Progress 11/21/16 to 09/30/20
Outputs
Target Audience:Objective 1, 2 and 3: Researchers in the field of reproductive biology and gene expression. Individuals in the field of beef/ruminant production including farmers, forage specialists, and persons in the field of animal health Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest?Objective 1: Abstracts were presented at the ASAS Southern Section meetings in Chattanooga, TN. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Goals 2 and 3: Research was conducted to evaluate: 1) the use of novel, nonergot alkaloid producing tall fescue (NOV) compared to E+ fescue pastures during critical stages of production, last trimester of gestation and early lactation, on cow/calf performance and milk production, and 2) if maternal genotype for the DRD2 SNP interacted with the response to grazing tall fescue by endophyte type. Pregnant cows with homozygous alleles (A A, n = 38 and G G, n = 37) were used in this study over a two-year period. Pregnant cows were randomly assigned to fescue endophyte type: 1) endophyte-infected ergot alkaloid producing tall fescue (E+; Kentucky 31) or 2) endophyte-infected non-ergot alkaloid producing tall fescue (NOV, Texoma MaxQ II , Pennington Seed, Madison, GA) within maternal genotype during the last trimester of pregnancy (90 d) and first 30 d of lactation. Cows remained in the same fescue endophyte type treatment during year 2. Each year, there were two pasture replicates (10 ha pastures/rep; 2 rep/fescue type) per fescue endophyte type. Cows were maintained on non-fescue pastures during the first and second trimester of gestation when not on fescue endophyte treatments. There were no interactions between fescue endophyte type and DRD2 genotype indicating that genotype did not alter the response to grazing E+ fescue. Grazing E+ fescue pastures during the last trimester of gestation and first 30 d of lactation reduced cow body weight gain but did not alter calf birth weight compared to NOV. Milk production and calf ADG during the first 30 d of lactation were lower for E+ than NOV. Calving rate was reduced but not calving interval for E+ cows. Adjusted 205-d weight of calves was lower in those grazing E+ with their dams compared to NOV. Overall, grazing E+ tall fescue pastures during late gestation reduced cow body weight gain and muscle mass but maintained similar calf birth weights. Milk production was lower for cows grazing E+ fescue, which reduced early calf growth rate and lowered adjusted 205-d weight.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2020
Citation:
Greene MA, Klotz JL, Goodman JP, May JB, Harlow BE, Baldwin WS, Strickland JR, Britt JL, Schrick FN, Duckett SK. Evaluation of oral citrulline administration as a mitigation strategy for fescue toxicosis in sheep. Transl Anim Sci. 2020 Oct 30;4(4):txaa197. doi: 10.1093/tas/txaa197.
- Type:
Journal Articles
Status:
Under Review
Year Published:
2020
Citation:
Wilbanks SA, Justice SM, West T, Klotz JL, Andrae JG and Duckett SK. Effects of tall fescue endophyte type and dopamine receptor D2 genotype on cow-calf performance during the last trimester of gestation and early lactation. Toxins 2020 (In review).
- Type:
Journal Articles
Status:
Published
Year Published:
2020
Citation:
1. DeCarlo, A.N., Burnett, C.R., Rowan, P., Johnston, R., Ricks, R.E., Bridges, W.C., Jr., and Pratt, S.L. 2020. The Effect of Ergot Alkaloid Exposure on Bull Sperm Chromatin Structure and Acrosome Integrity. EC Veterinary Science 5.6 (2020): 12-21
- Type:
Journal Articles
Status:
Published
Year Published:
2020
Citation:
Citation: Britt JL, Noorai RE, Duckett SK. Differentially expressed genes in cotyledon of ewes fed mycotoxins. BMC Genomics. 2020 Oct 1;21(1):680. doi: 10.1186/s12864-020-07074-z. PMID: 32998709
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2020
Citation:
DeCarlo, A.N., Parrish, J., Bridges, W.C., and Pratt, S.L. 2020. Assessment of consistency in quantification of ribonucleic acid across multiple methods , ASAS Southern Section, Chattanooga, TN.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2020
Citation:
DeCarlo, A.N., McCarty, K.J., Richey, S.K., Long, N.M., and Pratt, S.L. 2020.The role of an intronic single nucleotide polymorphism within the dopamine receptor type-2 gene on pituitary prolactin protein expression in bulls. ASAS Southern Section, Chattanooga, TN.
