Non-Invasive Assessment of Equine Bone: An Update

Veterinary Journal

Volumn 161, Issue 1, 2001, Pages 10-23

  Lepage, Olivier M ^a   Carstanjen, B ^b   Uebelhart, D ^c,d  

^a VETAGRO SUP   (France)

^b UNIVERSITY OF LIÈGE   (Belgium)

^c UNIVERSITY HOSPITAL ZURICH   (Switzerland)

^d RUSH UNIVERSITY MEDICAL CENTER   (United States)

Author keywords

Biochemical markers; Bone and connective tissue metabolism; Horse; Quantitative ultrasonography

Indexed keywords

BIOLOGICAL MARKER;

ANIMAL; ANIMAL DISEASE; BLOOD; BONE; BONE DENSITY; ECHOGRAPHY; HORSE; METABOLISM; OSTEOLYSIS; RADIODENSITOMETRY; RADIOGRAPHY; REVIEW;

ANIMALS; BIOLOGICAL MARKERS; BONE AND BONES; BONE DENSITY; BONE RESORPTION; DENSITOMETRY, X-RAY; HORSES; ULTRASONOGRAPHY;

EID: 0035219863     PISSN: 10900233     EISSN: None     Source Type: Journal    
DOI: 10.1053/tvjl.2000.0541     Document Type: Review

References (94)

