Veterinary Physiology Commons^™

Nerve Transfer For Restoration Of Lower Motor Neuron-Lesioned Bladder, Urethral, And Anal Sphincter Function In A Dog Model. Part 3. Nicotinic Receptor Characterization, Nagat Frara, Mary F. Barbe, Dania Giaddui, Danielle S. Porreca, Alan S. Braverman, Ekta Tiwari, Attia Ahmad, Justin M. Brown, Benjamin R. Johnston, Stanley F. Bazarek, Michael R. Ruggieri

Department of Neurology Faculty Papers

Very little is known about the physiological role of nicotinic receptors in canine bladders, although functional nicotinic receptors have been reported in bladders of many species. Utilizing in vitro methods, we evaluated nicotinic receptors mediating bladder function in dogs: control (9 female and 11 male normal controls, 5 sham operated), Decentralized (9 females, decentralized 6–21 mo), and obturator-to-pelvic nerve transfer reinnervated (ObNT-Reinn; 9 females; decentralized 9–13 mo, then reinnervated with 8–12 mo recovery). Muscle strips were collected, mucosa-denuded, and mounted in muscle baths before incubation with neurotransmitter antagonists, and contractions to the nicotinic receptor agonist epibatidine were determined. Strip response …

Contrafreeloading In Kea (Nestor Notabilis) In Comparison To Grey Parrots (Psittacus Erithacus), Gabriella E. Smith, Amalia P. M. Bastos, Martin Chodorow, Alex H. Taylor, Irene M. Pepperberg

Publications and Research

Contrafreeloading—working to access food that could be freely obtained—is rarely exhibited and poorly understood. Based on data from Grey parrots ( Psittacus erithacus ), researchers proposed a correlation between contrafreeloading and play: that contrafreeloading is more likely when subjects view the task as play. We tested that hypothesis by subjecting a relatively more playful parrot species, the kea ( Nestor notabilis ), to the same experimental tasks. Experiment 1 presented eight kea with container pairs holding more- or less-preferred free or enclosed food items, and examined three types of contrafreeloading: calculated (working to access preferred food over less-preferred, freely available …

Miniature Companion Pig Sedation And Anesthesia, Joseph Smith, Reza Seddighi

Faculty Publications and Other Works -- Large Animal Clinical Sciences

• Miniature companion pigs (MCP) are increasing in popularity, and as such, there is an increased need for veterinarians trained in sedation and anesthesia for the species.

• MCPs have several species-specific qualities that can complicate injectable drug administration and create challenges for inhalational anesthesia (eg, with endotracheal intubation).

• General anesthetic complications, such as hypothermia and hypotension, are commonly described in miniature companion pigs, so monitoring of vital parameters during anesthetic procedures and recovery is crucial.

The Acute Physiological Response Of Polar Bears To Helicopter Capture, John P. Whiteman, Henry J. Harlow, George M. Durner, Eric V. Regehr, Steven C. Amstrup, Anthony M. Pagano, Merav Ben-David

Biological Sciences Faculty Publications

Many wildlife species are live captured, sampled, and released; for polar bears (Ursus maritimus) capture often requires chemical immobilization via helicopter darting. Polar bears reduce their activity for approximately 4 days after capture, likely reflecting stress recovery. To better understand this stress, we quantified polar bear activity (via collar‐mounted accelerometers) and body temperature (via loggers in the body core [T_abd] and periphery [T_per]) during 2–6 months of natural behavior, and during helicopter recapture and immobilization. Recapture induced bouts of peak activity higher than those that occurred during natural behavior for 2 of 5 bears, …

Behavioural Risks In Female Dogs With Minimal Lifetime Exposure To Gonadal Hormones, Melissa J. Starling, Anne Fawcett, Bethany Wilson, James Serpell, Paul Mcgreevy