- Type:
Journal Articles
Status:
Under Review
Year Published:
2020
Citation:
Sell, G.S., Bridges, W.C., and Pratt, S.L. 2020. A Retrospective Study Comparing Growth and Breeding Soundness Exam Outcomes on Beef Bulls Developed on Forage or Forage Plus Concentrate Rations in the South Eastern United States.
- Type:
Journal Articles
Status:
Other
Year Published:
2020
Citation:
Pratt, S.L. 2020. Growth rate and breeding soundness evaluations of beef bulls at approximately 14 and 20 months of age developed on forage.
|
Progress 10/01/18 to 09/30/19
Outputs
Target Audience:Objective 1: Researchers in the field of reproductive biology and gene expression. Individualsin the field of beef production including farmers, forage specialists, and persons in the field of animal health. Objective 4: Methods of establishment and management of novel and toxic tall fescue were summarized and presented in published and oral formats to Extension forage specialists, county and area Extension agents and livestock/forage producers. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Results of literature review and associated professional guide were presented in multiple agent trainings located across the tall fescue region of the southeastern U.S. How have the results been disseminated to communities of interest?Objective 1: Abstracts were presented at the ASAS Southern Section meetings in Ft. Worth, TX. Objectives 2 and 3: Abstracts were presented at the Perinatal Biology Symposium in August 2019 at Snowmass CO. Presentations were given to livestock producers at the Simpson Research and Education field day and Veterinarians at the SC Veterinary Association Meeting on how fescue toxicosis impacts fetal growth and development. Objective 4: In addition to the professional development trainings Powerpoint presentations were developed by multiple state Extension specialists and were presented in day long tall fescue renovation and management workshops located in six southeastern states. In April of 2019, workshops were held in Blackstone VA, Salisbury NC, Newberry SC, Calhoun GA, Mt. Vernon MO and Princeton KY. In addition, an hour long presentation was delivered to producers at the Appalachian Grazing Conference in Morgantown WV as a portion of a tall fescue management breakout session. What do you plan to do during the next reporting period to accomplish the goals?Objective 1: Using isolated DNA, we will examine known SNPs in the PRL signaling cascade and examine their association, if any, on pituitary PRL content. It is planned to isolate total RNA and perform semi-quantitative RT-PCR for message abundance of specific gene products in the bovine pituitary and associate their abundance with known SNPs. Objectives 2 and 3: Additional research projects on DRD2 genotype and fescue toxicosis in gestating sheep and cows are completed, and laboratory and data analyses are on-going. An additional experiment was conducted to examine how endophyte-infected tall fescue seed fed during different stages of late gestation altered placental development and fetal muscle growth. Histology and mRNA sequencing are in-progress. Objective 4: We will continue to collect row occupancy data of the grazed replicated plots at the Simpson Research and Education Center near Pendleton SC. Tillers of plants collected from 2019 will be lyophilized and ground for subsequent ergot alkaloid determination. Locations for additional producer workshops are planned for April 2020 in VA, NC, GA, TN, KY, MO, and AR.
Impacts
What was accomplished under these goals?
