Reproduction in Domestic Animals - Facultad de Ciencias Veterinarias

16 t h International Congress on Animal Reproduction
Poster Abstracts 51
study investigated the relationships between these factors. A total of
84 normal beef heifers had their oestrous cycles synchronised using
two injections of prostaglandin (PG), 11 days apart and were fitted
with HeatWatch® devices. The time of initial standing event followed
by successive mounting activity was taken as the onset of oestrus
(D0). Heifers recorded in oestrus were inseminated 5 – 21hrs after
onset using semen from a single ejaculate from a high fertility bull.
Ovarian structures were ultrasonically examined with a 7.5-MHz
probe starting 12 hours after onset of oestrus and repeated every 6
hours thereafter until ovulation (OV) occurred. Time of OV was
determined from the time of the first scan on which the dominant
follicle (DF) had disappeared minus 3 hrs. Ovaries were re-examined
on day D7 to confirm OV and to measure luteal structures. Blood
samples were collected at 12 hour intervals on D -1, D0 and again on
D7 for IGF-I and P4 which were measured by IRMA and RIA,
respectively. Embryo survival (EmSurv) was confirmed by
ultrasonography at D30 and D100 post AI. The relationships between
EmSurv and continuous variables were evaluated using logistic
regression. EmSurv at D30 was 69% with two of the heifers suffering
foetal loss between D30 and D100. OV occurred (Mean±S.D) 27.4 ±
5.9 h after the onset of heat. There was no relationship between the
interval from onset of heat to OV or the interval from AI to OV and
EmSurv. (P>0.05). There was evidence of a relationship between the
size of the ovulatory follicle and EmSurv (Odds ratio=0.79; P=0.07).
There was a positive relationship between concentration of P4 on Day
7 and EmSurv (Odds ratio=1.4; P0.05) between P4 on D7 and ovulatory follicle size, CL volume or
concentrations of IGF-I on D-1, D0 or D7. Similarly there was no
relationship (P>0.05) between IGF-I concentrations and EmSurv. We
conclude that there was considerable variation in the timing of OV
relative to the onset of oestrus. Time of AI relative to heat onset and
or time of ovulation had no effect on embryo survival rate. There was
a positive association between P4 on day 7 and embryo survival but
not for IGF-I. Plasma P4 was not related to the size of the ovulatory
follicle, CL volume or plasma IGF-I. Oocytes produced from large
dominant follicles may have impaired embryo survival.
P071
Prevalence of clinical and subclinical endometritis in
dairy cows and the impact on reproductive performance
Madoz, L 1 *, Ploentzke, J 2 , Albarracin, D 3 , Mejia, M 4 , Drillich, M 2 , Heuwieser,
WS 2 , De La Sota, RL 1
1Catedra y Servicio de Reproduccion Animal, Facultad de Ciencias
Veterinarias, Universidad Nacional de La Plata, Argentina; 2 Bovine
Reproduction Clinic, Fac. Veterinary Sciences, Free University of Berlin,
Germany; 3 Catedra de Patologia, Fac.de Cs. Veterinarias, Univ. Nac. de La
Plata, Argentina; 4 Practica privada, Argentina
The aim of this study was to evaluate the prevalence of clinical (CE)
and subclinical (SE) endometritis and their impact on reproductive
performance in dairy cows. Samples were collected from 211 Holstein
cows in three farms in Argentina. Cows were examined for diagnosis
of clinical endometritis (CE) between 21 and 62 days postpartum
(dpp) at a monthly herd visit. At examination, cows were first
inspected for presence of fresh and/or dry discharge on the vulva,
perineum, or tail. Then the mucus content of the vagina was evaluated
for color, proportion of pus to mucus, and odor; and a score was
assigned as follows: clear mucus (0, [NOR]), predominantly clear
mucus with flecks of pus (1, [CE1]), purulent mucus but not foulsmelling
(2, [CE2]), or purulent or red-brown mucus and foul
smelling (3, [CE3]). After clinical examination, if mucus content was
NOR, cows were examined (EX1) for diagnosis of SE by endometrial
cytology (n=165). Cows were reexamined 14±3 d later (EX2).
Endometrial cytology samples were collected using a cytobrush
modified for use in cattle. Cytology slides were prepared by rolling
the CB on a clean glass microscope slide, air dried, fixed with ethylic
alcohol and stored in a slide box. Slides were stained with a modified
Wright-Giemsa stain and the degree of endometrial inflammation was
assessed by counting a minimum of 200 cells at 400 x magnifications
and expressed as the percent neutrophils (PPMN). The diagnosis
criteria for SE was >18% PPMN in samples collected 21-33 dpp,
>10% neutrophils in samples collected 34-47 dpp and >5% PPMN in
samples collected 48-62 dpp. At 50 dpp, cows with normal mucus
were detected in heat twice a day and AI. All AI cows were diagnosed
pregnant by transrectal palpation at 35-65 d post AI. At examination,
78.2% (165/211) of cows were diagnosed NOR and 21.8% with CE
(56.5% [26/46] CE1, 37.0% [17/46] CE2 and 6.5% [3/46] CE3). The
cytobrush was done in 149 of 169 NOR cows. The prevalence of SE
was 10.1% (15/149). At EX2, 87.5% (49/56) remained negative,
10.7% (6/56) changed from positive to negative and 1.8% (1/56)
remained positive. Cows with SE needed more services per
conception (2.77±0.45 vs. 1.96±0.18, p