Effect of interval from induction of puberty to initiation of a timed AI protocol on pregnancy rate in Nellore heifers》.pdf

Theriogenology 82 (2014) 760–766 Contents lists available at ScienceDirect Theriogenology journal homepage: Effect of interval from induction of puberty to initiation of a timed AI protocol on pregnancy rate in Nellore heifers A.D.P. Rodrigues a, R.F.G. Peres a, A.P. Lemes b, T. Martins a, M.H.C. Pereira a, E.R. Carvalho a, M.L. Day c, J.L.M. Vasconcelos a, * a Departamento de Produção Animal, Faculdade de Medicina Veterinária e Zootecnia-UNESP, Botucatu, São Paulo, Brazil b Embrapa Southeast Livestock, São Carlos, São Paulo, Brazil c Department of Animal Sciences, The Ohio State University, Columbus, Ohio, USA a r t i c l e i n f o a b s t r a c t Article history: Prepubertal Bos indicus heifers (n ¼ 774) were submitted to an E /P -based timed artificial 2 4 Received 9 April 2014 insemination (TAI) protocol at three different intervals after induction of their pubertal Received in revised form 4 June 2014 ovulation by insertion of an intravaginal progesterone (P4 ) device for 12 days. Heifers were Accepted 10 June 2014 randomly assigned to start the TAI protocol at 10 (group 10; n ¼ 253), 12 (group 12; n ¼ 265), or 14 (group 14; n ¼ 256) days after the P4 device was removed. The TAI protocol consisted of Keywords: the following: insertion of intravaginal device containing P4 (Controlled internal drug release Prepu