Reproduction in Domestic Animals - Facultad de Ciencias Veterinarias

16 t h International Congress on Animal Reproduction
34 Poster Abstracts
purpose cows. An important observation was the presence of vagina
infection on the sponge treatment group. In conclusion, the use of
progesterone devices can improve overall conception rate in double
purpose herd. Therefore, the timed AI protocols can be used as tool
for reproductive management in tropical farms.
P020
The effect of high levels of proximal cytoplasmic droplets
on sperm functional competence.
Carreira, J 1 *; Koivisto, M 1 ; Mingoti, G 1 ; Leite, J 1 ; Perri, S 1 ; Rodrigues, L 2
1São Paulo State University, Araçatuba, Brazil; 2 Lagoa da Serra Artificial
Insemination Centre, Sertãozinho, Brazil
Introduction Semen conventional analysis may not adequately
represent the diverse number of biological properties that this highspecialized
cell can express (Hum. Repr.18:1023-1028,2003). The use
of more objective techniques, such as fluorescent probes to assess the
integrity of membranes and mitochondrial function of the sperm may
provide data on the occurrence of cryoinjuries (Acta Sci.Vet.33:327-
327, 2005). Frozen-thawed ejaculates with high levels of proximal
cytoplasmic droplets (PCD) produces low fertility rates
(J.Repr.Fert.51:109-116, 1997). The goal of this study was to evaluate
plasma membrane integrity (PL), acrossome status (ACR) and
mitocondrial function (MIT) of bovine semen with high levels of PCD
after cryopreservation, comparing to samples with normal parameters.
Methods Three batches of five (control group G1: with ≤ 15% of total
defects) and eight Bos indicus bulls (G2: ≥15% PCD) were analyzed.
The following tests were carried out: post thaw motility (MOT), vigor
(VI), concentration (CO) and morphology. The samples were
centrifuged (750rpm/ 5 min) twice with 500μL of TALP-Semen. CO
was adjusted to 25x10 6 sptz/mL. To an 30μL aliquot, 2μL of PI
(0,2mg/mL), 1,6 μL of JC-1 (0,5mg/mL) and 10 μL FITC-PSA
(100μg/mL) was added, after incubation at 38.5°C/8 min, 8μL was
evaluated by epifluorescent microscopy. Data were analyzed with
ANOVA. Results MOT, VI and CO were nor significant in both
groups (MOT: 45.42 vs 40.31; VI: 4.47 vs 4.03; CO: 29.18 vs 31.23
x10 6 sptz/mL for G1 and G2, respectively). The percentage of PCD
(G1= 0.51%; G2=24.35%), major defects (4.98% G1; 38.9% G2), and
total defects (G1 10.32%; G2 48.38%) were significantly higher in G1
when compared to G2. Minor defects were not different between
groups (G1= 5.38%; G2= 9.48%). G1 had significant higher results
for ACR (38.48% vs 29.70% G2), PL (38.16% vs 21.39%) and also
MIT (41.90% vs 23.22%) for G1 and G2, respectively. Conclusion
The results indicate that semen with high levels of PCD may be
functionally deficient and more susceptible to cryoinjuries as show the
lower levels of acrossome, membrane integrity and mitochondrial
potential.
P021
Evaluation of slow-release parenteral natural
progesterone and its effects in a modified Ovsynch
protocol in Holstein dairy heifers
Cavestany, D 1,2 *; Sanchez, A 3 ; Fernandez, D 3 ; Salazar, E 3 ; Leyton, L 4 Crespi,
D 2 , Meikle, A 5
1National Institute of Agricultural Research (INIA) Uruguay; 2 Department of
Reproduction, Veterinary Faculty, Uruguay; 3 Private veterinarians, Uruguay;
4Faculty of Agronomy, University of El Salvador, San Salvador; 5 Laboratory of
Nuclear Techniques, Faculty of Veterinary, Uruguay
The efficiency of the ovulation synchronisation (Ovsynch/TAI
protocol) can be improved by progesterone (P4) supplementation and
this increases the ovulation synchrony and pregnancy rate. The most
common P4 sources are intra-vaginal devices impregnated by natural
P4 and/or oral progestagens. In this experiment a slow-release
parenteral natural P4 was tested in the above-mentioned protocol.
Three trials were conducted. In trial 1, three multiparous milking
Holstein-Friesian (HF) cows (511±28 kg) and 3 HF heifers (372±21
kg) received three prostaglandin (PG) treatments at weekly intervals,
after which they received 400 mg of progesterone (4-pregnano-3.20-
dione) (Laboratory Rio de Janeiro, Santa Fé, Argentina)
subcutaneously and were bled frequently for 5 days to check plasma
P4 levels. Peak P4 levels were achieved 4 hours post treatment
(10.2±0.8 & 6.2±0.7 ng/mL, P0.1) for cows and heifers. In
trial 2, one-hundred-eleven heifers (374±4 kg) were allocated into 2
groups (control: Ovsych and treatment: Ovsynch + 400 mg P4 SC at
the time of the GnRH treatment). Oestrus detection was done from
day 5, and heifers in heat were inseminated. While synchrony of
ovulations improved in the treated group, 78% vs. 52% (P