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Israel Journal of Veterinary Medicine  Vol. 69 (3)  September 2014 141 Options for Handling Mastitis
INTRODUCTION
Dairy farming economics are greatly infuenced by animal
diseases. Mastitis, infammation of the mammary gland/s, is
one of the major causes of milk loss and culling of animals.
Moreover, in countries where milk payment is evaluated ac-
cording to milk quality, the producers sufer further losses
due to reduced milk prices. Recently a protocol for handling
mastitis during lactation in modern dairy farms has been
suggested (1). Te protocol described the practical use of on-
line computerized herd management systems together with
the routine monthly testing of milk yield, milk composition
and somatic cell count (SCC) for identifying and treating
cows suspected to have infected quarter/s, as close as possible
to the bacterial invasion. Te protocol is aimed mainly at
subclinical mastitis cases and suggests bacteriological test-
ing together with cow data: history of SCC, lactation, days
in milk, pregnancy and milk yield, before making treatment
decisions.
Options for Handling Mastitis during Lactation in Modern Dairy Farms
Leitner, G.,
1
* Jacoby, S.,
2
Frank, E.
2
and Shacked, R.
2
1
National Mastitis Reference Center, Kimron Veterinary Institute, P.O. Box 12, Bet Dagan 50250, Israel.
2
Institute of Animal Science, A.R.O. Te Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel.
* Corresponding Author: Dr. G. Leitner, Kimron Veterinary Institute, P.O. Box 12, Bet Dagan 50250, Israel. Email: leitnerg@moag.gov.il
ABSTRACT
Mastitis in both clinical and subclinical forms has a signifcant negative afect on dairy economics. Previously,
we suggested making treatment decisions according to the monthly milk testing and/or the constant on-
line data available on each cow during routine implementation of performance evaluation and lactation. Tis
decision relied on expected costs/losses resulting from the treatment during the cow’s productive life. Tis
study reports on-line computerized data surveillance together with routine monthly milk quality testing for
controlling mastitis and maintaining high milk yields and low somatic cell counts (SCC) in medium dairy
herds. During one year of the surveillance, 77 of 220 cows were detected on-line and/or by the monthly
milk testing as suspected of having intramammary infection, about 30% of them with clinical symptoms. All
suspected glands were tested for the causative pathogen. Clinical infections diagnosed by the on-line and/or
visual inspection, were caused by Escherichia coli, Streptococcus dysgalactiae or Strep. uberis, and in certain cases
no causative agent was found. Subclinical infections were diagnosed mainly by the monthly milk testing, where
the causative bacteria found were mainly Streptococcus dysgalactiae and Staphylococcus chromogenes. In some cases
no causative agent was identifed. Clinically infected cows were treated with penicillin and gentamycin on the
day of appearance of mastitis. Following antibiotic withdrawal milk from the infected gland was tested for
quality and quantity. Milking resumed from glands that returned to normal, whereas those retaining a high
somatic cell count were dried-of. Some of the glands infected with Strep. dysgalactiae and Staph. were treated
with Nafpenzal Dry Cow as a group. When treatment failed and bacteria were isolated in cases of cows high
SCC, the cows were dried-of (300 mg Procaine benzylpenicillin (300,000 I.U.), 100 mg Dihydrostreptomycin,
100 mg Nafcillin) (Intervet, Boxmeer, Te Netherlands). Te bulk milk tank SCC at the beginning of the
surveillance contained 240-300 × 10
3
cells/mL and was reduced to 93-140 × 10
3
cells/ mL in 7-9 months. Te
milk price for the bulk milk containing <200 × 10
3
cells mL
-1
received a 0.5% bonus.
Keywords: Mastitis, Treatment, Casein hydrolyzate, Herd management.
Israel Journal of Veterinary Medicine  Vol. 69 (3)  September 2014 Leitner, G. 142
Many modern dairy herds number hundreds and thou-
sands of cows. In these large herds, management and health
control should focus on the herd rather than on the individ-
ual cow (2). However, even among large herds the availabil-
ity of on-line computerized data enables modern farmers to
reach decisions regarding individual cows (3). Consequently,
integrated herd management, focusing on each animal by
utilizing the on-line daily information can achieve synergistic
efects. Prevention of udder infection is the best approach of
control, however, even with the optimal environment and
nutritional conditions, clinical and subclinical mastitis still
exists. Handling herd udder infection is a continuous efort.
