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Synchronization Of Follicular Wave Dynamics And Ovulation For Fixed Time Artificial Insemination In Cattle
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Book Synopsis Synchronization of Follicular Wave Dynamics and Ovulation for Fixed-time Artificial Insemination in Cattle by :
Download or read book Synchronization of Follicular Wave Dynamics and Ovulation for Fixed-time Artificial Insemination in Cattle written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The overall objective was to develop new synchronization protocols that facilitate fixed-time artificial insemination (AI). A series of experiments were designed to evaluate the effects of estradiol and progesterone on gonadotrophin release, follicular wave emergence and ovulation in beef cattle. In ovariectomized cows, a new CIDR-B device increased plasma progesterone to near-luteal concentrations, but for only 2 to 3 days. Injection of 100 mg progesterone increased plasma progesterone approximately 2 ng/mL. Progesterone suppressed plasma LH concentrations but did not affect plasma FSH concentrations. Estradiol, with or without progesterone, resulted in FSH suppression with resurgence (and follicular wave emergence) at an interval that varied according to the estradiol formulation. Estradiol administration following CIDR-B removal resulted in LH release (and ovulation in intact animals). Both estradiol-17Î2 and estradiol benzoate (EB) synchronized ovarian follicular wave emergence in CIDR-Bï¿ư-treated animals and the interval from CIDR-B removal to ovulation (72 to 120 h) was shorter and more synchronous in estradiol-treated animals than in controls. In cattle given a CIDR-B device and estradiol plus progesterone, estradiol treatment following CIDR-B removal 7 days later resulted in acceptable conception rates to fixed-time AI. Estradiol or GnRH at the beginning and end of a 7-day MGA-based synchronization regimen resulted in acceptable pregnancy rates to fixed-time AI. In a single experiment, EB, GnRH or pLH in CIDR-B- or MGA-treated beef heifers effectively synchronized ovulation for fixed-time AI. Pregnancy rates were, on average, 58.0% (range 52.5 to 65.0%). A 6- or 7-d interval from GnRH to PGF in a Cosynch regimen resulted in similar pregnancy rates in cows. The addition of a progestin to a Cosynch or Ovsynch regimen improved pregnancy rates in heifers but not in cows. Synchronization of follicular wave emergence and ovulation in a two-dose PGF-based protocol.
Book Synopsis Synchronization of Follicular Wave Dynamics and Ovulation for Fixed-time Artificial Insemination in Cattle by :
Download or read book Synchronization of Follicular Wave Dynamics and Ovulation for Fixed-time Artificial Insemination in Cattle written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The overall objective was to develop new synchronization protocols that facilitate fixed-time artificial insemination (AI). A series of experiments were designed to evaluate the effects of estradiol and progesterone on gonadotrophin release, follicular wave emergence and ovulation in beef cattle. In ovariectomized cows, a new CIDR-B device increased plasma progesterone to near-luteal concentrations, but for only 2 to 3 days. Injection of 100 mg progesterone increased plasma progesterone approximately 2 ng/mL. Progesterone suppressed plasma LH concentrations but did not affect plasma FSH concentrations. Estradiol, with or without progesterone, resulted in FSH suppression with resurgence (and follicular wave emergence) at an interval that varied according to the estradiol formulation. Estradiol administration following CIDR-B removal resulted in LH release (and ovulation in intact animals). Both estradiol-17Î2 and estradiol benzoate (EB) synchronized ovarian follicular wave emergence in CIDR-Bï¿ư-treated animals and the interval from CIDR-B removal to ovulation (72 to 120 h) was shorter and more synchronous in estradiol-treated animals than in controls. In cattle given a CIDR-B device and estradiol plus progesterone, estradiol treatment following CIDR-B removal 7 days later resulted in acceptable conception rates to fixed-time AI. Estradiol or GnRH at the beginning and end of a 7-day MGA-based synchronization regimen resulted in acceptable pregnancy rates to fixed-time AI. In a single experiment, EB, GnRH or pLH in CIDR-B- or MGA-treated beef heifers effectively synchronized ovulation for fixed-time AI. Pregnancy rates were, on average, 58.0% (range 52.5 to 65.0%). A 6- or 7-d interval from GnRH to PGF in a Cosynch regimen resulted in similar pregnancy rates in cows. The addition of a progestin to a Cosynch or Ovsynch regimen improved pregnancy rates in heifers but not in cows. Synchronization of follicular wave emergence and ovulation in a two-dose PGF-based protocol.
