by the EU for dairy products being
exported by the United States to EU
member countries, the United States
dairy industry is striving to reduce
the level of mastitis, improve product
quality, and increase economic returns
to producers. It is speculated that
the United States legal limit for SCC
The Professional Animal Scientist 30 ( 2014 ):115–124
R EVIEW: How well have United
States dairy producers adopted
mastitis-control technologies for
reducing herd somatic
cell counts and improving
milk quality?
S. C. Nickerson *
1
and S. P. Oliver †
* Department of Animal and Dairy Science, University of Georgia, Athens 30602-2771; and
UT AgResearch, University of Tennessee, Knoxville 37996-4506
1
Corresponding author: scn@uga.edu
Nickerson and Oliver
116
in raw milk will be reduced from the
current regulatory limit of 750,000/
mL (USDHHS, PHS, FDA, 2009) to
400,000/mL in the future. The SCC
is an indirect measure of the level of
mastitis in a herd and is used to as-
sess milk quality. Elevated herd bulk-
tank SCC are almost always associat-
ed with poor milk quality as a result
of mastitis-management deficiencies.
Dohoo and Meek (1982) showed that
the most important factor affecting
SCC was the quarter infection status,
and other factors such as age, stage of
lactation, season, stress, and diurnal
and day-to-day variation had only
minor effects.
A common belief held by milk-qual-
ity and mastitis-control professionals
is that it is important to improve milk
quality for several reasons including
1) improved consumer confidence in
the safety and wholesomeness of the
United States milk supply and that
milk is produced by healthy cows;
2) harmonization of standards for
international trade of milk and milk
products; 3) improved competitive
position of the United States dairy
industry in the global market place;
4) reduced risk of antimicrobial
residues; 5) reduced risk of human
bacterial pathogens and their tox-
ins; and 6) greater producer profits
through decreased mastitis and SCC.
In addition, it must be emphasized
that 1) elevated SCC indicate poor
farm hygiene practices, improper
sanitation, and mastitis, as well as
an increased potential for antibiotic
residues; 2) high SCC are always as-
sociated with reduced milk yield; 3)
low SCC milk has a longer shelf life,
better taste, and greater cheese yield;
and 4) processors shipping to the EU
must prove that each supply farm
SCC is <400,000/mL.
Already, milk purchasers are requir-
ing milk with lower SCC from their
suppliers. Kroger (Cincinnati, OH),
for example, recently set their SCC
limit to 250,000/mL, which is down
from 350,000/mL a year ago. Also, in
April of 2013, a proposal to lower the
United States legal SCC limit from
750,000 to 400,000/mL sequentially
over a 2-yr period was submitted to
the National Committee on Inter-
state Milk Shipments (NCIMS).
This proposal was voted down by
a very narrow margin (22:28). Two
more proposals to lower the SCC to
400,000/mL were also submitted in
2013 but received “no action” votes by
the NCIMS. It is likely that similar
proposals will continue to be submit-
ted to the NCIMS and probable that
one such proposal will be approved,
thereby lowering the legal SCC limit
for raw milk in the United States to
400,000/mL or lower.
More recently, effective January 1,
2012, the United States dairy industry
began the transition to a farm-level
milk-sampling program to verify SCC
compliance with EU regulations (SCC
limit of 400,000/mL) for milk buyers
that are manufacturing products for
export to the EU and the produc-
ers whose milk they are receiving.
Moreover, after March 31, 2012, all
shipments of dairy products requiring
an EU health certificate must comply
with the updated certification pro-
gram and must be accompanied by an
updated Certificate of Conformance.
COMPLIANCE WITH
THE 400,000/mL SCC LIMIT
Complying with a legal limit of
400,000/mL set for milk destined for
export or processing in the United
States for the vast majority of dairy
producers would not be a problem,
even if it was imposed immediately.
In 2008, a United States Animal
and Plant Health Inspection Service
(APHIS, 2008) survey found that the
average SCC was 245,000/mL and at
the time, about 90% of United States
bulk-tank SCC were below that level.
The Dairy Herd Improvement Asso-
ciation (DHIA) also found that the
SCC of herds on test decreased from
276,000/mL in 2007 to 228,000/mL
in 2010. Moreover, a 2012 Hoard’s
survey (Anonymous, 2012) showed
that more than 95% of United States
bulk tanks had SCC of <400,000/
mL. Thus, although the average SCC
of the vast majority of United States
dairy farms is well below the pro-
posed legal limit, it appears that the
5 to 10% of farms that would have
problems complying are those mainly
located in the Southeast, which poses
significant problems for their sustain-
ability. On a positive note, a recent
survey revealed that producers in
the southeastern state of Kentucky
indicated that the mastitis and milk-
quality issue was the most important
management topic, which suggests
their awareness of the problem (Rus-
sell and Bewley, 2011).
SUSTAINABILITY
OF THE SOUTHEAST
DAIRY INDUSTRY
The 12 southeastern states include
AL, AR, FL, GA, KY, LA, MO, MS,
NC, SC, TN, and VA, and a recent
trend analysis (Herndon, 2011) points
to the distressed economic health and
profitability of the dairy industry of
this region and questions how sustain-
able the industry is. For example, the
Southeast realized a 37% decline in
milk production from 1995 to 2010,
whereas during this same period,
the United States experienced a 24%
increase in production. Extending
these trends reveals that production
is forecasted to decline by 35% in the
Southeast between 2010 and 2025,
whereas United States production
will increase by 23%. Likewise, on a
per-cow basis, the Southeast realized
a 13% increase in milk production
per cow from 6,350 kg/yr in 1995 to
7,185 kg/yr in 2010; however, this
elevation in production in the United
States overall was 29%, increasing
from 7,439 to 9,593 kg/yr. Moreover,
the 12 states making up the South-
east have seen a 64% decline in the
number of dairy farms over this time
period compared with a 52% decline
for United States farms (Table 1).
AL, AR, KY, LA, MS, and TN lost
the most farms (66 to 81%). Over this
same period, the Southeast lost 47%
of its dairy-cow population (Table
1), with AL, AR, KY, LA, MS, and
TN losing the most cows (52 to 80%;
Herndon, 2011). Such reductions in
dairy operations as well as in cow
populations question the long-term
Adoption of mastitis-control technologies 117
sustainability of the Southeast indus-
try.
By focusing on milk production per
farm as a barometer of profitability,
the sustainability of Southeast herds
is further brought into question: from
1995 to 2010, the Southeast realized
a 51% increase in output per farm,
whereas output for the United States
increased 161%, a 3-fold rise in pro-
duction (Herndon, 2011). An exami-
nation of the facts brings the produc-
tivity of Southeast dairy farms into
focus. Table 2 illustrates the test-day
milk production in Southeast herds
enrolled in the DHI Program from
2001 to 2010 (USDA, ARS, 2011).
The 10-yr Southeast average produc-
tion was 13% less than the national
average (27.8 vs. 32.1 kg). Whereas
average United States production
increased by 1.7 kg/d from 2001 to
2010, the Southeast average increase
was only 0.6 kg/d, ~30% as much;
3 states actually realized a decrease
in daily yield. Clearly, the Southeast
needs to enhance the profitability of
its dairy industry if it is to be com-
petitive with the rest of the United
States (Herndon, 2011).
In addition to overall milk produc-
tion, milk quality in the Southeast
is also at issue. Poor-quality milk is
Table 1. Changes in the number of dairy farms and dairy cows in the Southeast from 1995 to 20101
State
Number of dairy farms % Change,
1995–2010
Number of dairy cows (× 1,000) % Change,
1995–2010
1995 2000 2005 2010 1995 2000 2005 2010
AL 246 154 90 60 76 34 25 16 11 68
AR 693 427 210 130 81 60 39 22 12 80
FL 300 231 180 140 53 162 157 137 11 4 30
GA 536 404 320 260 52 100 88 81 78 22
KY 2,731 1,932 1,335 940 66 162 132 106 78 52
LA 646 468 280 150 77 76 58 35 20 74
MS 515 356 234 130 75 55 36 25 17 69
NC 683 447 365 290 58 86 71 54 44 49
SC 178 116 11 0 85 52 27 23 18 16 41
TN 1,544 999 710 490 68 127 95 70 52 59
VA 1,225 998 815 705 42 129 120 105 95 26
Total 9,297 6,532 4,649 3,380 64 1,018 844 669 537 47
1
Adapted from USDA/ARS Animal Improvement Program Laboratory reports on somatic cell counts of milk from DHI herds (1995–
2010). Information from all states can be found at http://aipl.arsusda.gov/publish/dhi/scc.html.
Table 2. Test-day milk production and SCC in Southeast DHI program herds program from 2001 to 20101
State
Milk production (kg/d)
Average
Somatic cell count (× 1,000)
Average2001 2003 2005 2007 2010 2001 2003 2005 2007 2010
AL 23.5 23.3 23.4 23.0 22.0 23.2 444 517 433 407 415 445
AR 23.5 25.7 26.5 25.0 24.0 25.1 486 387 448 441 421 433
FL 30.1 30.6 33.1 31.3 31.1 31.2 548 633 473 333 274 421
GA 28.5 27.5 28.6 27.8 29.0 28.3 407 479 433 422 337 406
KY 26.9 27.6 29.5 28.7 29.6 28.5 413 419 392 354 313 375
LA 24.4 25.0 25.0 23.2 24.4 24.5 479 498 416 446 380 450
MS 27.4 28.7 29.1 29.4 28.5 28.6 442 480 386 337 290 388
NC 30.3 29.9 30.3 30.9 30.0 30.3 364 414 358 324 279 345
SC 27.8 27.4 28.3 28.5 28.7 28.2 404 448 387 355 349 379
TN 26.8 26.7 27.5 27.0 27.5 27.2 413 476 504 418 396 434
VA 30.5 29.9 31.3 31.1 31.8 31.1 333 374 320 309 285 320
Southeast average 27.3 27.5 28.4 27.8 27.9 27.8 430 466 414 377 342 400
US average 31.3 31.6 32.3 32.4 33.0 32.1 322 319 296 276 228 284
% Difference −13 −13 −12 −14 −15 −13 +25 +20 +28 +27 +33 +29
1
Adapted from USDA/ARS Animal Improvement Program Laboratory reports on somatic cell counts of milk from DHI herds (2001–
2010). Information from all states can be found at http://aipl.arsusda.gov/publish/dhi/scc.html.
Nickerson and Oliver
118
associated with an elevated SCC and
is an inferior product with reduced
processing properties resulting in
reduced shelf life of dairy products
(Jayarao et al., 2004). Conversely,
high-quality milk has a very low SCC,
has a longer shelf-life, tastes better,
and is more nutritious. Milk from
uninfected mammary glands contains
<100,000 somatic cells/mL. A milk
SCC of >200,000/mL suggests that
an inflammatory response has been
elicited, that a mammary quarter is
infected or is recovering from an infec-
tion, and is a clear indication that
milk has reduced manufacturing prop-
erties. It is not uncommon for milk
from cows with mastitis to contain
several hundred thousand and even
millions of somatic cells per milliliter
of milk. Thus, an increase in milk
SCC is a good indicator of mastitis,
which alters milk composition and
reduces milk yield. Most studies that
evaluated the influence of mastitis on
milk composition used SCC as the ba-
sis for determining the infection sta-
tus of udders and for determining the
degree of inflammation as reviewed by
Sharif and Muhammad (2008).
The United States average DHIA
SCC in 2010 as a measure of quality
was 228,000/mL, but this figure for
the Southeast was 342,000/mL (range
274,000–421,000), or approximately
50% higher than the national average
(Table 2). Over the 10-yr period cov-
ering 2001 to 2010, the 12 Southeast
states, for the most part, have pro-
gressively decreased their DHIA SCC;
however, each state’s 10-yr average is
still >100,000 cells/mL higher than
the national average, demonstrating
poorer milk quality in this region. It
should be noted that although climac-
tic differences likely contribute to the
differences in SCC, the differences in
mean SCC between geographically
close or adjacent Southeast states are
substantial, suggesting that imple-
mentation of mastitis-control pro-
grams can have a positive effect under
similar climactic conditions and that
milk quality in the Southeast can be
improved through use of cost-effective
control strategies.
NEED FOR BETTER
ADOPTION OF MASTITIS-
CONTROL MEASURES
Dairy producers in the Southeast
region will have to adopt stricter
methods of mastitis control in their
milking herds, dry cows, as well as in
their heifers to reduce the incidence of
mastitis, increase production, and suc-
cessfully lower their bulk-tank SCC
to be competitive with the rest of the
nation. Producers have had several
tools at their disposal that have been
available for many years to incorpo-
rate into mastitis-control programs.
The vast majority of those with
herd SCC above 400,000/mL are
located in the Southeast, and one
excuse has been that the heat and
humidity experienced during sum-
mer months make it difficult, perhaps
impossible, to lower SCC in this re-
gion. Heat and humidity do not cause
mastitis, yet these factors increase the
ability of mastitis-causing bacteria to
grow and thrive in the environment of
cows. However, it is the management
deficiencies on many Southeast farms
that allow these potential pathogens
to actually cause infections. There are
many well-managed operations in the
Southeast that consistently have SCC
well under 400,000/mL throughout
the year; thus, maintaining this level
can be achieved. A 2012 survey re-
vealed that among Georgia, Kentucky,
Tennessee, and Virginia dairy farm-
ers, the percentage of bulk-tank SCC
below 400,000/mL ranged between
64.3% (August) and 87.9% (Novem-
ber; Oliver et al., 2013). Traditional
mastitis-control measures as well as
newer management strategies have
been proven to work and have been
adopted by those Southeast dairymen
producing high-quality and low-SCC
milk; those struggling with milk qual-
ity need to emulate their successful
neighbors.
Traditional methods for control-
ling this disease have been based on
the 5-point plan of mastitis control
(Neave et al., 1969), which has been
implemented for more than 4 decades,
and includes 1) teat disinfection, 2)
dry-cow therapy, 3) use of function-
ally adequate milking machines, 4)
therapy of clinical infections, and 5)
culling of chronically infected cows.
Additional measures of control have
been implemented to further reduce
mastitis prevalence and the associated
elevation in SCC. Such management
practices include vaccination, use of
teat sealants, environmental sanita-
tion, record keeping, herd biosecurity,
dietary supplementation, and mastitis
control in bred heifers.
Full adoption of both proven tra-
ditional methods and the more novel
technological approaches toward mas-
titis management by dairy producers
will be necessary to lower the preva-
lence of this disease, lower bulk-tank
SCC, and improve milk quality. The
effect of udder-health-management
practices on herd SCC was recently
reviewed (Dufour et al., 2011), which
emphasized a comprehensive under-
standing of the management practices
that influence SCC as well as the
SCC control tools that are ineffective.
This paper discusses both the tradi-
tional and supplemental mastitis-con-
trol recommendations and the extent
to which they have been adopted (or
not adopted) by United States dairy-
men based on 2 national surveys. The
outcome should help milk-quality and
mastitis-control experts focus on those
practices that need to be adopted to
a greater degree for more successful
management of this livestock disease.
The 2012 Hoard’s Dairyman Con-
tinuing Market Study (Anonymous,
2012) was based on a questionnaire
mailed out to 3,000 producer names
selected randomly from a subscription
list by a computer count and covered
the year 2011. The return rate was
1,310 questionnaires or 43.6%. The
2007 National Animal Health Moni-
toring System (NAHMS) survey
was based on 17 of the nation’s
major dairy states in the western and
eastern regions representing 79.5% of
United States dairy operations and
82.5% of United States dairy cows
(NAHMS, 2008). Where possible, the
NAHMS survey reported data from
small (<100 cows), medium-sized (100
to 499 cows), and large (>500 cows)
Adoption of mastitis-control technologies 119
herds. Mastitis-control measures
surveyed and their rates of adop-
tion determined by the 2 surveys are
discussed below. Most management
practices evaluated revolve around
the milking process itself, and each
practice is discussed in sequence from
the beginning of milking to the end of
this process. Additional mastitis-man-
agement practices not directly related
to milking are also discussed.
MASTITIS-CONTROL
MEASURES SURVEYED AND
THEIR RATES OF ADOPTION
The Milking Process
Wearing of Gloves. The wearing
of disposable latex or nitrile gloves in
the milking parlor is recommended to
reduce the transfer of mastitis-causing
bacteria from milkers’ hands to the
teats of cows during the milking
process. Rodrigues et al. (2005) dem-
onstrated that always wearing gloves
during milking was significantly asso-
ciated with lower bulk-tank SCC. For
example, in herds with low bulk-milk
SCC (<250,000/mL), 86.1% of herds
used gloves, whereas in herds with
high bulk-milk SCC (>400,000/mL),
only 55.0% of herds used gloves.
Bacteria that can cause mastitis
naturally colonize the skin of hu-
man hands, and bacteria originating
from infected udders can contami-
nate human hands. Both serve as
sources of new infection during the
udder-preparation process as milk-
ers forestrip teats. By wearing gloves,
the teat skin of cows is protected
against bacteria residing on milkers’
hands. Additionally, bacteria are less
likely to adhere to the smooth surface
of gloves compared with the rough
texture of milkers’ hands, thus fewer
pathogens are transferred to the teats
of cows. Of course, if gloves become
heavily soiled with organic material,
they should be replaced or washed in
sanitizing solution.
Results of the NAHMS (2008)
survey showed that 55.2% of all dairy
operations used gloves, and in these
operations, gloves were worn when
milking 76.8% of cows. Thus, 45% of
farms do not use gloves when milking
cows, and the reduction in spread of
mastitis-causing bacteria, especially
contagious bacteria such as Staphylo-
coccus aureus, could be accomplished
by following this simple mastitis-
management technique. The practice
of wearing gloves was not evaluated
by the Hoard’s survey.
Forestripping. This practice in-
volves the manual removal of several
streams of milk from each mammary
quarter of the udder before machine
attachment as part of the premilking
udder-preparation routine. The pur-
pose of forestripping is to 1) flush the
teat canal of bacteria and other or-
ganic contaminants that could elevate
bulk-tank bacteria counts and cause
machine-induced infections; 2) allow
the milker to observe milk for any
abnormalities, such as clots or flakes
associated with clinical mastitis, so
that affected cows can be separated
and treated; and 3) promote milk let-
down. In a study of herd management
practices and their association with
bulk-tank SCC, Wenz et al. (2007)
observed that herds that practiced
forestripping of all or some (i.e., mas-
titic and fresh cows) of the cows tend-
ed to have lower SCC (<400,000/mL)
than higher SCC herds (>400,000/
mL) that did not forestrip.
According to the NAHMS (2008)
survey, 58.9% of all dairy opera-
tions forestrip all cows as part of
their udder-prep procedure. Large
herds (83.5%) followed the practice
of forestripping all cows more than
medium-sized (66.9%) and small
herds (53.7%). The approximate 41%
of operations that do not forestrip
all cows are most likely omitting this
procedure to save time in the parlor.
