Corpora lutea diameter, plasma progesterone concentration and follicular development in PGF2c, and CIDR estrus synchronized goats

The current study compares the number and diameter of the corpora lutea (CL),
plasma progesterone concentrations and follicular development in PGF2a and CIDR
synchronized estrus cycle, their subsequent estrus cycles, and in unsynchronized,
naturally cycling Boer x Feral crossbred goats. The PGF20, group was synchronized
with a double intramuscular injection of 125 ug cloprostenol 11 days apart, the
progesterone group was synchronized with CIDR left in place for 17 days, while the
third group was not synchronized and served as control. All the estrus synchronized
goats ovulated and formed normal CL while 25% in the subsequent estrus cycle and
50% of the naturally cycling goats did not ovulate and hence might be a cause of
reduced fertility in the goats. The diameter of the CL, and the plasma progesterone
concentration between the PGF2.a synchronized (11.910.5 mm; 3.5110.19 ng/ml)
and their subsequent estrus cycle (12.010.4 mm; 3.2210.71 ng/ml), as well as
between CIDR synchronized (12.310.4 mm; 5.9811.11 ng/ml) and subsequent
estrus cycle (12.510.8 mm; 4.2511.37 ng/ml) were not significantly different
(P>0.05) but were higher than in the unsynchronized goats (9.313.8 mm;
2.991s1.64 ng/ml). The day of emergence and duration of follicular waves, as well
as the maximum diameter attained by the largest follicle in the follicular waves was
unaffected irrespective of whether PGF2.a or CIDR was used for estrus
synchronization. This indicated that the morphology and function of the CL did not
influence these aspects of follicular development in non-seasonally polyestrus Boer
crossbred goats in the humid tropics.