Physiology Collection

Spaying of female dogs is a widespread practice, performed primarily for population control. While the consequences of early spaying for health are still being debated, the consequences for behaviour are believed to be negligible. The current study focused on the reported behaviour of 8981 female dogs spayed before 520 weeks (ten years) of life for reasons other than behavioural management, and calculated their percentage lifetime exposure to gonadal hormones (PLGH) as a proportion of their age at the time of being reported to the online Canine Behavioral Assessment and Research Questionnaire (C-BARQ). We found that 23 behaviours differed between entire …

Equine Arteritis Virus Has Specific Tropism For Stromal Cells And Cd8+ T And Cd21+ B Lymphocytes But Not For Glandular Epithelium At The Primary Site Of Persistent Infection In The Stallion Reproductive Tract, Mariano Carossino, Alan T. Loynachan, Igor F. Canisso, Richard Frank Cook, Juliana Roberta Campos, Bora Nam, Yun Young Go, Edward L. Squires, Mats H. T. Troedsson, Thomas W. Swerczek, Fabio Del Piero, Ernest F. Bailey, Peter J. Timoney, Udeni B. R. Balasuriya

Veterinary Science Faculty Publications

Equine arteritis virus (EAV) has a global impact on the equine industry as the causative agent of equine viral arteritis (EVA), a respiratory, systemic, and reproductive disease of equids. A distinctive feature of EAV infection is that it establishes long-term persistent infection in 10 to 70% of infected stallions (carriers). In these stallions, EAV is detectable only in the reproductive tract, and viral persistence occurs despite the presence of high serum neutralizing antibody titers. Carrier stallions constitute the natural reservoir of the virus as they continuously shed EAV in their semen. Although the accessory sex glands have been implicated as …

Vmed 646: Animal Physiology Ii—A Peer Review Of Teaching Project Benchmark Portfolio, Renee M. Mcfee

UNL Faculty Course Portfolios

This Peer Review of Teaching Project portfolio focuses on the Animal Physiology II course which is required for first year veterinary medicine students. Weekly quizzes assess baseline knowledge and had been administered individually and in groups. I hypothesized the discontinuation of group quizzes would increase student effort when preparing for quizzes. Unit exams involve scenario-based questions and require students to apply information. I hypothesized the implementation of group exams would help under-performing students improve their ability to apply information they had learned. Exams were still taken individually prior to being taken in groups to encourage adequate preparation. Student impacts were …

Whole Genomic Sequence Analysis Of Bacillus Infantis: Defining The Genetic Blueprint Of Strain Nrrl B-14911, An Emerging Cardiopathogenic Microbe, Chandirasegara Massilamany, Akram Mohammed, John Dustin Loy, Tanya Purvis, Bharathi Krishnan, Rakesh H. Basavalingappa, Christy M. Kelley, Chittibabu Guda, Raúl G. Barletta, Etsuko N. Moriyama, Timothy P.L. Smith, Jay Reddy

Jay Reddy Publications

Background: We recently reported the identification of Bacillus sp. NRRL B-14911 that induces heart autoimmunity by generating cardiac-reactive T cells through molecular mimicry. This marine bacterium was originally isolated from the Gulf of Mexico, but no associations with human diseases were reported. Therefore, to characterize its biological and medical significance, we sought to determine and analyze the complete genome sequence of Bacillus sp. NRRL B-14911.

Results: Based on the phylogenetic analysis of 16S ribosomal RNA (rRNA) genes, sequence analysis of the 16S-23S rDNA intergenic transcribed spacers, phenotypic microarray, and matrix-assisted laser desorption ionization time-offlight mass spectrometry, we propose that this …

Insulin-Dependent Glucose Metabolism In Dairy Cows With Variable Fat Mobilization Around Calving, C. Weber, C. T. Schäff, U. Kautzsch, S. Börner, S. Erdmann, S. Görs, M. Röntgen, H. Sauerwein, R. M. Bruckmaier, C. C. Metges, B. Kuhla, H. M. Hammon

