Reproduction in Domestic Animals - Facultad de Ciencias Veterinarias

16 t h International Congress on Animal Reproduction
Poster Abstracts 43
and both ITGAD and ITGB7 were only expressed at the hatched
blastocyst stage.
This study demonstrates the variability in integrin expression during
preimplantation embryo development and pushes ITGα3β1, ITGα5β1
and ITGαVβ3 forward as candidate receptors for the embryo specific
FN1 splice variant. Further research is necessary to reveal the
subcellular distribution and organization of the integrin proteins as
well as downstream adhesion and signal transduction pathways.
P046
Reproductive management strategies to improve
pregnancy rate following Ovsynch/TAI protocol in dairy
cows and heifers
Gordon, M 1 *, Dinn, N 2
1Animal Science, University of British Columbia, Canada; 2 Ubc Dairy
Education & Research Centre, Canada
Physiological and environmental stresses of high milk production and
intensive management systems have affected the onset of postpartum
ovarian activity, expression of estrus, embryonic development, and
pregnancy in lactating dairy cows. Though prostaglandin (PGF2α) is
still the most widely used drug for the induction and synchronization
of estrus, the Ovsynch/TAI protocol, which strategically uses GnRH
and PGF2α to synchronize ovulation offers potential freedom to dairy
farmers from the time consuming chore of estrus detection. The
ovulation rate and pregnancy rate (PR) with Ovsynch/TAI protocol in
postpartum cows are around 80% and 30 to 40%, respectively and
lower in heifers. However, pre-synchronization before Ovsynch/TAI
protocol or the use of GnRH five to seven days after breeding has the
potential to improve PR and this was tested in the current study.
Multiparous and primiparous lactating cows (n=225) and nulliparous
heifers (n = 87) were used. Animals were randomly assigned to one of
three treatments for timed first service breeding (TAI) at about 75
days in milk (DIM) for cows and 15 months of age for heifers: A)
Control - Ovsynch protocol (GnRH injection given 7 d before and
another 48 h after one PGF2α injection); B) Presynch + Ovsynch (two
injections of PGF2α 14 d apart followed by Ovsynch 14 d later); C)
Ovsynch + post-AI GnRH (a GnRH injection given 6 d after TAI
following Ovsynch). A total of 10 blood samples (from heifers) or
milk samples (from cows) were taken from each animal (on days -38,
-31, -24, -10, -3, 0 (TAI), 7, 14, 21, 28) for progesterone (P4)
analysis. Pregnancy rate for heifers were 65%, 59%, and 59% and for
lactating cows were 44%, 48%, and 46% for treatments A, B, and C,
respectively, revealing no treatment effect on PR (p>0.05). However,
there was an interaction of DIM and BCS at TAI with PR (p=0.008
and p=0.20, respectively). The trend for cows in less BCS and less
DIM to have lower PR was seen most in the Ovsynch group.
Moreover, pregnant animals in group B and C had higher P4 levels on
day 21 and day 28 than did pregnant animals from control group
(p=0.15), which could be indicative of better functioning CL’s and
thus enhancing PR. These results show that the Ovsynch protocol can
be used to achieve acceptable PR rates in heifers using a synchronized
TAI protocol. Although differences in pregnancy were not significant
among treatments, PR and P4 results from this study show that
presynchronization and post insemination GnRH tend to benefit cows
which are in more negative energy balance.
