Reproduction in Domestic Animals - Facultad de Ciencias Veterinarias

16 t h International Congress on Animal Reproduction
Poster Abstracts 65
P112
Genomic characterization of Arcanobacterium pyogenes
isolates recovered throughout the puerperium of dairy
cows
Silva, E 1 *; Gaivão, M 1 ; Leitão, S 1 ; Jost, B 2 ; Carneiro, C 3 ; Vilela, C 3 ; Costa, L 1 ;
Mateus, L 1
1Department of Reproduction and Obstetrics, C.I.I.S.A., Faculty of Veterinary
Medicine, Portugal; 2 Department of Veterinary Science and Microbiology,
University of Arizona, USA; 3 Department of Microbiology and Immunology,
C.I.I.S.A., Faculty of Veterinary Medicine, Portugal
In dairy cows, the establishment and persistence of the puerperal
uterine infection is related to the characteristics of the bacteria that
colonize the uterus. The clinical signs and reproductive consequences
of the uterine disease are generally attributed to the presence of a few
pathogens, mainly Arcanobacterium pyogenes (A. pyogenes) alone or
in synergy with other bacteria. In order to identify factors that might
be associated with the establishment and persistence of uterine
infection, we characterized A. pyogenes isolates obtained throughout
the puerperal period of dairy cows from two unrelated herds.
The isolates were recovered from 26 cows (8 had normal puerperium
and 18 developed uterine infection). The genomic characterization of
A. pyogenes (n= 57) was performed by BOX-PCR typing and by
screening of putative virulence factors through conventional PCR.
Considering a genomic similarity of at least 86%, a total of ten
different clonal types (5 in each herd) were identified. These clonal
types were totally herd-specific and a single type appeared to
predominate in each herd. Only one clonal type was not associated
with endometritis, while four others were always associated with
uterine disease. However, 5 clonal types were present in cases of both
normal puerperium and endometritis. Throughout the puerperal
period, 1 to 3 clonal types were sequentially or simultaneously
isolated from the same animal.
In order to identify virulence factors associated with the development
of infection, all isolates were tested for the presence of 8 putative A.
pyogenes virulence genes: plo (encoding pyolysin), nanH and nanP
(encoding neuraminidases), cbpA (encoding a collagen-binding
adhesin) and four different fimbrial genes (fimA, fimC, fimE, fimG).
The 8 genes were present in 66% of the isolates, 5 of 8 genes (plo,
nanH, nanP, cbpA, fimA) were detected in all isolates, fimE in 97%,
while fimC and fimG were only present in a subset of isolates. There
was no association between BOX-PCR type, presence of the above
genes and development of uterine infection.
The results of this study suggest that the type of A. pyogenes may not
be a determinant factor in the development of uterine infection. Host
intrinsic factors and/or the synergism between A. pyogenes and other
bacteria may play a more relevant role in the establishment of
puerperal infections.
This research was funded by the grant POCTI/CVT/48773/2002 from
“Fundação para a Ciência e Tecnologia”. Maria Elisabete Silva is a
post-doc fellow from FCT.
P113
Bacteriological and histological studies of cow’s uterus
without and with retained fetal membranes
Skuja, S 1 *; Antāne, V 1 ; Feldmane, L 2
1Faculty of Veterinary Medicine, Latvian University of Agriculture, Latvia;
2Department of Pathological Anatomy, Riga Stradins University, Latvia
Introduction Retention of fetal membranes is economically important
disturbances during the postpartum period in cattle in Latvia. Several
methods have been suggested for the treatment of retained fetal
membranes, and controversial results have been published. The aim of
the study was to investigate the postpartum period of cows without
and with retained fetal membranes.