However, all sized operations with
high herd bulk-tank SCC should be
using this practice to prevent new
cases of mastitis as well as to iden-
tify existing clinical cases of mastitis
for treatment. The practice of for-
estripping was not evaluated by the
Hoard’s survey.
Surprisingly, 43.3% of all operations
forestripped teats after disinfection
(predipping), drying, or both, which is
not the recommended practice. Small
herds were the biggest culprit (47%),
followed by medium herds (38.7%)
and large herds (22.4%). Only 27.4%
of all herds forestripped before teat
disinfection, which is the recommend-
ed practice, and 29.3% forestripped
after teat disinfection but before dry-
ing of teats. By forestripping first, any
bacteria already present on the teat
skin as well as from milkers’ hands
are killed by the premilking teat dis-
infectant. However, milkers should not
forestrip after predipping and drying.
By forestripping the sanitized and
dried teat with contaminated hands,
bacteria are redeposited on teat
surfaces, which can potentially cause
mastitis, and this is the case in 43.3%
of all operations. Based on regional
data, the percentage of operations
that forestripped after disinfection
and drying (not the recommendation)
was 2-fold higher in the east (45.2%)
than the west (22.8%).
Predipping. The practice of im-
mersing teats in a germicidal solution
before milking (predipping) kills a
large number of bacteria on the teat
skin and reduces the chances of them
entering the teat canal and caus-
ing intramammary infection (IMI).
The germicide is applied by dip-
ping, spraying, towels, or as a foam
and must remain on the teat skin
for 30 s to allow sufficient time for
microbiocidal activity to take place.
Predipping is 40 to 50% effective in
preventing new IMI by environmental
pathogens such as Escherichia coli,
Klebsiella, Enterobacter, Citrobacter,
Serratia, Streptococcus uberis, and
Streptococcus dysgalactiae and is even
effective against the contagious patho-
gen Staph. aureus (Nickerson, 2001).
The NAHMS (2008) survey showed
that across all modes of germicide
application and across all herd sizes,
79% of operations used a form of teat
preparation. Dipping by immersion
was most popular, followed by spray-
ing, and use of foam was very low.
Use of presanitized towels to prepare
teats was not reported. Large herds
(38.2%) used spray application of la-
beled disinfectant more than medium
(25.4%) and small (13.6%) herds, and
Nickerson and Oliver
120
use of a predip cup to apply labeled
disinfectant was more popular in
small herds (49.8%) compared with
medium (51%) and large (32.3%)
herds. Western herds were more likely
to apply germicide as a spray, whereas
eastern herds were more likely to ap-
ply via dipping.
Likewise, the Hoard’s (Anonymous,
2012) survey showed that 72.9% of
operations use predipping or spray-
ing before milking. Based on these
2 surveys, approximately 20 to 25%
of dairy operations do not sanitize
teats before milking. Predipping (as
well as postdipping) is one of the best
and inexpensive milking-management
practices to prevent new infections,
especially with environmental patho-
gens, and with the trend toward
larger dairies and confined opera-
tions with greater exposure to these
bacterial species, all producers should
be sanitizing teats before milking to
reduce the level of mastitis in their
herds. According to the NAHMS
(2008) survey, the most common
germicide in predip formulations was
iodine (59.7%), followed by chlorhexi-
dine (11.8%), other—unspecified
(7.9%), chlorine (7.2%), fatty-acid
based (2.5%), quaternary ammonium
(0.3%), and phenol (0.1%).
Drying Teats Before Milking.
After sanitization, teats must be dried
before machine attachment to remove
1) germicidal residues, 2) bacteria,
and 3) organic material such as
dirt, bedding material, and manure.
Recommendations for drying include
single-service paper towels or individ-
ual, rewashable cloth towels. A study
of management practices associated
with low, medium, and high bulk-milk
SCC showed that herds that practiced
drying of teats before milking were
associated with low bulk-milk SCC
(<150,000/mL), whereas herds that
did not follow this practice were asso-
ciated with high bulk-milk SCC (251
to 400/mL; Barkema et al., 1998).
According to the Hoard’s (Anony-
mous, 2012) survey, 67.4% of respon-
dents follow recommendations; 44%
use single-service paper towels and
23.4% use rewashable cloths. Unfortu-
nately, 5.2% use either common rags
(4.5%) or common sponges (0.7%),
both which become contaminated
and actually promote the spread of
mastitis-causing bacteria.
Similarly, the NAHMS (2008)
survey demonstrated that ~76% of
producers use single-service paper
(54.7%) or rewashable cloth (21.5%)
towels; however, 7.8% are spread-
ing mastitis-causing bacteria using
multiple-use cloth or paper towels.
Thus, based on the 2 surveys, 25 to
30% of producers are not following
recommendations for drying teats
before milking, and between 7.8 and
9.7% are actually promoting the
development of infections by using
either common rags and sponges or
multiple-use cloth or paper towels.
After teats are prepared, the milk-
ing machine is applied, usually within
1 min of forestripping to take maxi-
mum advantage of the milk let-down
response. The milker holds the claw
in hand, the vacuum is turned on,
and the 4 teat cups are applied with
minimal intake of air. Milk begins
flowing immediately, and the machine
may need adjusting so that it hangs
squarely and straight down from the
cow. Maximal intramammary pressure
caused by milk let-down continues for
about 5 min, and most cows will milk
out in 5 to 7 min. Shortly after that,
milk flow will decrease to a point
where automatic take-offs cause the
milking machine to detach.
Automatic Take-Offs. Automatic
take-offs detect a low flow of milk
from the teat end and cause the milk-
ing cluster to detach from the udder,
whether the cow is fully milked out
in all 4 quarters or not. This action
prevents overmilking and helps to
maintain proper teat end condition.
Healthy teat canals and teat orifices
are less prone to bacterial colonization
and subsequent development of IMI.
In an effort to develop guidelines for
monitoring bulk-milk SCC, Jayarao et
al. (2004) observed that dairy herds
that used automatic milking detachers
had significantly lower bulk-tank SCC
than herds that did not use detachers
(298,560/mL vs. 352,650/mL).
Results of the NAHMS (2008) sur-
vey indicated that only 45.4% of dairy
operations use automatic take-offs.
Use of these devices was more com-
mon in large dairies (89.5%), followed
by medium dairies (76.9%), and small
operations (30.2%). The 55% that do
not use take-offs should consider do-
ing so to improve teat end condition
and reduce the prevalence of IMI as-
sociated with poor teat end condition.
The use of automatic take-offs was
not evaluated by the Hoard’s (Anony-
mous, 2012) survey.
Back-Flushing the Milking
Unit. The process of back-flushing
sanitizes the milking cluster between
cows to reduce the spread of conta-
gious pathogens among cows during
milking. This action includes a blast
of sanitizer through the cluster and
teat cups to disinfect the lining, fol-
lowed by a blast of water to rinse out
the sanitizer, and last, a blast of air
to dry the system. This process is
effective in removing contaminants
from teat cup liners before placement
on teats of uninfected cows and helps
to reduce spread of the contagious
mastitis-causing bacteria such as
Staph. aureus. Two trials conducted
to test the efficacy of an iodine back-
flush system for reducing new IMI
demonstrated that the back-flushing
of milking clusters reduced infections
caused by Staph. aureus and Coryne-
bacterium bovis; however, use of the
system produced no clear advantage
for reducing new IMI with coagulase-
negative staphylococci, gram-negative
bacilli, or the environmental strep-
tococci (Hogan et al., 1984). In trial
1, numbers of new Staph. aureus IMI
were reduced in quarters exposed to
back-flushing compared with controls
(3 vs. 10), and numbers of new C.
bovis IMI were also reduced (7 vs.
17). In trial 2, numbers of new Staph.
aureus IMI were reduced in quarters
exposed to back-flushing compared
with controls (1 vs. 4), and numbers
of new C. bovis IMI were also reduced
(10 vs. 39).
The NAHMS (2008) survey showed
that across all dairy operations, only
6.8% used back-flush systems, which
were slightly more common in large
operations (9.3%) than medium
(8.6%) or small operations (5.9%).
Adoption of mastitis-control technologies 121
Thus, over 93% of operations have not
installed a back-flush system. Most
experts agree, however, that if an ef-
fective postmilking teat disinfectant
is being used, a back-flush system is
not necessary. Back-flushing was more
common in western herds versus east-
ern herds. The use of back-flushing
was not evaluated by the Hoard’s
survey.
Postdipping. The practice of im-
mersing teats in a germicidal solution
immediately after milking (postdip-
ping) kills a large number of conta-
gious bacteria on the teat skin that
originate from contaminated teat
cup liners and reduces the chances
of them entering the dilated teat
canal and causing IMI. Postdipping
is one of the points in the 5-point
plan of mastitis control developed in
the 1960s (Neave et al., 1969) and
continues to be a major milking-man-
agement practice to prevent new IMI.
The germicide is applied by dipping,
spraying, inline sprayers, or as a foam.
Postdipping is 50 to 95% effective in
preventing new IMI with the conta-
gious pathogens such as Staph. aureus
and Streptococcus agalactiae (Nicker-
son, 2001).
The NAHMS (2008) survey showed
that across all modes of germicide
application and across all seasons,
94.8% of operations used some form
of postmilking teat antisepsis. Dip-
ping by immersion was most popular,
followed by spraying; use of foam was
very low.
Likewise, the Hoard’s (Anonymous,
2012) survey showed that 90.5% of
operations followed the practice of
postdipping after milking. Based on
these 2 surveys, approximately 5 to
10% of dairy operations do not sani-
tize teats after milking. Postdipping is
one of the best milking-management
practices to prevent new infections,
especially with contagious pathogens,
so all producers should be sanitizing
teats after milking to reduce the level
of mastitis in their herds.
According to the NAHMS (2008)
survey, the most common germi-
cide in postdip formulations was
iodine (68.8%). This was followed
by chlorhexidine (12.8%), fatty-acid
based (6.8%), other—unspecified
(3.9%), chlorine (2.0%), and quater-
nary ammonium (0.6%).
Other Mastitis-Management
Practices
Vaccination Against Mastitis.
Immunization is used to stimulate
the production of antibodies against
mastitis-causing bacteria in the body
of the cow to prevent the establish-
ment of infection as well as to reduce
the severity of infection. The major-
ity of research trials have focused on
coliform and Staph. aureus vaccines.
Early studies on the commercially
available J5 mutant coliform bac-
terin revealed that the percentage of
clinical-mastitis cases caused by E.
coli and Klebsiella spp. was lower in
vaccinated cows (2.4%) compared
with unvaccinated controls (12.1%;
Gonzalez et al., 1989). Efficacy stud-
ies on the only commercial Staph.
aureus vaccine (Lysigin) suggest that
it will increase the spontaneous cure
rate against Staph. aureus IMI and
lower SCC but not prevent new IMI
in adult cows (Pankey et al., 1985).
However, this vaccine was shown to
be effective in preventing new Staph.
aureus IMI when administered to bred
dairy heifers (Nickerson et al., 1999).
The NAHMS (2008) survey showed
that 39.7% of dairy operations re-
ported using some type of mastitis
vaccine on all of their cows. The most
common vaccine was directed against
coliforms (32.6%), followed by Salmo-
nella (11.1%), Staph. aureus (5.7%),
siderophore receptors and porins
(3.3%), and Mycoplasma (1.4%).
In the Hoard’s (Anonymous, 2012)
survey, the percentage usage was
slightly higher but similar at 41.9%;
however, it was not broken down into
vaccine types. Thus, overall, ap-
proximately 60% of farms do not use
a mastitis vaccine. Certainly most
farms would benefit by using some
type of coliform vaccine program. It is
well known that 20 to 40% of clini-
cal cases are caused by environmental
pathogens, including coliforms, and
that fresh, high-producing cows are
very susceptible to new infections. In
addition, the cost for each clinical epi-
sode of coliform mastitis ranges from
$100 to $400. In one study, a partial
budget analysis of vaccinating dairy
cattle against coliform mastitis dem-
onstrated that the cost-to-benefit ra-
tio of immunizing all cows in the herd
with a coliform vaccine was $1 to $57
(DeGraves and Fetrow, 1991). Among
the 3 coliform vaccines commercially
available in the United States, the J-5
Bacterin enjoys the majority of the
market (42.3%), followed by the J-Vac
(37.8%) and Endovac-Bovi (16.7%).
Antibiotic Treatment of Clinical
Mastitis Cases During Lactation.
As with postdipping, the prompt
treatment of clinically infected
quarters with antibiotics is also one
of the points in the 5-point plan of
mastitis control (Neave et al., 1969).
This practice decreases the duration
of IMI as long as treatment is success-
ful in curing the infecting organism.
Although a true cure, whereby all
infecting microorganisms are eliminat-
ed from the affected quarter, occurs
in only 10 to 50% of cases, successful
therapy removes the main source of
contagious pathogens from the herd,
thus treatment of clinical infections is
still a recommended practice (Nicker-
son, 1996).
The Hoard’s (Anonymous, 2012)
survey reported that 59.6% of dairy
operations use some type of remedy
for treating lactating cows for mas-
titis, and of these operations, 89.9%
infused antibiotics into the affected
quarter, e.g., 53.5% of all operations
used lactating cow therapy to treat
clinical cases of mastitis. Other means
of administering antibiotics included
intramuscular and intravenous injec-
tions. Thus, almost 50% of producers
do not follow the practice of prompt
treatment of clinical mastitis as rec-
ommended in the 5-point plan. Treat-
ment of clinical cases was not evalu-
ated by the NAHMS (2008) survey.
Antibiotic Therapy at the Be-
ginning of the Nonlactating Pe-
riod. Also known as dry-cow therapy,
this practice also is a component of
the 5-point plan (Neave et al., 1969)
and involves infusing all quarters of
all cows with a nonlactating-cow infu-
Nickerson and Oliver
122
sion product at the end of lactation.
The purpose of this therapy is 2-fold
as it 1) cures existing IMI and 2)
prevents new cases of mastitis during
the early dry period when mammary
glands are highly susceptible to new
infection. Dry-cow therapy is very
advantageous to udder health because
the practice prevents mastitis in the
early dry period, reduces the preva-
lence of infection at calving, mini-
mizes antibiotic contamination, allows
milk-producing tissue to redevelop in
cured quarters, and reduces clini-
cal mastitis at freshening. Efficacy
against pathogens such as Staph.
aureus may range from 33 to 70%,
but despite this low cure rate, the end
of lactation provides the optimum
time for treatment because efficacy of
lactational therapy is even lower and
requires milk withdrawal (Erskine et
al., 1998).
The NAHMS (2008) survey showed
that 72.3% of all operations dry treat
all cows, and the Hoard’s survey
found that this figure was 82.2%;
thus, about 23% of United States
dairies do not use dry-cow therapy.
According to the NAHMS survey, the
most-used antibiotic for dry-cow ther-
apy was penicillin G/dihydrostrepto-
mycin (36.9%), followed by cephapirin
benzathine (31%), penicillin/novo-
biocin (13.2%), cloxacillin benzathine
(7.9%), ceftiofur hydrochloride (7.0%),
and other products.
Use of Internal Teat Sealants
at Drying Off. Internal teat seal-
ants, commonly composed of bismuth
and paraffin, are infused into each
quarter at the end of lactation. The
teat-sealant material is very heavy
and viscous and forms a physical seal
in the distal teat cistern as well as
in the teat canal against bacterial
penetration. It is removed after calv-
ing at the first milking, but it is inert
and so does no harm if ingested by
the calf. Studies have shown that use
of teat sealants is 50 to 90% effective
in preventing new IMI. For example,
Laven and Lawrence (2008) showed
that cows and heifers treated with
a teat sealant at dry-off (cows) or 1
mo prepartum (heifers) experienced
a 51.4% reduction in clinical mastitis
during early lactation compared with
untreated controls (6.9 vs. 14.2%).
Results of the NAHMS (2008) sur-
vey showed that 30.1% of all opera-
tions used a sealant in all cows at
drying off. Teat sealants were more
commonly used in large (49%) and
medium herds (45.7%) than small
herds (22.7%). Likewise, the Hoard’s
(Anonymous, 2012) survey showed
that 32% of operations used a teat
sealant. So, based on results of these 2
surveys, close to 70% of dairy opera-
tions do not use this management
technique.
Potential Mastitis-
Management Practices
Fly Control. Fly control is used
to reduce these insect pests on farm
premises and subsequently to reduce
animal stress, but its application as
an adjunct management practice for
preventing new cases of mastitis and
reducing SCC has not been considered
or embraced by producers. However,
an initial survey in Louisiana showed
that prevalence of mastitis in bred
heifers was significantly lower in
dairy herds that used some form of
fly control for their lactating cows,
dry cows, and heifers compared with
herds applying no fly control (Nicker-
son et al., 1995). A subsequent study
demonstrated that the horn fly is
responsible for teat lesions on heifers
that can develop into Staph. aureus
IMI, which are then spread among
heifers by these insect vectors, and
these pathogens may be transmitted
to the entire lactating and nonlactat-
ing herds (Owens et al., 1998). The
use of an insecticidal pour-on every
2 wk for 6 wk followed by treatment
with insecticidal ear tags reduced
fly populations and decreased the
incidence of new Staph. aureus IMI
by 83% during a 6-mo trial in heifers
during the warm season in Louisiana
(Owens et al., 2002).
Although not specifically used to
control mastitis, the Hoard’s (Anony-
mous, 2012) survey reported that
81.1% of producers used some type of
fly control. The majority of products
were used as a pour-on (44.3%) and
aerosol (32.4%), followed by bait,
paper, foggers, and others. The good
news is that more than 80% of opera-
tions use fly control; it just needs to
be incorporated into a heifer mastitis
program.
Dietary Supplementation.
Supplementing the diets of cows with
certain trace minerals and vitamins
has been shown to have immuno-
modulatory effects on the mammary
gland and include vitamin E, sele-
nium, vitamin A, β-carotene, vitamin
D, copper, and zinc (Sordillo et al.,
1997). Most of these substances serve
as fundamental components of anti-
oxidant processes that are involved in
the reduction of reactive oxygen spe-
cies released during phagocytosis and
killing of bacteria by leukocytes.
More recently, commercial feed ad-
ditives incorporating an array of the
above supplements plus microbial by-
products have been formulated. The
Hoard’s (Anonymous, 2012) survey re-
ported that 32.3% of dairy operations
use some type of commercial yeast or
yeast culture as a feed additive. It is
believed that the yeast supplement
acts as a probiotic, positively influ-
encing rumen microflora and diges-
tion and subsequently improving milk
yield, especially in early lactation.
