ESTRUS SYNCHRONIZATION WITH MEDROXYPROGESTERONE ACETATE IMPREGNATED SPONGES IN
GOATS (CAPRA HIRCUS)
R. KAUSAR, S. A. KHANUM, M. HUSSAIN AND M. S. SHAH
Animal Science Division, Nuclear Institute for Agriculture and Biology
(NIAB), P. O. Box: 128, Jhang Road,
Faisalabad,
Pakistan
Abstract
An experiment was performed to synchronize estrus
in goats by locally prepared progesterone-impregnated sponges and to determine
the time of onset and duration of estrus alongwith subsequent fertility rate.
The study was conducted from May to December, 2007 at NIAB (Nuclear Institute
for Agriculture and Biology), Faisalabad.
Polyurethane sponges were prepared with medroxyprogesterone acetate (MAP: 60 mg)
and inserted intra-vaginally in a lot of 8 female postpartum goats (Beetal x
Dwarf). Two goats were kept as control and were treated with sponges without
MAP. Sponges were removed on 17th day of insertion and goats were
examined for the signs of estrus at 6 h intervals.A buck was introduced in the herd for breeding, one day after removal of
sponges. Estrus was further confirmed by determining serum estradiol levels
using radioimmunoassay (RIA). All the experimental goats exhibited estrus within
21-100 h of removal of sponges, whereas one control animal also showed estrus.
The average time from sponge withdrawal to the onset of estrus was 65.4 ± 24.0 h
and duration of estrus was 29.8 ± 6.7 hours in experimental group. The control
animal showed estrus after 22.0 h of sponge removal with estrus duration of 36
h. Estradiol concentrations in experimental lot were in the range of 2.2-15.0
pg/ml during estrus. Animals were observed for reversal towards estrus after 21
days. Only one experimental animal exhibited 2nd estrus. Pregnancy
was confirmed by ultrasound after 60 days of sponge removal. The gestation
period of 150.4 ± 3.4 days, a litter size of 1.3 ± 0.5 and a fertility rate of
87.5% were observed in the experimental lot. The control doe produced a male kid
after 150.0 days of gestation. It is evident from this experiment that estrus
can be synchronized in goats (Beetal x Dwarf) by locally prepared progesterone
sponges with good fertility rate.