Book Synopsis Synchronization of Follicular Wave Emergence, Luteal Regression, and Ovulation for Fixed-time Artificial Insemination in Beef Cows and Heifers by : Kyle Jeffrey Stutts
Download or read book Synchronization of Follicular Wave Emergence, Luteal Regression, and Ovulation for Fixed-time Artificial Insemination in Beef Cows and Heifers written by Kyle Jeffrey Stutts and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Two experiments tested the efficacy of gonadotropin-releasing hormone (GnRH) or estradiol cypionate (ECP) administration in combination with controlled internal drug release (CIDR) inserts on pregnancy rate to fixed-time artificial insemination (FTAI) in beef heifers. In the first experiment, heifers in the two ECP groups received ECP in conjunction with the CIDR insert. The CIDR insert was removed and PGF was administered on either d 7 or 9. Heifers received ECP 24 h after CIDR removal and were inseminated 30 h after ECP. Heifers in the two GnRH groups received GnRH in conjunction with the CIDR insert. Heifers received PGF on either d 6 or 7, and the CIDR insert was removed on d 7. Heifers were inseminated and received GnRH 48 h after CIDR removal. Pregnancy rates to FTAI were higher for heifers treated with GnRH. Pregnancy rate to FTAI was highest for heifers in the GnRH group that received PGF on d 6 and was lowest for the group that received ECP in combination with a 7-d CIDR insert. In the second experiment, heifers received GnRH in conjunction with the CIDR insert. CIDR inserts were removed and PGF was administered on d 7. Heifers were inseminated 60 h later, with one group receiving GnRH at insemination. Pregnancy rate to FTAI was higher for heifers that received GnRHat insemination. The final experiment tested the efficacy of estradiol 17 _(E17) or GnRH in combination with a CIDR insert on pregnancy rate to FTAI in Brahman cows. Either E17 or GnRH was administered in conjunction with the CIDR insert. CIDR inserts were removed on d 7. Cows in the GnRH group received PGF on d 6 and GnRH at insemination which occurred 48 h after CIDR removal. Cows in the E17 group received PGF on d 7, E17 24 h later, and were inseminated 30h after E17 administration. Pregnancy rate to FTAI was higher for cows treated with E17. These data indicate acceptable pregnancy rates were obtained when the CIDR insert was combined with either GnRH in beef heifers or with E17 in Brahman cows.
Book Synopsis Control of Follicular Development and Ovulation for Fixed-time Artificial Insemination (AI) in Cattle, SRP Transition by :
Download or read book Control of Follicular Development and Ovulation for Fixed-time Artificial Insemination (AI) in Cattle, SRP Transition written by and published by . This book was released on 2004 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: Estrus synchronization and artificial insemination (AI) have not been widely used by cow-calf producers due to costs, time, & labour needed for treatments & estrus detection, as well as unpredictable results. This report describes a series of experiments designed to simplify treatment protocols & reduce costs, and to utilize readily available pharmaceuticals, to facilitate the use of AI in beef cattle. The experiments investigated such topics as synchronization of follicular wave emergence with estradiol valerate; the effect of estradiol treatment during late stages of the estrous cycle; synchronization of follicular wave emergence for resynchronization of non-pregnant cows; the effects of new or used controlled internal drug release (CIDR) devices and estradiol cypionate treatment, with or without progesterone, on pregnancy rate following fixed-time AI in beef heifers; and embryo transfer without estrus detection.
Book Synopsis Synchronization of Ovulation in Dairy Cattle by : James Richard Pursley
Download or read book Synchronization of Ovulation in Dairy Cattle written by James Richard Pursley and published by . This book was released on 1996 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Development of Hormonal Protocals for Synchronization of Ovulation and Timed Artificial Insemination in Dairy Heifers by : Humberto Rivera
Download or read book Development of Hormonal Protocals for Synchronization of Ovulation and Timed Artificial Insemination in Dairy Heifers written by Humberto Rivera and published by . This book was released on 2004 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Comparison of Progestin Based Protocols to Synchronize Estrus and Ovulation in Beef Cows by : Daniel Joseph Schafer
Download or read book Comparison of Progestin Based Protocols to Synchronize Estrus and Ovulation in Beef Cows written by Daniel Joseph Schafer and published by . This book was released on 2005 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Manipulating Follicle and Corpus Luteum Function to Improve Efficiency of Synchronizaton of Ovulaton in Lactating Dairy Cattle by : Michael W. Peters
Download or read book Manipulating Follicle and Corpus Luteum Function to Improve Efficiency of Synchronizaton of Ovulaton in Lactating Dairy Cattle written by Michael W. Peters and published by . This book was released on 2000 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Bovine Reproduction by : Richard M. Hopper
Download or read book Bovine Reproduction written by Richard M. Hopper and published by John Wiley & Sons. This book was released on 2014-08-18 with total page 2206 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bovine Reproduction is a comprehensive, current reference providing information on all aspects of reproduction in the bull and cow. Offering fundamental knowledge on evaluating and restoring fertility in the bovine patient, the book also places information in the context of herd health where appropriate for a truly global view of bovine theriogenology. Printed in full color throughout, the book includes 83 chapters and more than 550 images, making it the most exhaustive reference available on this topic. Each section covers anatomy and physiology, breeding management, and reproductive surgery, as well as obstetrics and pregnancy wastage in the cow. Bovine Reproduction is a welcome resource for bovine practitioners, theriogenologists, and animal scientists, as well as veterinary students and residents with an interest in the cow.
