follicular turnover and estradiol 17-β (E2) concentration
during the estrus cycle in the subtropics was studied in 13
ewes (7 ewes subjected to high energy, HEG and 6 as
normal energy group, NEG). After ovulation (day 0), a
high-energy diet (10.87MJ ME/kg diet; 130 % of
maintenance) was fed to HEG from day 1 to day 4 after
ovulation and from day 8 to Day 11 of the cycle (4 days
each). The high-energy diet consisted of 850 g
concentrate mixture and 150 g alfalfa hay, plus ad libitum
access to wheat straw. The NEG was offered as
maintenance diet throughout the experiment. Follicular
development was ultrasonographically observed every
other day while blood samples were collected daily
throughout the experiment for the analysis of albumin,
globulin, glucose, total cholesterol, urea, triglycerides,
total proteins, E2 and progesterone (P4). Mean plasma
concentrations of glucose were significantly (P < 0.05)
higher in the HEG animals than in the NEG ones at
almost all days during the treatment period. For ovarian
performance, the total number of medium and large
follicles that developed on the day prior to the 2nd
ovulation in the HEG ewes (3.5±0.17) was significantly
higher than that of the NEG (1.87±0.26) ones. Ovulation
rate (2.8±1.0) in the HEG animals was significantly
higher than that of the NEG counterparts (1.15±0.6). No
significant difference was detected in the concentrations
of P4 and E2 throughout the experiment between animals
of the different groups except for E2 peak concentration
on Day 8. The present experiment demonstrated that
short-term intermittent nutritional stimulus in cyclic ewes
increased the total number of ovulatory follicles and the
ovulation rate in association with increasing plasma
concentrations of glucose and peak levels of E2.