ABSTRACT
The fertility of 1/2 Damascus-Baladi goats was evaluated when treated with
FGA-sponge plus injection of GnRH. Thirty does were divided into 3 equal
groups: A, B and C. All groups were synchronized during the breeding season
with FGA-sponges for 15 days then single intra-muscular injection of 4 g
GnRH on day 13, 14 and 15 from the time of sponge insertion was tried with
groups A, B and C, respectively. Estrous behavior was observed on 83.3% of the
does in the three treatment groups (A, B and C). All does in group A exhibited
estrus (100%) which was higher (P < 0.05) than groups B and C (80% and 70%,
respectively). All does in the three treatment groups showed estrus 24 to 36 h
after sponge withdrawal (overall mean 30.5  0.9 h); most does exhibited estrus
at 28 h (P < 0.05). Percentages of does showed estrus 24, 28, 32 and 36 h after
sponge withdrawal were 8, 40, 32 and 20%, respectively. Estrus duration was
longer for does in group A (31.93.8 hr) (P < 0.05) than groups B and C
(24.63.7 and 23.03.7 hr, respectively). Does in group C had the lowest (P <
0.05) conception rate (50%) compared to groups A and B (70% and 80%,
respectively). Does in group B showed the highest conception rate and litter size
(80% and 1.6 ± 0.2, respectively), suggesting that treatment with single intramuscular
injection of 4 g GnRH 24 h before FGA-sponge removal could give a
good result of estrus synchronization, super ovulation and conception.