1. ARNAUD, C. D. (1996). Osteoporosis: Using "bone markers" for diagnosis and monitoring. Geriatrics 51, 24-30.
2. BAMBER, J. C. & TRISTAM, M. (1988). Diagnostic ultrasound. In The physics of medical imaging, ed. S. Webb., pp. 319-86. Bristol: Adam Hilger.
3. BARKMANN, R., KANTOROVICH, E., SINGAL, C., HANS, D., GENANT, H. K., HELLER, M. & GLÜER C.-C. (2000). A new method for quantitative ultrasound measurements at multiple skeletal sites. Journal of Clinical Densitometry 3, 1-7.
4. BLACK, A., SCHOKNECHT, P. A., RALSTON, S. L. & SHAPES, S. A. (1999). Diurnal variation and age differences in biochemical markers of bone turnover in horses. Journal of Animal Science 77, 75-83.
5. BUCKINGHAM, S. H. W., MCCARTHY, R. N., ANDERSON, G. A., MCCARTNEY R. N. & JEFFCOTT L. B. (1992). Ultrasound speed in the metacarpal cortex - a survey of 347 thoroughbreds in training. Equine Veterinary Journal 24, 191-5.
6. CAMARDA, A. J., BUTLER, W. T., FINKELMAN, R. D. & NANCI, A. (1987). Immunocytochemical localization of carboxyglutamic acid-containing proteins (osteocalcin) in rat bone and dentin. Calcified Tissue International 40, 349-55.
7. CARSTANJEN, B., LEPAGE, O. M. & LANGLOIS, P. (1999). Quantitative ultrasound: a non invasive method for bone assessment in Thoroughbred horses. Journal of Equine Veterinary Science 19, 556.
8. CARSTANJEN, B., DUBOEUF, F., DETILLEUX, J., BARTHEZ, P. & LEPAGE, O. M. (2000). Quantitative ultrasound- and dual-X-ray absorptiometry-measurements of the third metacarpal bone in horses: An in vivo-ex vivo study. Journal of Bone and Mineral Research 15, 5529.
9. CHIAPPE, A., GONZALEZ, G., FRADINGER, E., IORIO, G., FERRETI, J.-L. & ZANCHETTA, J. (1999). Influence of age and sex in serum osteocalcin levels in thoroughbred horses. Archives Internationales de Physiologie et de Biochimie 107, 50-4.
10. CHRISTIANSEN, C., HASSAGER, C. & RIIS, B. J. (1998). Biochemical markers of bone turnover. In Metabolic Bone Disease and Clinically Related Disorders, 3d edn, ed. Avioli L. V. & Krane S. M., pp. 313-26 San Diego: Academic Press.
11. COCHRANE C., A. (1997). Models in vivo of wound healing in the horse and the role of growth factors. Veterinary Dermatology 8, 259-72.
12. COCHEN-SOLAL, A. (1988). Variations sanguines et urinaires suite au traitement par un bisphosphonate (AHPrBP ou APD) chez le poney Shetland. Travail de fin d'étude, Faculté de médecine vété;rinaire, Université de Liège.
13. DAVICCO, M. J., FAULCONNIER, Y., COXAM, V., DUBROEUCQ, H., MARTIN-ROSSET, W. & BARLET, J. P. (1994). Systematic bone growth factors in light breed mares and their foals. Archives. Internationales de Physiologie, Biochimie et de Biophysique 102, 115-9.
14. DE LA PIEDRA, C., RAPADO, A., DIAZ DIEGO, E., M., DIAZ MARTIN, M., A., AGUIRRE, C., LOPEZ GAVILANES, E. & DIAZ CURIEL, M. (1996). Variable efficacy of bone remodelling biochemical markers in the management of patients with Paget's disease of bone treated with Tiludronate. Calcified Tissue International 59, 95-9.
15. DELMAS, P. D. Biochemical markers of bone turnover (1993). Journal of Bone Mineral Research 8, S549-S55.
16. DESBOIS, C., HOGUE, D. A. & KARSENTY, G. (1994). The mouse osteocalcin gene cluster contains three genes with two separate spatial and temporal patterns of expression. Journal of Biology and Chemistry 269, 1183-90.
17. DUCY, P., DESBOIS, C. H., BOYCE, B., PINERO, G., STORY, B., DUNSTAN, C., SMITH, E., BONADIO, J., GOLDSTEIN, S., GUNDBERG, C., BRADLEY, A. & KARSENTY, G. (1996). Increased bone formation in osteocalcin-deficient mice. Nature 382, 448-52.
18. EPSTEIN, S., MCCLINTOCK, R., BRYCE, G., POSER, J., JOHNSTON, C. C. & HUIS, S. (1984). Differences in serum bone Gla Protein with age and sex. Lancet 1, 307-10.
19. ESTBERG, L., STOVER, S. M., GARDNER, I. A., DRAKE, C. M., JOHNSON, B. & ARDANS, A. (1996). High-speed exercise history and catastrophic racing fracture in Thoroughbreds. American Journal of Veterinary Research 57, 1549-55.
