Study On Relationships Between Follicular Waves And Reproductive Hormone's Variations In Jilin Sika Deer During Estrous Cycle

The studies were conducted to investigate the follicular dynamics during spontaneous and PGF2α-induced oestrous cycles of 9 mature hinds by B-mode transrectal ultrasonography. The synchronization rate of two methods and its effects on follicular development dynamics were studied. Blood samples were collected simultaneously on the same day and were analysed for concentration of FSH, LH, oestradiol and progesterone during the oestrous cycles as monitoring the follicular by ultrasonography. The hormone concentration and its relationships with follicular waves of two different spontaneous methods were compared.Results indicated as follows:(1) CIDR+PMSG+PG group had three deer estrus synchronization 64±24h in average after the withdrawal of CIDR (3/4). PG group had two deer estous on day 20 after deal (2/5). No.520, 3, 4 rut twice (about 19, 13 and 17 days long respectively), the others only rut once. Nine deer rut eight times, three of them are inducing estrus and five of them are natural estrus.(2) Both in the inducing cycles and the natural cycles, follicle development was considered wave-like, 1, 2 or 3 follicular waves were discovered in one estrous cycle in sika deer in Jilin, including three one-wave cycles, three two-wave cycles and two three-wave cycles. The length of one-wave, two-wave and three wave cycles were 5.3±0.6d, 12.3±4.0d and 25.5±2.1d, respectively. No. 1 and No. 216 did not rut during the whole experiment, the former had no follicular waves and the latter had two follicular waves.(3) The largest follicle of one-wave cycle (5.4±0.5mm) was larger than the largest follicles in the first (5.1±0.6mm) and second (4.8±0.5mm) wave of two-wave cycles and the second wave (5.2±0.4mm) of three-wave cycles (P>0.05), was smaller than the largest follicle in the first (5.6±0.3mm) and third (5.7±1.1mm) wave of three-wave cycles (P>0.05). The largest follicles of all the waves of two-, and three cycles were significantly different (P<0.05), the largest follicles of two-wave cycles were smaller than that of three-wave cycles.(4) All the interwave intervals in three-wave cycles (9.8±1.5d and 5.7±1.4d) were longer than the interwave interval (6.0±1.4d) in two-wave cycles (P>0.05).(5) The duration of growth in one-wave cycle was 4.5±0.7d. The duration of growth (4.7±1.5d and 4.0±1.7d) in two-wave cycles and three-wave cycles (4.5±2.1d,6.5±2.1d and 2.5±0.7d) were not significantly different (P>0.05). There was no difference of the duration of growth in the ovulatory waves and anovulatory waves (P>0.05).(6) There was a big peak of the serum FSH concentrations in No.496 sika deer on Day 14 before eatrous and a small peak on the day of estrous in one-wave cycles. In two-wave cycles, No.3's FSH peak occurred on Day 4 before estrous and Day 7 after estrous. FSH concentrations bolt down to basic level after buried CIDR in three-wave cycles in No.3. There was a small peak on Day 4 before estrous, another peak occurred on Day 3 after the second estrous. A surge in circulating FSH concentrations precedes emergence of each wave. (7) The serum LH concentrations keep stable level after settled, and serum peak occurred on Day 17 before eatrous and the day of estrous in No.496 sika deer in one-wave cycles. In two-wave cycles, there were two small peaks on Day 4 and 1 day before estrous respectively in No.520. LH peaks occurred on Day 3 and Day 12 after estrous in three-wave cycles in No.3. A surge in circulating LH concentrations precedes ovulation.(8) P₄ concentrations in No.496 dropped sharply after buried CIDR, and there was a small peak on Day 5 before eatrous, it began rapidly rising from Day 8 after estrous and reached peak on Day 11 in one-wave cycles. In two-wave cycles, P₄ concentrations dropped sharply after injecting PG, small peaks occurred on Day 4 before estrous and Day 11 after estrous in No.520. P₄ concentrations in No.4 also dropped sharply after buried CIDR in three-wave cycles. High-progesterone suppressed the growth of dominant follicle, and drived the emergence of the next wave.(9) There was a big peak of the serum E₂ concentrations in No.496 sika deer on Day 2 before eatrous and a small peak on Day 14 before estrous in one-wave cycles. The general trend is rising from buring CIDR to estrous. In two-wave cycles, E₂ concentrations began rising slowly after injecting PG, and there were two peaks occurred on Day 5 and Day 16 after estrous in No.520. E₂ concentrations in No.4 in three-wave cycles rised sharply after buried CIDR, there are two small peaks occurred on Day 6 and Day 12 after oestrous, a big peak occurred on Day 6 after the second oestrus. Serum estradiol concentration was the highest when the dominant follicle emerged.