Pregnancy rates per artificial insemination for cows and heifers inseminated at a synchronized ovulation or synchronized estrus.
- J. R. Pursley, M. Wiltbank, J. Stevenson, J. Ottobre, H. Garverick, L. Anderson
- MedicineJournal of Dairy Science
- 1 February 1997
One fixed-time AI at a synchronized ovulation provided similar pregnancy rates per AI as did AI following the a.m-p.m. rule after estrus had been induced by PGF2 alpha in lactating cows, but the fixed- time AI was not effective for heifers because of the lack of synchronization.
Pregnancy in dairy cows after synchronized ovulation regimens with or without presynchronization and progesterone.
- S. Z. El-Zarkouny, J. Cartmill, B. A. Hensley, J. Stevenson
- MedicineJournal of Dairy Science
- 1 April 2004
Pregnancy after synchronized ovulation (Ovsynch) with or without progesterone (P4) administered via controlled internal drug release (CIDR) intravaginal inserts improved conception and embryo survival in experiment 1 but not in experiment 2, in part due to differing proportions of cyclic cows at the outset.
Inclusion of an intravaginal progesterone insert plus GnRH and prostaglandin F2alpha for ovulation control in postpartum suckled beef cows.
- G. Lamb, J. Stevenson, D. Kesler, H. Garverick, D. Brown, B. E. Salfen
- Biology, MedicineJournal of Animal Science
- 1 September 2001
Treatment of suckled cows with Cosynch yielded acceptable pregnancy rates, but addition of a CIDR improved pregnancy rates in noncycling cows.
Influence of dietary energy on follicular development, serum gonadotropins, and first postpartum ovulation in suckled beef cows.
- R. Perry, L. Corah, J. Brethour
- Biology, MedicineJournal of Animal Science
- 1 September 1991
Pre- and postpartum level of dietary energy influenced birth weight and weight gain of calves, milk production, concentrations and pulse frequency of LH in serum, appearance rate of large follicles, and the interval to first ovulation.
Stage of cycle, incidence, and timing of ovulation, and pregnancy rates in dairy cattle after three timed breeding protocols.
- J. Cartmill, S. Z. El-Zarkouny, B. A. Hensley, G. Lamb, J. Stevenson
- MedicineJournal of Dairy Science
- 1 May 2001
In multiparous cows, PGF2alpha before Ov synch increased pregnancy rates, whereas the 2xPG12 protocol produced similar pregnancy rates as Ovsynch across parities.
Treatment of cycling and noncycling lactating dairy cows with progesterone during Ovsynch.
- J. Stevenson, J. R. Pursley, M. Wiltbank
- MedicineJournal of Dairy Science
- 1 July 2006
A CIDR insert during the Ovsynch protocol increased fertility in lactating cows having low serum P4 before PGF(2alpha) injection, and improved pregnancy outcomes were observed at some, but not all locations.
An alternative AI breeding protocol for dairy cows exposed to elevated ambient temperatures before or after calving or both.
- J. Cartmill, S. Z. El-Zarkouny, B. A. Hensley, T. Rozell, J. Smith, J. Stevenson
- MedicineJournal of Dairy Science
- 1 April 2001
It was concluded that a timed AI protocol increased pregnancy rates at d 27 to 30 because its success was independent of either expression or detection of estrus, whereas the reverse was true for cows after the Ovsynch protocol.
Interventions after artificial insemination: conception rates, pregnancy survival, and ovarian responses to gonadotropin-releasing hormone, human chorionic gonadotropin, and progesterone.
- J. Stevenson, M. Portaluppi, J. M. Dejarnette
- Biology, MedicineJournal of Dairy Science
- 2007
GnRH and hCG effectively induced ovulation, and increased number of CL, but only increased serum P4 in hCG-treated cows, and treatment with the CIDR or hCG increased conception rates but only in some herds.
Synchronization of estrus and artificial insemination in replacement beef heifers using gonadotropin-releasing hormone, prostaglandin F2alpha, and progesterone.
- G. Lamb, J. Larson, D. Landblom
- MedicineJournal of Animal Science
- 1 November 2006
The G+FTAI protocol produced the most consistent pregnancy rates among locations and eliminated the necessity for detection of estrus when inseminating replacement beef heifers.
Resynchronization of estrus in cattle of unknown pregnancy status using estrogen, progesterone, or both.
- J. Stevenson, S. Johnson, M. A. Medina-Britos, A. M. Richardson-Adams, G. Lamb
- Biology, MedicineJournal of Animal Science
- 1 July 2003
In both heifers and lactating beef cows, the P4-based resynchronization treatments increased synchronized return rates when estrus detection rates were low, had no negative effects on established pregnancies, and decreased or tended to decrease conception rates at the resynchronized estrus.
...
...