NC_old1201: Methods to Increase Reproductive Efficiency in Cattle (NC1038)
(Multistate Research Project)
Status: Inactive/Terminating
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STATEMENT OF THE ISSUES
Need as Indicated by Stakeholders
The United Nations 2009 Food and Agricultural Organization (FAO) indicated that the worlds agriculture will face one of the greatest challenges of all times: to produce enough food to feed the 9 billion people the earth will harbor by 2050. Without question, this will demand the concerted efforts of producers, researchers, and policy makers, to provide the experience and technology to achieve such an endeavor. Obviously, increasing reproductive efficiency of both beef and dairy cattle will contribute to the milk and meat supplies for our future world food needs and for the U.S. to maintain a competitive advantage in production of milk and meat products.
A recent report, Power & Promise: Agbioscience in the North Central United States was prepared for the 12 North Central Land-Grant Universities by Battelle, a Columbus Ohio-based independent research and development group (full report is available at http://nccea.org/documents/powerandpromiseweb.pdf). The report, released August 2011, finds that agriculture and agricultural bioscience -- collectively termed Agbioscience -- are providing wide-ranging opportunities for economic growth and job creation in the U.S.
The report also notes that bioscience professionals at U.S. land-grant universities are leveraging advancements in modern science and technology to address crucial national and global needs, including improving agricultural productivity, food security, human health, renewable resource development (such as bioenergy and biobased materials) and environmental sustainability.
In our science and technology-based economic development practice at Battelle, we have observed the consistent rise of agbioscience as a core driver of economic growth and business expansion opportunities for the U.S., said Simon Tripp, lead author of the study. This is an extremely dynamic sector, leveraging sustainable bio-based resources to produce goods that meet large-scale market needs. Tripp said the North Central region is well positioned to fulfill the promise of new product development and job growth in modern agbioscience.
The North Central region contains 37% of all U.S. farmland. Further, the North Central region is Americas agricultural export engine with 60% of all U.S. live animals and meat exports notwithstanding the region accounts for exports of 83% of soybeans, 85% of all feed grains, and 51% of wheat. Although the North Central region contains but 21% of U.S. land area, it accounts for 45% of all U.S. agricultural exports.
The NC-1038 committee is a long-standing group (previously known as the NC-113 and NC-1006 with more than 35 years of multi-state cooperation since its inception in the early 1970s) that has contributed greatly to the increase in reproductive efficiency of cattle. Its long-term goal is to identify and develop strategies to improve reproductive efficiency for sustainable cattle production and is consistent with the consensus goals set forth by FAIR 2002 and the FAO 2009 and directions described by Tripps Power and Promise .
Importance of the Work, and What the Consequences Are If It Is Not Done
Beef Cattle. Successful management of estrus and ovulation to facilitate artificial insemination (AI) are reproductive management tools available to beef and dairy producers since the 1990s. Manipulation of the estrous cycle shortens the calving season, increases calf uniformity, and facilitates the use of AI. Artificial insemination allows infusion of superior genetics at costs far below the cost of purchasing a herd sire of less than similar standards. These tools remain the most important and widely applicable assisted-reproductive technologies available to beef cattle operators. Current and past research by NC-1038 committee tested protocols for synchronizing estrus, ovulation, or both, which addressed two strategies that are key factors for their implementation by producers. The protocols: 1) minimize the frequency of times cattle must be moved through a cattle-handling facility; and 2) eliminate or minimize detection of estrus before AI or before a timed AI. Application of these methods has already increased the use of AI in beef cattle.
Unless owners of commercial herds aggressively implement genetic improvement through reproductive management, the U.S. will lose its competitive advantage in high quality beef production to countries such as Brazil and Argentina, which are the leading export countries for U.S. beef genetics. According to the U.S. National Association of Animal Breeders and the Association for Brazilian Artificial Insemination, sales of beef semen for AI increased from 3.3 to 10.5 million units between 1993 and 2010 in Brazil, whereas that in the U.S. it only increased from 2.9 to 3.7 million units during the same period. International players, now becoming more technically astute and competitively advantaged, have positioned themselves to dominate the production and sale of beef worldwide.
