Spring postpartum reproductive performance was investigated in
19 Awassi and 15
Finn×Texel×Awassi (FTA) crossbred ewes, weaned at 2 months
postpartum and simultaneously
exposed to rams for a period of 48 days. The study was conducted in 1991/92
in the Bekaa Valley
Postpartum FTA ewes tended to have higher fecundity and prolificacy
than those of Awassi ewes.
Forty percent of the FTA ewes conceived and gave birth to 1·3 lambs
per lambing, while 31·4% of
the Awassi ewes conceived and lambed (1·1 lambs per lambing). Lambing
to lambing and ram
introduction to lambing intervals were similar in both genotypes and confirmed
that a sizeable
proportion (30–40%) of Awassi ewes and their crosses may rebreed
during spring postpartum
anoestrus and lamb at c. 8 months interval. Furthermore, relative
progesterone values revealed
continuous ovarian activity in 16% of Awassi ewes and 40% of FTA ewes and
of conception in ewes. All ewes with continuous ovulation mated and lambed.
Weekly estimates of
milk production over a 2-month period, starting the second week of lactation,
showed that daily milk
yields were almost twice as much in Awassi as in FTA ewes (P<0·01).
These results indicate the
potential for Awassi ewes and their crosses to be incorporated into frequent
Reproductive efficiency in these ewes could be monitored efficiently by
measuring progesterone at 2-weekly intervals.