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Full-Text Articles in Life Sciences
Gonadotropin-Releasing Hormone Increased Pregnancy In Suckled Beef Cows Not Detected In Estrus And Subjected To A Split-Time Artificial Insemination Program, S. L. Hill, D. M. Grieger, K C. Olson, J. R. Jaeger, K. R. Harmoney, C. R. Dahlen, M. R. Crosswhite, N. Negrin Pereira, S. R. Underdahl, B. W. Neville, J. Ahola, M. C. Fischer, G E. Seidel, J. Stevenson
Gonadotropin-Releasing Hormone Increased Pregnancy In Suckled Beef Cows Not Detected In Estrus And Subjected To A Split-Time Artificial Insemination Program, S. L. Hill, D. M. Grieger, K C. Olson, J. R. Jaeger, K. R. Harmoney, C. R. Dahlen, M. R. Crosswhite, N. Negrin Pereira, S. R. Underdahl, B. W. Neville, J. Ahola, M. C. Fischer, G E. Seidel, J. Stevenson
Kansas Agricultural Experiment Station Research Reports
Estrus-synchronization programs allow insemination of all females in a herd at one fixed time on the first day of the breeding season. Inseminating cows after they have expressed estrus increases pregnancy rate (PR) compared with cows that do not display estrus in a timed AI (TAI) program. Identification of estrus status can be facilitated by using estrus-detection patches. Varying AI timing according to estrus status has increased PR in some previous studies. Reducing the number of injections in a TAI program decreases labor requirements, stress on cows, and overall cost of the program. Previous studies have demonstrated that PR is …
Resynchronization Of Lactating Dairy Cows At Open Pregnancy Diagnosis Based On The Presence Or Absence Of A Corpus Luteum: A Practical Approach, J. A. Sauls, J. S. Stevenson
Resynchronization Of Lactating Dairy Cows At Open Pregnancy Diagnosis Based On The Presence Or Absence Of A Corpus Luteum: A Practical Approach, J. A. Sauls, J. S. Stevenson
Kansas Agricultural Experiment Station Research Reports
Lactating Holstein cows in three herds were enrolled in a study at the time of nonpregnancy diagnosis. Cows were assigned to a resynchronization program based on ovarian structures determined by transrectal ultrasonography. Three resynchronization treatments were employed starting on the day of open diagnosis to test: (1) accuracy of ultrasound technician’s ability to identify a functional corpus luteum (CL); (2) whether an initial GnRH injection is required to start resynchronization when a CL is present at nonpregnant diagnosis (Short Synch: PGF2α— 24 hours — PGF2α— 32 hours — GnRH — 16 hours — timed artificial insemination …
Dose And Frequency Of Pgf2Α Administration To Lactating Dairy Cows Exposed To Presynchronization And Either Five- Or Seven-Day Ovsynch Protocols: Ovulation, Luteolysis, And Pregnancy Rates, J. S. Stevenson, J. A. Sauls
Dose And Frequency Of Pgf2Α Administration To Lactating Dairy Cows Exposed To Presynchronization And Either Five- Or Seven-Day Ovsynch Protocols: Ovulation, Luteolysis, And Pregnancy Rates, J. S. Stevenson, J. A. Sauls
Kansas Agricultural Experiment Station Research Reports
Lactating Holstein cows in one herd were milked three times daily and enrolled in a 2 × 2 × 2 factorial design with eight treatments before first postpartum artificial insemination (AI). These treatments were employed to test ovulatory, progesterone, and luteolytic outcomes to three main effects: (1) two GnRH-PGF2αpresynchronization programs (PG-3-G vs. Double Ovsynch); (2) 5- vs. 7-day Ovsynch-duration programs; and (3) two doses (25 mg on consecutive days) or one dose (50 mg) of PGF2αadministered before timed AI. Results from this experiment demonstrate no differences in the presynchronization treatments of PG-3-G vs. Double Ovsynch; both …