Dairy Cattle. Total milk production in dairy cattle is determined by the proportion of cows producing milk at any given time and the level of milk production of the individual cows within the herd. Both of these factors are dramatically affected by the rate at which cows become pregnant in the herd. Two factors that determine this rate are the AI submission rate (i.e., managements ability to inseminate nonpregnant cows thereby giving them a chance to conceive) and the conception rate (i.e., the proportion of inseminated cows that actually conceive). The body of scientific literature supports that conception rates in lactating dairy cows have decreased by 25 percentage points to less than 40% during the past 50 years (Lucy, 2001). Until the underlying causes of poor conception rates in lactating dairy cows can be understood and mitigated, pregnancy rates must be increased by focusing on improving the AI submission rate.
Three strategies can be implemented to improve AI submission rates: 1) submit all cows for first postpartum AI at the end of the voluntary waiting period rather than waiting for cows to express estrus; 2) identify nonpregnant cows early after AI; and 3) resynchronize estrus or ovulation in cows failing to conceive to previous AI services. Dairy managers traditionally relied on visual detection of estrus to submit cows for AI. Detection of estrus is often inefficient because of limited observations for estrus and expression of estrus. Development of Ovsynch, a hormonal protocol that synchronizes follicular development, luteal regression, and ovulation thereby allowing for timed AI has radically changed reproductive management by providing dairy managers a practical and effective tool for improving AI submission rate. Pregnancy rates after the Ovsynch protocol are increased by 10 to 12 percentage points compared with Ovsynch alone when estrous cycles are presynchronized (i.e., Presynch), before applying the Ovsynch protocol. Regardless of presynchronization scheme, improved pregnancy rates in timed AI programs is associated with: 1) greater ovulation response to the first GnRH injection of Ovsynch; 2) more cows with a functional corpus luteum at the first GnRH injection; 3) greater ovulatory response to the first and second GnRH injection; and 4) greater ovulation response after timed AI.
Anovulation is an increasing problem in lactating dairy cows. In previous research by the NC-1006 committee, we found that more than 26% of lactating dairy cows were anovulatory near the end of the voluntary waiting period. Recent studies by NC-1038 confirmed a similarly large percentage of anovulatory cows based on multiple blood samples and ultrasound evaluations of the ovaries. Thus, it is clear that anovulation is a significant problem in lactating dairy cows. Modifying timed AI programs to synchronize the time of ovulation in lactating cows may further reduce labor inputs for reproductive management; however, it may be possible to improve fertility with the Ovsynch protocol (one of the purposes of the current proposal).
Although use of reproductive programs to improve first service pregnancy rate reduces the impact of poor detection and expression of estrus, systematic strategies to improve fertility of those services and methods to resynchronize estrus or ovulation in nonpregnant cows (i.e., Resynch) are only beginning to be developed and evaluated. Because conception rates of high-producing lactating dairy cows average 40% or less, 60% or more of cows that receive a timed AI fail to conceive and, therefore, resynchronization strategies are necessary to aggressively initiate subsequent AI services. However, management strategies to reinseminate nonpregnant cows has improved reproductive efficiency, thereby increased AI submission rate. Development of management strategies to identify and resynchronize cows failing to conceive to a timed AI is still a critical step to improved reproduction in lactating dairy cows.
Technical Feasibility of the Research
During the last 25 years, the NC-1038 project (including its predecessor projects NC-113 and NC-1006) has contributed greatly to the development of several breeding programs to maximize pregnancy rates. These successes directly address the objections or reasons given by cow-calf producers for not adopting reproductive technologies. Information accrued by our group led to the development of the Ovsynch protocol in dairy cattle and its variations (i.e., the CO-Synch protocol, progestins + the Ovsynch protocol) used in beef cattle. These protocols generally increased pregnancy rates beyond controls, because in both dairy and beef cattle, they induce fertile ovulation in postpartum cows that have not resumed estrous cycles by the end of the voluntary waiting period (dairy cows) or at the onset of the breeding season (beef cows). During the last 15 years, we tested the efficacy of adding progesterone to the Ovsynch protocol in lactating dairy cows. This experiment was replicated at seven (IL, IN, KS, OH, MI, MO, and WI) of the experiment stations involved in NC-1038 (Stevenson et al., 2006). In beef cattle, the experiment was replicated at four (IL, KS, MN, and MO) of the stations (Lamb et al., 2001). During the past 5 years, a number of other large, multi-state collaborative studies have been completed in dairy (Stevenson et al., 2008; Chebel et al., 2010; Bilby et al., 2011) and beef (Larson et al., 2009; Dahlen et al., 2010; Bridges et al., 2011; Marquezini et al., 2011) reproduction.