Objecttive 1: Six hundred pituitaries were collected at a local slaughter house. The anterior and posterior pituitary was divided,frozen and stored at -80o C. Posterior pituitaries were used to isolate genomice DNA and for each pituitary the sex of the animal and the genotype for DRD2 determined using PCR and Southern blotting procedures; and PCR with RFLP and Taqman for SNP detection. Protein extracts were generated from the anterior pituitary and used for western blotting to detect PRL abundnance. Genotype distribution for the DRD2 SNP was 17.4% AA , 63% AG, and 19.6% GG, supporting our previous work showing no shift in the SNP genotype distributions. Prolactin protein expression in the pituitary was similar across genotype and agrees with our previous data in that DRD2 genotype is not associated with circulating PRL or pituitary PRL content. Objectives 2 and 3: Gestating ewes consuming ergot alkaloids, from endophyte-infected (E+) tall fescue seed, produce smaller lambs suffering from intrauterine growth restriction (IUGR). Arginine supplementation has been shown to increase birth weight and brown adipose tissue (BAT) development, and oral citrulline administration is reported to increase arginine concentrations. Two experiments were conducted to: 1) evaluate if oral supplementation with citrulline increases lamb birth weight and alleviates symptoms of IUGR caused by feeding E+ tall fescue seed and 2) determine the effectiveness of citrulline and citrulline-malate as an oral drench in elevating circulating levels of arginine and citrulline. In Experiment 1, gestating Suffolk ewes (n = 10) were assigned to one of two treatments [oral citrulline-malate 2:1 drench (CT+; 81 mg/kg/d of citrulline) or oral water drench (CT-)] to start on d 86 of gestation. All ewes were maintained on a total mixed ration and fed endophyte-infected tall fescue seed (1.77 mg ergovaline + ergovalinine/hd/d). Ewes drenched with CT+ had decreased (P < 0.05) arginine and phenylalanine concentrations during gestation. Lamb birth weight did not differ (P = 0.51) between CT+ and CT-. At birth, lambs from CT+ ewes had reduced (P < 0.05) crude fat as a percentage of the total lean and also tended to have increased (P < 0.08) hind limb muscle weights as percentages of the empty body weight. In Experiment 2, non-pregnant Suffolk ewes (n = 3) were assigned to either oral drench of citrulline (CIT; 81 mg/kg/d), citrulline-malate 2:1 (C:M; 81 mg/kg/d of citrulline), or water (CON) in a Latin Square design for a treatment period of 4 d with a washout period of 3 d. On d 4, blood samples were collected at 0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, and 18 h post drench. Oral drenching of CIT and C:M increased (P < 0.0001) citrulline concentrations within 2 h and remained elevated for 8 h post drenching compared to CON. Arginine concentrations were not increased (P = 0.45). Drenching pregnant ewes fed endophyte-infected tall fescue seed did not alter lamb birth weight but increased hind limb muscle weight percentages. Citrulline-malate drenches may need to be administered in greater concentrations or more frequently in order to sustain elevated serum citrulline levels in the gestating ewe. Additional research is needed to evaluate the effectiveness of this mitigation treatment on reducing the effects of fescue toxicosis during gestation. Objective 4: The literature review was summarized in the form of a professional guide and was reviewed, formatted and published by the American Society of Agronomy. This guide serves as the foundation for the ongoing Alliance for Grassland Renewal workshop material. In addition, the teaching method and results from these workshop series from 2012 to present have been summarized and published. We have also sampled the replicated novel tall fescue plots that were established near Pendleton SC in Spring, Summer and Fall 2019 and will collect row occupancy data to determine persistence of 15 tall fescue cultivars containing toxic and novel endophytes. These data will be collected over a minimum of two years prior to reporting results.
Publications
- Type:
Theses/Dissertations
Status:
Accepted
Year Published:
2019
Citation:
Britt, Jessica Lynn. THE IMPACT OF ERGOT ALKALOID CONSUMPTION DURING GESTATION ON MATERNAL PERFORMANCE AND FETOPLACENTAL DEVELOPMENT. Clemson University, Ph.D. Dissertation
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2019
Citation:
Britt, J. L., M.A. Greene, S.M. Justice, and S. K. Duckett. 2019. Impact of ergot alkaloid consumption on fetoplacental growth and development across late gestation in sheep. Perinatal Biology Symposium, August 2019, Snowmass, CO.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2019
Citation:
M. Greene, J. Klotz, J. Goodman, B. Harlow, J. Britt, and S. Duckett. 2019. Effects of oral citrulline-malate administration to ewes fed ergot alkaloids during late gestation on neonatal serum amino acids and growth. Perinatal Biology Symposium, August 2019, Snowmass, CO.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2019
Citation:
Justice, S. M., J. Britt, M. Greene, E. Jesch, S. Duckett. 2019. Effects of maternal ergot alkaloid exposure on male offspring carcass composition and yield. Perinatal Biology Symposium, August 2019, Snowmass, CO.
- Type:
Theses/Dissertations
Status:
Accepted
Year Published:
2019
Citation:
DeCarlo, Andrea N. THE IMPACT OF A DRD2 SINGLE NUCLEOTIDE POLYMORPHISM
ON GROWTH, REPRODUCTION AND PROLACTIN GENE EXPRESSION IN BEEF BULLS
- Type:
Journal Articles
Status:
Published
Year Published:
2019
Citation:
DeCarlo, A.N., Jennings, K., Pratt, S.L. Burnett, C.R., Long, N.M. and Kojima, C. 2019. Bovine dopamine type-2 receptor SNP has no effect on growth, semen characteristics and prolactin concentrations in beef bulls treated with a dopamine agonist. An Reprod Sci 207:73-82.
