AGE AT PUBERTY IN FEMALE DWARF GOAT KIDS AND
ESTROUS CYCLE LENGTH ON THE BASIS OF HORMONES
Shahnaz A. Khanum, M. Hussain, M. Ali, R. Kausar
and A.M. Cheema1
Nuclear Institute for Agriculture and Biology
(NIAB),
Faisalabad; 1Department of
Zoology, University of the Punjab,
Lahore,
Pakistan
Abstract
A lot of five healthy female dwarf goat kids was
reared at NIAB farm. Blood sampling was started at the age of 75 days.
Progesterone and oestradiol profiles were monitored duri.ng prepuberal period
and estrous cycle by using Radio-immunoassay (RIA) technique. During prepuberal
period progesterone remained at the basal levels of 0.1-0.5 ng/ml. A small rise
upto 2 pg/ml was noticed in oestradiol at the transition from prepuberal to
puberal period. Hormonal levels begin to rise at the age of 4-5 months ( 120-160
days). Oestradiol started to increase to peak levels indicating estrous phase.
After this period, progesterone values started to rise and attained the peak
levels of 4-9 nglml during the 15 days. In the next 4 to 5 days, it started to
fall and reached to basal levels. On the day of oestrous, peak values of
oestradiol, ranged from 10-16 pg/ml were observed. The overall pattern of
release of these hormones was similar in all the animals of the lot and the mean
age at puberty in the dwarf goat was found to be 1371+31 days with a mean
estrous cycle length of 201+1 days.