Advantages for Doing the Work as a Multi-State Effort
The past four NC-1038 projects have received considerable national attention and acceptance by producers, and it is the aim of the current project to improve fertility and ease of adoption of our developments. Our NC-1038 group has long-standing university and industry relationships and has demonstrated the ability to coordinate multi-location experiments designed to improve fertility in dairy and beef cattle. This is a distinct advantage to successful multi-state efforts. Common interests and strong relationships stem from three of the current collaborators in NC-1038 having been former students of other collaborators. The multi-state collaborations planned in this project will continue to provide new information applicable to beef and dairy producers and additional stakeholders. An important strength of our past multi-state collaborations is that they have increased the statistical power to detect differences in treatment alternatives and allow application of our results to other regions of the U.S. In addition, individual members of the NC-1038 have diverse skills and available laboratory expertise that strengthen our collaborations (e.g., genomics, reproductive biology, nutrition, and behavior expertise).
What the Likely Impacts Will Be from Successfully Completing the Work
Several factors, especially during early development of estrus-synchronization programs, may contribute to poor adoption rates. In addition, these earlier protocols failed to manage follicular waves, resulting in more days during the synchronized period in which detection of estrus was necessary. This ultimately precluded acceptable pregnancy rates after a timed AI. More recent developments focused on control of corpus luteum lifespan and follicular maturation in protocols to synchronize ovulation. These developments facilitate use of timed AI, and should result in increased adoption of these important management practices.
Modifying reproductive management programs to synchronize time of ovulation in lactating dairy cows may substantially reduce labor inputs for reproductive management; however, it may be possible to improve fertility. Development of resynchronization strategies to submit cows failing to conceive to previous inseminations will further improve overall pregnancy rates in lactating dairy cows. In addition, preliminary work from our group and elsewhere has shown promise to improve AI pregnancy rate at first services. This work requires multiple herd collaborations to acquire sufficient numbers of observations in varying environments, dictating multiple investigators working together.
Need as Indicated by Stakeholders
The United Nations 2009 Food and Agricultural Organization (FAO) indicated that the worlds agriculture will face one of the greatest challenges of all times: to produce enough food to feed the 9 billion people the earth will harbor by 2050. Without question, this will demand the concerted efforts of producers, researchers, and policy makers, to provide the experience and technology to achieve such an endeavor. Obviously, increasing reproductive efficiency of both beef and dairy cattle will contribute to the milk and meat supplies for our future world food needs and for the U.S. to maintain a competitive advantage in production of milk and meat products.
A recent report, Power & Promise: Agbioscience in the North Central United States was prepared for the 12 North Central Land-Grant Universities by Battelle, a Columbus Ohio-based independent research and development group (full report is available at http://nccea.org/documents/powerandpromiseweb.pdf). The report, released August 2011, finds that agriculture and agricultural bioscience -- collectively termed Agbioscience -- are providing wide-ranging opportunities for economic growth and job creation in the U.S.
The report also notes that bioscience professionals at U.S. land-grant universities are leveraging advancements in modern science and technology to address crucial national and global needs, including improving agricultural productivity, food security, human health, renewable resource development (such as bioenergy and biobased materials) and environmental sustainability.
In our science and technology-based economic development practice at Battelle, we have observed the consistent rise of agbioscience as a core driver of economic growth and business expansion opportunities for the U.S., said Simon Tripp, lead author of the study. This is an extremely dynamic sector, leveraging sustainable bio-based resources to produce goods that meet large-scale market needs. Tripp said the North Central region is well positioned to fulfill the promise of new product development and job growth in modern agbioscience.
The North Central region contains 37% of all U.S. farmland. Further, the North Central region is Americas agricultural export engine with 60% of all U.S. live animals and meat exports notwithstanding the region accounts for exports of 83% of soybeans, 85% of all feed grains, and 51% of wheat. Although the North Central region contains but 21% of U.S. land area, it accounts for 45% of all U.S. agricultural exports.