Physiology Collection

Dairy cows undergo significant metabolic and endocrine changes during the transition from pregnancy to lactation, and impaired insulin action influences nutrient partitioning toward the fetus and the mammary gland. Because impaired insulin action during transition is thought to be related to elevated body condition and body fat mobilization, we hypothesized that over-conditioned cows with excessive body fat mobilization around calving may have impaired insulin metabolism compared with cows with low fat mobilization. Nineteen dairy cows were grouped according to their average concentration of total liver fat (LFC) after calving in low [LLFC; LFC <24% total fat/dry matter (DM); n = 9] and high (HLFC; LFC >24.4% total fat/DM; n = 10) fat-mobilizing …

An Ethogram For Benthic Octopods (Cephalopoda: Octopodidae), Jennifer Mather, Jean S. Alupay

Physiology Collection

The present paper constructs a general ethogram for the actions of the flexible body as well as the skin displays of octopuses in the family Octopodidae. The actions of 6 sets of structures (mantle–funnel, arms, sucker–stalk, skin–web, head, and mouth) combine to produce behavioral units that involve positioning of parts leading to postures such as the flamboyant, movements of parts of the animal with relation to itself including head bob and grooming, and movements of the whole animal by both jetting in the water and crawling along the substrate. Muscular actions result in 4 key changes in skin display: (a) …

Circulating Amino Acids In Blood Plasma During The Peripartal Period In Dairy Cows With Different Liver Functionality Index, Z. Zhou, J. J. Loor, F. Piccioli-Cappelli, F. Librandi, G. E. Lobley, E. Trevisi

Physiology Collection

The liver functionality index (LFI) measures the changes of albumin, cholesterol, and bilirubin concentrations between 3 and 28 d postpartum. This composite index, based on variables with direct relevance to liver-specific plasma protein synthesis (albumin), hepatic/intestinal lipoprotein synthesis (cholesterol), and clearance of breakdown products of heme catabolism (bilirubin), provides a tool for evaluating manifestations of hepatic disease. Both energy and protein metabolism are likely to be affected by various physiological challenges in this period but have not been tested systematically. The present study was conducted to profile AA in cows with high or low LFI during the peripartal period …

Evaluation Of Calving Indicators Measured By Automated Monitoring Devices To Predict The Onset Of Calving In Holstein Dairy Cows, V. Ouellet, E. Vasseur, W. Heuwieser, O. Burfeind, X. Maldague, É. Charbonneau

Physiology Collection

Dystocias are common in dairy cows and often adversely affect production, reproduction, animal welfare, labor, and economics within the dairy industry. An automated device that accurately predicts the onset of calving could potentially minimize the effect of dystocias by enabling producers to intervene early. Although many well-documented indicators can detect the imminence of calving, research is limited on their effectiveness to predict calving when measured by automated devices. The objective of this experiment was to determine if a decrease in vaginal temperature (VT), rumination (RT), and lying time (LT), or an increase in lying bouts (LB), as measured by …

Body Condition Score And Plane Of Nutrition Prepartum Affect Adipose Tissue Transcriptome Regulators Of Metabolism And Inflammation In Grazing Dairy Cows During The Transition Period, M. Vailati-Riboni, M. Kanwal, O. Bulgari, S. Meier, N. V. Priest, C. R. Burke, J. K. Kay, S. Mcdougall, M. D. Mitchell, C. G. Walker, M. Crookenden, A. Heiser, J. R. Roche, J. J. Loor

Physiology Collection

Recent studies demonstrating a higher incidence of metabolic disorders after calving have challenged the management practice of increasing dietary energy density during the last ~3 wk prepartum. Despite our knowledge at the whole-animal level, the tissue-level mechanisms that are altered in response to feeding management prepartum remain unclear. Our hypothesis was that prepartum body condition score (BCS), in combination with feeding management, plays a central role in the peripartum changes associated with energy balance and inflammatory state. Twenty-eight mid-lactation grazing dairy cows of mixed age and breed were randomly allocated to 1 of 4 treatment groups in a 2 × …

