Progress 09/15/05 to 09/14/10
Outputs
Progress Report Objectives (from AD-416) The National Animal Germplasm Program (NAGP) and the Cooperator (Purdue University, Department of Animal) desire to enter into this Cooperative Agreement for the purpose of developing the NAGP swine germplasm collection by (1) Characterizing the relationships of measures of semen quality and numbers sperm cell inseminated to resulting conception rates and litter size; and (2) Evaluating alternative commercially available semen extenders for their efficacy in cell preservation during transportation. Such an effort is consistent with the goals of the NAGP and Purdue University. The above steps are critical in utilizing a collection of swine germplasm to regenerate live animals. Approach (from AD-416) Cryopreservation of boar semen has been utilized for several decades. However, unlike other livestock species, such as the bovine, boar spermatozoa are sensitive to cryopreservation and only approximately 50% of the spermatozoa survive the cryopreservation procedure (Watson, 1995). Utilizing frozen/thawed (FT) boar semen with traditional intra-cervical insemination requires high numbers of sperm cells (5-6 x 109) to be used and conception rates achieved are less than attained with liquid-stored fresh boar semen (Johnson et al., 2000). These factors limit the utilization of FT semen on commercial swine operations. However, cryopreservation of boar semen is beneficial for numerous reasons such as for gene banking boars of high genetic merit and for preserving genetic diversity (Guthrie and Welch, 2005). When these fore mentioned procedures are utilized the amount of cyropreserved semen available is often limited. Therefore, improved methods to inseminate sows with FT boar semen are required. A potential solution to reduce the number of FT spermatozoa required for successful conception is intrauterine insemination (IUI). IUI places the semen closer in proximity to the site of fertilization compared to traditional intra-cervical insemination and thus, has the potential to reduce the number of spermatozoa required. Additionally, IUI may be beneficial when inferior spermatozoa are being used, such as the case with FT semen. It has been demonstrated that fewer spermatozoa are needed with IUI to achieve similar conception rates and litter sizes as traditional intra-cervical insemination when fresh semen is used (Watson and Behan, 2002). Therefore, the objective of this research is to determine the minimum number of FT spermatozoa needed to achieve acceptable conception rates when IUI is utilized. Objectives: Determine the minimum number of spermatozoa required and most effective insemination schedule to achieve acceptable conception rates when FT semen is used in conjunction with IUI. Rationale: When utilizing gene banked cryopreserved boar semen the amount of FTsemen available to use is often limited. Hence, more efficacious methods to utilize FT boar semen are needed to maximize conception rate and litter size while simultaneously minimizing the number of spermatozoa required. A potential method to minimizing the number of FT spermatozoa needed while maintaining acceptable conception rates and liter sizes while is IUI. However, limited data is available on the efficacy of IUI with FT boar semen or the minimum number of FT spermatozoa required to achieve acceptable reproductive performance when used in combination with IUI. Final Report - Under this SCA a series of activities were conducted. One of the major activities during the life of the agreement was the collection of swine semen for entry into the repository. Numerous collections were performed both at the university and n the field. Field collections included traveling to rare breed shows and sales for the purpose of collecting boars and shipping the collected semen to Ft. Collins for cryopreservation. This approach represents the most efficient way for NAGP to collect germplasm samples from rare breeds which are rarely found in commercial studs. An experiment with three replications and 106 sows was designed to evaluate the optimal insemination dose (1.0, 0.75, 0.5, and 0.25 billion sperm) for boar semen. This is important for gene banks because there may be a limited supply of semen to use in reconstituting a population. In this experiment no statistical differences in pregnancy rate were found, however, the 0.25 treatment had the lowest pregnancy rate (25 vs 44, 54, and 42%, respectively. To ascertain the dose most appropriate to use if semen is limited, the total number of fetuses per sow inseminated was multiplied by the number of potential potential doses available if only one billion motile sperm cells existed. While non-significant, the results suggest that the optimal dose of semen to utilize per insemination was between 0.50 and 0. 75 x one billion motile sperm cells. Such information significantly aids NAGP in planning germplasm collections and assures that effective use of stored germplasm can be made when needed. This project was monitored by frequent calls, emails, and person-to-person meetings with the collaborator and other Purdue faculty members.
