Vle CONG. INTERN. REPROD. ANIM. INSEM. ARTIF., PARIS, 1968, VOL. II

Synchronization of the parturition in ewe groups.

0. Garm and 0. Nedkvitne.
Veterinary College of Norway, Oslo, Norway.

The spread of lambing around the average parturition date
varies within breeds as well as between breeds. In the
most popular Norwegian sheep breeds this spread is about
8 days even if the group is oestrous synchronizated and
then inceminated on the one and the same day. In bregds
in which parturition difficulties are common a decrease
of this spread means a proportional decrease in night
watching of the ewes in the lambing period. A pilot
project in order to synchronizate the lambing was this
spring carried out on ewes of the Norwegian Dalabreed.

 

14 ewes were inceminated 1/12/67 and one ewe 2/12/67, and
the lambing was according to the average gestation length
in this breed expected in the period 24/4 - 2/5/68.

50 mg MAP per ewe and day was given in concentrates the
24/4, 25/4 and 26/4. (The administration of MAP was ment
to start 20/4, but due to transport difficulties the first
dose of MAP could not be given before the 24/4.)

Two of the 15 ewes lambed the 25/4 - the day after the
first MAP dose was given. The remaining 13 ewes lambed
in the course of 48 hours after the last dose of MAP was
given.

The results indicate that administration of a synthetic
gestogen some days before expected parturition can de-
crease the spread of lambing around the average parturi-
tion date in groups of oestrus synchronizated sheep. The
experiment further indicates that syntehtic gestogen given
in concentrates immediatly before lambing have no injuri-
ous effect to the parturition, to the health of the off-
springs or to the lactation.

1439