EFFECT OF PROGESTERONE BEFORE AN OVSYNCH-CIDRPROTOCOL ON FERTILITY IN DAIRY COWS WITH LOW BODY CONDITION SCORE

SCANDOLO LUCINI, DIEGO GERMÁN; MELENDEZ, PEDRO; BILBAO, MARÍA GUILLERMINA; PÉREZ WALLACE, SANTIAGO; BARTOLOMÉ, JULIÁN A.

Cincinnati, Ohio

Congreso; American Dairy Science Association ANNUAL MEETING 2019; 2019

American Dairy Science Association

The aim was to assess the effect of progesterone before an Ovsynch-CIDR protocol on fertility in dairycows with low BCS (≤ 2.75; scale 1-5). Lactating Holstein cows (n = 299) were assignedto a presynchronization treatment to receive a 1.9 g CIDR on Day -12 (Progesterone group, n=148) or no treatment (Control group, n=151).On Day -3, CIDR was removed and both groups received two doses of 25 mg ofPGF2α (5 mL, i.m., Lutalyse®) 12 h apart. On Day 0 all cows were enrolled in a synchronizationprotocol and treated with 10 µg of GnRH analogue (2.5 mL, i.m., Receptal®) and 1.9 g CIDR. On Day 7, CIDR was removed and cows received twodoses of 25 mg of PGF2α12 h apart. Cows received a second dose of GnRH analogue 56 h after first dose of PGF2 and were TAI 16 h later (Day 10). On Day -12, parity, BCS, milk yield, DIM and stage of the estrous cycle were recorded. Ultrasonographyof the ovaries was conducted on Day ? 12 to determine the presence of a CL. Pregnancy was diagnosed by ultrasonography at 32 d after AI (PAI).The effect of group, parity, and presence of CL at Day ? 12 and two-way interactions on pregnancy was evaluated by logistic regression.There was no difference (P = 0.18) in PAI neither between the progesterone group (33.1 %) and control group (30.5 %) nor interaction between group and parity (P = 0.65). However, progesterone treatment before the CIDR-Ovsynch protocol increased (P = 0.04) PAI in cows without a CL on Day ? 12 (32.2 % vs. 18.7 %) but not in cows with a CL (34.5 % vs. 42.1 %).