Book Synopsis Synchronization of Estrus and Artificial Insemination in Cattle by : Michael L. O'Connor
Download or read book Synchronization of Estrus and Artificial Insemination in Cattle written by Michael L. O'Connor and published by . This book was released on 1980 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author :Saskatchewan. Agriculture Development Fund Publisher :[Regina] : Agriculture Development Fund ISBN 13 : Total Pages :14 pages Book Rating :4.:/5 (27 download)
Book Synopsis Control of Follicular Development and Ovulation for Fixed-time Artificial Insemination (AI) in Cattle (SRP Transition) : Final Report by : Saskatchewan. Agriculture Development Fund
Download or read book Control of Follicular Development and Ovulation for Fixed-time Artificial Insemination (AI) in Cattle (SRP Transition) : Final Report written by Saskatchewan. Agriculture Development Fund and published by [Regina] : Agriculture Development Fund. This book was released on 2004 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Synchronization and Ovarian Development in Dairy Cows and Heifers by : Rebecca L. J. Coral Escalante
Download or read book Synchronization and Ovarian Development in Dairy Cows and Heifers written by Rebecca L. J. Coral Escalante and published by . This book was released on 2012 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reproductive management is an important factor for improving reproductive efficiency in the dairy industry. Reproductive efficiency affects the profitability of the dairy herd by decreasing days not pregnant and increasing milk produced in a cow's lifetime. There are many reproductive programs used to synchronize the estrous cycle. Prostaglandin F2[alpha] (PGF2[alpha])-based programs synchronize estrus before artificial insemination (AI) after observed estrus. Some disadvantages to PGF2[alpha]-based reproductive programs are time requirements necessary for estrus detection (2 to 3 times/d for about 30 min) and lack of estrus activity observed in dairy cows (only about 40% will show estrus). An advantage to PGF2[alpha]-based reproductive programs is acceptable conception rates (about 45 to 60%) that can surpass timed AI (TAI). Reproductive programs that employ TAI are achieved by synchronization of ovulation with a series of PGF2[alpha] and gonadotropin releasing hormone (GnRH) injections followed by insemination 16 h later. Some of the advantages to synchronization of ovulation followed by TAI are: no estrus detection and acceptable conception rates (40 to 50%). Many reproductive programs include a presynchronization step. The advantage to presynchronization is a tightened synchrony by getting more cows and heifers in the same stage of the estrous cycle before estrous synchronization and AI or TAI. There are a variety of presynchronization methods used in cattle. One of the most common programs is two injections of PGF2[alpha] 14 d apart 12 d before initiation of Ovsynch (d 0 GnRH, 7 d, PGF2[alpha], 56 h, GnRH, 16 h, TAI) (Moreira et al., 2001). Another is double Ovsynch where the Ovsynch program is administered 7 d before another Ovsynch program (Giordano et al., 2012). Long-term progestogens can also be used as a means to presynchronize the estrous cycle and has been successful in beef cows and heifers. Long term progestogens, such as a CIDR (controlled internal drug release) for 14 d, will suppress estrus, inhibit ovulation, and induce the development of a persistent dominant follicle that can ovulate after CIDR removal (Ahmad et al., 1995; Revah and Butler, 1996; Roche et al., 1999). Ovulation of the dominant follicle allows for cows and heifers to be late in the luteal stage of the estrous cycle before PGF2[alpha] and AI or PGF2[alpha], 56 h, GnRH, 16 h, TAI. Presynchronization has shown to decrease the days to pregnancy. This is an advantage because it will directly affect the number of days a cow is not pregnant and the amount of milk she will produce in her lifetime. The objective of this research was to evaluate pregnancies per AI, ovarian follicular and luteal development of postpartum dairy cows and dairy heifers in response to long term progestin-based programs (14dCIDR) compared with PGF2[alpha]-based programs. Experiment 1 (Chapter 2) evaluated the use of a 14dCIDR-PGF2[alpha] program to a PGF2[alpha]-alone program for synchronizing dairy heifers before AI. Heifers were examined by real-time ultrasonography during treatment to assess the ovarian response. Heifers were also monitored for estrus following presynchronization and treatment of PGF2[alpha] to assess ovulation response. The 14dCIDR-PGF2[alpha] system resulted in more heifers with a larger CL at the time of PGF2[alpha]. This is ideal because of the greater luteolytic effects of PGF2[alpha] has on a more mature CL. The 14dCIDR-PGF2[alpha] heifers were AI and became pregnant sooner compared with the PGF2[alpha]-alone