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Progress 10/01/08 to 09/30/09
Outputs
Progress Report Objectives (from AD-416) The National Animal Germplasm Program (NAGP) and the Cooperator (Purdue University, Department of Animal) desire to enter into this Cooperative Agreement for the purpose of developing the NAGP swine germplasm collection by (1) Characterizing the relationships of measures of semen quality and numbers sperm cell inseminated to resulting conception rates and litter size; and (2) Evaluating alternative commercially available semen extenders for their efficacy in cell preservation during transportation. Such an effort is consistent with the goals of the NAGP and Purdue University. The above steps are critical in utilizing a collection of swine germplasm to regenerate live animals. Approach (from AD-416) Cryopreservation of boar semen has been utilized for several decades. However, unlike other livestock species, such as the bovine, boar spermatozoa are sensitive to cryopreservation and only approximately 50% of the spermatozoa survive the cryopreservation procedure (Watson, 1995). Utilizing frozen/thawed (FT) boar semen with traditional intra-cervical insemination requires high numbers of sperm cells (5-6 x 109) to be used and conception rates achieved are less than attained with liquid-stored fresh boar semen (Johnson et al., 2000). These factors limit the utilization of FT semen on commercial swine operations. However, cryopreservation of boar semen is beneficial for numerous reasons such as for gene banking boars of high genetic merit and for preserving genetic diversity (Guthrie and Welch, 2005). When these fore mentioned procedures are utilized the amount of cyropreserved semen available is often limited. Therefore, improved methods to inseminate sows with FT boar semen are required. A potential solution to reduce the number of FT spermatozoa required for successful conception is intrauterine insemination (IUI). IUI places the semen closer in proximity to the site of fertilization compared to traditional intra-cervical insemination and thus, has the potential to reduce the number of spermatozoa required. Additionally, IUI may be beneficial when inferior spermatozoa are being used, such as the case with FT semen. It has been demonstrated that fewer spermatozoa are needed with IUI to achieve similar conception rates and litter sizes as traditional intra-cervical insemination when fresh semen is used (Watson and Behan, 2002). Therefore, the objective of this research is to determine the minimum number of FT spermatozoa needed to achieve acceptable conception rates when IUI is utilized. Objectives: Determine the minimum number of spermatozoa required and most effective insemination schedule to achieve acceptable conception rates when FT semen is used in conjunction with IUI. Rationale: When utilizing gene banked cryopreserved boar semen the amount of FTsemen available to use is often limited. Hence, more efficacious methods to utilize FT boar semen are needed to maximize conception rate and litter size while simultaneously minimizing the number of spermatozoa required. A potential method to minimizing the number of FT spermatozoa needed while maintaining acceptable conception rates and liter sizes while is IUI. However, limited data is available on the efficacy of IUI with FT boar semen or the minimum number of FT spermatozoa required to achieve acceptable reproductive performance when used in combination with IUI. Significant Activities that Support Special Target Populations A series of activities were conducted under this SCA. During the past year two replicates of an experiment designed to evaluate the optimal insemination dose for boar semen were performed. Data to date show no significant differences between sows� fertility and litter size when inseminated with 1.0, 0.75, 0.5, and 0.25 billion sperm, however the fertility and litter size for the 0.25 billion cell treatment lower and biologically and economically important. The collaborator has been working with swine breeding companies to obtain pedigree information of the boars from those companies that have semen samples in the repository. This project was monitored by frequent calls with the collaborator and other Purdue faculty members.
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Progress 10/01/06 to 09/30/07
Outputs
Progress Report Objectives (from AD-416) ARS National Animal Germplasm Program (NAGP) and the Cooperator (Purdue University, Department of Animal Science, PU) desire to enter into this Cooperative Agreement for the purpose of developing the NAGP swine germplasm collection by: 1. Providing logistical support to identify boars for collection and securing semen from sire owners. 2. Co-sponsor and facilitate educational programs for the swine industry related to germplasm preservation and utilization. 3. Perform research that evaluates post-thaw semen viability. Such an effort is consistent with the goals of the NAGP and the PU. Taking such steps is critical in developing a collection of swine germplasm. Approach (from AD-416) Developing a national collection of swine germplasm will require the collection of semen samples from a wide range of boars owned by a multitude of individuals. Purdue University has established working relationship with key producer organizations and companies in the swine industry. Purdue University will utilize its relationships to obtain freshly collected swine semen which will be shipped to NAGP for cryopreservation. Developing collections of rare swine breeds requires a producer educational process in collecting boars and assisting those breed associations in understanding their breed�s population structure. Therefore, PU will organize and co-sponsor with NAGP a workshop(s) that will focus on these topics for small hog producers. There is a need to quantify the heritability of cryopreserved semen. Boars from several lines per commercial breeding company will be sampled. Samples will be collected from commercial boar studs shipped to NAGP for freezing and evaluation. Significant Activities that Support Special Target Populations This report serves to document research conducted under a specific cooperative agreement between ARS and Purdue University. Additional details of research can be found in the report for the parent project 5402-31000-001-00D, National Animal Germplasm Program. With this agreement Purdue has continued efforts to assist this project in identifying boars for collection. Specifically, during this year a new student was sent to our laboratory to learn boar semen handling procedures. Upon his return to Purdue he will be responsible for performing on farm boar collections. In addition, the collaborator has initiated an effort to validate the viability of cryopreserved boar semen by regenerating a research population at Purdue University. Regular contact and oversight is performed by email and phone contact.
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Progress 10/01/05 to 09/30/06
Outputs
Progress Report 4d Progress report. This report documents research conducted under a specific cooperative agreement between ARS and Purdue University, Animal Science Department. Additional details of research can be found in the report for the parent project, 5402-31000-002-00D National Animal Germplasm Program. Purdue has identified boars for collection from major swine breeds. They have accomplished this by interacting with the National Swine Registry and contacting breeders who own the boars of interest. Understanding the basis for genetic variation in sperm characteristics is necessary to avoid biases in sampling swine populations. An experiment evaluating the pre-freeze and post-thaw sperm motion was performed on 163 boars from four commercial lines. No significant difference between lines was found. This result implies that specific line based cryoprotectants are not required for boars being added to the repository.
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