Osteocalcin is a non-collagenous protein found in bone and dentin, produced by osteoblasts, and plays a role in the regulation of bone mineralization and calcium ion homeostasis in horses. It is considered an important marker for bone turnover and is used in studies to assess bone health and metabolic activity. Osteocalcin levels in horses can vary with age, diet, and exercise, providing insights into bone metabolism and skeletal development. This page compiles peer-reviewed research studies and scholarly articles that explore the function, regulation, and clinical implications of osteocalcin in equine physiology and health.
Colbath AC, Fortin JS, Burglass CM, Panek C, Vergara-Hernandez FB, Johnson TN, Robison CA, Logan AA, Nelson NA, Nielsen BD, Schott HC.Pathological fractures have been reported in equids with pituitary pars intermedia dysfunction (PPID) but their prevalence and pathogenesis is unknown. Objective: To compare: (1) bone mineral density (BMD) in weight bearing and nonweight bearing bones in PPID+ equids and aged and young PPID- controls; and (2) biomechanical properties of the fourth lumbar vertebral body in PPID+ equids and aged PPID- equids. Methods: Case-control study: five PPID+ equids and six aged and four young PPID- control horses. Methods: PPID status was based on clinical signs and necropsy examination of the pituitary g...
Kamr AM, Dembek KA, Gilsenan W, Bozorgmanesh R, Hassan HY, Rosol TJ, Toribio RE.Hypocalcemia is a common finding in critically ill equine patients. Parathyroid hormone (PTH) helps to maintain calcium homeostasis in hypocalcemic patients by promoting renal calcium reabsorption and bone resorption. Increased serum PTH concentrations have been reported in critically ill people and animals, including horses and foals. It is unknown whether increased secretion of PTH is associated with markers of bone turnover in hospitalized foals. The goals of this study were to measure markers of bone resorption (C-terminal telopeptide of type I collagen [CTX-I]) and bone formation (osteoca...
Filipović N, Stojević Z, Plevnik N, Mašek T, Prvanović N, Tuček Z.The concentrations of carboxyterminal cross-linked telopeptide of type I collagen (CTx), osteocalcin (OCN), parathyroid hormone (PTH) and insulin-like growth factor (IGF-I) were measured in the blood serum of two age groups of mares during late pregnancy (70-50 days before foaling), during early lactation and at the peak of lactation (10-30 and 55-80 days after foaling, respectively). During late pregnancy, the PTH was higher in older (8-19 years old), compared to younger animals (3.5-4 years old) (P < 0.05). The OCN was higher in younger group during late pregnancy (P < 0.05). IGF-I was...
Frisbie DD, Mc Ilwraith CW, Arthur RM, Blea J, Baker VA, Billinghurst RC.Biomarkers have shown some in vivo promise for the detection of musculoskeletal injuries, but further study to assess biomarker levels in clinical orthopaedic disease is required. Objective: To assess 7 serum biomarkers for the detection of musculoskeletal injuries. Methods: Two- and 3-year-old racehorses were entered into the study (n = 238). Exit criteria were lack of training for >30 days, or completion of 10 study months. Data from horses with solitary musculoskeletal injuries and completion of >2 months were analysed. Musculoskeletal injury was considered intra-articular fragmentation (IA...
Pastoret V, Carstanjen B, Lejeune JP, Farnir F, Remy B, Reginster JY, Serteyn D, Gabriel A.The first aim of this study was to establish a profile of age-related normal serum concentrations of osteocalcin (OC) in Ardenner horses. For this first part, blood samples from 49 healthy Ardenner horses were collected. The second aim was to study two biochemical markers of bone metabolism, OC and a carboxy-terminal cross-linking telopeptide of type I collagen (CTX-I), in 30 young Ardenner horses during 1 year. Amongst them, 17 showed lesions of juvenile degenerative joint disease in the distal forelimbs. A specific radioimmunoassay for equine OC was used to measure the serum concentration of...
Inoue Y, Asai Y, Tomita M, Kuribara K, Kobayashi M, Kaneko M, Toba Y.In laboratory animals, man and cell culture experiments, milk basic protein was reported to suppress bone resorption and promote bone formation. However, no studies in horses have previously examined the effect of milk basic protein. Objective: To evaluate the effect of milk basic protein supplementation on bone metabolism in young Thoroughbred horses in training. Methods: Twenty 2-year-old horses in training were used for 90 days in this study. The treatment group was fed a basal diet with 1 g of milk basic protein and the control group a basal diet only. Blood samples were collected on Days ...