- Type:
Books
Status:
Published
Year Published:
2018
Citation:
Roberts, Craig and John Andrae. Fescue Toxicosis and Management. 2nd Ed. American Society of Agronomy. Crop Science Society of America. Madison, WI. ISBN: 978-0-89118-630-4. Doi: 10.2135/2018.fescuetoxicosis. 20 pgs.
|
Progress 10/01/17 to 09/30/18
Outputs
Target Audience: Researchers in the field of reproductive technologies and gene expression. Persons in the field of beef production including farmers, forage specialists, and persons in the field of animal health. Changes/Problems:Objective 1:It was our intent to utilize testicular tissues for the study of PRL regulation via DRD2 genotypes; however, protein concentrations are almost non-detectable with current commercial antibodies and we have decided to focus on pituitary tissues. The determination of PRL expression in relation to DRD2 genotype will not differ. What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest?Objective 1: The IHC results and DRD2 genotype association with bull growth and semen quality have been submitted for publication and are being presented at regional meetings. The presence of dopamine agonists in semen results obtained in the previous year were not included as it was determined that these observations needed to be confirmed by another method to justify distribution of the results and publication. Objectives 2 and 3:Abstracts on the DRD2 SNP in ovine and bovine results were presented at American Society of Animal Science Meetings in Vancouver, Canada. July 2018; Impact of fescue toxicosis in pregnant ewes, SC Farm Bureau tour at Simpson REC, Pendleton, SC, Feb. 2018. Objective 4:Invited presentations of the curricula developed and listed in "Other Products" section were delivered in Pendleton SC and Raleigh NC in March, 2018. Invited presentations of the curricula were delivered in Pendleton SC and Raleigh NC in March, 2018. Additional presentations of this material (and the full curricula) are planned in 2019 in MO, KY, GA, SC, NC, and VA. What do you plan to do during the next reporting period to accomplish the goals?Objective 1: The focus for the next year will be to determine if any DRD2 genotype previously reported to impact the circulating levels of serum PRL actually impact PRL production and/or release. Therefore, we will be evaluating pituitary tissue for genotype and determining PRL content at the nucleic acid and protein level. Objectives 2 and 3:Further analyses are being conducted to examine ergot alkaloid derived residues in liver and adipose tissues of ewes fed E+ tall fescue seed. Two sheep studies DRD2 SNP and fescue toxicosis were conducted and data analyses/publications are in progress. A two-year study on DRD2 SNP and fescue toxicosis in cows is on-going and will be completed late fall of 2019. Two Texel rams, both with two copies of the myostatin gene, were bred to 56 ewes in October for objective 3.Results from these studies will be used to develop mitigation strategies for fescue toxicosis in gestating ruminants to enhance fetal and postnatal muscle growth. Objective 4:Additional curricula presentations of the literature review material and curricula are planned in 2019 in MO, KY, GA, SC, NC, and VA at statewide tall fescue toxicosis management workshops.
Impacts
What was accomplished under these goals?