The NC-1038 committee is a long-standing group (previously known as the NC-113 and NC-1006 with more than 35 years of multi-state cooperation since its inception in the early 1970s) that has contributed greatly to the increase in reproductive efficiency of cattle. Its long-term goal is to identify and develop strategies to improve reproductive efficiency for sustainable cattle production and is consistent with the consensus goals set forth by FAIR 2002 and the FAO 2009 and directions described by Tripps Power and Promise .
Importance of the Work, and What the Consequences Are If It Is Not Done
Beef Cattle. Successful management of estrus and ovulation to facilitate artificial insemination (AI) are reproductive management tools available to beef and dairy producers since the 1990s. Manipulation of the estrous cycle shortens the calving season, increases calf uniformity, and facilitates the use of AI. Artificial insemination allows infusion of superior genetics at costs far below the cost of purchasing a herd sire of less than similar standards. These tools remain the most important and widely applicable assisted-reproductive technologies available to beef cattle operators. Current and past research by NC-1038 committee tested protocols for synchronizing estrus, ovulation, or both, which addressed two strategies that are key factors for their implementation by producers. The protocols: 1) minimize the frequency of times cattle must be moved through a cattle-handling facility; and 2) eliminate or minimize detection of estrus before AI or before a timed AI. Application of these methods has already increased the use of AI in beef cattle.
Unless owners of commercial herds aggressively implement genetic improvement through reproductive management, the U.S. will lose its competitive advantage in high quality beef production to countries such as Brazil and Argentina, which are the leading export countries for U.S. beef genetics. According to the U.S. National Association of Animal Breeders and the Association for Brazilian Artificial Insemination, sales of beef semen for AI increased from 3.3 to 10.5 million units between 1993 and 2010 in Brazil, whereas that in the U.S. it only increased from 2.9 to 3.7 million units during the same period. International players, now becoming more technically astute and competitively advantaged, have positioned themselves to dominate the production and sale of beef worldwide.
Dairy Cattle. Total milk production in dairy cattle is determined by the proportion of cows producing milk at any given time and the level of milk production of the individual cows within the herd. Both of these factors are dramatically affected by the rate at which cows become pregnant in the herd. Two factors that determine this rate are the AI submission rate (i.e., managements ability to inseminate nonpregnant cows thereby giving them a chance to conceive) and the conception rate (i.e., the proportion of inseminated cows that actually conceive). The body of scientific literature supports that conception rates in lactating dairy cows have decreased by 25 percentage points to less than 40% during the past 50 years (Lucy, 2001). Until the underlying causes of poor conception rates in lactating dairy cows can be understood and mitigated, pregnancy rates must be increased by focusing on improving the AI submission rate.
Three strategies can be implemented to improve AI submission rates: 1) submit all cows for first postpartum AI at the end of the voluntary waiting period rather than waiting for cows to express estrus; 2) identify nonpregnant cows early after AI; and 3) resynchronize estrus or ovulation in cows failing to conceive to previous AI services. Dairy managers traditionally relied on visual detection of estrus to submit cows for AI. Detection of estrus is often inefficient because of limited observations for estrus and expression of estrus. Development of Ovsynch, a hormonal protocol that synchronizes follicular development, luteal regression, and ovulation thereby allowing for timed AI has radically changed reproductive management by providing dairy managers a practical and effective tool for improving AI submission rate. Pregnancy rates after the Ovsynch protocol are increased by 10 to 12 percentage points compared with Ovsynch alone when estrous cycles are presynchronized (i.e., Presynch), before applying the Ovsynch protocol. Regardless of presynchronization scheme, improved pregnancy rates in timed AI programs is associated with: 1) greater ovulation response to the first GnRH injection of Ovsynch; 2) more cows with a functional corpus luteum at the first GnRH injection; 3) greater ovulatory response to the first and second GnRH injection; and 4) greater ovulation response after timed AI.
Anovulation is an increasing problem in lactating dairy cows. In previous research by the NC-1006 committee, we found that more than 26% of lactating dairy cows were anovulatory near the end of the voluntary waiting period. Recent studies by NC-1038 confirmed a similarly large percentage of anovulatory cows based on multiple blood samples and ultrasound evaluations of the ovaries. Thus, it is clear that anovulation is a significant problem in lactating dairy cows. Modifying timed AI programs to synchronize the time of ovulation in lactating cows may further reduce labor inputs for reproductive management; however, it may be possible to improve fertility with the Ovsynch protocol (one of the purposes of the current proposal).