One such commercial supplement con-
taining yeast, B vitamins, and various
trace nutrients (OmniGen-AF) has
been shown to have immunostimulat-
ing properties in addition to a role in
improving milk production. Although
this product is not recommended for
its immunostimulatory properties at
this time, research suggests a possible
future role in disease control, such as
mastitis. For example, Wang et al.
(2007) found that immunosuppression
in sheep could be reversed in animals
supplemented with OmniGen-AF.
Likewise, Rowson et al. (2011) infused
various mastitis-causing pathogens
into the mammary glands of mice and
found that mice that received dietary
OmniGen-AF daily for 2 wk before in-
fusion exhibited significantly reduced
bacterial loads, indicating a positive
Adoption of mastitis-control technologies 123
effect of the feed supplement on the
ability of the murine mammary gland
to resist IMI.
In cows, Eubanks et al. (2012) dem-
onstrated that feeding of the dietary
supplement OmniGen-AF to a limited
number of dairy heifers before calving
resulted in a 69.2% reduction in prev-
alence of mastitis in early lactation, a
74.7% reduction in SCC, and a 3.2-kg
increase in milk production compared
with unsupplemented controls, sug-
gesting that dietary supplementation
may alleviate stress associated with
calving and enhance immunity during
the periparturient period. However,
results are preliminary, and further
testing is required before making a
general recommendation.
IMPLICATIONS
Based on the responses from the
2 surveys, adoption rates for recom-
mended milking procedures and other
management practices (vaccination,
antibiotic therapy, teat sealants) are
summarized in Table 3. Adoption
rates observed in both surveys were
surprisingly similar across all mastitis-
management practices evaluated, and
the overall adoption rate (Table 3)
is an average of the 2 surveys where
applicable. Some practices were only
evaluated by one of the surveys, not
both.
Survey results revealed that ap-
proximately 40% of dairy producers
are not following the recommended
management practices to control
mastitis in their herds, and it is likely
that many of these producers are
located in the Southeast. In view of
these findings, it will be necessary for
extension and outreach personnel to
train producers and employees on how
best to use current and newly devel-
oped mastitis-management tools to
make on-farm decisions that improve
milk quality and increase milk pro-
duction. Likewise, continuing educa-
tion programs need to be developed
to create human resources needed
for a more knowledgeable work force
to promote mastitis control and
improved milk quality. Implementa-
tion of cost-effective mastitis preven-
tion and control strategies for the
Southeast region will result in higher
milk quality, increased milk produc-
tion, and improved profitability, all
of which will benefit dairy producers
in the Southeast and enhance the
sustainability of the dairy industry in
this region.
LITERATURE CITED
Anonymous. 2012. Continuing market study.
Hoard’s Dairyman, pp. 33–37. Res. Dept.,
Fort Atkinson, WI.
APHIS (US Animal and Plant Health Inspec-
tion Service). 2008. Determining U.S. Milk
quality using bulk-tank somatic cell counts.
Accessed Nov. 2012. http://www.aphis.usda.
gov/animal_health/nahms/dairy/downloads/
dairy_monitoring/BTSCC_2008infosheet.pdf.
Barkema, H. W., Y. H. Schukken, T. J. G. M.
Lam, M. L. Beiboer, G. Benedictus, and A.
Brand. 1998. Management practices associ-
ated with low, medium, and high somatic cell
counts in bulk milk. J. Dairy Sci. 81:1917–
1927.
DeGraves, F. J., and J. Fetrow. 1991. Partial
budget analysis of vaccinating dairy cattle
against coliform mastitis with an Escherichia
coli J5 vaccine. J. Am. Vet. Med. Assoc.
199:451–455.
Dohoo, I. R., and A. H. Meek. 1982. Somatic
cell counts in bovine milk. Can. Vet. J.
23:119–125.
Dufour, S., A. Fréchette, H. W. Barkema,
A. Mussell, and D. T. Scholl. 2011. Effect of
udder health management practices on herd
somatic cell count. J. Dairy Sci. 94:563–579.
Erskine, R. J., P. C. Bartlett, S. R. Tavernier,
L. H. Fowler, R. D. Walker, J. H. Seguin,
and D. Shuster. 1998. Recombinant bovine
interleukin-2 and dry cow therapy: Efficacy
to cure and prevent intramammary infections,
safety, and effect on gestation. J. Dairy Sci.
81:107–115.
Eubanks, V. J., D. J. Hurley, L. O. Ely, F.
M. Kautz, S. C. Nickerson, N. E. Forsberg,
Y. Q. Wang, K. Zanzalari, and J. Chapman.
2012. Pre- and postpartum immunomodula-
tory effects of a dietary supplement on the
immune system of dairy heifers. J. Dairy Sci.
95(Suppl. 2):222. (Abstr.)
Gonzalez, R., J. Cullor, D. Jasper, T. B.
Farver, R. B. Bushnell, and M. N. Oliver.
1989. Prevention of clinical coliform mastitis
in dairy cows by a mutant Escherichia coli
vaccine. Can. J. Vet. Res. 53:301–305.
Herndon, C. W. 2011. Part I: How the South-
east is different. Hoard’s Dairyman May 10,
2011, p. 336.
Hogan, J. S., R. J. Harmon, B. E. Langlois,
R. W. Hemken, and W. L. Crist. 1984. Ef-
ficacy of an iodine backflush for preventing
new intramammary infections. J. Dairy Sci.
67:1850–1859.
Jayarao, B. M., S. R. Pillai, A. A. Sawant,
D. R. Wolfgang, and N. V. Hegde. 2004.
Guidelines for monitoring bulk tank milk
somatic cell and bacterial counts. J. Dairy
Sci. 87:3561–3573.
Laven, R. A., and K. E. Lawrence. 2008. Ef-
ficacy of blanket treatment of cows and heif-
ers with an internal teat sealant in reducing
the risk of mastitis in dairy cattle calving on
pasture. N. Z. Vet. J. 56:171–175.
Lombard, J. E., H. D. Norman, C. A. Kopral,
and J. M. Rodriguez. 2011. European Union
bulk tank SCC standards and proposed US
standards: Compliance based on data from
four federal milk marketing orders. Pages 5–9
Table 3. Adoption rates of recommended milking practices and other
management practices to control mastitis in dairy cows
Item Adoption rate (%)
Recommended milking procedure
Forestripping 60
Predipping 77.5
Postdipping 92.5
Wearing gloves 55
Segregate/milk last 65
Use automatic take-offs 45
Other management practices
Vaccination 45
Treating clinical mastitis 50
Dry-cow therapy 77
Teat sealants 35
Overall adoption rate 60
Nickerson and Oliver
124
in Proc. 3rd Int. Symp. Mastitis Milk Quality,
St. Louis, MO. Natl. Mastitis Counc., Verona,
WI.
NAHMS (National Animal Health Moni-
toring System). 2008. Dairy 2007 Part III:
Reference of dairy cattle health and manage-
ment practices in the United States. USDA.
Accessed Jan. 2012. http://www.aphis.usda.
gov/animal_health/nahms/dairy/index.
shtml#dairy2007.
National Mastitis Council. 1996. Current
Concepts of Bovine Mastitis. 4th ed. Natl.
Mastitis Counc. Inc., Verona, WI.
Neave, F. K., F. H. Dodd, R. G. Kingwell,
and D. R. Westgarth. 1969. Control of masti-
tis in the dairy herd by hygiene and manage-
ment. J. Dairy Sci. 52:696–707.
Nickerson, S. C. 1996. Clinical mastitis:
To treat or not to treat. Pages 355–377 in
Proc. 1996 West. Can. Dairy Sem. Vol. 8.
Red Deer, Alberta, Canada. Univ. Alberta,
Edmonton, AB, Canada.
Nickerson, S. C. 2001. Choosing the best
teat dip for mastitis control and milk quality.
Page 43 in Proc. Natl. Mastitis Counc.—Prof.
Dairy Prod. Wisconsin Milk Quality Conf.,
Madison, WI. Natl. Mastitis Counc., Verona,
WI.
Nickerson, S. C., W. E. Owens, and R. L.
Boddie. 1995. Mastitis in dairy heifers: Initial
studies on prevalence and control. J. Dairy
Sci. 78:1607–1618.
Nickerson, S. C., W. E. Owens, G. M. To-
mita, and P. W. Widel. 1999. Vaccinating
dairy heifers with a Staphylococcus aureus
bacterin reduces mastitis at calving. Large
Anim. Pract. 20:16–20.
Oliver, S. P., G. M. Pighetti, R. A. Almeida,
P. D. Krawczel, J. M. Fly, C. S. Petersson-
Wolfe, J. M. Bewley, L. E. Garkovich, D.
M. Amaral-Phillips, L. M. Arnold, S. C.
Nickerson, S. Hill-Ward, and A. DeVries.
2013. Southeast Quality Milk Initiative:
Implementing science-based recommendations
to control mastitis and improve milk quality
in the Southeast. Poster presented at the
Ann. USDA Natl. Inst. Food Agric. (NIFA)
Agric. Food Res. Initiative (AGRI) Project
Dir. Workshop, Washington, DC. USDA,
Washington, DC.
Owens, W. E., S. C. Nickerson, and C. H.
Ray. 2002. Effect of a pour-on and fly tag in-
secticide combination in controlling horn flies
and Staphylococcus aureus mastitis in dairy
heifers. Pages 39–42 in 2002 Louisiana Dairy
Report. Louisiana State Univ. Agric. Center,
Baton Rouge.