20. EYRE, D. R. (1997). Bone biomarkers as tools in osteoporosis management. Spine 22, 17S-24S.
21. EYRE, D. R., VAN NESS, K. & KOOP, T. J. (1984) Quantitation of hydroxypyridinium crosslinks in collagen by high performance liquid chromatography. Annals of Biochemistry 137, 380-8.
22. FARRUGIA, W., FORTUNE, F. L., HEATH, J., CAPLE, I. W. & WARK J. D. (1989). Osteocalcin as an index of osteoblast function during and after ovine pregnancy. Endocrinology 125, 1705-10.
23. FLETCHER, K. L., TOPLIFF, D. R., FREEMAN, D. W., COOPER, S. R. & LOOPER, M. L. (1998). Effects of sex and weaning on serum osteocalcin concentration in horses. Animal Science Report, Agricultural Experimental Station, Oklahoma State University, 121-4.
24. GEOR, R., HOPE, E., LAUPER, L., PIELA, S., KLASSEN, J., KING, V. & MURHY, M. (1995). Effect of glucocorticoids on serum osteocalcin concentration in horses. American Journal of Veterinary Science 56, 1201-5.
25. GIRARD, C., LEPAGE, O. M. & ROSSIER, Y. (1997). Multiple Vertebral osteochondrosis in a foal. Journal of Veterinary Diagnostic Investigation 9, 436-8.
26. GLADE, M. J. & BELLING, T. H. (1984). Growth plate cartilage metabolism, morphology and biochemical composition in over- and underfed horses. Growth 48, 473-82.
27. GRAFENAU, P., EICHER, R., UEBELHART, B., TSHUDI, P. & LEPAGE O. M. (1999). General anesthesia decreases osteocalcin plasma concentrations in horses. Equine veterinary Journal 31, 533-6.
28. HANK, A. M., HOFFMAN, W. E., SANEKI, R. K., SHAFFER, D. J. & DORNER, J. L. (1993). Quantitative determination of equine alkaline phosphatase isoenzymes in foal and adult serum. Journal of Veterinary Internal Medicine 7, 20-4.
29. HANS, D., GLUËR, C. C. & NJEH, C. F. (1998). Ultrasonic evaluation of osteoporosis. In Osteoporosis: diagnosis and management, ed. P. J. Meunier, pp. 59-78. London: Martin Dunitz Ltd.
30. HAUSCHKA, P. V. & REID, M. L. (1978). Vitamin K dependence of a calcium-binding protein containing carboxyglutamic acid in chicken bone. Journal of Biological Chemistry 253, 9063-8.
31. HAUSCHKA, P. V., LIAN, J. B., COLE, D. E. C. & GUNDBERG, C. M. (1989). Osteocalcin and matrix Gla protein: Vitamin K-dependent proteins in bone. Physiological Reviews 69, 990-1047.
32. HENSON, F. M. D., DAVIES, M. E., SKEPPER, J. N. & JEFFCOTT, L. (1995). Localisation of alkaline phosphatase in equine growth cartilage. Journal of Anatomy 187, 151-9.
33. HOECKSTRA, K. E., NIELSEN, B. D., ORTH, D. S., ROSENSTEIN, D. S., SCHOTT, H. C. & SCHELL, J. E. (1999). Comparison of bone mineral content and biochemical markers of bone metabolism in stall- vs. pasture-reared horses. Equine veterinary Journal 30, 601-4.
34. HOPE, E., JOHNSTON, S. D., HEGSTADT, R. L., GEOR, R. J. & MURPHY, M. J. (1993). Effects of sample collection and handling on concentration of osteocalcin in equine serum. American Journal of Veterinary Research 7, 1017-20.
35. HURTIG, M. B., GREEN, S. L., DOBSON, H. & BURTON, J. (1991). Defective bone and cartilage in foals fed a low-copper diet. Proceedings of the American Association of Equine Practitioners 36, 637-43.
36. JACKSON, B., WILSON, A. M., EASTELL, R., RUSSELL, R. G. G., LANYON, L. E., GOODSHIP, A. E. & OPRICE, P. S. (1995). The effects of exercise on biochemical markers of bone metabolism in the horse. 41st Annual Meeting, Orthopedic Research Society 20, 201-34.
37. JACKSON, B., EASTELL, R., RUSSEL, R. G., LANYON, L. E. & PRICE, J. S. (1996). Measurement of bone specific alkaline phosphatase in the horse: a comparison of two techniques. Research in Veterinary Science 61, 160-4.
38. JACKSON, B., EASTELL, R. E., WILSON, A. M., LANYON, L. E., GOODSHIP, A. E. & PRICE, J. S. (1998). The effect of exercise on biochemical markers of bone metabolism and insulin-like growth factor-I in two year old thoroughbreds. Journal of Bone and Mineral Research 13, 521.
39. JAESCHKE, G. (1975) Routine determination of free hydroxyproline in horse serum. Methods and normal values. Zentralblatt Fur Veterinarmedizin. Reihe A 22, 89-101.