P047
The effect of early or late breeding on milk production in
lactating dairy cows
Gumen, A 1 *, Keskin, A 1 , Yılmazbas, G 1 , Celik, Y 2 , Burucu, Y 2
1University of Uludag, Faculty of Veterinary Medicine, Department of
Obstetrics and Gynecology, Bursa, Turkey; 2 Tarfaş A. Ş., Karacabey, Bursa,
Turkey
Milk production and reproduction are two important factors with
respect to profitability of dairy farms and much attention has been
given to fertility parameters and their association with milk
production. Previous studies was reported that pregnancy adversely
affect milk production. Delaying of first breeding in high producing
dairy cows may increase overall milk yield. The objective of this
study was to compare effect of early or late breeding on milk
production in lactating dairy cows. Dairy cows (n=52) were divided
into two groups. In group 1 (early bred), cows (n=22) were
inseminated between 45 to 75 postpartum and group 2 (n=30; late
bred) were inseminated between 76 to 130 postpartum. All cows were
in second lactation. Cows were fed twice daily with a high-energy
lactating dairy cow ration fed as a TMR following NRC
recommendations. Estrus detection was recorded with pedometer and
visual observation. Milk yield was recorded every 5 days after calving
first 45 days then every 15 days until 270 days. Breeding of cows
were initiated after voluntary waiting period (45 days in milk) with
artificial insemination. Cows were inseminated only once and became
pregnant following their first postpartum estrus included in this study.
Average days in milk in early and late bred cows at the time of
artificial insemination were 65.2 and 102.6 days, respectively.
Average milk yield first 270 days was 37.8 and 39.0 kg for early and
late bred cows. Milk yield was not different between early and late
bred cows from calving to 270 days after calving. There was no
relationship between first 3 months milk yield and postpartum days of
insemination. Also, there was no relationship between overall milk
yied (calving to 270 days) and postpartum days of insemination.
Thus, milk yield was not affected by early or late breeding of cows
but further trials are needed to evaluate the repeatability of this
response.
P048
Effect of ketoprofen administration 15 and 16 days after
AI on conception rates in lactating Holstein cows
Guzeloglu, A 1 *, Erdem, H 2 , Cinar, M 3 , Kilic, K 4 , Talmac, M 4 , Gorgundur, A 4 ,
Gumen, A 5
1Obstetrics And Gyneacology, Selcuk University Faculty of Veterinary
Medicine, Turkey; 2 Selcuk University Faculty of Veterinary Medicine, Turkey;
3Nigde University, Bor Vocational School, Turkey; 4 Kocas Tigem Agricultural
Station Aksaray, Turkey; 5 Uludag University Faculty of Veterinary Medicine,
Turkey
It has been reported that timely administration of a non-steroid antiinflammatory
drug (NSAID), flunixin meglumine, around the time of
luteolysis (day 15 and day 16) increased pregnancy rates in heifers
(Guzeloglu et al., 2007) and lactating cows (Pfeifer et al., 2007). The
objective of this study was to determine if two injections of
ketoprofen would demonstrate the same effect as flunixin meglumine.
Ketoprofen has no milk residue in contrast to flunixin meglumine.
Two experiments were done in lactating Holstein dairy cows (milk
yield average 25 kg/day, 3 to 10 years old, average DIM 125 days). In
experiment 1, 86 cows were inseminated at detected heat and
randomly assigned to receive treatment (n=45; ketoprofen, i.m., 3
mg/kg BW on day 15 and 16 after insemination; 24 hours apart) or
control (n=41). In experiment 2, 84 cows were inseminated at fixed
time (TAI) following ovsynch program and randomly assigned to
treatment (n=43) and control (n=41) groups as described for
experiment 1. Pregnancy diagnosis was performed by ultrasonography
30 days after TAI. Conception rates did not differ between treatment
and control groups (In experiment 1, 47% (21/45) for treatment and
49% (20/41) control; in experiment 2, 30% (13/43) for treatment and
27% (11/41) control). In both experiments, no significant effects of
sire, days in milk, milk yield and parity were detected. In conclusion,
ketoprofen did not have beneficial effect on conception rates in
lactating cows as flunixin meglumine. Moreover, data suggests that
ketoprofen can be used in early pregnancy for treatment of possible
inflammatory conditions without having detrimental effects on
pregnancy.
P049
Relationship between uterine involution and pregnancy
rate in dairy cows
Hajurka, J
Equine clinic, University of Vterinary Medicine, Slovakia
The objectives of this study were to assess uterine involution and
pregnancy rate in dairy cows under field condition. Animals were