Fradette ME, Céleste C, Richard H, Beauchamp G, Laverty S.To evaluate the effects of continuous oral administration of phenylbutazone on serum and synovial fluid biomarkers of skeletal matrix metabolism in horses. Methods: 11 adult female horses without clinical or radiographic evidence of joint disease. Methods: Horses were randomly assigned to control or treatment groups. Phenylbutazone was administered orally twice daily at a dose of 4.4 mg/kg for 3 days to the treatment group and subsequently at a dose of 2.2 mg/kg for 7 days. Serum and radiocarpal synovial fluid samples were obtained at baseline and thereafter at regular intervals for 4 weeks. B...
Jackson BF, Dyson PK, Hattersley RD, Kelly HR, Pfeiffer DU, Price JS.To investigate the relationship between stage of estrous cycle and bone cell activity in Thoroughbreds. Methods: Blood samples collected from forty-seven 2-year-old Thoroughbred mares in training for racing. Methods: Blood samples were collected monthly (in April through September) from the mares. Stage of estrus was determined by assessing serum progesterone concentration. Bone cell activity was determined by measuring concentrations of 2 markers of bone formation (osteocalcin and the carboxy-terminal propeptide of type I collagen [PICP]) and a marker of bone resorption (the cross-linked carb...
Jackson BF, Blumsohn A, Goodship AE, Wilson AM, Price JS.Studies in humans have found circadian changes to be one of the most important sources of controllable preanalytical variability when evaluating bone cell activity using biochemical markers. It remains unclear whether similar circadian changes influence bone marker concentrations in the horse. The aim of this study was to characterize changes in serum concentrations of three biochemical markers of bone cell activity over a 24-h period in six 2-yr-old Thoroughbred mares, and to determine circadian variability in IGF-I, which regulates bone turnover. Three bone markers were measured in serum: os...
Caron JP, Peters TL, Hauptman JG, Eberhart SW, Orth MW.To determine the effects of orally administered glucosamine on concentrations of markers of bone and cartilage metabolism in Standardbred horses during race training. Methods: Twenty 16- to 20-month-old Standardbreds beginning race training. Methods: Horses were randomly assigned to 2 groups. One group received glucosamine hydrochloride (4 g, PO, q 12 h), and the second (control) group received glucose (4 g, PO, q 12 h). Serum samples were obtained prior to onset of the study (baseline) and at regular intervals for 48 weeks for determination of concentrations of keratan sulfate (KS), osteocalc...
Price JS, Jackson BF, Gray JA, Harris PA, Wright IM, Pfeiffer DU, Robins SP, Eastell R, Ricketts SW.This study describes longitudinal changes in serum levels of biochemical markers of bone cell activity in a group of 24 thoroughbred foals from birth to 18 months of age. The markers of bone formation included the type I collagen carboxy-terminal propeptide (PICP), the bone-specific isoenzyme of alkaline phosphatase (BAP), and osteocalcin (OC). Levels of the cross-linked telopeptide of type I collagen (ICTP), a marker of bone resorption, and the N-terminal propeptide of type III collagen (PNIIIP), a marker of soft tissue turnover, were also measured. Levels of all markers fell significantly be...
Fenton JI, Orth MW, Chlebek-Brown KA, Nielsen BD, Corn CD, Waite KS, Caron JP.The effect of longeing and glucosamine supplementation on known biological markers of joint disease was studied in yearling quarter horses. Twenty-one yearling quarter horses were randomly assigned to one of 4 treatments: 1) longeing (longeing 20 min daily) supplement control (LN); 2) longeing/glucosamine (LG); 3) walking (mechanical walker for 120 min daily (WN)); and 4) walking/glucosamine (WG). Oral glucosamine was administered at 5.5 g b.i.d. weeks 1-4, 3.5 g b.i.d. during weeks 5-6, and 2.0 g b.i.d. during weeks 7-8. Serum was obtained weekly for 8 wk and analyzed for keratan sulfate and ...