Dry Period Plane Of Energy: Effects On Glucose Tolerance In Transition Dairy Cows, S. Mann, F. A. Leal Yepes, M. Duplessis, J. J. Wakshlag, T. R. Overton, B. P. Cummings, D. V. Nydam

Physiology Collection

Overfeeding energy in the dry period can affect glucose metabolism and the energy balance of transition dairy cows with potential detrimental effects on the ability to successfully adapt to early lactation. The objectives of this study were to investigate the effect of different dry cow feeding strategies on glucose tolerance and on resting concentrations of blood glucose, glucagon, insulin, nonesterified fatty acids (NEFA), and β-hydroxybutyrate (BHB) in the peripartum period. Cows entering second or greater lactation were enrolled at dry-off (57 d before expected parturition) into 1 of 3 treatment groups following a randomized block design: cows …

Noninvasive Assessment Of Cardiac Abnormalities In Experimental Autoimmune Myocarditis By Magnetic Resonance Microscopy Imaging In The Mouse, Chandirasegaran Massilamany, Vahid Khalilzad-Sharghi, Arunakumar Gangaplara, David Steffen, Shadi F. Othman, Jay Reddy

Jay Reddy Publications

Myocarditis is an inflammation of the myocardium, but only ~10% of those affected show clinical manifestations of the disease. To study the immune events of myocardial injuries, various mouse models of myocarditis have been widely used. This study involved experimental autoimmune myocarditis (EAM) induced with cardiac myosin heavy chain (Myhc)-α 334-352 in A/J mice; the affected animals develop lymphocytic myocarditis but with no apparent clinical signs. In this model, the utility of magnetic resonance microscopy (MRM) as a non-invasive modality to determine the cardiac structural and functional changes in animals immunized with Myhc-α 334-352 is shown. EAM and healthy mice …

Autonomic Nervous System Reactivity In A Free-Ranging Mammal: Effects Of Dominance Rank And Personality, Elodie F. Briefer, James A. Oxley, Alan G. Mcelligott

Ethology Collection

Modulation of the autonomic nervous system (ANS) activity allows animals to effectively respond to internal and external stimuli in everyday challenges via changes in, for example, heart and respiration rate. Various factors, ranging from social such as dominance rank to internal such as personality or affective states can impact animal physiology. Our knowledge of the combinatory effects of social and internal factors on ANS basal activity and reactivity, and of the importance that each factor has in determining physiological parameters, is limited, particularly in nonhuman, free-ranging animals. In this study, we tested the effects of dominance rank and personality (assessed …

The Physiological Consequences Of Crib-Biting In Horses In Response To An Acth Challenge Test, S. Briefer Freymond, D. Bardou, Elodie F. Briefer, R. Bruckmaier, N. Fouché, J. Fleury, A.-L. Maigrot, A. Ramseyer, K. Zuberbühler, I. Bachmann

Physiology Collection

Stereotypies are repetitive and relatively invariant patterns of behavior, which are observed in a wide range of species in captivity. Stereotypic behavior occurs when environmental demands produce a physiological response that, if sustained for an extended period, exceeds the natural physiological regulatory capacity of the organism, particularly in situations that include unpredictability and uncontrollability. One hypothesis is that stereotypic behavior functions to cope with stressful environments, but the existing evidence is contradictory. To address the coping hypothesis of stereotypies, we triggered physiological reactions in 22 horses affected by stereotypic behavior (crib-biters) and 21 non-crib-biters (controls), using an ACTH challenge test. …

Prediction Of Parturition In Holstein Dairy Cattle Using Electronic Data Loggers, M. Titler, M. G. Maquivar, S. Bas, P. J. Rajala-Schultz, E. Gordon, K. Mccullough, P. Federico, G. M. Schuenemann