40. JEFFCOTT, L. B. & MCCARTNEY, R. N. (1985). Ultrasound as a tool for assessment of bone quality in the horse. Veterinary Record 116, 337-42.
41. JEFFCOTT, L. B., BUCKINGHAM, S. H. W., MCCARTHY, R. N., CLEELAND J. C., SCOTI, E. & MCCARTNEY, R. N. (1988). Non-invasive measurement of bone: A review of clinical and research applications in the horse. Equine veterinary Journal suppl 6, 71-9.
42. JULEN DAY, T. R., POTTER, G. D., MORRIS, E. L., GREENE, L. W. & SIMMONS, J. B. (1998). Physiologic and skeletal response to exogenous equine somatotropin (eST) in two-year-old Quarter Horse in race training. Journal of Equine Veterinary Science 18, 321-328.
43. KANIS, J. A. (1994). Assessment of bone mass and osteoporosis. In Osteoporosis, ed. Blackwell, pp. 114-47 Cambridge: Science Ltd.
44. LAWRENCE, L. A. & OTT, E. A. (1985). The use of non-invasive techniques to predict bone mineral content and strength in the horse. Proceedings of 9th Equine Nutrition and Physiology Symposium, 110-116.
45. LEPAGE, O. M. (1997). Contribution à l'étude du tissu osseux équin. Thêse d'Habilitation, Université de Berne (Suisse)
46. LEPAGE, O. M., & FRANCOIS, R. J. (1989). Aspects microradiographiques et en microscopic de fluorescence d'une exostose expérimentale du métacarpien chez le poney Shetland et de son traitement par un bisphosphonate, l'AHPrBP (APD). Applications possibles au cheval d'arme. Annales Medicinae Militaris Belgicae 3, 38-44.
47. LEPAGE, O. M., MARCOUX, M. & TREMBLAY, A. (1990). Serum osteocalcin or bone Gla-protein, a biochemical marker for bone metabolism in horses: differences in serum levels with age. Canadian Journal of Veterinary Research 54, 223-6.
48. LEPAGE, O. M., DESCOTEAUX, L., MARCOUX, M. & TREMBLAY, A. (1991). Circadian rhythms of osteocalcin in equine serum. Correlation with alkaline phosphatase, calcium, phosphate and total protein levels. Canadian Journal of Veterinary Research 55, 5-10.
49. LEPAGE, O. M., MARCOUX, M., TREMBLAY, A. & DUMAS, G. (1992). Sex does not influence serum osteocalcin levels in Standardbred horses of different ages. Canadian Journal of Veterinary Research 56, 379-81.
50. LEPAGE, O. M., LAVERTY, S., MARCOUX, M. & DUMAS, G. (1993). Serum osteocalcin concentration in horses treated with triamcinolone acetonide. American Journal of Veterinary Research 54, 1209-12.
51. LEPAGE, O. M., FRANCOIS, R. J. & PERRON-LEPAGE, M.-F. (1997a). Modelage et remaniement osseux. Observation sur les os métacarpiens du poney Shetland. Pratique Vétérinaire Equine 29, 47-57.
52. LEPAGE, O. M., EICHER, R., UEBELHART, B. & TSHUDI, P. (1997b). Influence of type and breed of horses on serum osteocalcin concentration and evaluation of the applicability of a bovine RIA and a human IRMA. American Journal of Veterinary Research 58, 574-8.
53. LEPAGE, O. M., HARTMANN, D., EICHER, R., UEBELHART, B., TSCHUDI, P. & UEBELHART, D. (1998a). Biochemical markers of bone metabolism in draught and warmblood horses. The Veterinary Journal 156, 169-75.
54. LEPAGE, O. M., WHITTON, C., DANIELI, A., NIV, Y. (1998b). Multi site quantitative ultrasound measurements in horses: preliminary results for metacarpal bone assessment. Bone 23, F214.
55. MAENPAA, P. H., PIRSKANEN, A. & KOSKINEN, E. (1988). Biochemical indicators of bone formation in foals after transfer from pasture to stables for the winter months. American Journal of Veterinary Research 49, 1990-2.
56. MCCARTNEY, R. N. & JEFCOTT L. B. (1987). Combined 2.25 Mhz ulltrasound velocity and bone mineral density measurements in the equine metacarpus and their in vivo applications. Medical and Biological Engineering and Computing 25, 620-6.
57. MCCARTHY, R. N., JEFFCOTT, L. B. (1992). Effects of treadmill exercise on cortical bone in the third metacarpus of young horses. Research in Veterinary Science 52, 28-37.
58. MCCARTHY, R. N., JEFFCOTT, L. B. & MCCARTNEY, R. N. (1990). Ultrasound speed in equine cortical bone: Effects of orientation, density, porosity and temperature. Journal of Biomechanics 23, 1139-43.