Although use of reproductive programs to improve first service pregnancy rate reduces the impact of poor detection and expression of estrus, systematic strategies to improve fertility of those services and methods to resynchronize estrus or ovulation in nonpregnant cows (i.e., Resynch) are only beginning to be developed and evaluated. Because conception rates of high-producing lactating dairy cows average 40% or less, 60% or more of cows that receive a timed AI fail to conceive and, therefore, resynchronization strategies are necessary to aggressively initiate subsequent AI services. However, management strategies to reinseminate nonpregnant cows has improved reproductive efficiency, thereby increased AI submission rate. Development of management strategies to identify and resynchronize cows failing to conceive to a timed AI is still a critical step to improved reproduction in lactating dairy cows.
Technical Feasibility of the Research
During the last 25 years, the NC-1038 project (including its predecessor projects NC-113 and NC-1006) has contributed greatly to the development of several breeding programs to maximize pregnancy rates. These successes directly address the objections or reasons given by cow-calf producers for not adopting reproductive technologies. Information accrued by our group led to the development of the Ovsynch protocol in dairy cattle and its variations (i.e., the CO-Synch protocol, progestins + the Ovsynch protocol) used in beef cattle. These protocols generally increased pregnancy rates beyond controls, because in both dairy and beef cattle, they induce fertile ovulation in postpartum cows that have not resumed estrous cycles by the end of the voluntary waiting period (dairy cows) or at the onset of the breeding season (beef cows). During the last 15 years, we tested the efficacy of adding progesterone to the Ovsynch protocol in lactating dairy cows. This experiment was replicated at seven (IL, IN, KS, OH, MI, MO, and WI) of the experiment stations involved in NC-1038 (Stevenson et al., 2006). In beef cattle, the experiment was replicated at four (IL, KS, MN, and MO) of the stations (Lamb et al., 2001). During the past 5 years, a number of other large, multi-state collaborative studies have been completed in dairy (Stevenson et al., 2008; Chebel et al., 2010; Bilby et al., 2011) and beef (Larson et al., 2009; Dahlen et al., 2010; Bridges et al., 2011; Marquezini et al., 2011) reproduction.
Advantages for Doing the Work as a Multi-State Effort
The past four NC-1038 projects have received considerable national attention and acceptance by producers, and it is the aim of the current project to improve fertility and ease of adoption of our developments. Our NC-1038 group has long-standing university and industry relationships and has demonstrated the ability to coordinate multi-location experiments designed to improve fertility in dairy and beef cattle. This is a distinct advantage to successful multi-state efforts. Common interests and strong relationships stem from three of the current collaborators in NC-1038 having been former students of other collaborators. The multi-state collaborations planned in this project will continue to provide new information applicable to beef and dairy producers and additional stakeholders. An important strength of our past multi-state collaborations is that they have increased the statistical power to detect differences in treatment alternatives and allow application of our results to other regions of the U.S. In addition, individual members of the NC-1038 have diverse skills and available laboratory expertise that strengthen our collaborations (e.g., genomics, reproductive biology, nutrition, and behavior expertise).
What the Likely Impacts Will Be from Successfully Completing the Work
Several factors, especially during early development of estrus-synchronization programs, may contribute to poor adoption rates. In addition, these earlier protocols failed to manage follicular waves, resulting in more days during the synchronized period in which detection of estrus was necessary. This ultimately precluded acceptable pregnancy rates after a timed AI. More recent developments focused on control of corpus luteum lifespan and follicular maturation in protocols to synchronize ovulation. These developments facilitate use of timed AI, and should result in increased adoption of these important management practices.
Modifying reproductive management programs to synchronize time of ovulation in lactating dairy cows may substantially reduce labor inputs for reproductive management; however, it may be possible to improve fertility. Development of resynchronization strategies to submit cows failing to conceive to previous inseminations will further improve overall pregnancy rates in lactating dairy cows. In addition, preliminary work from our group and elsewhere has shown promise to improve AI pregnancy rate at first services. This work requires multiple herd collaborations to acquire sufficient numbers of observations in varying environments, dictating multiple investigators working together.