FREE SHIPPING over $40
OVER 9000 FIVE-STAR REVIEWS
5% OFF ALL SUBSCRIPTIONS
100% HAPPINESS GUARANTEE
Analyze Diet
0
Home / Equine Research Bank / Equine Vet J / Effects of pasture consumption and obesity on insulin dysreg...
Equine veterinary journal2025; doi: 10.1111/evj.14507

Effects of pasture consumption and obesity on insulin dysregulation and adiponectin concentrations in UK native-breed ponies.

Abstract: Insulin dysregulation (ID) and hypoadiponectinaemia (total [adiponectin] <7.9 μg/mL) are risk factors for laminitis. They are sometimes, but not always, associated with obesity. Objective: To investigate the effects of pasture consumption and obesity on ID and circulating total [adiponectin] in ponies. Methods: Longitudinal. Methods: Seven native-breed ponies with normal basal and post-oral sugar test (OST) [insulin] and body condition score (BCS) 4.3-5.5/9 were allowed to graze until they reached BCS 7/9. Ponies were then maintained at BCS 7/9 until completion of the study (week 22). Morphometric measures, OST, insulin tolerance test (ITT), plasma [adiponectin], whole-blood expression of receptors for adiponectin, insulin, and insulin-like growth factor 1, and pasture conditions (height and vigour) were determined fortnightly. Results: Median (range) BCS increased significantly (p < 0.001) from 5.0 (4.3-5.5; week 0) to 7.2 (5.7-7.5; week 22). Basal [insulin] did not change significantly over the study, but median post-OST [insulin] was significantly higher (p < 0.05) at week 14 (95.2 [17.9-114.0] μIU/mL), week 16 (103.0 [16.4-166.0] μIU/mL), and week 20 (93.6 [10.0-153.0] μIU/mL) than week 0 (25.0 [10.0-64.0] μIU/mL). Compared with week 0, ITT results were significantly lower at weeks 2-6 and 12-20, and [adiponectin] was significantly lower at weeks 10-22 (p < 0.05). [Adiponectin] decreased in all ponies during the study. Both low (3/10) and high (8-9/10) pasture scores were significantly associated with low ITT results. Low pasture scores were associated with low [adiponectin]. BCS was significantly associated with basal [insulin], post-OST [insulin], ITT results, but not [adiponectin]. Conclusions: No control group with maintenance of ideal BCS; small sample size comprising native UK ponies. Conclusions: Six ponies developed hypoadiponectinaemia, and all showed transient or consistent ID during the study. Both short, stressed grass and long, lush grass were associated with decreased tissue insulin sensitivity. Unassigned: La desregulación insulínica (ID) y la hipoadiponectinemia ([adiponectina]total < 7.9 μg/mL) son factores de riesgo para laminitis. Se asocian, algunas veces, pero no siempre, con obesidad. Objective: Investigar los efectos del consumo de pasto y obesidad sobre la ID y la [adiponectina] total en ponis. DISEÑO DEL ESTUDIO: Longitudinal. MÉTODOS: Siete ponis de razas nativas con una prueba oral basal y post glucosa normales (OST) de [insulina] y clasificación de condición corporal (BCS) 4.3–5.5/9, fueron permitidos pastar hasta que llegasen a tener un BCS 7/9. Los ponis luego fueron mantenidos en BCS 7/9 hasta completar el estudio (semana 22). Medidas morfométricas, OST, prueba a la tolerancia a la insulina (ITT), [adiponectina] plasmática, expresión de receptores en sangre entera a adiponectina, insulina, and factor 1 de crecimiento tipo insulina, y condiciones del pasto (altura y vigor) fueron medidos cada 2 semanas. Results: La mediana de los BCS (rango) aumento significativamente (P<0.001) de 5.0 (4.3–5.5; semana 0) a 7.2 (5.7–7.5; semana 22). [Insulina] basal no cambio significativamente durante el estudio pero la mediana post‐OST [insulina] fue significativamente mayor (P<0.05) en la semana 14 (95.2 [17.9–114.0] μIU/mL), semana 16 (103.0 [16.4–166.0] μIU/mL), y semana 20 (93.6 [10.0–153.0] μIU/mL) que la semana 0 (25.0 [10.0–64.0] μIU/mL). En comparación con la semana 0, los resultados de ITT fueron significativamente menores en las semana 2–6 y 12–20, y [adiponectina] fue significativamente menor a las semanas 10–22 (P<0.05). La [adiponectina] disminuyó en todos los ponis durante el estudio. Tanto los niveles bajos (3/10) y altos (8‐9/10) de pasto, fueron significativamente asociados con resultados de ITT bajos. Niveles bajos de pasto fueron asociados con bajas [adiponectina]. Los BCS fueron asociados significativamente con [insulina] basal, [insulina] post‐OST, resultados de ITT, pero no con [adiponectina]. Unassigned: No hay grupo control con mantención de BCS ideales; tamaño de muestra pequeño que incluye razas nativas del RU. Conclusions: Seis ponis desarrollaron hipoadiponectemia y todos mostraron una ID transitoria o consistente durante el estudio. Tanto el pasto corto, estresado y aquel largo y frondoso, se asocio con una reducción en la capacidad tisular de respuesta a la insulina.
© 2025 Mars Horsecare and The Author(s). Equine Veterinary Journal published by John Wiley & Sons Ltd on behalf of EVJ Ltd.
Get Full Text
Publication Date: 2025-04-21 PubMed ID: 40257424DOI: 10.1111/evj.14507Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
LinkedInCopy
  • Journal Article