59. MEAKIM, D. W., OTT, E. A., ASQUITH, R. L. & FEASTER, J. P. (1981). Estimation of mineral content of the equine third metacarpal by radiographic photometry. Journal of Animal Science 55, 1019-26.
60. MELICK, R. A., FARRUGIA, W., HEATON, C. L., QUELCH, K. J., SCOGGINS, B. A. & WARK, J. D. (1988). The metabolic clearance rate of osteocalcin in sheep. Calcified Tissue International 42, 185-90.
61. NIELSEN, B. D., POTTER, G. D., GREENE, L. W., MORRIS, E. L., MURRAY-GERZIK, M., SMITH, W. B. & MARTIN, M. T. (1998). Characterization of changes related to mineral balance and bone metabolism in the young racing Quarter Horse. Journal of Equine Veterinary Science 18, 190-200.
62. NISHIMOTO, S. K. & PRICE, P. A. (1979). Proof that the gamma-carboxyglutamic acid-containing bone protein is synthesized in calf bone. Journal of Biological Chemistry 254, 437-41.
63. NJEH, C. F., BOIVIN, C. M. & LANGTON, C. M. (1997). The role of ultrasound in the assessment of osteoporosis: a review. Osteoporosis International 7, 7-22.
64. NJEH, C. F., HANS, D., WU, C., KANTOROVICH, E., SISTER, M., FUERST, T. & GENANT, H. K. (1999). An in vitro investigation of the dependence on sample thickness of the speed of sound along the specimen. Medical Engineering & Physics 21, 651-9.
65. ORWOLL, E. S. (1999). Osteoporosis in men. In Primer on the metabolic bone disease and disorders of mineral metabolism, ed. M. J. Favus, pp. 289-92 Philadelphia: Lippincott Williams & Wilkins.
66. PARFITT, A. M., SIMON, L. S., VILLANUEVA, A. R. & KRANE, S. M. (1987). Procollagen type I carboxy-terminal extension peptide in serum as a marker of collagen biosynthesis in bone. Correlation with Iliac bone formation rates and comparison with total alkaline phosphatase. Journal of Bone and Mineral Research 2, 427-36.
67. PATTERSON-ALLEN, P., BRAUTIGAM, C. E., GRINDELAND, R. E., ASLING, C. W. & CALLAHAN, P. X. (1982). A specific radioimmunoassay for osteocalcin with advantageous species crossreactivity. Analytical Biochemistry 120, 1-7.
68. PORR, C. A., KRONFELD, D. S., LAWRENCE, L. A., PLEASANT, R. S. & HARRIS, P. A. (1998). Deconditioning reduces mineral content of the third metacarpal bone in horses. Journal of Animal Science 76, 1875-9.
69. PRATT, G. W. (1980). An in vivo method of ultrasonically evaluating bone strength. Proceeding 26th Annual Convention of American Association of Equine Practitioners 295-301.
70. PRICE, J. S. (1998). Biochemical markers of bone metabolism in horses: potentials and limitations? Veterinary Journal 156, 163-5.
71. PRICE, P. A. & BAUKOL, S. A. (1980). 1,25-dihydroxyvitamin D3 increases synthesis of the vitamin K-dependent bone protein by osteosarcoma cells. Journal of Biological Chemistry 255, 11660-3.
72. PRICE, P. A., POSER, J. W. & RAMAN, N. (1976). Primary structure of the gamma-carboxyglutamic acid-containing protein from bovine bone. Proceeding of the National Academy of Science 73, 3374-75.
73. PRICE, J. S., COLWELL, A., EASTELLL, R., GOODSHIP, A. E. & RUSSELL, R. G. G. (1992). Urinary excretion of deoxypyridinoline as a marker of bone resorption in the thoroughbred racehorse. Bone 13, 279.
74. PRICE, J. S., JACKSON, B., EASTELL, R., GOODSHIP, A. E., BLUMSOHN, A., WRIGHT, I., STONEHAM, S., LANYON, L. E. & RUSSELL, R. G. G. (1995a). Age related changes in biochemical markers of bone metabolism in horses. Equine veterinary Journal 27, 201-7.
75. PRICE, J. S., JACKSON, B., EASTELL, R., WILSON, A. M., RUSSELL, R. G. G., LANYON, L. E. & GOODSHIP, A. E. (1995b). The response of the skeleton to physical training: A Biochemical Study in Horses. Bone 17, 221-7.
76. PRICE, J. S., JACKSON, B., GRAY, J., WRIGHT, I. M., HARRIS, P. E., RUSSELL, R. G. G., EASTELL, R. E., MCILWRAIHT, C. W., RICKETTS, S. W. & LANYON, L. E. (1997). Serum levels of molecular markers in growing horses: the effects of age, season and orthopaedic disease. Proceedings 43d Annual Meeting Orthopaedic Research Society 587.
