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Author (up) Aldridge, B.; Lescun, T.; Radcliffe, J.S. pdf  openurl
  Title Recent Molecular Advances in Equine Nutrition – from Test Tube to Practice Type Conference Article
  Year 2012 Publication Proceedings of the 2. International Equine Science Meeting Abbreviated Journal Proc. 2. Int. Equine. Sci. Mtg  
  Volume in press Issue Pages  
  Keywords Molecular Biology, Equine, Gut  
  Abstract The use of molecular techniques has increased our understanding of biological systems; in particular how genes and proteins operate within a cell or organ in response to various stimuli. These techniques can be used to study modes of action or mechanisms in disease states, or in response to applied management or nutritional changes. While applied and basic research are often conducted independent of one another, the real advantages to the equine industry will come from the use of molecular techniques to address applied challenges and/or opportunities within the industry. Therefore, the overall goal of our research has been to use basic and molecular tools to investigate modes of action resulting from changes in nutrition or management. We investigated active nutrient transport capacities of the small and large intestine, the effects of feed withdrawal on intestinal transporter gene expression and function, as well as other measurements pertaining to gut health (gut barrier function and gastrointestinal morphology). This novel and thorough approach to characterize sectional differences (fore- and hind- gut) of nutrient absorption has resulted in quantitative measures of active transport capacity for glucose, phosphorus, glutamine, lysine, and di-peptides in the horse. This research demonstrates that by-products of fermentation in the cecum such as microbial proteins and hydrolyzed phytate phosphorus, can be absorbed in the colon. Previously unidentified in the hindgut of the horse, we reported the expression of the di-and tri-peptide transporter, PepT1, as well as the neutral amino acid transporter, ASCT2, and transport of their substrates. We observed that nutrient transporters for glucose (SGLT1), glutamine (ASCT2) and for di-peptides (PepT1) can be regulated by diet, implying biological relevance to feeding management strategies. Feed withdrawal in horses pre- or post-surgery, prior to or during horse shows, during transport, or for other management reason is common. It is therefore important to understand how the removals of nutrients impacts gut health and/or disease susceptibility. The use of molecular techniques has provided a basis for the roles of certain core nutrients during times of feed withdrawal. For example, nutrients such as glutamine play a major role in proliferation and repair in the gut, serve as a major energy substrate, and may provide a means of assessing nutritional stress in the gut. Recent data concludes that following a feed withdrawal, the need for glutamine increases up to 116% in the proximal jejunum, and the gene expression of its transporter (ASCT2) increases by 78%. Additional studies utilizing molecular techniques to address nutritional challenges in the horse include how hormone loss due to ovariectomization impacts the homeostatic regulation of calcium and phosphorus in the horse. To improve nutrition and feeding management practices in horses, knowledge regarding how and where nutrients are absorbed, utilized and regulated under varying physiologic stressors (disease, exercise, reproductive status, etc.) is needed. The integration of applied and basic research facilitates a better and more complete understanding of mechanisms underlying common health and nutritional challenges facing the equine industry.  
