Success of several programed AI-breeding protocols including ovsynch

Kansas Agricultural Experiment Station Research Reports, Dec 1996

In Experiment 1, four programmed AIbreeding treatments were tested. The so-called OvSynch program, which requires no heat detection before a fixed-time insemination, decreased conception rates compared with a similar treatment in which inseminations occurred after detected estrus (30 vs 51%). The traditional two-injection prostaglandin program produced greater conception rate for cattle inseminated after a detected estrus (53%) than after one fixed-time insemination was given in the absence of estrus (31%). A similar protocol of two prostaglandin injections plus an injection of gonadotropin-releasing hormone (GnRH or Cystorelin®) before one fixed-time insemination produced lower conception rates (33%) than when cattle were inseminated after detected estrus (53%). In Experiment 2, the OvSynch program was retested with the interval between the PGF and the second GnRH 2a injection being 48 hr (36 hr in Experiment 1). Conception in 27 cows on the OvSynch48 program with timed insemination (37%) was comparable with 43% in 21 cows on a similar program without the second GnRH injection but inseminated at estrus.; Dairy Day, 1996, Kansas State University, Manhattan, KS, 1996;

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Success of several programed AI-breeding protocols including ovsynch

Success of several programed AI-breeding protocols including ovsynch Jeffrey S. Stevenson K . E. Thomp son Y. Kobayashi Follow this and additional works at: https://newprairiepress.org/kaesrr Part of the Dairy Science Commons Recommended Citation Stevenson, Jeffrey S.; Thomps on, K. E.; and Kobayashi, Y. (1996) "Success of several programed AI-breeding protocols including ovsynch," Kansas Agricultural Experiment Station Research Reports: Vol. 0: Iss. 2. https://doi.org/10.4148/2378-5977.3252 - Article 327 Thi s report is brought to you for free and open access by New Prairie Press. It has been accepted for inclusion in Kansas Agricultural Experiment Station Research Reports by an authorized administrator of New Prairie Press. Copyright 1996 Kansas State University Agricultural Experiment Station and Cooperative Extension Service. Contents of this publication may be freely reproduced for educational purposes. All other rights reserved. Brand names appearing in this publication are for product identification purposes only. No endorsement is intended, nor is criticism implied of similar products not mentioned. K-State Research and Extension is an equal opportunity provider and employer. Success of several programed AI-breeding protocols including ovsynch Abstract In Experiment 1, four programmed AIbreeding treatments were tested. The s o-called OvSynch program, which requires no heat detection before a fixed-time insemination, decreased conception rates compared with a similar treatment in which inseminations occurred after detected estrus (30 vs 51%). The tr aditional twoinjection prostaglandin program produced greater conception rate for cattle inseminated after a detected estrus (53%) than after one fixed-time insemination was given in the absence of estrus (31%). A similar protocol of two prostaglandin injections plus an injection of gonadotropin-releasing hormone (GnRH or Cystorelin®) before one fixed-time insemination produced lower conception rates (33%) than when cattle were inseminated after detected estrus (53%). In Experiment 2, the OvSynch program was retested with the interval between the PGF and the second GnRH 2a injection being 48 hr (36 hr in Experiment 1). Conception in 27 cows on the OvSynch48 program with timed insemination (37%) was comparable with 43% in 21 cows on a similar program without the second GnRH injection but inseminated at estrus.; Dairy Day, 1996, Kansas State University, Manhattan, KS, 1996; Creative Commons License Thi s work is licensed under a Creative Commons Attribution 4.0 License. Thi s Research Report article is available in Kansas Agricultural Experiment Station Research Reports: https://newprairiepress.org/ kaesrr/vol0/iss2/327 Dairy Day 1996 SUCCESS OF SEVERAL PROGRAMMED AI-BREEDING PROTOCOLS INCLUDING OVSYNCH Summary In Experiment 1, four programmed AI breeding treatments were tested. The so-called OvSynch program, which requires no heat detection before a fixed-time insemination, decreased conception rates compared with a similar treatment in which inseminations occurred after detected estrus (30 vs 51%). The traditional two-injection prostaglandin program produced greater conception rate for cattle inseminated after a detected estrus (53%) than after one fixed-time insemination was given in the absence of estrus (31%). A similar protocol of two prostaglandin injections plus an injection of gonadotropin-releasing hormone (GnRH or Cystorelin®) before one fixed-time insemination produced lower conception rates (33%) than when cattle were inseminated after detected estrus (53%). In Experiment 2, the OvSynch program was retested with the interval between the PGF2α and the second GnRH injection being 48 hr (36 hr in Experiment 1). Conception in 27 cows on the OvSynch48 program with timed insemination (37%) was comparable with 43% in 21 cows on a similar program without the second GnRH injection but inseminated at estrus. (Key Words: OvSynch, Synchronized Estrus, Conception Rates.) Introduction Since prostaglandin F2α (PGF2α) was demonstrated to be effective in controlling the estrous cycle for programmed breeding, attempts to develop estrus-synchronization systems for lactating dairy cows and dairy heifers to accommodate fixed-time inseminations have met with limited success. Conception rates following PGF2α usually produced the best results when inseminations were performed after observed signs of heat. Our early attempts to use fixed-time inseminations at first services in lactating dairy cows demonstrated that conception rates were less than desirable. Follicular development must be controlled and synchronized with the regression of the corpus luteum after PGF2α in order to reduce variation in the intervals to estrus. Precise control of follicular development with the regression of the corpus luteum should allow improved conception rates associated with one fixed-time insemination. Such a synchronized ovulation protocol (OvSynch) has been tested. (...truncated)


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Jeffrey S. Stevenson, K. E. Thompson, Y. Kobayashi. Success of several programed AI-breeding protocols including ovsynch, Kansas Agricultural Experiment Station Research Reports, 1996, Issue 2,