Materials and methods Bacteriological samples of the cow’s uterus
and biopsies of the uterus mucous membranes were collected from 29
Holstein cows. The bacteriological examination was performed in
cows with and without retained fetal membranes (RFM) two, 14, 40 –
50 days postpartum (PP). On day 40-50 all cows were biopsied from
the uterus endometrium and the uterus status was estimated
histologically. According to the 3rd stage of parturition process
(expulsion of fetal membranes), cows were divided into the following
groups:Control group – fetal membranes were expelled in 6-12 h
PP;Group 1 – cows with RFM, removed manually and treated;Group
2 – cows with RFM, it was not removed manually.Group 2 cows with
health disturbances (fever, milk fever, mastitis) were treated
adequately.
Results Bacterial isolates of uterus on day two PP in all cows (100%)
contained a wide spectrum of microorganism associations: in 41% of
cases there were single isolates – E. coli 33%, Streptococcus spp. 5%
and Clostridia spp. 3% , and in 59% there were mixed isolates – E. c.
27%, Streptococcus spp 3%, Clostridia spp 26%, Staphylococcus spp.
3%. On day 14 PP, 93% of cows had microorganisms in the uterus. In
addition to the above findings there was one isolate of A. pyogenes in
the cow with RFM that was removed manually two days PP. In the
next bacteriological examination (40-50 days PP) no bacteria were
found, and in 84 days PP after two times of artificial insemination the
cow became pregnant. In group 2 cows, which were treated, the
number of isolated bacterial species increased on day 14 PP. At the
same time cows of group 2, which were untreated, the number of
isolated bacterial species remained the previous one, and the number
of isolates decreased. On day 40-50 PP, bacterial isolates were found
in 86.2% of cows. Cows with a normal parturition process were 50%
with single bacterial isolates (Streptococcus spp. and
Corynebacteriom spp.). There were no differences between the
bacterial species and their number of group 2 treated and untreated
cows. In 82.8 % of all investigated cows, histological findings showed
evidence of mild to moderate endometritis.At this time, 33.3% ( 8
cows) become pregnant.
P114
Identifying AI bulls associated with poor fertility and high
rates of embryo loss
Sunde, J. 1 * and Refsdal, AO. 2
1Team Semin BA, P.O. Box 8146 Dep., N-0033 Oslo, Norway; 2 Geno
Breeding and AI association, N-2326 Hamar, Norway
The relationship between fertility and semen quality is not always
clear. Occasional AI bulls may show poor fertility even though semen
passes quality testing. These bulls represent a potential loss for the
dairy farmer, and may even possess undesirable genetic traits that
could affect fertility in future generations. It is therefore important
that these bulls are identified at an early stage in the breeding
programme as soon as insemination data are available for analysis.
Norwegian Red (NRF) is the dominant dairy breed in Norway and
semen is distributed by Geno, a farmer-owned cooperative. Close to
100% of inseminations are reported back to Geno and 95 % of
farmers also report data on calvings, stillbirths and culls through the
Norwegian Dairy Herd Recording System. These data allow
calculation of accurate non-return rates (NRR) and calving rates (CR)
on sire basis. At present, bulls with NRR60 < 65 % after approx. 1000
first inseminations of semen for progeny testing are routinely culled.
However, this parameter alone may not be sufficient to identify
animals with potential negative impacts on fertility traits. It was
therefore investigated whether further analysis of sire fertility data
would yield additional information.
The data set consisted of 479330 first inseminations on Norwegian
Red (NRF) heifers and cows, with semen from 692 qualified NRF test
and elite sires. Inseminations were performed between January 2000
and Oct 2007. The first day of return-to-service was registered as a
second insemination within 92 days after first insemination (pfi), and
a minimum of 1000 first inseminations per bull was required to
qualify for the study.
NRR curves were modelled using survival analysis, with day of return
as outcome parameter, adjusted for confounding factors. Sires were
classified as having either‘poor’ or ‘good’ fertility if their NRR92
deviated from the mean by more than 3 standard deviations.
Compared to high fertility sires, poor fertility sires showed a more
abrupt fall in NRR from 21 days onwards, suggesting a lower rate of
fertilisation and/or higher incidence of early embryo death (before
maternal recognition). These sires also displayed a higher number of
returns-to-service outside of the normal oestral cycle length. This