Chiappe A, Gonzalez G, Fradinger E, Iorio G, Ferretti JL, Zanchetta J.In this study, we assessed the potential value of free serum osteocalcin or bone gla protein (BGP), the most abundant non collagenous matrix protein found in bone and dentin, to reflect changes of bone turnover in thoroughbred horses. Levels of osteocalcin were analyzed in serum samples of 54 clinically normal animals divided into three groups (A, B, C) according to age: 8, 16-18 and 24-36 months, in order to determine the standard for young horses of different age and sex. Serum BGP was measured by an in-house developed double antibody radioimmunoassay using bovine antigen. The mean BGP level...
Black A, Schoknecht PA, Ralston SL, Shapses SA.Biochemical markers of bone turnover provide sensitive, rapid, and noninvasive monitoring of bone resorption and formation. Serum concentrations of osteocalcin (OC) reflect rates of bone formation, and urinary concentrations of the pyridinium crosslinks pyridinoline (Pyd) and deoxypyridinoline (Dpd) are specific and sensitive markers of bone resorption. These markers are age-dependent and are used to detect and monitor changes in the rates of bone turnover in a variety of orthopedic diseases in humans and may prove to have similar application in horses. This study examined age differences and ...
Porr CA, Kronfeld DS, Lawrence LA, Pleasant RS, Harris PA.Diet and exercise are two management factors that affect bone density and strength. We proposed that bone density and calcium status would be affected by deconditioning for 12 wk and by dietary Ca concentration. Eleven highly conditioned Arabian horses were taken out of training and placed in stalls for 12 wk. Horses were walked on a mechanical walker in two 30-min sessions, 7 d/wk. Diets were designated CC (.36% Ca) and HC (.62% Ca). Data were collected every 21 d. Serum or plasma were analyzed for total and ionized Ca, parathyroid hormone, osteocalcin, hydroxyproline, electrolytes, and blood...
Lepage OM, DesCôteaux L, Marcoux M, Tremblay A.The purpose of the study was to determine whether there were circadian variations in serum osteocalcin in normal horses and to determine whether it was important to regulate the time of blood sampling in clinical investigations. Osteocalcin or bone Gla-protein (BGP), alkaline phosphatase, total calcium, phosphate and total protein were studied over a 24 h period. Blood samples were taken every 60 min from nine adult Standardbred horses. There was a correlation between serum levels of alkaline phosphatase (r = 0.3, p less than 0.01), phosphate (r = 0.42, p less than 0.01) and serum osteocalcin ...
Frisbie DD, Mc Ilwraith CW, Arthur RM, Blea J, Baker VA, Billinghurst RC.Biomarkers have shown some in vivo promise for the detection of musculoskeletal injuries, but further study to assess biomarker levels in clinical orthopaedic disease is required. Objective: To assess 7 serum biomarkers for the detection of musculoskeletal injuries. Methods: Two- and 3-year-old racehorses were entered into the study (n = 238). Exit criteria were lack of training for >30 days, or completion of 10 study months. Data from horses with solitary musculoskeletal injuries and completion of >2 months were analysed. Musculoskeletal injury was considered intra-articular fragmentation (IA...
Porr CA, Kronfeld DS, Lawrence LA, Pleasant RS, Harris PA.Diet and exercise are two management factors that affect bone density and strength. We proposed that bone density and calcium status would be affected by deconditioning for 12 wk and by dietary Ca concentration. Eleven highly conditioned Arabian horses were taken out of training and placed in stalls for 12 wk. Horses were walked on a mechanical walker in two 30-min sessions, 7 d/wk. Diets were designated CC (.36% Ca) and HC (.62% Ca). Data were collected every 21 d. Serum or plasma were analyzed for total and ionized Ca, parathyroid hormone, osteocalcin, hydroxyproline, electrolytes, and blood...
Chiappe A, Gonzalez G, Fradinger E, Iorio G, Ferretti JL, Zanchetta J.In this study, we assessed the potential value of free serum osteocalcin or bone gla protein (BGP), the most abundant non collagenous matrix protein found in bone and dentin, to reflect changes of bone turnover in thoroughbred horses. Levels of osteocalcin were analyzed in serum samples of 54 clinically normal animals divided into three groups (A, B, C) according to age: 8, 16-18 and 24-36 months, in order to determine the standard for young horses of different age and sex. Serum BGP was measured by an in-house developed double antibody radioimmunoassay using bovine antigen. The mean BGP level...