Objective 1: IHC and qRT-PCR was conducted on sperm and bull testis and epididymus for DRD2 expression. The DRD2 mRNA abundance did not differ due to dopamine agonist exposure in the epididymus and testis. The receptor was present in all tissue and cell types examined. Objectives 2 and 3:Pregnant ewes (n = 32) were assigned to one of four treatments: E-/E-, E-/E+, E+/E- or E+/E+ and fed either endophyte-free tall fescue seed (E-; 0 μg ergovaline + ergovalinine /hd/d) or endophyte infected tall fescue seed (E+; 1772 μg ergovaline + ergovalinine/hd/d) during MID (d 35- d85) / LATE (d 86 - d 133) gestation. Genomic DNA was isolated from liver samples collected after terminal surgeries on ewes at d 133 of gestation and used to screen the ovine DRD2 gene for SNP. One SNP, g270a, in exon 1 was discovered and investigated further. Results showed that genotype at the ovine DRD2 SNP appears to be associated with circulating hormone concentrations in the ewe and fetal birth weight, regardless of fescue treatment. The interest in this study was to determine if DRD2 genotype influenced the response to E+ fescue. We did not find any interactions between fescue treatment and DRD2 genotype; however, it is important to note that genotyping was conducted after the completion of the study. Additional studies in sheep and cattle are on-going to further examine the influence of DRD2 SNP on response to fescue toxicosis. Liver samples were obtained from all ewes in experiment 1 for metabolomic analyses using GC-MS. Samples from the E+/E+ (n = 6) and E-/E- (n = 6) fescue treatments were used to examine differences in metabolic compounds. The metabolomics analyses discovered that 45 compounds were differentially regulated between E+ compared to E- fescue treatment. Principal component analyses found the component 1 and component 2 explained 44.8% of the variation and clustered each treatment group separately. Additional research is on-going to map these compounds to targeted networks in order to identify metabolic pathways that are altered with E+ fescue exposure. Objective 4:All commercial cultivar/endophyte tall fescue combinations have been acquired, established, and sampled for baseline endophyte infection rates, row occupancy and periodic total ergot alkaloid concentrations utilizing an ELISA kit. Herbicide applications containing metsulfuron applied in the late boot stage of tall fescue growth were extremely effective (>95%) in suppressing seedhead emergence. Orchardgrass made up a minor component of the sward and seedheads of this species did not appear to be suppressed.Establishing plantain and chicory plots has been difficult, and is likely attributable to quality and timing of seed at planting. Metsulfuron herbicide applications will be conducted again in Spring 2019 in new replicates and the renovation portion of this study attempted again with a single cultivar/endophyte tall fescue combination in Fall 2019. The replicated plots of multiple existing novel endophyte tall fescue cultivars are well established and have been tested for ergot alkaloid infection rates and total ergot alkaloid levels. Plots were grazed lightly and intermittently in 2018 and row occupancy among entries does not differ (P>0.05). These plots will be placed under intense grazing pressure in 2019 in an attempt to differentiate plant persistence among cultivars and endophytes in the Piedmont of South Carolina. In addition, nonreplicated strip plots of 8 commercially available cultivar/endophyte combinations were planted in fall 2018 in Newberry county SC for similar in field measures.
Publications
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2018
Citation:
A.N. DeCarlo, K. Jennings, S.L. Pratt, C.R. Burnett, N.M. Long, W.C. Bridges and C. Kojima. 2019. Genotypic effects of a Dopamine receptor type-2 SNP on growth and semen quality in beef bulls exposed to a dopamine agonist. ASAS Southern Section Meetings, Fort Worth, TX
- Type:
Journal Articles
Status:
Published
Year Published:
2018
Citation:
C.R. Burnett, S.L. Pratt, N.M. Long, G.S. Sell, and F.N. Schrick. 2018. Assessment of semen quality and fertility in young growing beef bulls exposed to ergot alkaloids. Theriogenology. 2018 Sep 15;118:219-224. doi: 10.1016/j.theriogenology.2018.06.007. Epub 2018 Jun 12.
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2018
Citation:
Wilbanks, Sarah Adams. ASSOCIATION OF DRD2 SINGLE NUCLEOTIDE POLYMORPHISM AND FESCUE TOXICOSIS IN RUMINANTS. Clemson University, Ph.D. Dissertation
- Type:
Journal Articles
Status:
Submitted
Year Published:
2018
Citation:
Wilbanks, S. A., C. J. Kojima , J. L. Brit, F. N. Schrick, and S. K. Duckett. 2018. Does genotype play a role in resistance to fescue toxicosis in ovine? Small Ruminant Research (In revision).
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2018
Citation:
Adams, S.K., C.J. Kojima, J. L. Britt, M. F. Miller, Jr., B. M. Koch, J.G. Andrae and S.K. Duckett. 2018. Investigation of Ovine DRD2 Single Nucleotide Polymorphism g270A on fescue toxicosis, subsequent lamb growth and production. J. Anim. Sci. abstract. Presented at 2018 ASAS-CAS Annual Meeting, July, Vancouver, Canada
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2018
Citation:
Adams, S.K., C. J. Kojima+, J.G. Andrae* and S.K. Duckett. 2018. Investigation of DRD2 Single Nucleotide Polymorphism and grazing toxic tall fescue during late gestation on cow and calf performance in Spring calving herds. J. Anim. Sci. abstract. Presented at 2018 ASAS-CAS Annual Meeting, July, Vancouver, Canada
- Type:
Books
Status:
Awaiting Publication
Year Published:
2018
Citation:
Roberts, Craig and John Andrae. 2018. Fescue Toxicosis and Management. 2nd Edition. 16 pg softcover. American Society of Agronomy and Crop Science Society of America. Madison, WI.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2018
Citation:
Andrae, J.G. 2018. Management Considerations and Methods for Replacing Toxic Tall Fescue with Nontoxic Novel Endophyte Infected Tall Fescue. American Forage and Grassland Council National Meeting. January, 16, 2018. Louisville, KY.