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

This research investigates the impact of pasture consumption and obesity on insulin regulation and concentrations of a protein hormone called adiponectin in native UK ponies. Specifically, the study examined potential risks for laminitis, a painful condition in the hooves of horses. A small group of ponies were allowed to graze until they became obese, under controlled conditions, and their blood insulin and adiponectin levels were monitored along with their insulin sensitivity.

Methodology

  • The study was conducted on seven native-breed ponies, initially in normal health, with standard body condition scores (BCS) and insulin concentration.
  • The ponies were allowed to graze freely until they reached a BCS of 7/9, indicating obesity. Their condition was then maintained at this level until the end of the study (week 22).
  • The researchers performed various tests and measurements fortnightly, including oral sugar tests (OST), insulin tolerance tests (ITT), plasma adiponectin concentrations, and assessments of whole-blood expression of receptors for adiponectin, insulin, and insulin-like growth factor 1. Pasture conditions were also recorded.

Results

  • The ponies’ median BCS increased significantly over the study duration from 5.0 initially, to 7.2 by week 22, indicating successful induction of obesity.
  • Basal insulin concentrations did not change significantly during the study, but insulin concentrations after OST were substantially higher at weeks 14, 16, and 20 as compared to the beginning of the study.
  • Insulin tolerance was lower at certain points during the study when compared with the start. Adiponectin concentrations also consistently decreased from weeks 10 to 22.
  • Pasture quality, whether low or high, was associated with lower insulin tolerance. Lower pasture scores were linked with lower adiponectin levels. Additionally, BCS was significantly associated with basal insulin, post-OST insulin, and ITT results, but not with adiponectin.

Conclusions

  • Six of the ponies developed hypoadiponectinaemia, or abnormally low adiponectin levels in the blood, and all displayed varying levels of insulin dysregulation during the study.
  • Both short, stressed grass and long, lush grass were associated with decreased tissue sensitivity to insulin.
  • The key limitations were the lack of a control group and the small sample size. Only native UK ponies were studied, limiting the generalizability of the results.

Cite This Article

APA
Barnabé MA, Elliott J, Harris PA, Menzies-Gow NJ. (2025). Effects of pasture consumption and obesity on insulin dysregulation and adiponectin concentrations in UK native-breed ponies. Equine Vet J. https://doi.org/10.1111/evj.14507

Publication

Equine veterinary journal
ISSN: 2042-3306
NlmUniqueID: 0173320
Country: United States
Language: English

Researcher Affiliations

Barnabé, Marine A
  • Department of Clinical Sciences and Services, Royal Veterinary College, Hertfordshire, UK.
Elliott, Jonathan
  • Department of Comparative Biomedical Sciences, Royal Veterinary College, Hertfordshire, UK.
Harris, Patricia A
  • Equine Studies Group, Waltham Petcare Science Institute, Leicestershire, UK.
Menzies-Gow, Nicola J
  • Department of Clinical Sciences and Services, Royal Veterinary College, Hertfordshire, UK.