Black A, Schoknecht PA, Ralston SL, Shapses SA.Biochemical markers of bone turnover provide sensitive, rapid, and noninvasive monitoring of bone resorption and formation. Serum concentrations of osteocalcin (OC) reflect rates of bone formation, and urinary concentrations of the pyridinium crosslinks pyridinoline (Pyd) and deoxypyridinoline (Dpd) are specific and sensitive markers of bone resorption. These markers are age-dependent and are used to detect and monitor changes in the rates of bone turnover in a variety of orthopedic diseases in humans and may prove to have similar application in horses. This study examined age differences and ...
Jackson BF, Blumsohn A, Goodship AE, Wilson AM, Price JS.Studies in humans have found circadian changes to be one of the most important sources of controllable preanalytical variability when evaluating bone cell activity using biochemical markers. It remains unclear whether similar circadian changes influence bone marker concentrations in the horse. The aim of this study was to characterize changes in serum concentrations of three biochemical markers of bone cell activity over a 24-h period in six 2-yr-old Thoroughbred mares, and to determine circadian variability in IGF-I, which regulates bone turnover. Three bone markers were measured in serum: os...
Price JS, Jackson BF, Gray JA, Harris PA, Wright IM, Pfeiffer DU, Robins SP, Eastell R, Ricketts SW.This study describes longitudinal changes in serum levels of biochemical markers of bone cell activity in a group of 24 thoroughbred foals from birth to 18 months of age. The markers of bone formation included the type I collagen carboxy-terminal propeptide (PICP), the bone-specific isoenzyme of alkaline phosphatase (BAP), and osteocalcin (OC). Levels of the cross-linked telopeptide of type I collagen (ICTP), a marker of bone resorption, and the N-terminal propeptide of type III collagen (PNIIIP), a marker of soft tissue turnover, were also measured. Levels of all markers fell significantly be...
Lepage OM, DesCôteaux L, Marcoux M, Tremblay A.The purpose of the study was to determine whether there were circadian variations in serum osteocalcin in normal horses and to determine whether it was important to regulate the time of blood sampling in clinical investigations. Osteocalcin or bone Gla-protein (BGP), alkaline phosphatase, total calcium, phosphate and total protein were studied over a 24 h period. Blood samples were taken every 60 min from nine adult Standardbred horses. There was a correlation between serum levels of alkaline phosphatase (r = 0.3, p less than 0.01), phosphate (r = 0.42, p less than 0.01) and serum osteocalcin ...
Jackson BF, Dyson PK, Hattersley RD, Kelly HR, Pfeiffer DU, Price JS.To investigate the relationship between stage of estrous cycle and bone cell activity in Thoroughbreds. Methods: Blood samples collected from forty-seven 2-year-old Thoroughbred mares in training for racing. Methods: Blood samples were collected monthly (in April through September) from the mares. Stage of estrus was determined by assessing serum progesterone concentration. Bone cell activity was determined by measuring concentrations of 2 markers of bone formation (osteocalcin and the carboxy-terminal propeptide of type I collagen [PICP]) and a marker of bone resorption (the cross-linked carb...
Caron JP, Peters TL, Hauptman JG, Eberhart SW, Orth MW.To determine the effects of orally administered glucosamine on concentrations of markers of bone and cartilage metabolism in Standardbred horses during race training. Methods: Twenty 16- to 20-month-old Standardbreds beginning race training. Methods: Horses were randomly assigned to 2 groups. One group received glucosamine hydrochloride (4 g, PO, q 12 h), and the second (control) group received glucose (4 g, PO, q 12 h). Serum samples were obtained prior to onset of the study (baseline) and at regular intervals for 48 weeks for determination of concentrations of keratan sulfate (KS), osteocalc...
Pastoret V, Carstanjen B, Lejeune JP, Farnir F, Remy B, Reginster JY, Serteyn D, Gabriel A.The first aim of this study was to establish a profile of age-related normal serum concentrations of osteocalcin (OC) in Ardenner horses. For this first part, blood samples from 49 healthy Ardenner horses were collected. The second aim was to study two biochemical markers of bone metabolism, OC and a carboxy-terminal cross-linking telopeptide of type I collagen (CTX-I), in 30 young Ardenner horses during 1 year. Amongst them, 17 showed lesions of juvenile degenerative joint disease in the distal forelimbs. A specific radioimmunoassay for equine OC was used to measure the serum concentration of...
