Oral and Poster Abstracts

Conclusion: the results of the present study indicated that the
incidence of genital tract abnormalities/diseases between the
slaughtered cows were relatively high (12.6%). Moreover, an
outstanding number of the pregnant cows were slaughtered since the
lack of early pregnancy detection.
927 Bovine Embryo Fertility Rates Comparision in Morula and
Blastocyst Stage, with the Frozen Embryos Transfer
Technique in Field Conditions with a Manual Device
P. Cano-Celada 1 , J. Avila-Garcia 1 , L. Ocampo-Camperosv,
J. Valencia-Mendez 1
1 Universidad Nacional Autónoma de México,Facultad de Medicina
Veterinaria y Zootecnia, Producción Animal:Rumiantes, Mexico,
DF., Mexico
2 Universidad Nacional Autónoma de México,Facultad de Medicina
Veterinaria y Zootecnia, Animal Medicin, México D.F., Mexico
The goal of this paper was to compare the bovine embryo fertility
rates in morula and blastocyst stage frozen in field conditions with a
manual device. The research was carried out in Casa Blanca ranch, in
Acatzingo, Puebla, Mexico. 387 transferences were made from
Black swiss donor cows embryos. The embryo collection was made
by the non surgical method. Immediatly after the morfological
evaluation, embryos were placed in Phosphate Bufer suftate (PBS)
with 10% of glycerol, and they were placed individually in 0.25 ml
strays. An identification was placed in each stray and then we start
the freezing process, this process consisted in passing from the
environment temperature to the ethanol bath in the manual freezer at
a temperature of -6 C to -7 C, after this cristalization induction in
which they remained for ten minutes, the descent of the temperature
was made at a 0.5 C/min rate until we reach -35 C, at this
temperature the strays were submerged In liquid nitrogen, in which
they were stored until they were used. Only Quality 1 (excellent)
morulas and blastocyst were frozen. Defrosting was carried out I
four steps and only the embryos who stayed in the Quality 1 level
(excellent) were tansfered. Transferece was made through the
surgical method through an incision in the side ipsilaterally to the
ovary presenting the corpus luteum.387 embryos were transferred,
138 were morulas and 249 were blastocyst. Pregnancy diagnosis was
made 45 days after the transference. The pregnancy rate for morulas
was of 58.69% and 53.41 for blastocysts there was no stadistical
significance (Ji square, P 0.05). Total pregnancy rate was 55.29%.
We conclude that when we transfer embryos maintaining quality 1
when they are defrosted, there is no difference related with their
fertility rates when they are transferred. The total pregnancy rate in
this research, tell us that is profitable the frozen embryo transfer
technique and that is useful for the bovine genetic improvement.
928 Effect of Two Sperm Preservation Methods on Conception
Rate after Fixed-time Artificial Insemination
A. Crespilho 1 , F. Papa 1 , A. Martins Jr 1 , R. Calegari 1 ,
J. Dell’ Aqua Jr 1 , C. Silvav
1 Sao Paulo State University, Animal Reproduction and Veterinary
Radiology, Botucatu-SP, Brazil
2 Sao Paulo State University - UNESP, Clinical, Surgery and Animal
Reproduction, Aracatuba SP, Brazil
Viability of frozen bovine semen is of importance to obtain
acceptable conception rates (CR). Although much progress has been
made, several studies concerning sperm fertilizing ability are under
intensive investigations since there is still considerable variation in
success rates. This study was conducted to compare the effect of two
preservation methods on CR after fixed-time artificial insemination
(FTAI). For this purpose, ejaculate of 1 Nellore (Bos taurus indicus)
bull was collected by eletroejaculator, polled and divided into two
equal aliquots. The control (CG) and tested (TG) groups consisted of
sperm either frozen in Botu-Bov ® (Biotech, Brazil) or cooled in
BotuBov ® (without glycerol) extender to yield 20 x 10 6 or 5 x 10 6
spermatozoa/0.5 ml straw, respectively, after appropriate dilution.
Extended sperm was cooled to 5 °C for 3 h using a refrigerator
(Mini-Tübe, Germany) and then frozen in liquid N 2 vapor for 20
min, before final freezing through direct immersion in N 2 (CG) or
refrigerated and kept at 5 °C in a Botutainer ® (Biotech, Brazil) for 48
h prior to use (TG). Afterwards, semen samples were utilized for
FTAI of 147 cows following estrus synchronization. At a random
day of the estrous cycle (Day 0) all the animals received 2 mg
estradiol benzoate (Estrogin ® , Farmavet, Brazil) and a progesterone
intravaginal device (Primer ® , containing 1g of progesterone,
Tecnopec, Brazil). On Day 6 and 8, 12.5 mg PGF 2a (Lutalyse ® ,
Pfizer, Brazil) was administered and progesterone device was
removed, respectively. Then, cows received another estradiol
injection (1 mg) on Day 9 and were inseminated 24 h later.
Pregnancy was diagnosed by ultrasonography 30 days following
insemination. Comparison of pregnancy rates between CG and TG
groups was analyzed using Chi-square test with P