Grant Funding

  • Royal Veterinary College Mellon Fund
  • Waltham Petcare Science Institute

References

This article includes 57 references
  1. Durham AE, Frank N, McGowan CM, Menzies‐Gow NJ, Roelfsema E, Vervuert I. ECEIM consensus statement on equine metabolic syndrome. J Vet Intern Med 2019;33:335–349.
  2. Frank N, Tadros EM. Insulin dysregulation. Equine Vet J 2014;46(1):103–112.
    doi: 10.1111/evj.12169google scholar: lookup
  3. Robin CA, Ireland JL, Wylie CE, Collins SN, Verheyen KLP, Newton JR. Prevalence of and risk factors for equine obesity in Great Britain based on owner‐reported body condition scores. Equine Vet J 2015;47(2):196–201.
  4. Knowles EJ, Elliott J, Harris PA, Chang YM, Menzies‐Gow NJ. Predictors of laminitis development in a cohort of nonlaminitic ponies. Equine Vet J 2022;55(1):12–23.
    doi: 10.1111/evj.13572google scholar: lookup
  5. Menzies‐Gow NJ, Harris PA, Elliott J. Prospective cohort study evaluating risk factors for the development of pasture‐associated laminitis in the United Kingdom. Equine Vet J 2017;49:300–306.
  6. Wooldridge AA, Gray Edwards H, Plaisance EP, Applegate R, Taylor DR, Taintor J. Evaluation of high‐molecular weight adiponectin in horses. Am J Vet Res 2012;73:1230–1240.
  7. Fitzgerald DM, Anderson ST, Sillence MN, De Laat MA. The cresty neck score is an independent predictor of insulin dysregulation in ponies. PLoS One 2019;14(7):e0220203.
  8. Bamford N, Potter SJ, Harris PA, Bailey SR. Effect of increased adiposity on insulin sensitivity and adipokine concentrations in horses and ponies fed a high fat diet, with or without a once daily high glycaemic meal. Equine Vet J 2016;48:368–373.
  9. Barnabé MA, Elliott J, Harris PA, Menzies‐Gow NJ. Relationships between total adiponectin concentrations and obesity in native‐breed ponies in England. Equine Vet J 2023;56(2):264–272.
    doi: 10.1111/evj.14013google scholar: lookup
  10. Bamford N, Potter SJ, Baskerville CL, Harris PA, Bailey SR. Effect of increased adiposity on insulin sensitivity and adipokine concentrations in different equine breeds adapted to cereal‐rich or fat‐rich meals. Vet J 2016;214:14–20.
  11. Barnabé MA, Elliott J, Harris PA, Menzies‐Gow NJ. Short‐term induced hyperinsulinaemia and dexamethasone challenge do not affect circulating total adiponectin concentrations in insulin‐sensitive ponies. Equine Vet J 2023;56(2):332–341.
    doi: 10.1111/evj.14012google scholar: lookup
  12. Wylie CE, Ireland JL, Collins SN, Verheyen KLP, Newton JR. Demographics and management practices of horses and ponies in Great Britain: a cross‐sectional study. Res Vet Sci 2013;95:410–417.
  13. Baskerville CL, Chockalingham S, Harris PA, Bailey SR. The effect of insulin on equine lamellar basal epithelial cells mediated by the insulin‐like growth factor‐1 receptor. PeerJ 2018;6:e5945.
  14. Henneke DR, Potter GD, Kreider JL, Yeates BF. Relationship between condition score, physical measurements and body fat percentage in mares. Equine Vet J 1983;15:371–372.
  15. Frank N, Bailey S, Bertin F‐R, de Laat M, Durham A, Kritchevsky J. Recommendations for the diagnosis and management of equine metabolic syndrome (EMS). Equine Endocrinology Group .
  16. Hart K, Durham AE, Frank N, McGowan CM, Schott HC, Stewart AJ. Recommendations for the diagnosis and management of pituitary pars intermedia dysfunction (PPID). Equine Endocrinology Group .
  17. Kohnke J. Feeding and nutrition: the making of a champion. Pymble, Australia: Birubi Pacific; 1992.
  18. Knowles EJ, Harris PA, Elliott J, Menzies‐Gow NJ. Use of the oral sugar test in ponies when performed with or without prior fasting. Equine Vet J 2017;49:519–524.