Proper handling of infected glands can reduce loss of milk,
culling and fnancial losses due to high SCC. Te decision
whether to treat a cow or to ignore the infection is complex:
unlike many cases of clinical mastitis requiring treatment,
antibiotic treatment for cows not at risk requires justifca-
tion with respect to the costs of drugs and milk loss (4, 5,
6). Regarding SCC, the infuence of a few or even one cow
with a million cells in the bulk tank SCC (BTSCC) has a
much higher signifcance than the other milk components
(fat, protein). Te current study reports the use of the above
mentioned protocol for the surveillance of one herd for one
year (1).
MATERIALS AND METHODS
Study protocol
Te study was carried out in a dairy herd of 200-220 lac-
tating Israeli Holstein cows at the Agricultural Research
Organization, the Volcani Center, Beit Dagan. Te dairy
parlor was equipped with an on-line computerized AfFarm
Herd Management data acquisition system that includes
the AfLab milk analyzer, which provides on-line data on
gross milk composition (fat, protein and lactose) and milk
conductivity (a measure of mastitis) (Afmilk, Afkim, Israel;
http://www.afmilk.com). Te cows were milked three times
daily: average milk yield throughout 2012, 10,475 L during
305 days of lactation. Routine monthly milk yield and SCC
were recorded by the Israeli Cattle Breeders Association
(Caesarea, Israel). Food was ofered ad libitum in mangers
located in the sheds.
Te possibility of udder infection was identifed by the
farm personnel and/or by the daily computerized informa-
tion on the basis of individual deviations from averages re-
ported during the previous 10 days (conductivity, milk yield
and animal behavior). Te suspected glands were tested by
the California mastitis test (CMT) and a milk sample was
sent to the National Mastitis Laboratory, Kimron Veterinary
Institute for bacteriological testing (7). Clinical mastitis was
treated by antibiotics or anti-infammation drugs accord-
ing to the decision of the herd veterinarian (see below).
Moderate udder infections and the monthly routine milk
recordings served as the basis for identifcation of suspected
cows. Cows with SCC >200,000 cells/mL (monthly rou-
tine milk recording) were examined on the quarter level,
for bacteriology, CMT and SCC. If bacteria were isolated,
accompanied by SCC >200,000 cells/mL, an antimicrobial
susceptibility test was performed (National Committee for
Clinical Laboratory Standards guidelines) (8). According to
the results of the bacteriology and the history of SCC, lacta-
tion, day in milk, pregnancy and milk yield, cows were treated
with antibiotics, quarter drying-of with casein hydrolyzate
and then dried-of, or culled. Cows that failed the antibiotic
treatment underwent quarter drying-of, complete drying-
of, or were culled.
All treatments protocols were approved by the
Institutional Animal Care Committee of the Agricultural
Research Organization, Te Volcani Center, Beit Dagan,
Israel.
Treatment protocol
Clinical infection: 30 mL of “PEN 30” and
“GENTAJECT” (ABIC Biological Laboratories, Teva
Ltd., Israel) intramuscularly injected daily for 3 days +
NSAID 30 mL Flunixin or 17 mL Carprieve (Norbrook,
laboratories, Ireland). Treatments were carried out after
the midday milking and the treated cows were not milked
in the evening. Te milk was discarded for a few days in
accordance with the instructions of Delvotest antibiotic
residue test resutls (DSM Food Specialties, Delft, Te
Netherlands).
Subclinical infection: antibiotics were infused with a
tube of Nafpenzal DC- (300 mg Procaine benzylpenicil-
lin (300,000 I.U.), 100 mg Dihydrostreptomycin, 100 mg
Nafcillin) (Intervet, Boxmeer, Te Netherlands) once into
the infected quarter. Treatments were carried out after the
midday milking and the treated cows were not milked in
the evening.