Owens, W. E., S. P. Oliver, B. E. Gillespie,
C. H. Ray, and S. C. Nickerson. 1998. Role of
horn flies (Haematobia irritans) in Staphylo-
coccus aureus-induced mastitis in dairy heif-
ers. Am. J. Vet. Res. 59:1122–1124.
Pankey, J. W., N. T. Boddie, J. L. Watts,
and S. C. Nickerson. 1985. Evaluation of
protein A and a commercial bacterin as vac-
cines against Staphylococcus aureus mastitis
by experimental challenge. J. Dairy Sci.
68:726–731.
Rodrigues, A. C. O., D. Z. Caraviello, and P.
L. Ruegg. 2005. Management of Wisconsin
dairy herds enrolled in milk quality teams. J.
Dairy Sci. 88:2660–2671.
Rowson, A. D., Y. Q. Wang, E. Aalseth, N.
E. Forsberg, and S. B. Puntenney. 2011. Ef-
fects of an immunomodulatory feed additive
on the development of mastitis in a mouse
infection model using four bovine-origin iso-
lates. Animal 5:220–229.
Russell, R. A., and J. M. Bewley. 2011.
Producer assessment of dairy extension
programming in Kentucky. J. Dairy Sci.
94:2637–2647.
Sharif, A., and G. Muhammad. 2008. Somatic
cell count as an indicator of udder health sta-
tus under modern dairy production: A review.
Pakistan Vet. J. 28:194–200.
Sordillo, L. M., K. Shafer-Weaver, and C.
DeRosa. 1997. Immunobiology of the mam-
mary gland. J. Dairy Sci. 80:1851–1865.
USDA, ARS. 2011. Animal Improvement
Program Laboratory reports on somatic cell
counts of milk from DHI herds published
from 2001–2010. Accessed Nov. 2012. http://
aipl.arsusda.gov/publish/dhi/scc.html.
USDHHS, PHS, FDA (US Department of
Health and Human Services, Public Health
Service, Food and Drug Administration).
2009. Grade “A” pasteurized milk ordinance.
2009 Rev. Accessed Dec. 2012. http://www.
fda.gov/downloads/Food/FoodSafety/
ProductSpecific Information/Milk Safety/
NationalConferenceonInterstateMilkShip
mentsNCIMSModelDocuments/UCM209789.
pdf
Wang, Y. Q., S. B. Puntenney, J. L. Bur-
ton, and N. E. Forsberg. 2007. Ability of
a commercial feed additive to modulate
expression of innate immunity in sheep immu-
nosuppressed with dexamethasone. Animal
1:945–951.
Wenz, J. R., S. M. Jensen, J. E. Lombard, B.
A. Wagner, and R. P. Dinsmore. 2007. Herd
management practices and their associa-
tion with bulk tank somatic cell count on
United States dairy operations. J. Dairy Sci.
90:3652–3659.
... The contrast was seen with use of AMD containing penicillins on dry-off treatment which was reportedly greater in our study 33.6% compared to the 26.8% (Boviclox Ò , Dry-clox Ò , Orbenin Ò , Albadry Ò plus) in NAHMS 2014 Dairy study; and with Quartermaster Ò which was less in our study (14.4% compared to 24.0% in NAHMS 2014 Dairy study) (National Animal Health Monitoring System (NAHMS), 2016a). Several studies have described the benefits of dry cow therapy to udder health (Nickerson & Oliver, 2014;Owens et al., 2001;Vilar et al., 2018). The practice prevents mastitis in the early dry period, allows milkproducing tissue to redevelop in cured quarters, and reduces clinical mastitis at freshening. ...
Full-text available
Article
Background A survey of California (CA) dairies was performed in spring 2018 to characterize antimicrobial stewardship practices, antimicrobial drug (AMD) use, and health management of adult cows on CA dairies since the implementation of the Veterinary Feed Directive (VFD) and the CA Senate Bill 27 (SB 27). Effective January 1, 2017, the U.S. Food and Drug Administration (FDA) implemented regulatory changes requiring veterinary oversight for therapeutic uses of medically-important antimicrobial drugs (MIADs) administered in feed (VFD) and water (veterinary prescription). Similarly, effective January 1, 2018, the CA legislature enacted California Food and Agricultural Code (FAC) 14400–14408, formerly known as Senate Bill 27 (SB 27) requiring veterinary prescriptions for all other dosage forms of MIADs. Methods The questionnaire consisted of 43 questions partitioned into three sections to assess herd information, management practices, and AMD use and perspectives. The questionnaire was mailed to 1,282 grade A licensed dairies in CA and 149 responses (11.6%) were collected from 19 counties across the three defined regions of CA: Northern CA (NCA), Northern San Joaquin Valley (NSJV), and Greater Southern CA (GSCA). Results Most dairies reported treating all dry cows with intramammary AMD and/or teat sealant at the end of a lactation (87.2%). In 92.3% of dairies, producers relied on the veterinarian for information about AMD used to treat cows. Treatment duration for cows treated with AMD was based on the drug manufacturer’s label and veterinarian’s instructions in most dairies (98.6%). Most respondents to the survey confirmed having a valid veterinarian-client-patient-relationship (VCPR) for their dairies (91.7%), participated in animal welfare audit programs (81.8%) and dairy quality assurance programs (52.9%). Approximately 98.6% respondents were aware that all uses of MIADs in livestock required a veterinary feed directive (VFD) or prescription and are no longer sold over-the-counter (OTC) in CA since January 1, 2018. Multiple factor analysis (MFA) was performed and identified seven components composed of 21 variables (questions) that explained 99.7% of the total variance in the data. Hierarchical cluster analysis on the principal coordinates of the MFA based on conventional dairy survey responses identified two clusters characterized as large conventional dairies (median herd size: 1,265 cows) and mid-sized conventional dairies (median herd size: 715 cows) mostly in GSCA and NSJV. The organic dairies grouped into a single cluster of median herd size of 325 cows mostly in NCA. Conclusions The survey results contribute to the knowledge of AMD use and antimicrobial stewardship practices on CA dairies since the implementation of the SB 27 and VFD laws and provide useful information for future evaluation of resistance-related risk in adult cows.
... Bovine mastitis, an inflammation of mammary gland, is a serious infectious disease involved in the infection with a pathogen, such as Staphylococcus aureus (S. aureus), Escherichia coli, and Streptococcus [1], and results in decreased milk quality [2] and economic losses [3]. Bovine mastitis is divided into clinical and subclinical mastitis. ...
Full-text available
Article
Background: Tea tree oil (TTO) plays an important role in antibacterial activity and alleviating the inflammatory responses. Bovine mammary epithelium and polymorphonuclear leukocytes (PMNL) can actively respond to bovine mastitis infection. However, regulatory effects of TTO extracts on the innate immune response of bovine mammary epithelial cells (BMECs) and PMNL remain not reported. Therefore, aim of the study was to evaluate the effects of TTO extracts on the mRNA levels of the genes involved in the innate immune response of BMECs and PMNL. Results: Our results demonstrated that addition of 0.025% and 0.05% TTO increased the proliferation of BMECs, and significantly enhanced (P < 0.05) the viability of BMECs exposed to Staphylococcus aureus (S. aureus). An inhibitory effect was observed against the growth of S. aureus by TTO incubation. The 0.05% TTO reduced S. aureus biofilm formation, association and invasion of S. aureus to BMECs, and changed the morphological and structural features of S. aureus. The proinflammatory cytokines IL-1β, IL-6, and TNF-α were decreased (P < 0.001) by the incubation of TTO. Interestingly, the expression of IL-8 known for PMNL chemotactic function was elevated (P < 0.05) by 0.05% TTO treatment. Consistently, 0.05% TTO increased the migration of PMNL in S. aureus-exposed BMECs when compared with S. aureus treatment alone (P < 0.05). In addition, PMNL incubated with 0.05% TTO decreased the levels of NFKB inhibitor alpha (NFKBIA) and TNF-α. Conclusions: Our results indicate that use of TTO can relieve the BMECs pro-inflammatory response caused by S. aureus and promote the migration of PMNL to mount the innate immune responses, and it may be novel strategy for the treatment of bovine mastitis caused by S. aureus.
... La mastitis es una reacción inflamatoria de la glándula mamaria (GM) y produce alteraciones físicas y químicas en la leche, aumento del recuento de células somáticas (RCS) por la presencia de patógenos y finalmente pérdida de la funcionalidad de la GM [46]. Las pérdidas económicas que generan las infecciones intramamarias (IIM) a nivel mundial, ya sean clínicas o subclínicas, son elevadas, hasta el punto que se considera esta enfermedad junto a los problemas reproductivos, las que generan las mayores pérdidas en producción bovina por disminución en la producción de leche, descarte de leche, servicios profesionales, costo de los antibióticos, mano de obra y pérdidas del valor de las vacas [22,32,38]. Por ello las investigaciones en esta área buscan concentrar los esfuerzos en el conocimiento de los patógenos y la respuesta inflamatoria de la GM a cada uno de éstos con el fin de establecer de una manera correcta las medidas preventivas [36]. ...
