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Improving Synchronization And Pregnancy Rate In Dairy Cows
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Book Synopsis Improving Synchronization and Pregnancy Rate in Dairy Cows by : Omar Khadrawy
Download or read book Improving Synchronization and Pregnancy Rate in Dairy Cows written by Omar Khadrawy and published by LAP Lambert Academic Publishing. This book was released on 2013 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: An ideal oestrous synchrony regimen results in synchronous oestrous onset irrespective of reproductive status or stage of oestrous cycle at initiation of treatment without adversely affecting pregnancy rates after breeding. However following a synchronisation regimen, variation in onset of oestrus may occur. This variation is dependent on timing of (CL) regression, stage of follicular growth and when present the duration of dominance of the ovulatory follicle. Many different treatment regimens may be used to attempt to synchronise oestrus. These include the use of a luteolytic agent prostaglandin-F 2 (PGF2 ) alone or in combination with an agent to regulate ovarian follicular development. Alternative regimens involve the use of P4 or progestagen-based treatments used in combination with a luteolytic agent and or an agent to regulate follicle waves. Combining progestin treatments with protocols similar to Ovsynch show improved conception rates in rst-lactation cows treated with (CIDR) inserts during an Ovsynch protocol.
Book Synopsis Strategies to Improve Ovulation Synchronization/timed Artificial Insemination Protocol to Increase Pregnancy Rate in Dairy Cattle by : Miriam Bronwen Gordon
Download or read book Strategies to Improve Ovulation Synchronization/timed Artificial Insemination Protocol to Increase Pregnancy Rate in Dairy Cattle written by Miriam Bronwen Gordon and published by . This book was released on 2011 with total page 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 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 Effect of Presynchronization with GnRH for Resynchronization on Conception Rate in Lactating Dairy Cows by : Abdalhamid A. M. Alkar
Download or read book Effect of Presynchronization with GnRH for Resynchronization on Conception Rate in Lactating Dairy Cows written by Abdalhamid A. M. Alkar and published by . This book was released on 2011 with total page 47 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Reproduction in Cattle by : Peter J. H. Ball
Download or read book Reproduction in Cattle written by Peter J. H. Ball and published by John Wiley & Sons. This book was released on 2008-04-15 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cattle play a fundamental role in animal agriculture throughout the world. They not only provide us with a vital food source, but they also provide us with fertilizer and fuel. Keeping reproduction levels at an optimum level is therefore essential, but this is often a complicated process, especially with modern, high yielding cows. Written in a practical and user-friendly style, this book aims to help the reader understand cattle reproduction by explaining the underlying physiology of the reproductive process and the role and importance of pharmacology and technology, and showing how management techniques can improve reproductive efficiency. This edition includes: Recent research findings on the physiology of the oestrous cycle and its control; New techniques for monitoring and manipulating reproduction, including pregnancy diagnosis and embryo transfer; Advice on identifying common infertility problems and how to prevent and treat them. Reproduction Cattle 3e is essential reading for veterinary and agricultural students, as well as veterinarians and farmers involved in cattle reproduction.
Book Synopsis Evaluation of Reproductive Efficiency in Lactating Dairy Cows Through Physiologic Evaluation and Synchronization Modification by : Charles Dexter Young
Download or read book Evaluation of Reproductive Efficiency in Lactating Dairy Cows Through Physiologic Evaluation and Synchronization Modification written by Charles Dexter Young and published by . This book was released on 2015 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reproductive performance of lactating dairy cows has decreased as milk production has increased as a result of genetic selection. Milk production alone is not the reason for decreased reproductive performance, as fertility issues are multifactorial and collaborative. Research chapters contained within have taken an applied approach focusing in two different areas of fertility. One approach was development of an evaluation system to identify lactating cows with decreased fertility prior to breeding; while another approach was to modify an ovulation synchronization protocol during periods of heat stress in order to improve fertility. The first focus was development and evaluation of a size and position score based on a one to three scale and assigned to lactating cows during a pre-breeding exam. This score was a reflection of the cervical and uterine horn diameter, and of the position of the reproductive tract in relation to the pelvis. Results indicated that cows with the largest reproductive tracts (score 3) had a 15% decrease in conception rates following artificial insemination compared to the smallest reproductive tracts (score 1). Score two reproductive tracts (intermediate) exhibited decreased conception rates compared to score one, but greater than score three. Identification of cows with lower potential fertility will allow producers to make the most economically, efficient decision when artificially inseminating lactating dairy cows. The second research focus modified an ovulation synchronization protocol by including an intravaginal progesterone releasing device (CIDR) nine days prior to artificial insemination during periods of heat stress. Use of a CIDR has shown to be beneficial with modest improvements in fertility in cool seasons, especially in anovular cows. This modification did not prove to be beneficial in improving conception rates during periods of heat stress. Lactating dairy cows with or without a progesterone releasing device had comparable conception rates. This research remains informative since use of a CIDR is expensive. This research exhibits this additional expense does not lead to positive results, thereby discouraging producers from incurring an unnecessary expense.
