Oral and Poster Abstracts

hemolysis, catalase test, glucose and manitol fermentation in aerobiosis
and anaerobiosis and acetoin production by Voges-Proskauer test,
antibiotic sensitivity test. Organisms were identified as Staphylococcus
aureus with in vivo sensitivity for gentamicin. All 14 mastitis cases
treated with 300 mg q 12h of gentamicin, after complete milking from
the affected udder quarter, five minutes after intramuscular injection of
20UI ocytoxin, for five days. It was administred 3 mg/kg q12h of
gentamicin, for 5 days. At the end of the terapy five treated udder
quarters had developed both, clinical remission of symptons and
bacteriological cure at 8, 12, 16, 17 and 21 days, respectively. In six
udder quarters had no response to gentamicin therapy and, after another
therapeutic tentative was decided by chemical cauterization with 10%
iodine solution. Three udder quarters developed necrosis; overt
ischemia was observed 3-5 days after the onset of therapy. It was
observed complete sloughing of the affected mammary tissue.
Additionally to antibiotic therapy, were provided support fluid therapy
for these cows; one cow died. The results showed that the treatment of
acute mastitis induced by Sthaphylococcus aureus in early postpartum
period had no good efficacy, probably due to biological factors of S.
aureus, in particular in lactant mammary gland and, cow physiological
conditions at postpartum. Therefore, it is important to provide special
hygiene environmental conditions for periparturient cows.
Financial Support: FAPESP
Key words: cow, acute mastitis, Staphylococcus aureus
614 Comparison between Delaval Cell Counter DCC and
Fossomatic 5000 for the Determination of Somatic Cell Count
of Bovine Milk
JP. Roy, L. DesCôteaux, D. DuTremblay
Université de Montréal, Department of clinical science, St-Hyacinthe,
Canada
Objective: To compare somatic cell count (SCC) measured by the
DeLaval cell counter (DCC) and the Fossomatic 5000 (Foss 5000) on
individual quarter of Holstein cows.
Materials and methods: This study was part of another study to
evaluate extended lactational therapy for cows chronically infected
by S. aureus. Quarter milk samples were collected from 100 cows
coming from 14 dairy herds in St-Hyacinthe (Québec, Canada) at 3
sampling periods: 14 days before the beginning of the treatment, 10 and
31 days after the end of the treatment. At sampling, Bromopol was
added to milk samples as conservative agent. Milk samples were
analyzed with the DCC before being submitted within 2 days to
VALACTA (provincial DHI system) for an evaluation of the SCC by
the Foss 5000. Coefficients of determination (R2) were calculated
between DCC and Foss 5000 using real and logarithmic fits of the SCC.
Results: A total of 827 quarters were sampled and analyzed by both
methods. The mean values were 2 204 X10 3 c/mL (1 – 29 633 X10 3
c/mL) and 1 177 X10 3 c/mL (1 - 7 632 X10 3 c/mL) for Foss 5000 and
DCC, respectively. The median values were 395 X10 3 c/mL and 337
X10 3 c/mL for Foss 5000 and DCC, respectively. A total of 315
samples were below 200 X10 3 c/mL and 257 were over 1 000 X10 3
c/mL using Foss 5000. A total of 331 samples were below 200 X10 3
c/mL and 230 were over 1 000 X10 3 c/mL for DCC. When all results
were included in the analysis, coefficients of determination (R2)
were 0.62 and 0.99 for real and logarithmic fits of the SCC,
respectively (P < 0.001). Difference in R2 between both fits is
largely explained by the fact that the maximum value reported by the
DCC is limited to 4 000 X10 3 c/mL. For somatic cell counts below 1
000 X10 3 c/mL, the regression coefficient was 0.92 without
logarithmic conversion. Below 1 000 X10 3 c/mL the DCC gives
results 10 % lower than the Foss 5000 reader (parameter estimate:
1.103 ± 0.014) and the standard deviation of the residuals is 108
X10 3 c/mL.
Conclusion: DCC is an accurate tool to measure the somatic cell
counts in quarter milk samples. However, there is limitation for very
high values and a 10 % correction factor should be applied to the value
obtained by the DCC.
The study was supported by DeLaval and Fort Dodge Animal Health
615 Effect of Systemic Antibacterial Administration during
Prepartum Period on Coagulase Negative Staphylococcal
Intramammary Infection in Holstein Heifers
O. Ataie 1 , P. Hovareshti 2 , M. Bolourchi 2 , A. Barin 2 , A. Gerami 3 ,
A. Niasari-Naslaji 2
1
Faculty of Veterinary Medicine, Islamic Azad University, Karaj
Branch., Clinical Sciences, Karaj, Iran
2
Faculty of Veterinary Medicine, University of Tehran, Clinical
Sciences, Tehran, Iran
3
School of Mathematics, University of Tehran, Statistics and
Computer Science, Tehran, Iran
Pre- and peripartum intramammary infections may impair mammary
development and affect milk production after calving in dairy heifers.
In the present study, The efficacy and cure rate of prepartum
intramuscular injection of Tylosin and Cefquinome on coagulase
negative staphylococcal intramammary infection and reducing somatic
cell counts was evaluated during the early lactation period. A total of
183 coagulase negative staphylococcal infected quarters from 229
pregnant heifers were randomly allotted into 3 experimental groups:
infected quarters that did not receive any treatment (positive control
group; n=60); infected quarters that received Tylosin (Tylosin group;
n=61; 10 mg/kg of 20% solution; sid x 3; IM; Tyloject ® ; Razak, Iran)
or Cefquinome (Cefquinome group; n=62; 1 mg/kg of 2.5%
suspention; sid x 2; IM; Cobactan ® ; Intervet, The Netherlands).
Uninfected quarters that did not receive any treatment were considered
as negative control group (n=64). Treated heifers received Tylosin or
Cefquinome 10 to 14 days before expected calving date. Antibiotics
residues were monitored on Day 3 after calving using a commercial test
(Copan test; Hansen Company, Denmark). Cure rates, based on
sampling obtained 3 days after calving, were 85.3% and 69.4% in
Tylosin and Cefquinome treated groups, respectively. At the same
time, self limited rate in positive control group was 53.3%. Tylosin
treated heifers had significantly lower somatic cell count scores
(4.2±0.2) compared to positive control group (6.0±0.21; P