Physiology Collection

The objective of the present study was to assess the effect of parturition on behavioral activity [steps, standing time, lying time, lying bouts (LB), and duration of LB] 4 d before calving using electronic data loggers. Animals (n = 132) from 3 herds were housed in similar freestall barns using a prepartum pen 21 d before the expected calving date and were moved into a contiguous individual maternity pen for parturition. Electronic data loggers were placed on a hind leg of prepartum heifers (heifers, n = 33) and cows (cows, n = 99) at 7 ± 3 d before the …

Biomarkers Of Inflammation, Metabolism, And Oxidative Stress In Blood, Liver, And Milk Reveal A Better Immunometabolic Status In Peripartal Cows Supplemented With Smartamine M Or Metasmart, J. S. Osorio, E. Trevisi, P. Ji, J. K. Drackley, D. Luchini, G. Bertoni, J. J. Loor

Physiology Collection

The peripartal dairy cow experiences a state of reduced liver function coupled with increased inflammation and oxidative stress. This study evaluated the effect of supplementing basal diets with rumen-protected Met in the form of MetaSmart (MS) or Smartamine M (SM) (both from Adisseo Inc., Antony, France) during the peripartal period on blood and hepatic biomarkers of liver function, inflammation, and oxidative stress. Thirty-seven multiparous Holstein cows were fed the same basal diet from −50 to −21 d relative to expected calving [1.24 Mcal/kg of dry matter (DM); no Met supplementation]. From −21 d to calving, the cows received diets …

Physiological And Behavioural Responses To Noxious Stimuli In The Atlantic Cod (Gadus Morhua), Jared R. Eckroth, Øyvind Aas-Hansen, Lynne U. Sneddon, Helena Bichão, Kjell B. Døving

Aquaculture Collection

In the present study, our aim was to compare physiological and behavioural responses to different noxious stimuli to those of a standardized innocuous stimulus, to possibly identify aversive responses indicative of injury detection in a commercially important marine teleost fish, the Atlantic cod. Individual fish were administered with a noxious stimulus to the lip under short-term general anaesthesia (MS-222). The noxious treatments included injection of 0.1% or 2% acetic acid, 0.005% or 0.1% capsaicin, or piercing the lip with a commercial fishing hook. Counts of opercular beat rate (OBR) at 10, 30, 60, 90 and 120 min and observations of …

Effect Of Confinement On Water-Borne And Whole Body Cortisol In Wild And Captive-Eared Rainbowfish (Melanoteania Duboulayi), Amina Zuberi, Culum Brown, Sinan Ali

Physiology Collection

Whole body and water-borne cortisol levels were measured in captive reared and wild Rainbowfish (Melanoteania duboulayi Castelnau 1878) subjected to social isolation by confining them in a beaker for 30 min to induce an acute stress response. Wild fish had higher levels of cortisol before and after exposure to a mild stressor and also showed the greatest stress response. The differences in stress responses are likely the result of artificial selection in the captive environment. Importantly, there was a strong linear relationship between whole body and water-borne cortisol in wild and captive reared populations (r² =0. 95 and 0.84, …

Stress And Reproductive Hormones Reflect Inter-Specific Social And Nutritional Conditions Mediated By Resource Availability In A Bear–Salmon System, Heather M. Bryan, Chris T. Darimont, Paul C. Paquet, Katherine E. Wynne-Edwards, Judit E. G. Smits

Physiology Collection

Food availability can influence the nutritional and social dynamics within and among species. Our investigation focused on grizzly and black bears in coastal British Columbia, Canada, where recent and dramatic declines in their primary prey (salmon) raise concerns about potentially negative effects on bear physiology. We examined how salmon availability relates to stress and reproductive hormones in coastal grizzly (n = 69) and black bears (n = 68) using cortisol and testosterone. In hair samples from genotyped individuals, we quantified salmon consumption using stable isotope analysis and hormone levels by enzyme immunoassay. To estimate the salmon biomass available to each …