|
Progress 11/21/16 to 09/30/17
Outputs
Target Audience:Objective 1: Researchers in the field of reproductive technologies and gene expression. Persons in the field of beef production including farmers, forage specialists, and persons in the field of animal health. Objective 3: Results of a literature review that began during the preparation of this Hatch project and was completed in mid-2017 were presented to farmers and Extension agents/specialists. These farmers and Extension personnel are located in the fescue belt and they provided feedback regarding the previous methods of renovation and the proposed new methods in Objective Four of this project. Information regarding the literature review is in "Other Products" section. Changes/Problems:Objective 1: Do to the failure to detect ergot alkaloids in seminal fluid, objective 1, experiments 1 through 3 using sperm cells as the target examining DRD2 genotype and function in ejaculated sperm cells is likely not relevant; however, we will utilize testicular tissue previously collected and in other tissue samples collected to evaluate the impact of DRD2 genotype and ergot alkaloid exposure on DRD2 expression at the mRNA and protein levels. Objective 2: During our previous experiments evaluating toxic tall fescue, we observed some variation between animals on the same treatments. We wanted to explore if animal genotype at the dopamine receptor 2 (DRD2) single nucleotide polymorphism (SNP) influenced the response to toxic tall fescue. First, we isolated DNA from tissues of ewes fed toxic or non-toxic fescue seed during gestation to identify a DRD2 SNP in sheep. Then we stratified fescue treatments by genotypes to determine if it interacted with fescue treatment in gestating ewes. We also genotyped the Clemson cow herd for DRD2 SNP and stratified fescue treatment by genotype to determine interaction with fescue treatment in gestating cows. These results will help us determine if selecting for a specific genotype will mitigate or reduce the effects of toxic tall fescue, and reduce animal variation in our research projects exploring toxic tall fescue. Objective 4: See above. There were issues obtaining plantain seed, but that has been resolved. We have also established additional replicated (5) plots of all commercially available novel endophyte infected tall fescue and multiple experimental combinations slated for release. These include standard leaf types, soft leaf types and ultra soft leaf types. Plots were planted in fall 2017 and we anticipate will be ready for grazing in 2018. We intend to monitor persistence of these cultivar/endophtye combinations under grazing using row occupancy counts with Kentucky 31 E+ as a control. What opportunities for training and professional development has the project provided?
Nothing Reported
How have the results been disseminated to communities of interest?Objective 1: Currently, the results of ergot alkaloid concentration in bull semen are being included in a manuscript in association with data on the impact of DRD2 genotype on bull reproductive physiology. Objective 2: An abstract on the DRD2 SNP in ovine was presented at American Society of Animal Science Meetings in Baltimore, MD in July 2017. Objective 4: Portions of the Powerpoint presentation and literature review were presented in various county cattleman organizational meetings and field days (Aiken county, Anderson county, Abbeville county) as well as to the statewide South Carolina Forage and Grazinglands Council in 2017. What do you plan to do during the next reporting period to accomplish the goals?Objective 1: Evaluate the expression of DRD2 at the mRNA and protein levels in relation to genotype in testicular and other tissue samples. Objective 2: Further analyses are being conducted to examine metabolomics pathways that are altered with fescue toxicosis in tissues from ewes fed E+ or E- seed. Additional research projects on DRD2 genotype in gestating sheep and cows are on-going and will be completed in the summer and fall of 2018. Objecitve 3: Two Texel rams both with two copies of the myostatin gene were purchased but did not pass quarantine until late fall in 2017. They were not able to be used for breeding in the fall of 2017 but will be used to bred ewes in fall of 2018. Objective 4: Plantain seed have been acquired and herbicides sourced for the plots planned for planting earlier in the timeline. Plots will be established in two locations to accomplish our original research objectives. Plot treatments for objective four will begin in Spring 2018 with glyphosate applications, pearl millet smother crop plantings and metsulfuron applications.
Impacts
What was accomplished under these goals?
