Dairy Sheep Symposium - the Department of Animal Sciences ...

estrus synchronization
CLY: Saline CLY: +CIDR Saline +CIDRCLY:
PGF CLY: - PGF CIDR
2 2 2á -CIDR
CLN: PGFCLN: +CIDR PGF2á +CIDRCLN:
PGF 2 CLN: - PGF CIDR
2 2á -CIDR
ovulation
laparoscopy
pre treatment
-22 -20 -18 -16 -14 -12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28
Days relative to ovulation
laparoscopy
Figure 1. Schematic diagram of the experimental design. Estrus synchronization and induction
of ovulation were achieved with intravaginal progesterone (CIDR), PGF 2α , and gonadotropins.
Ewes were studied during three experimental periods: d 0 to 5 (pre-treatment),
d 6 to 18 (treatment), and d 19 to 25 (post-treatment). Laparoscopy was performed
on d 4 and 11 to affirm presence or absence of corpora lutea (CL). Treatments
were applied on d 5 and consisted of: injection of saline (CLY) or PGF 2α (CLN) to
achieve persistence or regression of CL, respectively. All ewes received two CIDRs
from d 5 to 18. Administration of PGF 2α was performed on d 18 to ensure luteolysis in
all ewes during the post-treatment period.
post