Spatial Analysis Of Factors Influencing Long-Term Stress In The Grizzly Bear (Ursus Arctos) Population Of Alberta, Canada, Mathieu Bourbonnais, Trisalyn Nelson, Mark Cattet, Chris T. Darimont, Gordon Stenhouse

Physiology Collection

Non-invasive measures for assessing long-term stress in free ranging mammals are an increasingly important approach for understanding physiological responses to landscape conditions. Using a spatially and temporally expansive dataset of hair cortisol concentrations (HCC) generated from a threatened grizzly bear (Ursus arctos) population in Alberta, Canada, we quantified how variables representing habitat conditions and anthropogenic disturbance impact long-term stress in grizzly bears. We characterized spatial variability in male and female HCC point data using kernel density estimation and quantified variable influence on spatial patterns of male and female HCC stress surfaces using random forests. Separate models were developed for regions …

Stress And Reproductive Hormones In Grizzly Bears Reflect Nutritional Benefits And Social Consequences Of A Salmon Foraging Niche, Heather M. Bryan, Chris T. Darimont, Paul C. Paquet, Katherine E. Wynne-Edwards, Judit E. G. Smits

Physiology Collection

Physiological indicators of social and nutritional stress can provide insight into the responses of species to changes in food availability. In coastal British Columbia, Canada, grizzly bears evolved with spawning salmon as an abundant but spatially and temporally constrained food source. Recent and dramatic declines in salmon might have negative consequences on bear health and ultimately fitness. To examine broadly the chronic endocrine effects of a salmon niche, we compared cortisol, progesterone, and testosterone levels in hair from salmon-eating bears from coastal BC (n = 75) with the levels in a reference population from interior BC lacking access to salmon …

Genome-Wide Analysis Reveals Selection For Important Traits In Domestic Horse Breeds, Jessica Lynn Petersen, James R. Mickelson, Aaron K. Rendahl, Stephanie K. Valberg, Lisa S. Andersson, Ernie Bailey, Danika L. Bannasch, Matthew M. Binns, Alexandre S. Borges, Pieter Brama, Artur Da Câmara Machado, Stefano Capomaccio, Katia Cappelli, E. Gus Cothran, Ottmar Distl, Laura Fox-Clipsham, Kathryn T. Graves, Gérard Guérin, Bianca Haase, Telhia Hasegawa, Karin Hemmann, Emmeline W. Hill, Tosso Leeb, Gabriella Lindgren, Hannes Lohi, Maria Susana Lopes, Beatrice A. Mcgivney, Sofia Mikko, Nicholas Orr, M. Cecilia T. Penedo, Richard J. Piercy, Marja Raekallio, Stefan Rieder, Knut H. Røed, June Swinburne, Teruaki Tozaki, Mark Vaudin, Claire M. Wade, Molly E. Mccue

Department of Animal Science: Faculty Publications

Intense selective pressures applied over short evolutionary time have resulted in homogeneity within, but substantial variation among, horse breeds. Utilizing this population structure, 744 individuals from 33 breeds, and a 54,000 SNP genotyping array, breed-specific targets of selection were identified using an F_ST-based statistic calculated in 500-kb windows across the genome. A 5.5-Mb region of ECA18, in which the myostatin (MSTN) gene was centered, contained the highest signature of selection in both the Paint and Quarter Horse. Gene sequencing and histological analysis of gluteal muscle biopsies showed a promoter variant and intronic SNP of MSTN were …

Immune Responses In Lactating Holstein Cows Supplemented With Cu, Mn, And Zn As Sulfates Or Methionine Hydroxy Analogue Chelates, L. M. Nemec, J. D. Richards, C. A. Atwell, D. E. Diaz, G. I. Zanton, T. F. Gressley