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 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:
Book Synopsis Strategies to Improve Synchronization of Ovulation and Use of Recombinant Bovine Somatotropin to Enhance Early Embryonic Development and Conception Rates in Dairy Cows by : Frederico Augusto Pena Moreira
Download or read book Strategies to Improve Synchronization of Ovulation and Use of Recombinant Bovine Somatotropin to Enhance Early Embryonic Development and Conception Rates in Dairy Cows written by Frederico Augusto Pena Moreira and published by . This book was released on 2001 with total page 676 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Improving Dairy Cattle Fertility by : Jennifer A. Spencer
Download or read book Improving Dairy Cattle Fertility written by Jennifer A. Spencer and published by . This book was released on 2014 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt: In cattle, early embryonic loss may occur due to the premature secretion of prostaglandin F2a (PGF2a) during days 14-16 after fertilization. The objective of the first experiment in this study was to determine aspirin's effects on PGF2a during the luteal phase of the estrous cycle in lactating dairy cows by characterizing blood plasma prostaglandin metabolites (PGFM) and progesterone (P4) concentrations. Aspirin decreased PGFM for 30 hours after last bolus administration and increased the day to luteolysis. The objective of the second experiment was to determine the effectiveness of the initial gonadotropin-releasing hormone (GnRH) in a 5-day CIDR (controlled internal drug releasing inserts)-Cosynch resynchronization protocol on fertility to second insemination in lactating dairy cows. No differences in pregnancy rate per artificial insemination (PR/AI) were observed between no GnRH (treatment) and GnRH (control) for the second insemination. Indicating that GnRH may not be necessary at the initiation of a CIDR-Cosynch resynchronization protocol.
Book Synopsis Large Dairy Herd Management by : H. H. Van Horn
Download or read book Large Dairy Herd Management written by H. H. Van Horn and published by American Dairy Science Association. This book was released on 1992 with total page 848 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Strategies for Reproductive Management of Lactating Dairy Cows After First Postpartum Timed Artificial Insemination by : Ryan Allen Sterry
Download or read book Strategies for Reproductive Management of Lactating Dairy Cows After First Postpartum Timed Artificial Insemination written by Ryan Allen Sterry and published by . This book was released on 2006 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Modifying the Double-ovsynch Protocol to Include Human Chorionic Gonadotropin to Synchronize Estrus in Dairy Cattle by : Joseph Andrew Binversie
Download or read book Modifying the Double-ovsynch Protocol to Include Human Chorionic Gonadotropin to Synchronize Estrus in Dairy Cattle written by Joseph Andrew Binversie and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The objectives of this study were to determine whether conception, ovulation rates, presynchronization rates, or follicle and CL characteristics were altered after modifying the Double-Ovsynch (DO) protocol to include human chorionic gonadotropin (hCG) compared to the conventional DO protocol in dairy heifers and lactating dairy cows. We hypothesized that replacing the first injection of gonadotropin releasing hormone (GnRH) in the DO protocol with hCG would increase the proportion of females that ovulate, thus improving the presynchronization rate leading to increased conception rates. Ovulation rates were increased in cows administered hCG compared to GnRH, but subsequent synchronization, and conception rates did not differ between treatments. A greater proportion of hCG-treated cows tended to fail to have undergone luteolysis compared to those treated with GnRH. In conclusion, no improvement in overall fertility was achieved by replacing the first injection of GnRH in the DO protocol with hCG.
Book Synopsis Strategies to Enhance Fertility in Dairy Cattle During Summer Including Use of Cryopreservation of in Vitro Produced Embryos by : C. Moisés Franco
Download or read book Strategies to Enhance Fertility in Dairy Cattle During Summer Including Use of Cryopreservation of in Vitro Produced Embryos written by C. Moisés Franco and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: There has been a precipitous decline in fertility of lactating dairy cows. In addition, heat stress can further compromise fertility. The goals of this thesis were to 1) evaluate strategies for enhancing fertility after artificial insemination using mid-cycle GnRH treatment and 2) further develop embryo transfer using in vitro produced embryos as a tool for increasing fertility. For the second objective, experiments tested whether pregnancy rate could be improved by transfer of twin embryos and whether the developmental competence of embryos after cryopreservation could be improved by hyaluronic acid or cytochalasin B treatment. A series of six experiments were conducted to test the efficacy of GnRH for increasing fertility. Except for one experiment, in which GnRH administration at day 14 after insemination increased pregnancy rate, GnRH was without effect whether given at day 11, 14 or 15 after insemination or at day 11 after anticipated ovulation in embryo transfer recipients. Neither unilateral transfer of two embryos nor administration of GnRH at Day 11 after anticipated ovulation improved pregnancy rates of dairy cattle exposed to heat stress. Cytochalasin B treatment before freezing improved cryosurvival of bovine embryos produced in vitro. In contrast, culture with hyaluronic acid was of minimal benefit. Taken together, GnRH treatment did not consistently increase pregnancy rates when administered at Day 11-15 after insemination and is not recommended as a fertility-enhancing treatment. Similarly, transfer of two embryos to the uterine horn ipsilateral to the CL was not an effective method for increasing pregnancy rates in recipients. Transfer of cryopreserved embryos may be enhanced by treatment of embryos with cytochalasin B since this molecule increased in vitro survival, and it remains to be tested whether survival of IVP embryos after vitrification can be improved by cytochalasin B treatment.
Book Synopsis Dairy Cattle Fertility & Sterility by :
Download or read book Dairy Cattle Fertility & Sterility written by and published by Hoard's Dairyman Books. This book was released on 1996 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:
