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5. List of contributors

Author

Aiken, Glen E., primary, Andrae, John, additional, Beck, Paul, additional, Blacklin, Sarah, additional, Corriher-Olson, Vanessa, additional, Dubeux, José C.B., additional, Franzluebbers, Alan J., additional, Harmon, Deidre, additional, Henning, Jimmy C., additional, Jennings, John, additional, Kohmann, Marta Moura, additional, Kubecka, Bradley W., additional, Martin, James A., additional, Moriel, Philipe, additional, Poore, Matt, additional, Rayburn, Ed, additional, Redmon, Larry, additional, Rogers, James, additional, Rogers, Johnny, additional, Rouquette, Monte, additional, Scaglia, Guillermo, additional, Silveira, Maria Lucia, additional, Smith, Gerald R., additional, Sollenberger, Lynn E., additional, Vendramini, Joao, additional, and Wallau, Marcelo O., additional

Published
2020
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16. Ergot alkaloid exposure during gestation alters. I. Maternal characteristics and placental development of pregnant ewes

Author

Britt, Jessica L, Greene, Maslyn A, Bridges, William C, Klotz, James L, Aiken, Glen E, Andrae, John G, Pratt, Scott L, Long, Nathan M, Schrick, F N, Strickland, James R, Wilbanks, Sarah A, Miller, Markus F, Koch, Brandon M, and Duckett, Susan K

Subjects
Festuca, Ergot Alkaloids, Sheep, Epichloe, Uterus, Toxicology, Animal Feed, Placentation, Southeastern United States, Ergotamines, Random Allocation, Pregnancy, Endophytes, Animals, Female
Abstract

Tall fescue [Lolium arundinaceum (Scheyreb.) Darbysh] is the primary cool season forage grass in the Southeastern United States. Most tall fescue contains an endophytic fungus (Epichloë coenophiala) that produces ergot alkaloids and upon ingestion induces fescue toxicosis. The objective of this study was to assess how exposure to endophyte-infected (E+; 1.77 mg hd(−1) d(−1) ergovaline and ergovalinine) or endophyte-free (E-; 0 mg hd(−1) d(−1) ergovaline and ergovalinine) tall fescue seed fed during 2 stages of gestation (MID, days 35–85/LATE, days 86–133) alters placental development. Thirty-six, fescue naïve Suffolk ewes were randomly assigned to 1 of 4 fescue treatments: E−/E−, E−/E+, E+/E−, or E+/E+. Ewes were individually fed the same amount of E+ or E− seed mixed into total mixed ration during MID and LATE gestation. Terminal surgeries were conducted on day 133 of gestation. Ewes fed E+ fescue seed had elevated (P < 0.001) ergot alkaloid excretion and reduced (P < 0.001) prolactin levels during the periods when fed E+ seed. Ewes switched on day 86 from E− to E+ seed had a 4% reduction (P = 0.005) in DMI during LATE gestation, which translated to a 2% reduction (P = 0.07) in DMI overall. Average daily gain was also reduced (P = 0.049) by 64% for E−/E+ ewes during LATE gestation and tended to be reduced (P = 0.06) by 33% overall. Ewes fed E+ seed during LATE gestation exhibited a 14% and 23% reduction in uterine (P = 0.03) and placentome (P = 0.004) weights, respectively. Caruncle weights were also reduced by 28% (P = 0.003) for E−/E+ ewes compared with E−/E− and E+/E−. Ewes fed E+ seed during both MID and LATE gestation exhibited a 32% reduction in cotyledon (P = 0.01) weights, whereas ewes fed E+ seed only during MID gestation (E+/E−) had improved (P = 0.01) cotyledon weights. The percentage of type A placentomes tended to be greater (P = 0.08) for E+/E+ ewes compared with other treatments. Other placentome types (B, C, or D) did not differ (P > 0.05). Total fetal weight per ewe was reduced (P = 0.01) for ewes fed E+ seed during LATE gestation compared with E−; however, feeding E+ seed during MID gestation did not alter (P = 0.70) total fetal weight per ewe. These results suggest that exposure to ergot alkaloids during LATE (days 86–133) gestation has the greatest impact on placental development by reducing uterine and placentome weights. This, in turn, reduced total fetal weight per ewe by 15% in ewes fed E+ seed during LATE gestation (E−/E+ and E+/E+).

Published
2019

18. Ergot alkaloid exposure during gestation alters. I. Maternal characteristics and placental development of pregnant ewes1

Author

Britt, Jessica L, primary, Greene, Maslyn A, additional, Bridges, William C, additional, Klotz, James L, additional, Aiken, Glen E, additional, Andrae, John G, additional, Pratt, Scott L, additional, Long, Nathan M, additional, Schrick, F N, additional, Strickland, James R, additional, Wilbanks, Sarah A, additional, Miller, Markus F, additional, Koch, Brandon M, additional, and Duckett, Susan K, additional

Published
2019
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20. Effect of consuming endophyte-infected fescue seed on transcript abundance in the mammary gland of lactating and dry cows, as assessed by RNA sequencing

Author

Capuco, Anthony V., Bickhart, Derek, Li, Congjun, Evock-Clover, Christina M., Choudhary, Ratan K., Grossi, Paolo, Bertoni, Giuseppe, Trevisi, Erminio, Aiken, Glen E., Mcleod, Kyle R., Baldwin, Ransom L., Trevisi, Erminio (ORCID:0000-0003-1644-1911), Capuco, Anthony V., Bickhart, Derek, Li, Congjun, Evock-Clover, Christina M., Choudhary, Ratan K., Grossi, Paolo, Bertoni, Giuseppe, Trevisi, Erminio, Aiken, Glen E., Mcleod, Kyle R., Baldwin, Ransom L., and Trevisi, Erminio (ORCID:0000-0003-1644-1911)

Abstract

Ergot alkaloids in endophyte-infected grasses inhibit prolactin secretion and reduce milk production in lactating cows. However, we previously showed that prepartum consumption of infected seed throughout the dry period did not inhibit subsequent milk production and prior exposure to bromocriptine (ergot peptide) actually increased production in the next lactation. To identify changes in the transcriptome and molecular pathways mediating the mammary gland's response to ergot alkaloids in the diet, RNA sequencing (RNA-seq) was performed on mammary tissues obtained from 22 multiparous Holstein cows exposed to 1 of 3 treatments. Starting at 90 ± 4 d prepartum, cows were fed endophyte-free fescue seed (control; CON), endophyte-free fescue seed plus 3×/wk subcutaneous injections of bromocriptine (BROMO; 0.1 mg/kg of BW), or endophyte-infected fescue seed (INF) as 10% of the diet. Cows were dried off 60 ± 2 d prepartum. Mammary biopsies from 4 (BROMO, INF) or 5 (CON) cows/treatment at each of the 3 phases were obtained: 7 d before dry off during the initial lactation (L1), mid-dry period (D), and 10 d postpartum (L2). Although tissue from the same cow was preferentially used at 3 phases (L1, D, L2), tissue from additional cows were used to as necessary to provide RNA of sufficient quality. Individual samples were used to generate individual RNA-seq libraries. Normalized reads of the RNA-seq data were organized into technical and biological replicates before processing with the RSEM software package. Each lactation phase was processed separately and genes that differed between any of 3 treatments were identified. A large proportion of genes differentially expressed in at least 1 treatment (n = 866) were found to be similarly expressed in BROMO and INF treatments, but differentially expressed from CON (n = 575, total for 3 phases). Of genes differentially expressed compared with CON, 104 genes were common to the L1 and L2 phases. Consistent with the production findings, net

Published
2018

21. Effect of consuming endophyte-infected fescue seed on transcript abundance in the mammary gland of lactating and dry cows, as assessed by RNA sequencing

Author

Capuco, Anthony V., primary, Bickhart, Derek, additional, Li, Congjun, additional, Evock-Clover, Christina M., additional, Choudhary, Ratan K., additional, Grossi, Paolo, additional, Bertoni, Giuseppe, additional, Trevisi, Erminio, additional, Aiken, Glen E., additional, McLeod, Kyle R., additional, and Baldwin, Ransom L., additional

Published
2018
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22. Mycotoxins in Florida Pastures

Author

Wallau, Marcelo O., primary, Justesen, Brittany L., primary, Blount, Ann R. Soffes, primary, Ferraretto, Luiz, primary, Aiken, Glen, primary, and Stam, Aaron, primary

Published
2018
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28. Ergot alkaloid exposure during gestation alters: II. Uterine and umbilical artery vasoactivity.

Author

Klotz, James L, Britt, Jessi L, Miller, Markus F, Snider, Miriam A, Aiken, Glen E, Long, Nathan M, Pratt, Scott L, Andrae, John G, and Duckett, Susan K

Subjects
ERGOT alkaloids, BLOOD vessels, PREGNANCY in animals, LIVESTOCK, EWES
Abstract

Previous research has shown that livestock exposed to ergot alkaloids results in decreased vasoactivity of gastrointestinal and peripheral vasculature. Little is known regarding the effect ergot alkaloid exposure during gestation may have on vasculature supporting the fetus. The objective of this study was to evaluate contractile responses of uterine and umbilical arteries collected from ewes consuming ergot alkaloids during gestation. On day 35 of gestation, 36 Suffolk ewes (78.24 ± 9.5 kg) were assigned to endophyte-infected (E+) or endophyte-free (E−) tall fescue seed treatments that were fed either throughout or switched on day 86 of gestation, creating four seed treatments E+E+, E+E−, E−E+, and E−E−. Ewes were fed E+ tall fescue seed to provide 1.77 mg of total ergovaline ⋅ hd−1 ⋅ d−1 with E− ewes receiving the same quantity of E− seed. Gestation was terminated on day 133, and sections of uterine artery and umbilical cord were surgically collected. Only collections from 28 ewes (n = 7/treatment) were of sufficient viability to proceed with the contractility experiments. Arteries were cleaned, sliced into 2-mm cross sections, and suspended in multi-myograph chambers containing 5 mL of continuously oxygenated Krebs–Henseleit buffer. Vessels were exposed to increasing concentrations (5 × 10−8 to 1 × 10−4 M) of norepinephrine, serotonin, ergotamine, and ergovaline (5 × 10−9 to 1 × 10−5 M ; extract of tall fescue seed) in 15-min intervals. Increasing concentrations of norepinephrine generated a contractile response by the uterine artery (P < 0.05), but no response in the umbilical artery. Increasing concentrations of serotonin resulted in negligible responses in uterine preparations, whereas umbilical artery preparations were responsive (P < 0.05) to serotonin. Ewes receiving E+E+ and E−E+ treatments had decreased vasoactivity in umbilical arteries to serotonin with a dextral shift in concentrations where the response curve initiated (P < 0.05). Interestingly, uterine arteries were not responsive to exposure to ergotamine or ergovaline, whereas umbilical arteries were responsive (P < 0.05). Umbilical arteries collected from ewes receiving E−E− and E+E− were more vasoactive to ergot alkaloids (P < 0.05) than other treatments. These findings indicate that maternal blood supply to the placenta appears protected from negative effects of ergot alkaloids; however, umbilical vasculature is not, and this could adversely influence fetal growth. [ABSTRACT FROM AUTHOR]

Published
2019
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29. Consumption of endophyte-infected fescue seed during the dry period does not decrease milk production in the following lactation

Author

Baldwin, Ransom L, Capuco, Anthony V, Evock Clover, Christina M, Grossi, Paolo, Choudhary, Ratan K, Vanzant, Eric S, Elsasser, Theodore H, Bertoni, Giuseppe, Trevisi, Erminio, Aiken, Glen E, Mcleod, Kyle R., Trevisi, Erminio (ORCID:0000-0003-1644-1911), Baldwin, Ransom L, Capuco, Anthony V, Evock Clover, Christina M, Grossi, Paolo, Choudhary, Ratan K, Vanzant, Eric S, Elsasser, Theodore H, Bertoni, Giuseppe, Trevisi, Erminio, Aiken, Glen E, Mcleod, Kyle R., and Trevisi, Erminio (ORCID:0000-0003-1644-1911)

Abstract

Ergot alkaloids in endophyte-infected grasses inhibit prolactin (PRL) secretion and may reduce milk production of cows consuming these grasses. We investigated the effects of consuming endophyte-infected fescue seed during late lactation and the dry period on mammary growth, differentiation, and milk production. Twenty-four multiparous Holstein cows were randomly assigned to 3 treatment groups. Starting at 90±4 d prepartum, cows were fed endophyte-free fescue seed (control; CON), endophyte-free fescue seed plus 3×/wk subcutaneous injections of bromocriptine (0.1mg/kg of body weight, positive control; BROMO), or endophyte-infected fescue seed (INF) as 10% of the diet on an as fed basis. Although milk yield of groups did not differ before treatment, at dry off (-60 d prepartum) INF and BROMO cows produced less milk than CON. Throughout the treatment period, basal concentrations of PRL and the prepartum increase in plasma PRL were reduced in INF and BROMO cows compared with CON cows. Three weeks after the end of treatment, circulating concentrations of PRL were equivalent across groups. In the subsequent lactation milk yield was not decreased; in fact, BROMO cows exhibited a 9% increase in milk yield relative to CON. Evaluation of mammary tissue during the dry period and the subsequent lactation, by quantitative histology and immunohistochemical analysis of proliferation markers and putative mammary stem or progenitor cell markers, indicated that feeding endophyte-infected fescue seed did not significantly affect mammary growth and development. Feeding endophyte-infected grasses during the dry period may permit effective utilization of feed resources without compromising milk production in the next lactation.

Published
2016

37. Biochanin A (an Isoflavone Produced by Red Clover) Promotes Weight Gain of Steers Grazed in Mixed Grass Pastures and Fed Dried-Distillers’ Grains.

Author

Harlow, Brittany E., Flythe, Michael D., Kagan, Isabelle A., and Aiken, Glen E.

Subjects
BIOCHANIN A, GRAZING, RED clover
Abstract

Biochanin A (BCA) is an isoflavone produced by red clover (Trifloium pratense L.) that can inhibit hyper-ammonia-producing bacteria (HAB) to reduce deamination in the rumen and increase the feed amino acids available for gastric digestion. An ex vivo experiment was conducted to evaluate the effect of dried distiller’s grains (DDG) and BCA (30 μg mL−1) on HAB in bovine rumen fluid. Following a 24-h incubation, HAB and ammonia concentrations in the media increased with addition of DDG. However, DDG fermentations with BCA had 100-fold fewer HAB and 37% less ammonia than DDG-only fermentations. A grazing experiment was conducted with crossbred steers grazing a mixture of predominately endophyte-free tall fescue [Lolium arundinaceum (Schreb.) Darbysh], Kentucky bluegrass (Poa pratense L.), and orchardgrass (Dactylis glomerata L.) in the early and late growing season. Average daily gains (ADG) were compared among treatments of pasture-only control, daily feeding of 1.4 kg DDG steer−1, and daily feeding of 1.4 kg DDG plus BCA (6.3 g steer−1, representing ∼30% red clover diet). Averaged over the early and late growing seasons, feeding DDG (0.83 ± 0.05 kg d−1) increased ADG by 15% over the pasture-only treatment (0.72 ± 0.03 kg d−1), but addition of BCA to the DDG (0.93 ± 0.04 kg d−1) provided an additive increase in ADG of 29% over the control treatment. Results of the ex vivo and grazing experiments provide evidence that BCA inhibits HAB in the rumen and that the reduced deamination in the rumen can enhance weight gain performance of steers. [ABSTRACT FROM AUTHOR]

Published
2017
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42. Effects of Fescue Toxicosis on Bovine Semen Quality.

Author

Stowe, Heather M., primary, Miller, Maggie C., additional, Calcatera, Samantha M., additional, Burns, Matthew G., additional, Andrae, John G., additional, Bridges, William C., additional, Schrick, F. Neal, additional, Aiken, Glen E., additional, and Pratt, Scott L., additional

Published
2012
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