  19. Knowles E. Predisposition to laminitis: a prospective study evaluating metabolic alterations and management practices. London, UK: RVC; 2021.
  20. Hollis AR, Dallap Schaer BL, Boston RC, Wilkins PA. Comparison of the Accu‐Chek Aviva point‐of‐care glucometer with blood gas and laboratory methods of analysis of glucose measurement in equine emergency patients. J Vet Intern Med 2008;22:1189–1195.
  21. Jocelyn NA, Harris PA, Menzies‐Gow NJ. Effect of varying the dose of corn syrup on the insulin and glucose response to the oral sugar test. Equine Vet J 2018;50:836–841.
  22. Clark BL, Stewart AJ, Kemp KL, Bamford NJ, Bertin FR. Evaluation of field‐testing protocols to diagnose insulin dysregulation in ponies using a Bayesian approach. Vet J 2023;298–299:106019.
  23. United States Department of Agriculture. Guide to pasture condition scoring. Washington, DC: USDA; 2020.
  24. Met Office. UK regional series. 2023.
  25. UK Environmental Agency. Weekly rainfall and river flow reports for England. 2023.
  26. Motulsky HJ, Brown RE. Detecting outliers when fitting data with nonlinear regression ‐ a new method based on robust nonlinear regression and the false discovery rate. BMC Bioinformatics 2006;7:123.
  27. Frank N, Walsh DM. Repeatability of oral sugar test results, glucagon‐like Peptide‐1 measurements, and serum high‐molecular‐weight adiponectin concentrations in horses. J Vet Intern Med 2017;31:1178–1187.
  28. Staub C, Venturi E, Cirot M, Léonard L, Barrière P, Blard T. Ultrasonographic measures of body fatness and their relationship with plasma levels and adipose tissue expression of four adipokines in Welsh pony mares. Domest Anim Endocrinol 2019;69:75–83.
  29. Gómez‐Abellán P, Gómez‐Santos C, Madrid JA, Milagro FI, Campion J, Martínez JA. Circadian expression of adiponectin and its receptors in human adipose tissue. Endocrinology 2010;151(1):115–122.
  30. Akram F, Gragnoli C, Raheja UK, Snitker S, Lowry CA, Stearns‐Yoder KA. Seasonal affective disorder and seasonal changes in weight and sleep duration are inversely associated with plasma adiponectin levels. J Psychiatr Res 2020;122:97–104.
  31. Safai N, Eising S, Hougaard DM, Mortensen HB, Skogstrand K, Pociot F. Levels of adiponectin and leptin at onset of type 1 diabetes have changed over time in children and adolescents. Acta Diabetol 2015;52(1):167–174.
  32. Kalkman HO. An explanation for the adiponectin paradox. Pharmaceuticals (Basel) 2021;14(12):1266.
  33. Rodríguez C, Muñoz M, Contreras C, Prieto D. AMPK, metabolism, and vascular function. FEBS J 2021;288:3746–3771.
    doi: 10.1111/febs.15863google scholar: lookup
  34. Elliott J, Bailey SR. A review of cellular and molecular mechanisms in endocrinopathic, sepsis‐related and supporting limb equine laminitis. Equine Vet J 2023;55(3):350–375.
    doi: 10.1111/evj.13933google scholar: lookup
  35. Ye J, Gao Z, Yin J, He Q. Hypoxia is a potential risk factor for chronic inflammation and adiponectin reduction in adipose tissue of ob/ob and dietary obese mice. Am J Physiol Endocrinol Metab 2007;293(4):E1118–E1128.
  36. van Andel M, Heijboer AC, Drent ML. Adiponectin and its isoforms in pathophysiology. Advances in clinical chemistry 2018;85:115–147.
  37. Yamauchi T, Nio Y, Maki T, Kobayashi M, Takazawa T, Iwabu M. Targeted disruption of AdipoR1 and AdipoR2 causes abrogation of adiponectin binding and metabolic actions. Nat Med 2007;13(3):332–339.
  38. Yamauchi T, Iwabu M, Okada‐Iwabu M, Kadowaki T. Adiponectin receptors: a review of their structure, function and how they work. Best Pract Res Clin Endocrinol Metab 2014;28:15–23.
  39. Dugdale AHA, Curtis GC, Harris PA, Argo CM. Assessment of body fat in the pony: part I. Relationships between the anatomical distribution of adipose tissue, body composition and body condition. Equine Vet J 2011;43:552–561.