heifers. Experiment 2 (Chapter 3) evaluated the use of a 14dCIDR_TAI program compared with a PGF2[alpha]-based program in grazing dairy cows. The 14dCIDR_TAI program employed synchronization of ovulation before TAI and the PGF2[alpha]-based program employed synchronization of estrus with AI after observed estrus. The evaluation of reproductive efficiency for each program was examined. Cows assigned to the 14dCIDR_TAI program were AI early in the breeding season and were all AI by the end the breeding season compared with the PGF2[alpha]-based program. The PGF2[alpha]-based program had a greater first service conception rate (FSCR) compared with the 14dCIDR_TAI program but did not achieve a greater number of pregnancies after two inseminations. Experiment 3 (Chapter 4) evaluated the use of a 14dCIDR_TAI program compared with another common TAI program (Presynch-Oysynch56) in postpartum lactating dairy cows. Follicular dynamics and luteal development were monitored in both programs. Each program was evaluated for effectiveness to presynchronize the estrous cycle and establish pregnancy. The 14dCIDR_TAI and the Presynch-Ovsynch56 programs were comparable in their effectiveness to presynchronize the estrous cycle and establish pregnancy in cows that were cycling. Non-cycling cows treated with the Presynch-Ovsynch56 program had lesser conception rate compared with those that were cycling. There was no difference in conception rate with non-cycling or cycling cows treated with the 14dCIDR_TAI. Experiment 4 (Chapter 5) evaluated the use of the 14dCIDR_TAI program with or without PGF2[alpha] at CIDR removal. It is possible for cows to still have a CL after the end of the 14dCIDR treatment either due to longer estrous cycles or the cow was early in her estrous cycle when the CIDR was inserted. The addition of PGF2[alpha] may help improve the synchrony and conception rates after presynchronization of the estrous cycle before TAI. The addition of the PGF2[alpha] at CIDR removal demonstrated an increase in the number of cows that showed estrus after presynchronization but conception rates were comparable. Overall, the use of the 14dCIDR as means to presynchronize the estrous cycle has been demonstrated as an effective way to enhance the synchrony and decrease the interval to pregnancy in dairy cows and heifers.
Book Synopsis Follicular Waves and Their Impact on the Dominant Follicle, Uterus, and Subsequent Pregnancy Rates in Beef Cattle by : Ashleigh Marie Muth-Spurlock
Download or read book Follicular Waves and Their Impact on the Dominant Follicle, Uterus, and Subsequent Pregnancy Rates in Beef Cattle written by Ashleigh Marie Muth-Spurlock and published by . This book was released on 2016 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ovarian steroids assist in the development of the follicle and its enclosed oocyte as well as prepare the maternal environment for pregnancy. The objective of experiment 1 was to elucidate the differences between dominant follicles of each follicular wave in terms of intra-follicular concentration of steroids after 4 d of dominance. Differences in blood perfusion between the dominant follicle of the first and second non-ovulatory wave were also examined. Follicular waves were monitored daily via ultrasonography from emergence to aspiration of the dominant follicle. It was determined that although the dominant follicles aspirated from ovulatory waves possessed a greater concentration of estradiol and a greater ratio of estradiol to progesterone, there was no difference in concentrations of steroid hormones or the ratio of estradiol to progesterone between dominant follicles collected from non-ovulatory waves and ovulatory waves. In a subset of cows, blood perfusion tended to be greater in dominant follicles that developed during the second non-ovulatory wave. The objective of experiment 2 was to determine whether or not the follicular wave had an effect on diameter of the ovulatory follicle, thickness of the endometrium, or subsequent pregnancy rates. Estrus was synchronized in females in such a way that females would ovulate the dominant follicle of the first or second follicular wave at timed artificial insemination. Diameter of the ovulatory follicle and endometrial thickness were not different between treatments; however, increased pregnancy rates were observed in heifers that ovulated the dominant follicle of the second follicular wave. There was no effect of follicular wave on pregnancy rates in cows. In conclusion, the role of follicular wave on the dominant follicle, maternal environment, and subsequent pregnancy rates is not fully understood. Additional experiments need to be conducted to further elucidate the differences in developmental potential of the oocyte and maternal environment when the dominant follicle of the first and second wave are destined to become the ovulatory follicle at timed insemination.