Objective 1: it was determined neither ergovaline nor lysergic acid is present in bulls seminal fluid when bulls graze toxic pasture. In collaboration with Dr. J. Goodman at the USDA in Lexington, KY, bull semen samples were subjected for analysis using LC-MS methods. These data would indicate that there are no direct effects of ergot alkaloids on sperm in seminal fluid. Therefore, any effect of the toxins on spermatogenesis would most likely occur prior to release into the seminiferous tubules and storage in the male reproductive tract. Unfortunately, this finding greatly diminishes the need for executing experiments 1 through 3 of objective 1 assessing semen quality, DRD2 receptor localization on sperm and DRD2 signaling in post-ejaculated sperm. Objective 2: Pregnant ewes (n = 32) were fed one of two dietary treatments, endophyte-free tall fescue seed (E-) or endophyte-infected tall fescue seed (E+), during two stages of gestation, mid (d 35 - 85) or late (d 86-133), in a 2 x 2 factorial arrangement of treatments. Endophyte-infected seed (E+) was fed at a level of 1.77 mg of ergovaline + ergovalinine/hd/d and an equal weight of E- seed (0 mg ergovaline +ergovalinine) was fed to E- treatments. At d 133 of gestation, terminal surgeries were performed. Liver samples were obtained from all ewes for further analyses. Liver samples are in the process of being analyzed for ergovaline/ergovalinine and/or lysergic acid residues by LC-MS/MS. Preliminary analyses found that 480 unique compounds were present with 96 that differed due to fescue treatment (E+ vs. E-). Further analyses are underway to identify these compounds and potential biomarkers. Genomic DNA was also isolated from these livers to initially screen for ovine dopamine receptor 2 (DRD2) single nucleotide polymorphism (SNP). Products from PCR using seven pairs of primers covering the majority of the ovine DRD2 coding sequence were sequenced and SNPs identified. One SNP in exon 1, g270a, was investigated further due to favorable allele and genotypic frequencies. Allele frequencies at the g270a SNP were 0.64 for G and 0.36 for A; genotypic frequencies were 0.47, 0.34, and 0.19 for GG, AG, and AA genotypes, respectively. A genotyping assay was designed, tested, and found to be 100 percent concordant with sequencing results. In our initial studies, the ovine DRD2 SNP appeared to play a significant role in circulating hormone levels in the ewes and fetal lamb weight, regardless of dietary fescue treatment. Objective 4: Tall fescue tillers have been collected and analyzed for ergot alkaloid presence. We will initiate spring treatments (metsulfuron applications) in 2018 instead of the planned 2017 due to issues acquiring plantain seed for subsequent fall planting. There was some confusion as to noxious weed status and import of seed which has since been resolved. Seed has been acquired from two plantain cultivars (cv. Tonic and Boston) so the trial can proceed. An invitation has been accepted to present data from the literature review in an upcoming national symposium at the 2018 American Forage and Grassland Council meeting in Louisville KY. In addition, the results of the literature review and multiple slides have provided material for the "Establishment and First Year Management" presentation at an upcoming 2018 "Novel Tall Fescue Renovation Workshop" to be held in MO, KY, SC, NC, and VA.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2017
Citation:
S.L. Pratt, C.R. Burnett, N.M. Long, F.N. Schrick and G.S. Sell. 2017.
The effect of fescue toxicosis on semen quality and fertility of young growing beef bulls. J. Anim. Sci. Annual meeting abst # 159.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2017
Citation:
P. Rowan, R. Johnston, A. DeCarlo and S.L. Pratt. 2017. Assessment of Chromatin Damage in Bull Semen Utilizing an Acridine Orange Assay Adapted for Agilent 2100 Bioanalyzer. J. Anim. Sci. Annual meeting abst # 460.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2017
Citation:
A.N. DeCarlo, and S.L. Pratt. The presence of Prolactin and Tyrosine Hydroxylase Messenger Ribonucleic Acid in Bovine Testis and Epididymis. J. Anim. Sci. Annual meeting abst # 476.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2017
Citation:
J.L. Klotz, M.F. Miller, J.L. Britt, M.A. Snider, G.E. Aiken, N.M. Long, S.L. Pratt, J. Andrae, and S.K. Duckett. Effects of Ergot Alkaloid Exposure during Gestation on Maternal and Fetal Vasoactivity in Sheep. J. Anim. Sci. Annual meeting abst # 484.
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