Research Information System
ADSA- ASAS Joint Annual Meeting , Florida, United States Of America, 12 - 16 July 2015, pp.874
To assess the efficiency of 3 synchronization methods as postpartumreproductive management tools in dairy cattle on a commercial dairyfarm. Cyclic Holstein lactating cows (n = 167),55–90 DIM, were ran-domly allotted to 1 of 3 treatments. First group was (Ovsynch: n = 58)given a 2-mL i.m. injection of synthetic GnRH on d 0. After 7 d, PGF2a(2 mL i.m.) was injected. A second injection of GnRH was administered48 h after the PGF2a injection and all cows were bred by timed AI 16 hafter the second GnRH injection. Cows in second group (Ovsynch+P7:n = 55) were introduced a modified Ovsynch TAI treatment similar toOvsynch but CIDR was inserted for a 7-d period (CIDR was insertedwith GnRH and removed on PG Shot). In third group (Ovsynch+P5; n= 54), cows were subjected to Ovsynch protocol in addition to CIDRinsertion for 5 d (CIDR was inserted after 2 d of GnRH and removed withPG shot). P4 conc. was measured on d 30 and 60. Pregnancy diagnosiswas carried out at d 30, 60, 90 post insemination in all 3 groups. Pro -gesterone profile was significantly higher (P < 0.05) for Ovsynch + P5(7.75 ± 0.38 ng/mL) and Ovsynch + P7 (7.58 ± 0.26 ng/mL) comparedwith Ovsynch (6.52 ± 0.32 ng/ mL) on d 30 PTAI but nonsignificantamong all 3 synchronization treatments (i.e., 6.37 ± 0.49 in Ovsynch,6.75 ± 0.36 in Ovsynch+P5 and 6.80 ± 0.41 in Ovsynch+P7 group).Pregnancy rate in Control group was 39.7, 36.2, and 32.80 on d 30,60 and 90 post insemination. In second modified Ovsynch group with7d CIDR (Ovsynch+P7) insertion pregnancy rate was 42.6% on d 30,37% on d 60 and 90 PAI. In third group pregnancy rate was 45.5, 43.6and 41.8 on corresponding 30, 60, 90 d PAI. Although pregnancy ratewere statistically not significant but, by percentage points, improvedpregnancy rate was observed on all 3 time points in Ovsynch+p5 group.