Physiology Collection

The aim of this study was to compare effects of inorganic sulfate versus chelated forms of supplemental Cu, Mn, and Zn on milk production, plasma and milk mineral concentrations, neutrophil activity, and antibody titer response to a model vaccination. Holstein cows (n = 25) were assigned in 2 cohorts based on calving date to a 12-wk randomized complete block design study. The first cohort consisted of 17 cows that had greater days in milk (DIM; mean of 77 DIM at the start of the trial) than the second cohort of 8 cows (32 DIM at the start of the trial). …

Characterisation Of Chemosensory Trigeminal Receptors In The Rainbow Trout, Oncorhynchus Mykiss: Responses To Chemical Irritants And Carbon Dioxide, Jessica J. Mettam, Catherine R. Mccrohan, Lynne U. Sneddon

Veterinary Science and Medicine Collection

Trigeminally innervated, mechanically sensitive chemoreceptors (M) were previously identified in rainbow trout, Oncorhynchus mykiss, but it is not known whether these receptors are responsive only to noxious, chemical irritants or have a general chemosensory function. This study aimed to characterise the stimulus–response properties of these receptors in comparison with polymodal nociceptors (P). Both P and M gave similar response profiles to acetic acid concentrations. The electrophysiological properties were similar between the two different afferent types. To determine whether the receptors have a nociceptive function, a range of chemical stimulants was applied to these receptors, including non-noxious stimuli such as ammonium …

Mammary Cell Activity And Turnover In Dairy Cows Treated With The Prolactin-Release Inhibitor Quinagolide And Milked Once Daily, M. Boutinaud, V. Lollivier, L. Finot, R. M. Bruckmaier, P. Lacasse

Physiology Collection

To assess the regulation of mammary cell activity, survival, and proliferation by prolactin (PRL), 5 Holstein cows in early lactation received daily i.m. injections of 1 mg of quinagolide, a suppressor of PRL release, for 9 wk, whereas 4 control cows received the vehicle (water) only. During the last week of treatment, one udder half was milked once a day (1×) and the other twice a day (2×). Mammary biopsies were harvested 1 wk before and 4 and 8 wk after the start of quinagolide treatment. The quinagolide injections reduced milk yield and resulted in lower levels of κ-casein and …

A Non-Invasive Assay For Monitoring Stress Responses: A Comparison Between Wild And Captive-Reared Rainbowfish (Melanoteania Duboulayi), Amina Zuberi, Sinan Ali, Culum Brown

Aquaculture Collection

The stress response of wild and captive reared rainbowfish (Melanoteania duboulayi) following chasing by a simulated predator was examined. Cortisol release rate was monitored using a flow through system by measuring water borne hormone levels. Tests using known cortisol concentrations revealed that the technique yielded 95% of the cortisol present in the water. Cortisol release rates increased several fold in both populations after being chased but peaked at different time periods. Wild fish showed a typical stress response with release rate rising to (2.29±0.22 ng g⁻¹ h⁻¹) 2 h after exposure followed by rapid recovery. The captive-reared …

Heifer Estrous Cycle Stage Impacts Luteinizing And Growth Hormone Response To Kisspeptin, Brian K. Whitlock, Joseph A. Daniel, Robyn R. Wilborn, Barbara P. Steele, James L. Sartin

Animal Science Publications and Other Works

The reproductive neuropeptide, kisspeptin (KP), may have a role in regulation of growth hormone (GH) secretion. Expression of KP and its receptor (Kiss1r) are developmentally and hormonally regulated. This study was conducted to determine the effects of KP on plasma concentrations of luteinizing hormone (LH) and GH in pubertal heifers during different functional reproductive stages. Heifers received a single injection of KP (100 pmole / kg) or saline intravenously during proestrus, estrus, and diestrus, and serial blood samples were collected for 3 hours to determine the response of both LH and GH after treatment. Mean concentrations of LH were increased …