Full-text available
Article
The aim of this study was to evaluate the odds of having a subclinical intramammary infection (IIM) around calving, and its association with risk factors, such as herd, breed, parity, milk yield, and changes in body condition score in Holstein and Normande cows (n = 208) in dairy grazing systems in Caldas, Colombia. Two composite milk samples were collected from each cow at drying- off (n = 165), and once a week during the first month of lactation (n = 208, 43 heifers were enrolled). One sample was used for the analysis of somatic cell count (SCC), and the other one for bacteriological culture. An IMI was declared when a mastitis- causing pathogen was isolated from milk samples had a SCC ≥ 100,000 and ≥ 200,000 cells/mL in primiparous and multiparous cows, respectively. Multivariate logistic regression models were used to establish the association between the odds of having an IMI around calving with other variables. On average, SCC at drying-off was higher than the average in the first month of lactation. It was found that 44,8% of cows had an IMI at drying off. Drying-off therapy cured 21, 8% of cows with IIMs. At calving, 12,1% of cows had chronic subclinical IIM, 13,3% new infections, and 5,8% of cows had clinical infections. Herd, milk yield and changes in body condition score had a significant effect on the odds of having an IMI around calving. The most frequent bacteria isolated were Staphylococcus aureus, coagulase negative staphylococci (CNS), and Streptococcus uberis. These results suggested that subclinical IMI around calving were associated to management conditions on each herd, which is an indication that subclinical mastitis is still a multivariate problem. High milk yield was also associated with a low odds of infection.
... La mastitis es una reacción inflamatoria de la glándula mamaria (GM) y produce alteraciones físicas y químicas en la leche, aumento del recuento de células somáticas (RCS) por la presencia de patógenos y finalmente pérdida de la funcionalidad de la GM [46]. Las pérdidas económicas que generan las infecciones intramamarias (IIM) a nivel mundial, ya sean clínicas o subclínicas, son elevadas, hasta el punto que se considera esta enfermedad junto a los problemas reproductivos, las que generan las mayores pérdidas en producción bovina por disminución en la producción de leche, descarte de leche, servicios profesionales, costo de los antibióticos, mano de obra y pérdidas del valor de las vacas [22,32,38]. Por ello las investigaciones en esta área buscan concentrar los esfuerzos en el conocimiento de los patógenos y la respuesta inflamatoria de la GM a cada uno de éstos con el fin de establecer de una manera correcta las medidas preventivas [36]. ...
Full-text available
Article
The aim of this study was to evaluate the odds of having a subclinical intramammary infection (IIM) around calving, and its association with risk factors, such as herd, breed, parity, milk yield, and changes in body condition score in Holstein and Normande cows (n = 208) in dairy grazing systems in Caldas, Colombia. Two composite milk samples were collected from each cow at drying-off (n = 165), and once a week during the first month of lactation (n = 208, 43 heifers were enrolled). One sample was used for the analysis of somatic cell count (SCC), and the other one for bacteriological culture. An IMI was declared when a mastitis-causing pathogen was isolated from milk samples had a SCC ≥ 100,000 and ≥ 200,000 cells/mL in primiparous and multiparous cows, respectively. Multivariate logistic regression models were used to establish the association between the odds of having an IMI around calving with other variables. On average, SCC at drying-off was higher than the average in the first month of lactation. It was found that 44,8% of cows had an IMI at drying off. Drying-off therapy cured 21, 8% of cows with IIMs. At calving, 12,1% of cows had chronic subclinical IIM, 13,3% new infections, and 5,8% of cows had clinical infections. Herd, milk yield and changes in body condition score had a significant effect on the odds of having an IMI around calving. The most frequent bacteria isolated were Staphylococcus aureus, coagulase negative staphylococci (CNS), and Streptococcus uberis. These results suggested that subclinical IMI around calving were associated to management conditions on each herd, which is an indication that subclinical mastitis is still a multivariate problem. High milk yield was also associated with a low odds of infection.
... The economic losses due to mastitis in the United States exceed $2 billion annually (Nickerson and Oliver, 2014). Mastitis, an inflammation of the mammary gland, is usually associated with the presence of a pathogen such as Escherichia coli, Klebsiella spp., Streptococcus spp., and Staphylococcus spp. ...
Full-text available
Article
Research on the use of natural products to treat or prevent microbial invasion as alternatives to antibiotic use is growing. Polymorphonuclear leukocytes (PMNL) play a vital role with regard to the innate immune response that affects severity or duration of mastitis. To our knowledge, effect of cold-pressed terpeneless Valencia orange oil (TCO) on bovine PMNL function has not been elucidated. Therefore, the objective of this study was to investigate the effect of TCO on bovine blood PMNL chemotaxis and phagocytosis capabilities and the expression of genes involved in inflammatory response in vitro. Polymorphonuclear leukocytes were isolated from jugular blood of 12 Holstein cows in mid-lactation and were incubated with 0.0 or 0.01% TCO for 120 min at 37°C and 5% CO2, and phagocytosis (2 × 10(6) PMNL) and chemotaxis (6 × 10(6) PMNL) assays were then performed in vitro. For gene expression, RNA was extracted from incubated PMNL (6 × 10(6) PMNL), and gene expression was analyzed using quantitative PCR. The supernatant was stored at -80°C for analysis of tumor necrosis factor-α. Data were analyzed using a general linear mixed model with cow and treatment (i.e., control or TCO) in the model statement. In vitro supplementation of 0.01% of TCO increased the chemotactic ability to IL-8 by 47%; however, migration of PMNL to complement 5a was not altered. Treatment did not affect the production of tumor necrosis factor-α by PMNL. Expression of proinflammatory genes (i.e., SELL, TLR4, IRAK1, TRAF6, and LYZ) coding for proteins was not altered by incubation of PMNL with TCO. However, downregulation of TLR2 [fold change (FC = treatment/control) = -2.14], NFKBIA (FC = 1.82), IL1B (FC = -2.16), TNFA (FC = -9.43), and SOD2 (FC = -1.57) was observed for PMNL incubated with TCO when compared with controls. Interestingly, expression of IL10, a well-known antiinflammatory cytokine, was also downregulated (FC = -3.78), whereas expression of IL8 (FC = 1.93), a gene coding for the cytokine IL-8 known for its chemotactic function, tended to be upregulated in PMNL incubated with TCO. Incubation of PMNL with TCO enhanced PMNL chemotaxis in vitro. The expression of genes involved in the inflammatory response was primarily downregulated. Results showed that 0.01% TCO did not impair the function of PMNL in vitro. Future studies investigating the use of TCO as an alternative therapy for treatment of mastitis, including dose and duration, for cows during lactation are warranted. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
Full-text available
Research
Mastitis is a worldwide problem of dairy industry that has been the cause of concern from decades with no concrete preventive tool yet. Teat dips have been recommended but still not much in practice by our rural folk. This study determines the efficacy of some essential oils as an alternate to commercially available teat dips in reducing the teat end bacterial count and to optimize the time for post milking teat dips to reduce pathogen loads on teat skin. The percentage reduction of mastitis pathogens on teat skin with 3 teat dips: plain water, commercial antiseptic solution and mixture of cinnamon oil and tea tree oil at 30 second and 15 minute after post dipping was evaluated. The teat-end bacterial load (log 10 TBC value) after washing of udder with water as pre-milking teat disinfectant was 7.814 log 10 cfu/ml. Use of dettol as teat disinfectant reduces teat-end bacterial load (log 10 TBC) to 6.59 log 10 cfu/ml after 30 sec. of application of dettol disinfectant, but after 15 minute it again increased tolog10 TBC value 7.309 log 10 cfu/ml. Teat dipping with the mixture of Cinnamon and Tea-tree oil reduced the teat-end bacterial load to log10 TBC value 6.759 log 10 cfu/ml within 30 second and 6.944 log 10 cfu/ml at 15 min. interval. It can be concluded that different mastitis pathogens may possess different sensitivities to teat dips, and essential oils of Cinnamon and tea tree oil can be effectively used as post milking teat dip. Furthermore, a 15 minute post-milking dip contact time for oil and 30 s for dettol dips may be optimal in reducing pathogen load.
Conference Paper
Oxidized porous silicon nanostructures, Fabry-Pérot thin film, is synthesized and used as optical transducer element for early detection of bovine mastitis utilizing specific predicting biomarkers.
Full-text available
Article
l objetivo de la investigación fue determinar los principales factores que influyen en la prevalencia de mastitis subclínica en la cuenca lechera de Florida, Región Amazonas, Perú. Se utilizaron 50 vacas de 15 fincas bajo ordeño manual. La prevalencia de mastitis subclínica se determinó mediante el California Mastitis Test (CMT) y el Test DCC (DeLaval Direct Cell Counter). Para determinar los principales factores de prevalencia se utilizó un formato de observación sobre rutinas de ordeño. El análisis de datos se realizó mediante tablas de contingencia, la prueba de chi-cuadrado y correlaciones bivariadas. Se encontró una prevalencia de mastitis subclínica, según el método DCC del 52% y mediante CMT del 51%, sin diferencias significativas entre métodos. Los principales factores que influyeron en la prevalencia de mastitis subclínica se debieron a deficientes prácticas de higiene e inadecuadas instalaciones.
Full-text available
Article
The objective of this study was to evaluate the percentage of US dairy herds and milk not currently meeting the current and proposed bulk tank somatic cell counts (BTSCC) limits. Five different limits of BTSCC were evaluated for compliance: 750K, 600K, 500K, and 400K cells/mlusing the current US methods and 400K cells/ml using the geometric mean method used by the EU. For the 12 month period ending October 2010, 1.0% of herds and 0.2% of milk exceeded the current US limit of 750K; 4.7% of herds and 1.4% of milk would have exceeded the proposed 600K limit; 11.0% of herds and 3.8% of milk would have exceeded the proposed 500K limit; and 23.3% of herds and 10.1% of milk would have exceeded the 400K cells/ml limit. The percentages of herds and milk not meeting the geometric mean method used by the EU were 16.1% and 6.7%, respectively. Examination of monthly BTSCC patterns reveal July through October is the period where the percentage of herds and milk above the proposed limit are highest. For herds shipping <900 metric tonnes of milk in the 12 month period, 44.5% would have exceeded the proposed 400K cells/ml US limit while 8.0% of herds shipping more than 9,000 metric tonnes would have exceeded the proposed 400K cells/ml US limit. If implemented, and BTSCC counts remain unchanged, the proposed phased in reduction to a 400K cells/ml BTSCC limit would result in a substantial increase in herds and milk that exceed the regulatory limit.