Inoue Y, Asai Y, Tomita M, Kuribara K, Kobayashi M, Kaneko M, Toba Y.In laboratory animals, man and cell culture experiments, milk basic protein was reported to suppress bone resorption and promote bone formation. However, no studies in horses have previously examined the effect of milk basic protein. Objective: To evaluate the effect of milk basic protein supplementation on bone metabolism in young Thoroughbred horses in training. Methods: Twenty 2-year-old horses in training were used for 90 days in this study. The treatment group was fed a basal diet with 1 g of milk basic protein and the control group a basal diet only. Blood samples were collected on Days ...
Filipović N, Stojević Z, Plevnik N, Mašek T, Prvanović N, Tuček Z.The concentrations of carboxyterminal cross-linked telopeptide of type I collagen (CTx), osteocalcin (OCN), parathyroid hormone (PTH) and insulin-like growth factor (IGF-I) were measured in the blood serum of two age groups of mares during late pregnancy (70-50 days before foaling), during early lactation and at the peak of lactation (10-30 and 55-80 days after foaling, respectively). During late pregnancy, the PTH was higher in older (8-19 years old), compared to younger animals (3.5-4 years old) (P < 0.05). The OCN was higher in younger group during late pregnancy (P < 0.05). IGF-I was...
Fenton JI, Orth MW, Chlebek-Brown KA, Nielsen BD, Corn CD, Waite KS, Caron JP.The effect of longeing and glucosamine supplementation on known biological markers of joint disease was studied in yearling quarter horses. Twenty-one yearling quarter horses were randomly assigned to one of 4 treatments: 1) longeing (longeing 20 min daily) supplement control (LN); 2) longeing/glucosamine (LG); 3) walking (mechanical walker for 120 min daily (WN)); and 4) walking/glucosamine (WG). Oral glucosamine was administered at 5.5 g b.i.d. weeks 1-4, 3.5 g b.i.d. during weeks 5-6, and 2.0 g b.i.d. during weeks 7-8. Serum was obtained weekly for 8 wk and analyzed for keratan sulfate and ...
Kamr AM, Dembek KA, Gilsenan W, Bozorgmanesh R, Hassan HY, Rosol TJ, Toribio RE.Hypocalcemia is a common finding in critically ill equine patients. Parathyroid hormone (PTH) helps to maintain calcium homeostasis in hypocalcemic patients by promoting renal calcium reabsorption and bone resorption. Increased serum PTH concentrations have been reported in critically ill people and animals, including horses and foals. It is unknown whether increased secretion of PTH is associated with markers of bone turnover in hospitalized foals. The goals of this study were to measure markers of bone resorption (C-terminal telopeptide of type I collagen [CTX-I]) and bone formation (osteoca...
Fradette ME, Céleste C, Richard H, Beauchamp G, Laverty S.To evaluate the effects of continuous oral administration of phenylbutazone on serum and synovial fluid biomarkers of skeletal matrix metabolism in horses. Methods: 11 adult female horses without clinical or radiographic evidence of joint disease. Methods: Horses were randomly assigned to control or treatment groups. Phenylbutazone was administered orally twice daily at a dose of 4.4 mg/kg for 3 days to the treatment group and subsequently at a dose of 2.2 mg/kg for 7 days. Serum and radiocarpal synovial fluid samples were obtained at baseline and thereafter at regular intervals for 4 weeks. B...
Colbath AC, Fortin JS, Burglass CM, Panek C, Vergara-Hernandez FB, Johnson TN, Robison CA, Logan AA, Nelson NA, Nielsen BD, Schott HC.Pathological fractures have been reported in equids with pituitary pars intermedia dysfunction (PPID) but their prevalence and pathogenesis is unknown. Objective: To compare: (1) bone mineral density (BMD) in weight bearing and nonweight bearing bones in PPID+ equids and aged and young PPID- controls; and (2) biomechanical properties of the fourth lumbar vertebral body in PPID+ equids and aged PPID- equids. Methods: Case-control study: five PPID+ equids and six aged and four young PPID- control horses. Methods: PPID status was based on clinical signs and necropsy examination of the pituitary g...
