Pregnancy per artificial insemination and pregnancy loss in lactating dairy cows of a single herd following timed artificial insemination or insemination at detected estrus

Effects of resynchronization programs on pregnancy per artificial insemination, progesterone, and pregnancy-associated glycoproteins in plasma of lactating dairy cows.

Objectives were to develop a timed artificial insemination (TAI) resynchronization program to improve pregnancy per AI and to evaluate responses of circulating progesterone and pregnancy-associated glycoproteins in lactating cows. Cows (n=1,578) were presynchronized with 2 injections of PGF2alpha, given 14 d apart starting on d 45+/-3 postpartum, followed by Ovsynch [2 injections of GnRH 7 d be...

Importance of estrus on pregnancy per insemination in suckled Bos indicus cows submitted to estradiol/progesterone-based timed insemination protocols.

The objective was to evaluate the effect of estrus occurrence (based on removal of tail-head marks) on ovarian responses and pregnancy per AI (P/AI; 30 d after AI) in suckled Bos indicus beef cows submitted to timed AI (TAI) protocols. Cows received an intravaginal device containing 1.0 g progesterone, and 2.0 mg estradiol benzoate im; 8 d later, the intravaginal device was removed, and they we...

Synchronization of estrus in suckled beef cows for detected estrus and artificial insemination and timed artificial inseminati

We determined whether a fixed-time AI (TAI) protocol could yield pregnancy rates similar to a protocol requiring detection of estrus, or estrous detection plus TAI, and whether adding a controlled internal device release (CIDR) to GnRH-based protocols would enhance fertility. Estrus was synchronized in 2,598 suckled beef cows at 14 locations, and AI was preceded by 1 of 5 treatments: 1) a CIDR ...

Artificial Insemination in Dairy Cattle1

1. This document is DS58, one of a series of the Animal Science Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date September, 1992. Reviewed June, 20003. Visit the EDIS Web Site at http://edis.ifas.ufl.edu. 2. Professor, Dairy Science Department, Institute of Food and Agricultural Sciences, University ...

Maximizing Pregnancy Rates When Using Artificial Insemination