SADASIVA RAO, K (Major)RAM CHANDRA REDDY, KRAGHAVENDER, K. B. PGOPALA REDDY, ARAGHUNANDAN, TMURALI MOHAN, K2017-06-102017-06-102012-04http://krishikosh.egranth.ac.in/handle/1/5810019317THESESABSTRACT : A study was undertaken on synchronization of estrus in sheep. The ewes were synchronized with vaginal sponges containing 30 mg of Flurogestone acetate (FGA) and Controlled internal drug releasing (CIDR) device containing 300 mg of progesterone. A total of 240 post partum, parous, healthy ewes aged about 2 to 5 years were selected. Out of 240 ewes, 120 ewes were treated with vaginal sponge another 120 ewes treated with CIDR during breeding and non breeding season. Ewes treated with vaginal sponge and CIDR were divided into 5 groups each group consists of 24 animals. Each group was further subdivided into 2 groups consists of 12 animals and were studied during breeding and non breeding seasons. Group I ewes were considered as untreated control. Ewes in group II were treated with intravaginal sponge/CIDR and left in place for 12 days followed by intramuscular injection of 400 IU of PMSG at the time of sponge removal. Ewes in group III were treated with vaginal sponge/CIDR and 600 IU of PMSG was given intramuscularly at the time of removal of implant. Ewes in group IV were treated as in group II except 200 IU of hCG injection at the time of mating. Ewes in group V were treated as in group III except 200 IU of hCG injection at the time of mating. The haematological and biochemical parameters were studied on day 0, day 6 and day 12 treatment with either vaginal sponge or CIDR during breeding and non breeding seasons. The progesterone profiles were also recorded on day 0, 3. 6, 9 and 12 of the treatment, respectively. The haemoglobin, serum glucose, calcium and phosphorus levels were significantly higher during breeding season compared to non breeding season in ewes treated either with vaginal sponge or CIDR. In vaginal sponge group, the progesterone levels before insertion were 1.23±0.12 ng/ml during breeding season. The progesterone levels were 2.46±0.11, 3.40±0.13 and 4.71±0.14 ng/ml on day 3, 6 and 9 of treatment, respectively in breeding season. In non breeding season, the progesterone levels were 0.96±0.12 ng/ml before insertion of vaginal sponges. During treatment, the progesterone levels were 1.62±0.13 ng/ml on day 3, 2.32±0.11 ng/ml on day 6, 3.35 ±0.14 ng/ml on day 9 and 3.19±0.12 ng/ml on day 12 of treatment (at the time of removal). The progesterone levels were significantly (P<0.01) increased from day 0 to day 9 of treatment and thereafter it was significantly (P<0.01) decreased on day 12 of treatment. Significantly, higher progesterone levels were recorded in all groups of ewes inserted with vaginal sponges (2.76±0.06 to 2.84±0.07 ng/ml) compared to control group of ewes (1.67±0.08 ng/ml). In CIDR treatment ewes, the progesterone levels were 1.44±0.13, 2.64±0.11, 3.63±0.10, 5.11±0.16 and 3.34±0.12 ng/ml on day 0, 3, 6, 9 and 12 of treatment, respectively during breeding season. While in non breeding season, the corresponding values were 0.84±0.11, 1.84±0.14, 2.33±0.15, 3.01±0.18 and 2.55±0.10 ng/ml on day 0, 3, 6, 9 and 12, respectively. The progesterone levels were significantly (P<0.01) increased from day 0 to day 9 of treatment and thereafter decreased on day 12 of treatment during breeding and non breeding seasons. When compared the vaginal devices with CIDR, the progesterone levels were significantly (P<0.01) higher in CIDR treatment than the vaginal sponges treatments in the present study. The percentage of ewes responded for synchronization of estrus was 50.00, 83.33, 100.00, 91.67 and 100.00 in control, VS 4, VS 6, VS 4h and VS 6h, respectively in breeding season. In non breeding season, the estrus response was 25.00, 83.33, 100.00 83.33 and 100.00 per cent in control, VS 4, VS 6, VS 4h and VS 6h, respectively. Likewise the ewes treated with CIDR, the estrus response rates were 50.00 Vs. 16.67; 83.33 Vs. 83.33; 100.00 Vs. 100.00; 91.67 Vs. 83.33 and 100.00 Vs. 100.00 per cent in control, CIDR 4, CIDR 6, CIDR 4h and CIDR 6h in breeding Vs. non breeding seasons, respectively. The estrus response was significantly (P<0.01) higher in treated ewes than that of control groups in both treatments and both seasons. Estrus response were significantly (P<0.01) higher in VS6/CIDR6 and VS6h/CIDR6h groups of ewes followed by VS4/CIDR4, VS4h/CIDR4h and control groups of ewes in ewes synchronized with vaginal sponge and CIDR. The estrus response was significantly (P<0.01) differed during non breeding season in both vaginal sponge and CIDR synchronization protocol. The time taken for induction of estrus in vaginal sponges group was 46.58±2.28, 41.24±1.56, 46.95±2.66 and 40.62±2.73 h during breeding season and 48.01±2.81, 46.66±3.77, 48.55±3.03, and 46.69±3.89 h during non breeding season in control, VS 4, VS 6, VS 4h and VS 6h, respectively. Among the CIDR group of ewes, the time taken for induction of estrus was 35.56±2.36 Vs. 38.53±3.21 h in CIDR4, 34.78±2.32 Vs. 36.82±2.14 h in CIDR6, 35.63±2.84 Vs. 38.77±2.86 h in CIDR 4h and 34.80±2.21 Vs. 36.27±1.85 h in CIDR 6h group of ewes during breeding Vs. non breeding season, respectively. The time taken for induction of estrus was significantly (P<0.01) long in the vaginal sponge treatment than the CIDR treatment in the present study.ennullThesis