Book Synopsis Timing GnRH Administration with Split-time Artificial Insemination Following Administration of CIDR-based Protocols to Synchronize Estrus and Ovulation in Beef Heifers and Cows by : Brianne Elizabeth Bishop
Download or read book Timing GnRH Administration with Split-time Artificial Insemination Following Administration of CIDR-based Protocols to Synchronize Estrus and Ovulation in Beef Heifers and Cows written by Brianne Elizabeth Bishop and published by . This book was released on 2015 with total page 75 pages. Available in PDF, EPUB and Kindle. Book excerpt: Historically, adoption of AI within beef herds has increased due to improvements in methods to synchronize estrous and expanded use of fixed-time artificial insemination (FTAI) where all females are inseminated at a predetermined fixed time. Because pregnancy rates are higher among females that exhibit estrus prior to AI, split-time AI was developed as an alternative breeding strategy whereby insemination is delayed 20 to 24 hours (h) for females that fail to express estrus prior to a predetermined fixed time. Three experiments were designed to test hypotheses related to the timing and use of GnRH in breeding programs involving STAI based on results from previously published studies. Estrus was synchronized for heifers in experiment 1 with the 14-d CIDR-PG protocol, and for cows in experiment 2 using the 7-d CO-Synch + CIDR protocol. Females in each treatment that exhibited estrus by 66 h were inseminated at 66 h, whereas AI was delayed 24 h (90 h after PGF2?) for females failing to exhibit estrus by 66 h. Females in treatment 1 received GnRH 66 h after PGF2? irrespective of estrus expression; however, in treatment 2, GnRH was administered coincident with delayed AI only to females not detected in estrus at 66 h. GnRH administered to estrus females at 66 h did not affect AI pregnancy rate; however delaying GnRH to 90 h for non-estrous females at 66 h improved estrous response for cows but not for heifers, with no effect on AI pregnancy rate. A third experiment evaluated pregnancy rates of heifers that failed to exhibit estrus by 90 h after PGF2? following treatment with the 14-d CIDR-PG protocol. Treatments were compared on the basis of whether or not GnRH was administered concurrent with AI, 90 h after PG. There was no effect of treatment on AI pregnancy rate. Collectively, these results indicate: 1) GnRH is not required among females that exhibit estrus prior to AI; 2) delayed administration of GnRH increases total estrous response in cows when STAI is practiced; and 3) GnRH is not required when STAI is practiced in conjunction with the 14-d CIDR-PG protocol in heifers.
Book Synopsis Control of Follicular Development and Ovulation for Fixed-time Artificial Insemination (AI) in Cattle (SRP Transition) by : Reuben J. Mapletoft
Download or read book Control of Follicular Development and Ovulation for Fixed-time Artificial Insemination (AI) in Cattle (SRP Transition) written by Reuben J. Mapletoft and published by . This book was released on 2004 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Timed Artificial Insemination with Estradiol Cypionate Or Insemination at Detected Estrus in High-producing Dairy Cows by : Ronaldo Luis Aoki Cerri
Download or read book Timed Artificial Insemination with Estradiol Cypionate Or Insemination at Detected Estrus in High-producing Dairy Cows written by Ronaldo Luis Aoki Cerri and published by . This book was released on 2004 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Control of follicular development and ovulation for fixed-time artificial insemination (AI) in cattle (SRP transition) by : Reuben J. Mapletoft
Download or read book Control of follicular development and ovulation for fixed-time artificial insemination (AI) in cattle (SRP transition) written by Reuben J. Mapletoft and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Artificial insemination (AI) has not been widely used by the beef industry, in large part, because of the cost, time and effort required for detection of heat. However, fixed-time AI, without heat detection, can make AI feasible. Results show how fixed-time AI can be accomplished through hormonal manipulation, and how protocols can be improved, or why certain protocols are not efficacious under certain circumstances. Finally, approaches to the resynchronization of artificially inseminated cattle have been investigated. Results clearly show that fixed-time AI followed by resynchronization and AI can result in high pregnancy rates to AI sires.