Te milk was discarded for a 10 days in accordance with
Reserch Articles
Israel Journal of Veterinary Medicine  Vol. 69 (3)  September 2014 143 Options for Handling Mastitis
the instructions of the Manufacturer Delvotest (DSM Food
Specialties, Delft, Te Netherlands), and was then tested
daily for antibiotic residues until complete disappearance of
inhibition on the cow level (~20 days).
Cows treated with casein hydrolyzate (Home Made pre-
pared under Good Laboratory Practice conditions) (9) re-
ceived one or two infusions of 10 mL of peptide concentrate
of the casein hydrolyzate preparation, at ~7 mg/mL into the
infected quarter at the midday milking and were not milked
in the evening. Dried-of cows received the routine treat-
ment of the herd, i.e., Nafpenzal DC ampoules which were
inserted into the mammary streak canal.
RESULTS
In 2010, a previous study was conducted in the same herd
(1). Te average BTSCC then was 183±5.7 × 10
3
cells/mL.
Loosening the intensive udder health handling program
caused the BTSCC to increase steadily to 223±7.5 ×10
3
cells/
mL in 2011 and 230±13.2 × 10
3
cells/mL in 2012.
As a result, from the beginning of 2013 the current sug-
gested protocol was employed (1). BTSCC was ~300 × 10
3
cells/mL at the beginning of 2013 and as a result dropped
sharply to ~170 × 10
3
cells/ mL at the end of the year (Fig.
1). At the beginning of the year, there were 204 cows, the
number of which increased to 215 (~5%) towards the end of
the year in spite of culling of 41 cows (20%). 52 new heifers
(25%) replaced older cows.
During the year of the surveillance, 77 cows were
detected on-line and/or by the monthly milk testing as
suspected of having intramammary infection, of which
~30% presented clinical symptoms. Summary of the cow’s
diagnostics is presented in Table 1. Of the 27 cows that
developed clinical mastitis, in 10 cows (37%) no bacteria
were isolated and in the remaining Escherichia coli (10),
Streptococcus dysgalactiae (5) and Strep. uberis (2) were iden-
tifed. All the cows with clinical symptoms were intramus-
cularly treated with antibiotics as detailed in the materials
and methods section.
After the period of washout antibiotic of about 6 days,
quarter milk was tested by CMT and all quarters or only
those quarters that were not clinically treated continued to
be milked. Te 10 cows with no bacteria isolation completely
recovered and returned to their regular milk yield in 3-5
days. In contrast, of the 10 cows isolated with E. coli, only 4
cows completely recovered and returned to milk yield, while
the other 6 returned to a new milk yield level of ~80% of
that prior to the infection. In one cow, the infected gland
was dried-of after 40 days. No changes in milk yield were
noted for the 7 cows isolated with Strep. dysgalactiae or Strep.
uberis and all but one completely recovered and returned to
previous milk yield in 3-5 days. Cows for which the treat-
ment failed were retreated intramammary. If the treatment
failed the second time, the quarter was dried-of. For most of
the cows which were tested after treatment the SCC at the
monthly test decreased to <200,000 cell/mL. In most of these
cows, only one quarter was found with CMT greater than 3.
Of the 50 cows tested, in 17 (34%) the causative agent
was not found, therefore these cows were not treated, ex-
cept for one cow of which the quarter was dried-of and one
cow that was over 150 day pregnant which was dried-of as
well. Noteworthy was that the 2 cows whose quarters were
dried-of were infected with E. coli in their previous lactation.
In 18 cows Strep. was isolated: 13 Strep. dysgalactiae and 5
0 2 4 6 8 10 12
150
180
210
240
270
S
o
m
a
t
i
c
c
e
l
l
c
o
u
n
t
(
x
1
0
3
)
Month
Figure 1: Bulk milk tank mean somatic cell count during the year 2013.
Table 1: Cows diagnosed with infection: Bacteriological fndings and
the nature of treatment
Diagnostic Bacteriology
Antibiotic
treatment
Dried-of
quarters
Early
drying-of
Clinical
infection
27 cows
No fnding
E. coli
Strep.