  40. Dugdale AHA, Curtis GC, Cripps P, Harris PA, Argo MM. Effect of dietary restriction on body condition, composition and welfare of overweight and obese pony mares. Equine Vet J 2010;42:600–610.
  41. Harris P. Nutritional management for avoidance of pasture‐associated laminitis. Equine Laminitis 2016; p. 436–441.
    doi: 10.1002/9781119169239.ch50google scholar: lookup
  42. Longland AC, Byrd BM. Pasture nonstructural carbohydrates and equine laminitis. J Nutr 2006;136:2099S–2102S.
  43. Norton EM, Schultz NE, Rendahl AK, Mcfarlane D, Geor RJ, Mickelson JR. Heritability of metabolic traits associated with equine metabolic syndrome in Welsh ponies and Morgan horses. Equine Vet J 2019;51(4):475–480.
  44. Clark BL, Bamford NJ, Stewart AJ, McCue ME, Rendahl A, Bailey SR. Evaluation of an HMGA2 variant contribution to height and basal insulin concentrations in ponies. J Vet Intern Med 2023;37(3):1186–1192.
    doi: 10.1111/jvim.16723google scholar: lookup
  45. Treiber KH, Kronfeld DS, Hess TM, Byrd BM, Splan RK, Staniar WB. Evaluation of genetic and metabolic predispositions and nutritional risk factors for pasture‐associated laminitis in ponies. J Am Vet Med Assoc 2006;228(10):1538–1545.
  46. Chaucheyras‐Durand F, Sacy A, Karges K, Apper E. Gastro‐intestinal microbiota in equines and its role in health and disease: the black box opens. Microorganisms 2022;10(12):2517.
  47. Morrison PK, Newbold CJ, Jones E, Worgan HJ, Grove‐White DH, Dugdale AH. The equine gastrointestinal microbiome: impacts of weight‐loss. BMC Vet Res 2020;16(1):78.
    doi: 10.1186/s12917-020-02295-6google scholar: lookup
  48. Morrison PK, Newbold CJ, Jones E, Worgan HJ, Grovev‐White DH, Dugdale AH. The equine gastrointestinal microbiome: impacts of age and obesity. Front Microbiol 2018;9:3017.
    doi: 10.3389/fmicb.2018.03017google scholar: lookup
  49. de Laat MA, Fitzgerald DM. Equine metabolic syndrome: role of the enteroinsular axis in the insulin response to oral carbohydrate. Vet J 2023;294:105967.
    doi: 10.1016/j.tvjl.2023.105967google scholar: lookup
  50. Giles SL, Harris P, Rands SA, Nicol CJ. Foraging efficiency, social status and body condition in group‐living horses and ponies. PeerJ 2020;8:1–17.
  51. Giles SL, Nicol CJ, Harris PA, Rands SA. Dominance rank is associated with body condition in outdoor‐living domestic horses (Equus caballus). Appl Anim Behav Sci 2015;166:71–79.
  52. Weinert‐Nelson JR, Meyer WA, Williams CA. Diurnal variation in forage nutrient composition of mixed cool‐season grass, crabgrass, and bermudagrass pastures. J Equine Vet Sci 2022;110:103836.
  53. Ödberg FO, Francis‐Smith K. A study on eliminative and grazing behaviour—the use of the field by captive horses. Equine Vet J 1976;8:147–149.
  54. Carslake HB, Pinchbeck GL, McGowan CM. Equine metabolic syndrome in UK native ponies and cobs is highly prevalent with modifiable risk factors. Equine Vet J 2021;53(5):923–934.
  55. Bailey S, Menzies‐Gow NJ, Harris P, Habershon‐Butcher J, Crawford C, Berhane Y. Effect of dietary fructans and dexamethasone administration on the insulin response of ponies predisposed to laminitis. J Am Vet Med Assoc 2007;231(9):1365–1373.
  56. Treiber KH, Boston RC, Kronfeld DS, Staniar WB, Harris PA. Insulin resistance and compensation in Thoroughbred weanlings adapted to high‐glycemic meals 1. J Anim Sci 2013;83(10):2357–2367.
  57. Maisonpierre IN, Sutton MA, Harris P, Menzies‐Gow N, Weller R, Pfau T. Accelerometer activity tracking in horses and the effect of pasture management on time budget. Equine Vet J 2019;51(6):840–845.
Subscribe to our newsletter
Join 99,357 horse owners like you who receive our email updates on horse health and nutrition.