Presynchronization by induction of a largest follicle using a progesterone device in GnRH-based-ovulation synchronization protocol in crossbred dairy cows

The objective was to compare the fertility of dairy cows using a presynchronization protocol by induction of a largest follicle using a progesterone intravaginal device prior to an Ovsynch protocol (P4synch) with the Double-Ovsynch in lactating dairy cows. Lactating Bos indicus x Bos taurus crossbred cows (n=440) were randomly allocated to one of two treatments: (I) Double-Ov (n=228), GnRH (D-17), PGF2 α 7 days later (D-10) and GnRH 3 days later (D-7) followed by an Ovsynch protocol 7 days later (GnRH on D0, PGF on D7, GnRH on D9); (II) P4synch (n=212), insertion of a sustained release progesterone intravaginal device (D-10), 10 days later (D0) an Ovsynch protocol was initiated (GnRH on D0, PGF o n D7, GnRH on D9) with progesterone device withdrawal on Day 7.

Source: Theriogenology - April 27, 2018 Category: Genetics & Stem Cells Authors: L.A.C.L. Silva, L.M.S. Sim ões, M.P. Bottino, A.P.C. Santos, G. Santos, I.Y.H. Martinez, J.C. Souza, P.S. Baruselli, J.N.S. Sales Source Type: research