10 (37%)
10 (37%)
7 (26%)
10
10
7
-
1
1
-
-
-
Increased
SCC
50 cows
No fnding 17 (34%) 0 1 1
Strep. 18 (36%) 15 8 1
Staph. 13 (26%) 3 - -
S. aureus 2 (4%) 2 - -
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Israel Journal of Veterinary Medicine  Vol. 69 (3)  September 2014 Leitner, G. 144
Strep. Uberis and of those, 15 were treated intramammry. Te
treatment failed in all the Strep. Uberis- and 4 of the Strep.
dysgalactiae-infected glands. Tus, in 8 cows the quarters were
dried-of and one cow over 140 days pregnant was dried-of
as well. Te remaining 13 cows were identifed as infected
with Staphylococci; 11 with Staphylococcus chromogenes and 2
with Staph. aureus. Intramammry treatment was performed
in 3 cows with Staph. aureus and 1 with Staph. chromogenes. Of
the cows treated, SCC returned in 10-20 days post treatment
to <100,000 cell/mL and the milk yield stabilized. Of the
cows where quarters were dried-of due to treatment failure,
the cow SCC was reduced to <100,000 cell/mL and their
milk yield decreased by 75-90%.
DISCUSSION
Te current study reports a surveillance of one herd for a year
using the protocol for monitoring and handling cows with
udder infection as previously suggested (1). Te important
points exhibited were:
1. On-line computerized data available in modern farms
detected all the clinical infections.
2. On-line computerized data failed to detect all of the
subclinical infections.
3. Routine monthly milk testing identifed all the cows
with increased SCC and with additional individual
testing of quarter’s CMT and bacteriology identifed
all the subclinically infected cows.
4. Early treatment of clinical infections resulted in a high
rate of cure, however, at a relatively high price of milk
discarded for at least six days and antibiotic costs.
5. Treatment of only a gland with identifed bacteria to-
gether with high SCC indicated only partial cure, and
thus forced drying-of for those in which cases the
treatment failed.
Te presented procedure was costly due to discarded milk
during the treatment in addition to the cost of the antibiot-
ics. Nevertheless, after taking all these points into account,
the health of the herd improved as indicated by lowering the
number of culled cows as well as decreasing and maintaining
the BTSCC at ~150,000 cell/mL indicating high quality
milk and therefore a better milk price.
Te present results indicate that although a bacterium
may be found sensitive to a drug at the laboratory, it will not
always be eliminated in vivo, as in the case of Strep. uberis.
Tus if no alternative drugs to the ones used are available,
quarters identifed with Strep. uberis might be dried-of with
no treatment and in so doing the milk discarded during and
after treatment will be saved.
Another point regarding treatment is related to the time
of diagnosis. Te on-line recording system used in the farm
diagnosed all clinical cases based on a sharp increase in
conductivity together with a sharp decrease in milk yield.
It is important that in large dairy farms where there are no
pre-milking streak withdrawals, many of the cows are not
detected by the milking personnel due to a lack of clinical
symptoms. On the other hand, the on-line recording system
failed to diagnose all of the subclinical infections, despite of
the fact that some of the Streptococci infected cows already
had higher than usual SCC. A previous study has shown
the importance of identifying cows with subclinical mastitis
as soon as possible after the bacteria enter the gland. Tus
further studies are necessary to develop tools to identify those
cows using the on-line recording systems among using other
means.
Safety and quality of milk are probably equal or more
important than quantity of milk for the dairy industry and
consumers. In many countries, milk regulations exist both at
the cow/farm level and the dairy. For instance, on the farm
level, milk of clinically-infected, drug treated or a sick cow
is not allowed to be milked into the bulk tank. At the dairy,
antibiotic residues and regulation of maximum SCC with
a reward on low SCC and penalty on high SCC regulate
overall the safety and quality of the raw milk. Nevertheless,
diagnosing all the animals on the farm with udder infection,
mainly those with no clinical symptoms remains a challenge,
which calls for further eforts by researchers and equipment
manufacturers. Early diagnosis and appropriate handling can
decrease milk loss, and culling of cows, while increasing milk
price for the farmer and increasing quality and safety of milk
for the consumer.
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Israel Journal of Veterinary Medicine  Vol. 69 (3)  September 2014 145 Options for Handling Mastitis
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