  Address  
  Corporate Author Aldridge, B. Thesis  
  Publisher Xenophon Publishing Place of Publication Wald Editor Krueger, K.;  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 978-3-9808134-26 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5575  
Permanent link to this record
 

 
Author (up) Russell, M.A.; Aldridge, B.E. pdf  openurl
  Title Solving Current Domestic Horse Nutrition Challenges Type Conference Article
  Year 2012 Publication Proceedings of the 2. International Equine Science Meeting Abbreviated Journal Proc. 2. Int. Equine. Sci. Mtg  
  Volume in press Issue Pages  
  Keywords horse nutrition, clinical diseases, digestion, feeding, management  
  Abstract Solving horse nutrition challenges require contributions from Psychology, Biology, Agriculture, and Veterinary Medicine because these are biological challenges of an anthropological nature. The domesticated horse has shifted from an animal of war, transportation, and farmwork, to a companion enjoyed for sport, leisure and recreation. The first realization and responsibility must lie in the fact that it is the owners and managers which are the source of many of the horses’ challenges. Nutritional challenges include: defining requirements and absorption of nutrients, improving feed efficiencies for performance, improving feeding management and eating behaviors, and preventing or treating clinical problems. These challenges can be addressed through science, horse management, and education. Many of today’s challenges in horse nutrition can be related to the equine genome and genetics. Those that can be addressed with nutritional consequences include Polysaccharide Storage Myopathy, Equine Metabolic Syndrome, Recurrent Exertional Rhabdomyolysis, Glycogen Branching Enzyme Deficiency, Hyperkalemic Periodic Paralysis, and Development Orthopedic Disorders. It is the scientific understanding of cellular processes in relation to nutrients which address the symptoms associated with these diseases. Consequently, feeding management can be changed to actually treat the disease. The most recent advances in equine nutrition implement the use of molecular and cellular based techniques to understand how nutrients are needed during times of stress, feed withdrawal and to maintain gut health. For example, the absorptive capacity and transporter gene expression and localization, are now being quantified. We are also now assessing the impact of the loss of reproductive endocrines on calcium and phosphorus homeostasis in the horse. Additionally, bioluminescent pathogenic bacteria have been utilized to view attachment rates in the gastrointestinal tract of the horse. These are merely examples of the approaches of science to these nutritional challenges. Science is of little use unless it is incorporated into improved management of horses. Every type of horse requires different management and good husbandry. In our country, 70+% of the horses are kept in small herds, on limited acreage, and used for recreation and sport. Since we have taken the horse out of its natural environment and subjected it to these roles, we now seek to determine ways to feed the horse in our environments; i.e. obesity, inconsistent exercise, confinement, surgery, competition, diseases. Private horse feed agribusinesses have aggressively positioned excellent products with claims to improve health, reproduction, performance, and even horse happiness. Owners and managers seek unbiased science upon which they ultimately make their own decisions. General challenge categories seem to be feeding geriatric horses, active performance horses, and idle horses with secondary metabolic problems. Thus, feeding recommendations include the determination of specific horse nutrient requirements, maximization of available forages, providing other nutrients, and exercise to manage horses more as horses. Private and public companies and Extension systems exist to provide online and other sources of information. As more and more people own horses as a hobby and for recreation, they share responsibility to inform themselves on how to best feed and care for their horses.  
  Address  
  Corporate Author Russell, M.A. Thesis  
  Publisher Xenophon Publishing Place of Publication Wald Editor Krueger, K.  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 978-3-9808134-26 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5523  
Permanent link to this record
 

 
Author (up) Stull, C.L.; Spier, S.J.; Aldridge, B.M.; Blanchard, M.; Stott, J.L. url  doi
openurl 
  Title Immunological response to long-term transport stress in mature horses and effects of adaptogenic dietary supplementation as an immunomodulator Type Journal Article
  Year 2004 Publication Equine Veterinary Journal Abbreviated Journal  
  Volume 36 Issue 7 Pages 583-589  
  Keywords horse; transportation; Cd+; lymphocytes; stress; cortisol; adaptogens  
  Abstract Reasons for performing study: Little information exists on the immunological effects of transport or the use of supplements to minimise transport stress. Objectives: To establish baseline ranges and evaluate immunophenotypic and functional changes associated with transport and a nutritional ‘adaptogen’ supplement. Methods: Horses received either supplement (n = 10) or placebos (n = 9) during the 30 day study. After 28 days in stalls, 12 horses (6 supplement; 6 placebo) were transported for 24 h, then unloaded and recovered. Venous blood samples were collected on Days 1, 14 and 28 to establish baselines, and on Days 28, 29 and 30 to examine changes during transport and recovery. Results: Transport prompted elevations (P<0.05) in cortisol concentration, neutrophil count and white blood cell counts, while lymphocyte subpopulation counts (CD3+, CD4+, CD8+, CD21+) decreased (P<0.05). Normal phenotypic lymphocyte profiles returned within 24 h of recovery. Supplement effects on immunophenotype (CD21+ and CD8+) were observed in stabled horses (P<0.05), but not in transported horses. Conclusions: These results provide insights into the immunological mechanisms associated with long-term transport. Potential relevance: The existence of a small window of immunological uncertainty follows long-term transportation, enhancing the potential risk of infectious disease in susceptible individuals.  
  Address  
  Corporate Author Thesis  
  Publisher Blackwell Publishing Ltd Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2042-3306 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5845  
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