77. RABIN, D. S., RANTANEN, N. W., SEDER, J. A., MILLER, P. & HELLHAKE, P. (1983). The clinical use of bone strength assessment in the thoroughbred racehorse. Proceedings 28th American Association of Equine Practitioners 343-351.
78. RAHMAN, S., OBERDORF, A., MONTECINO, M., TANHAUSER, S. M., LIAN, J. B., STEIN, G. S., LAIPIS, G. S. & STEIN, L. J. (1993). Multiple copies of bone specific osteocalcin gene in mouse and rat. Endocrinology 133, 3050-3.
79. RIBOT, C., TREMOLLIERE, F. & POUILLES, J. M. (1995). Can we detect women with low bone mass using clinical risk factors? American Journal of Medicine 98, 52S-5S.
80. RIGGS, C. M. (1999). Aetiopathogenesis of parasagittal fractures of the distal condyles of the third metacarpal and third metatarsal bones - Review of the literature. Equine veterinary Journal 31, 116-20.
81. RISTELI, J., NIEMI, S., ELOMAA, I. & RISTELLI, L. (1993). Radioimmunoassay for the pyridinoline cross-linked carboxyterminal telopeptide of type I collagen: a new serum marker of bone collagen degradation. Clinical Chemistry 39, 635-40.
82. ROBINS, S. P., STEWART, P., ASTBURY, C. & BIRD, H. A. (1986). Measurement of the crosslinking compound pyridinoline in urine as an index of collagen degradation in joint disease. Annals of Rheumatism Disease 45, 969-73.
83. RODIN, A., DUNCAN, A., QUARTERO, H. W. P., PISTOFIDIS, G., MAHISTER, G., WHITAKER, K., CROOK, D., STEVENSON, J. C., CHAPMAN, M. G. & FOGELMAN, I. (1989). Serum concentrations of alkaline phosphatase isoenzymes and osteocalcin in normal pregnancy. Journal of Clinical Endocrinology and Metabolism 68, 1123-7.
84. SCHRYVER, H. F., MILLIS D. L., SODERHOLM, L. V., WILLIAMS, J., HINTZ, H. F. (1986). Metabolism of some essential minerals in ponies fed high level aluminium. Cornell Veterinarian 76, 354-60.
85. STEIGER, R., GEYER, H., PROVENCHER, A., PERRON-LEPAGE, M.-F., VON SALIS, B. & LEPAGE, O. M. (1999). Equine bone core biopsy: evaluation of collection sites using a new electric drilling machine. Equine Practice 21, 14-21.
86. STOVER, S. M., POOL, R. R., MARTIN, R. B. & MORGAN, J. P. (1992). Histiological features of the dorsal cortex of the third metacarpal bone mid-diaphysis during postnatal growth in thoroughbred horses. Journal of Anatomy 181, 455-69.
87. THOREN-TOLLING, K. (1988). Serum alkaline phosphatase isoenzymes in the horse - variation with age, training and in different pathological conditions. Journal of Veterinary Medicine 35, 13-23.
88. UEBELHART, D. & DELMAS, P. D. (1993). Le dosage des molécules de pontage du collagène (pyridinolines) dans l'étude de la dégradation du tissu osseux ex du cartilage articulaire. Pathologie et Biologie 41, 951-61.
89. UEBELHART, D., GINEYTS, E., CHAPUY, M. C. & DELMAS P. D. (1990). Urinary excretion of pyridinium crosslinks: a new marker of bone resorption in metabolic bone disease. Bone and Mineral 8, 87-96.
90. UFFMANN, M., FUERST, T. P., JERGAS, M. & GENANT, H. (1998). Non invasive assessment of bone. In Metabolic Bone Disease and Clinically Related Disorders, 3d edn, ed. Avioli L. V. & Krane S. M., pp. 275-311 San Diego: Academic Press.
91. WASNICH, R. D. (1999). Epidemiology of osteoporosis. In Primer on the metabolic bone disease and disorders of mineral metabolism, ed. M. J. Favus, pp. 257-59 Philadelphia: Lippincott Williams & Wilkins.
92. WEISS, M., BEN-SHLOMO, A., HAGAG, P. & ISH-SHALOM, S. (2000). Discrimination of proximal hip fracture by quantitative ultrasound measurement at the radius. Osteoporosis International 11, 411-6.
93. WEITZ, S. L., BENHAM, P. & LEUNG, S-S. (1999). Total deoxypyridinoline in serum and urine as measured by a novel adaptation of the Pyrilinks-D enzyme immunoassay. Journal of Bone and Mineral Research 14 (suppl. 1), 371.
94. ZICKER, S. C. & ROGERS, Q. R. (1994). Temporal changes in concentrations of amino acids in plasma whole blood of healthy neonatal foals from birth to two days. American Journal of Veterinary Research 55, 1012-9.