Full-text available
Article
In the first study, we tested the ability of a commercial feed additive (OmniGen-AF) to affect markers of innate immunity in immunosuppressed sheep and the ability of a pathogen challenge (mould) to affect the immune response to the additive. Treatments consisted of (1) control, (2) immunosuppressed with dexamethasone (DEX), (3) immunosuppressed plus the feed additive, (4) immunosuppressed plus Aspergillus fumigatus and (5) immunosuppressed, A. fumigatus and the additive. Animal health was monitored and indexes of innate immunity (neutrophil L-selectin and interleukin-1β (IL-1β)) were collected. DEX caused immunosuppression (i.e. reduced abundance of neutrophil L-selectin and IL-1β). This immunosuppressive effect was countered by the provision of the additive in the ration. Provision of mould in the ration increased the ability of the additive to regulate markers of innate immune function. A second study was completed to re-assess the properties of the additive and other feed products. The study consisted of seven treatments: (1) immunosuppressed, (2) immunosuppressed with additive, (3) immunosuppressed with additive in pelleted form (low-temperature pellet) and (4) immunosuppressed with additive in a high-temperature pellet. The remaining three treatments assessed abilities of three other additives to regulate markers of innate immune function. In this study, OmniGen-AF increased expression of neutrophil L-selectin abundance in immunosuppressed animals and this was unaffected by the pelleting temperature. None of the other additives affected markers of innate immunity. In these studies we discovered mechanisms by which a feed product may affect the immune function of ruminant livestock. The product countered DEX-dependent down-regulation of markers of innate immune function and its actions were enhanced by the presence of pathogen (mould) in the ration.
Full-text available
Article
The goal of this study was to examine the ability of a commercially available feed additive (OmniGen-AF) to reduce mammary infections caused by a single strain of mastitic pathogens (Streptococcus uberis, Escherichia coli, Staphylococcus aureus and Klebsiella pneumoniae) and to examine the effects of the additive on markers of mammary immunity. Four experiments were completed using a murine model of bovine mastitis. Infection progression was examined using Sybr-green- and TaqMan-based quantitative PCR assays of 16S ribosomal DNA. Infection of the mammary gland with all pathogens caused rapid (24 to 48 h) appearance of pathogen DNA in mammary tissue. Provision of the feed additive for 2 weeks before infection significantly (P < 0.05) reduced the extent of pathogen DNA accumulation in models of S. uberis, E. coli and S. aureus infection. The additive was ineffective in reducing mammary infections caused by K. pneumoniae. We examined mechanisms of action of the additive through assessment of mammary concentrations of mammary myeloperoxidase (MPO), major histocompatibility complex 2 class II (MHC) and macrophage inflammatory protein-1α (MIP) messenger RNA (mRNA) concentrations and by examining serum complement C3 concentration. Infection of the mammary gland increased concentrations of MPO and MHC mRNAs (P < 0.05). Ability of the pathogen to elicit changes in mammary MPO and MHC gene expression was enhanced by the provision of the additive for 2 weeks before infection. These data imply that the additive increased the mammary inflammatory response and increased antigen presentation during a mammary infection. Value of the additive in preventing mastitis in cattle awaits additional studies using a bovine model and further evaluation of additional strains of the pathogens used in this study.
Full-text available
Article
A systematic review of the scientific literature on relationships between management practices used on dairy farms and herd somatic cell count (SCC) was undertaken to distinguish those management practices that have been consistently shown to be associated with herd SCC from those lacking evidence of association. Relevant literature was identified using a combination of database searches (PubMed, Medline, CAB, Agricola, and Web of Science) and iterative screening of references. To be included in the review, a manuscript had to be published after 1979 in French, English, or Dutch; study design had to be other than case report or case series; herds studied had to be composed of ≥ 40 milking cows producing on average ≥ 7,000kg of milk in 305 d; interventions studied had to be management practices applied at the herd level and used as udder health control strategies; and SCC had to be measured using electronic cell counting methods. The 36 manuscripts selected were mainly observational cross-sectional studies; 8 manuscripts dealt exclusively with automatic milking systems and 4 with management of calves and heifers and its effect on SCC in early lactation heifers. Most practices having consistent associations with SCC were related to milking procedures: wearing gloves during milking, using automatic take-offs, using postmilking teat dipping, milking problem cows last, yearly inspection of the milking system, and use of a technique to keep cows standing following milking; all were consistently associated with lower herd SCC. Other practices associated with lower SCC were the use of a freestall system, sand bedding, cleaning the calving pen after each calving, surveillance of dry-cow udders for mastitis, use of blanket dry-cow therapy, parenteral selenium supplementation, udder hair management, and frequent use of the California Mastitis Test. Regarding SCC of heifers, most of the consistent associations reported were related to interventions made during the peripartum period. Studies on automatic milking systems have frequently reported elevation of the herd SCC following transition to the new system. These elevations seemed to be mediated both by the lack of monitoring of chronically infected cows and by an elevated incidence of intramammary infections. By assembling the results reported in many different studies, this review generates a more comprehensive understanding of the management practices influencing SCC and highlights areas of SCC control knowledge that lack evidence of effectiveness.
Full-text available
Article
To evaluate the benefit of blanket treatment of all milking cows at drying-off and all replacement heifers one month prior to the planned start of mating with an internal teat sealant on the incidence of mastitis, and somatic cell counts (SCC), postpartum in a 650-cow herd with a mastitis incidence in early lactation of 15% in cows and 26% in heifers. Prior to drying-off, lactating cattle were divided on the basis of SCC and mastitis history. Cattle with records of individual SCC >150,000 cells/ml or mastitis in the previous lactation were treated with a cloxacillin-based dry-cow therapy (DCT), while the remaining cattle received no antibiotics. Cattle in each of the two groups were then randomly assigned to receive either an internal teat sealant or no further treatment. Additionally, one month prior to the planned start of calving the rising 2-year-old heifers were also randomly assigned to receive either an internal teat sealant or no treatment. All clinical mastitis cases were recorded for the first 10 weeks after the start of calving, while SCC were measured on three occasions during the subsequent lactation. Data were available from 466 cows and 206 heifers; treatment with the internal teat sealant significantly reduced the incidence of mastitis in both groups. For cows, the reduced risk of mastitis due to treatment with the teat sealant was not significantly different between cows, which, based on their mastitis history, required dry-cow antibiotics and those which did not. There was no effect of teat sealant on the mean SCC of any group at any time-point. On this farm, treatment of all cows and heifers prior to parturition with an internal teat sealant significantly reduced the risk of clinical mastitis. The benefits of an internal teat sealant were the same when used in combination with antibiotics in cows with a history of mastitis as when used alone in cows with no such history. These data support the proposition that blanket treatment with an internal teat sealant of all cows due to enter the milking herd can be a useful method of mastitis control. They also suggest that combined therapy with dry-cow antibiotics and internal teat sealants can be beneficial under New Zealand conditions. More detailed research on more farms in more areas of New Zealand is required to confirm these suggestions.
Article
To assess the dairy production issues extension programming should be addressing, a survey was distributed to all licensed milk producers in Kentucky (n=1,074). A total of 236 surveys were returned; 7 were omitted due to incompletion, leaving 229 for subsequent analyses (21% response rate). Mean herd size was 83.0 ± 101.8 cows with a projected increase to 102.1 ± 114.4 cows by 2013. Mean producer age was 50.9 ± 12.9 with a range of 22 to 82. Mean milk production (kg/cow per day) was 23.9 ± 5.4 with a range of 6.8 to 38.6 kg. Mean somatic cell counts (SCC) were 304,824 ± 123,580 with a range of 75,000 to 750,000 cells/mL. When asked about meeting attendance frequency, 25% of producers indicated they attended meetings annually, whereas 29% attended twice yearly, 13% quarterly, 3% monthly, 2% at least twice monthly, and 28% indicated they never attended meetings. Surveyed producers were asked to assess what level of importance should be placed on a predetermined list of management topics. Mean response to each topic was calculated after assigning the following numeric values to producer response categories: not important: 1, important: 3, and very important: 5. Producers indicated mastitis and milk quality was the most important management topic with a response of 4.35 ± 1.05, followed by animal well-being (4.05 ± 1.14), disease prevention and vaccinations (4.01 ± 1.06), cow comfort (3.97±1.09), disease treatment (3.95 ± 1.10), and lameness and hoof health (3.95 ± 1.16). Producers were asked to identify their preferred information delivery method. The most effective delivery methods were printed farm magazines (81.0%), agricultural newspapers (77.4%), printed newsletters from county agricultural agents (75.7%), printed newsletters from university extension (65.0%), and local or regional meetings (55.8%). The least effective delivery methods were university website (11.9%), indirect access through allied industry consultants (11.5%), webinars (2.7%), podcasts (0.4%), and blogs (0.4%). These results provide invaluable insight for future dairy-related Cooperative Extension Service programming efforts.
Article
Tabular reference: animal disease exclusion, general management, milking procedures, antibiotic use, nutrient management