SRINIVAS, MANDA (MAJOR)MUTHA RAO, MDEVI PRASAD, VVIJAYA KUMAR REDDY, M2020-09-232020-09-232020-01https://krishikosh.egranth.ac.in/handle/1/5810151839THESESThe present study entitled “Relative efficacy of Doublesynch and Estradoublesynch protocols for improving fertility in repeat breeding Graded Murrah buffaloes (Bubalus bubalis)” was conducted to evaluate the efficacy of two estrus synchronization protocols, viz., Doublesynch and Estradoublesynch. The study was conducted during the low breeding season from March to August 2019. A total of 120 infertile Graded Murrah buffaloes were screened by performing per rectal palpation, white side test and PSP dye test. The causes for conception failure were established in the present study and were categorized as animals without any palpable abnormalities (repeat breeders), subclinical endometritis, tubal blockage and cystic ovaries were recorded with a per cent incidence of 30.0, 62.5, 5.0 and 2.5, respectively. After screening, 36 repeat breeder buffaloes were selected and were randomly assigned into 3 groups (12 buffaloes in each protocol and in control group). Group 1 (Doublesynch protocol) repeat breeder buffaloes were administered with PGF2α on day 0, GnRH on day 2, second PGF2α on day 9 and second GnRH on day 11 with FTAI twice at 16 and 24 hrs after second GnRH administration. Group 2 (Estradoublesynch protocol) repeat breeder buffaloes were administered with PGF2α on day 0, GnRH on day 2, second PGF2α on day 9 and estradiol benzoate (EB) on day 10 with FTAI twice at 48 and 60 hrs after EB injection while Group 3 (Control group) repeat breeder buffaloes were not given any treatment and were inseminated at detected natural estrus. Blood samples were collected for haemato-biochemical studies. The mean haemoglobin and PCV values varied non-significantly (P>0.05) between day 0 and day of induced estrus in both treatment and control groups. The serum glucose, total protein, total cholesterol and calcium profiles were significantly higher (P<0.05) in conceived than that of non-conceived buffaloes of both treatment and control groups. The serum phosphorus levels varied non-significantly (P>0.05) between conceived and non-conceived buffaloes of both treatment and control groups. There was no significance difference (P>0.05) in serum glucose, total protein, cholesterol, calcium and phosphorus levels on different days of treatment/AI among conceived and non-conceived buffaloes in both treatment and control groups. The mean serum progesterone profiles on day 9 and day 18 post AI were significantly higher (P<0.05) to that of day 0 and day 12 (day of induced estrus) in Doublesynch and Estradoublesynch treatment groups. Significantly higher levels (P<0.05) of serum biochemical and progesterone profiles in conceived than that of non-conceived buffaloes resulted in improved conception rates in both the treatment groups. The estrus induction response rates recorded were 91.66 % (11/12), 100 % (12/12) and 75 % (9/12) in Doublesynch, Estradoublesynch and control groups, respectively. Estradoublesynch treatment group animals exhibited more intense heat signs 41.66 % (5/12) when compared to Doublesynch 36.36 % (4/11). The artificial insemination submission rates were 91.66 % (11/12), 100 % (12/12) and 75 % (9/12) in Doublesynch, Estradoublesynch and control groups, respectively. The conception rates of repeat breeding Graded Murrah buffaloes at induced estrus with FTAI were 54.54 % (6/11) and 58.33 % (7/12) with Doublesynch and Estradoublesynch, respectively while the same was 22.22 % (2/9) at detected natural estrus in repeat breeder Graded Murrah buffaloes of untreated control group. From the results of the present study, it was concluded that the practicing veterinarians could effectively handle repeat breeding syndrome of buffaloes by adopting either Doublesynch or Estradoublesynch protocols. However, Estradoublesynch had a marginal advantage over Doublesynch protocol in the improvement of fertility in repeat breeder buffaloes as it resulted in intense estrus signs with ease in passage of AI gun at insemination.EnglishThesis