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1.
Seventeen Arabian weanlings were used to determine the influence of housing on third metacarpal bone mass. Animals were separated into three treatment groups: Pasture (n = 6), Stall (n = 5), and Partial-Pasture (n = 6). Radiographs of the left third metacarpus were taken every 28 d to determine radiographic bone aluminum equivalence (RBAE). Serum was collected every 14 d and analyzed for osteocalcin, carboxyterminal telopeptide of type I collagen (ICTP), and keratan sulfate. Hip and wither height, BW, and cannon circumference were measured every 28 d. Lateral RBAE in the pastured group increased linearly from d 0 to d 56 (P = 0.001). In the Pasture group, total RBAE increased from d 0 to 56 (P = 0.05) and medial RBAE tended to increase from d 0 to d 28 (P = 0.06). The Partial Pasture group increased from d 0 to 56 in medial (P = 0.02) and tended to increase in total RBAE (P = 0.08). Although the Stall group demonstrated an increase in total RBAE from d 0 to 56 (P = 0.04), the Partial Pasture group tended to have greater total RBAE than the Stall group at d 28 (P = 0.08), and the Pasture group had greater lateral RBAE at d 28 (P = 0.005) and 56 (P = 0.007) than did the Stall group. At d 28, medial RBAE was greater in the Pasture (P = 0.003) and Partial Pasture (P = 0.05) groups than in the Stall group. Pasture and Stall groups tended to decrease in osteocalcin (P = 0.06), whereas Partial Pasture weanlings decreased (P = 0.01) from d 0 to 56. All treatment groups decreased from d 0 to 56 in ICTP (P < 0.01). Pastured weanlings decreased from d 0 to 42 in serum keratin sulfate (P < 0.05), whereas the Stall group decreased from d 0 to 56 (P = 0.05). All treatment groups increased in wither height (P < or = 0.01), hip height (P < or = 0.001), and BW (P < or = 0.01). Both the Pasture and Partial Pasture weanlings demonstrated greater cannon circumference than Stall weanlings on d 28 (P < or = 0.05) and 56 (P < or = 0.005). These data demonstrate that pasture rearing or 12-h daily turnout is beneficial to maintaining and increasing bone mineral content in weanling Arabian horses.  相似文献   

2.
Thirty juvenile horses were paired by age within sex, and one horse from each pair was randomly assigned to either eST treatment or to a control group. The horses were “broke” to ride and trained in a regimen typical for young racehorses. Radiographs were taken on days 0, 32, 50, 64, 82, 96 and 128 of the study. Increase in total radiographic bone aluminum equivalence (RBAE) was significantly greater in eST treated horses than in the control group (P<.003). Increase in medial RBAE was also significantly greater due to eST treatment (P<.0001). Trends were apparent for increases due to eST treatment in dorsal RBAE (P=.07) and lateral RBAE (P=.07). Bone density was selectively increased in the dorsal, lateral and medial vs. the palmar cortex in the eST treated horses.  相似文献   

3.
An experiment was performed to determine the effects of Ca and P supplementation, inactivity, and subsequent aerobic exercise on bone metabolism in young, mature, and aged horses. Twelve stock-type geldings were blocked into three groups: 2 and 3, 7 to 11, and 15 to 21 years of age. Horses within age groups were evenly divided and randomly assigned to one of two dietary treatments; control (C) or Ca and P supplementation (T). Horses consuming C and T received about 133% and 275% of National Research Council (NRC) requirements for Ca and P, respectively. The trial consisted of eight 21-day periods. During periods I, II, and III, all horses were inactive and received no forced exercise. During periods IV, V, VI, VII, and VIII, all horses were placed on an ascending aerobic exercise regimen. Blood samples were taken at the beginning of period I and at 21-day intervals thereafter to determine serum concentrations of osteocalcin (OST) and type I carboxyterminal telopeptide (ICTP). Dorsal-palmar and lateral-medial radiographs were taken of the left third metacarpal at the beginning of period I and at 21-day intervals thereafter to monitor changes in bone densities, as indicated by radiographic bone aluminum equivalencies (RBAE). Mean serum OST was affected by age (P < .004) and the interaction of time and age (P < .006). Mean serum ICTP was affected by age (P < .001), time (P < .001), the interaction of time and age (P < .001); and the interaction of time and treatment (P < .05). There was an effect of treatment on overall mean medial (MRBAE; P < .04) and total (TRBAE; P < .04) RBAE. Overall mean dorsal RBAE (DRBAE; P < .001), palmar RBAE (PRBAE; P < .003), lateral RBAE (LRBAE; P < .001), MRBAE (P < .001), normalized MRBAE (P < .001), TRBAE (P < .05), and normalized TRBAE (P < .05) were affected by time. There was an effect of the interaction of time and age on overall mean DRBAE (P < .05), LRBAE (P < .002), MRBAE (P < .02), normalized MRBAE (P < .02), TRBAE (P < .005), and normalized TRBAE (P < .005). Overall mean DRBAE (P < .02) and PRBAE (P < .001) were affected by the interaction of time, treatment, and age. Biochemical and radiographic data from this experiment indicate that dietary Ca and P supplementation may affect bone remodeling in aerobically exercised horses of varying ages following a period of inactivity. Furthermore, the data indicate that bone in horses of varying ages responds differently to inactivity and exercise.  相似文献   

4.
An experiment was conducted to determine the effect of aerobic training after a sedentary period on bone remodeling and Ca and P balance and serum concentrations in varying ages of mature horses. Eighteen stock-type geldings were blocked into three age groups (6 to 10, 11 to 15, and 16 and older years of age), within two groups of nine, with horses randomly assigned to one of two exercise treatments, exercised for 112 days (control) or idle for 56 days followed by 56 days of exercise (treated). Blood samples were taken at the beginning of period I and at 14-day intervals thereafter to determine serum concentrations of osteocalcin (OST), Ca, and P. Dorsal-palmar and lateral-medial radiographs were taken of the left third metacarpal bone on days 0, 56, 84, and 112 to monitor changes in bone density. Total fecal and urine collections were taken for 72 hours on days 0, 56, and 112. Mean serum OST concentrations were affected by treatment (P<.02), time (P<.001); and the interactions of treatment and age (P<.003), time and treatment (P<.001), and time, treatment, and age (P<.001). Overall dorsal (DBRAE), palmar (PRBAE), and medial (MRBAE) RBAE means were affected by time (P<.001), as was overall lateral (LRBAE) RBAE mean (P<.005). Overall DBRAE and PRBAE means were lower (P<.04) at day 56, and higher at day 84 (P<.02) and 112 (P<.001) as compared to day 0. Mean serum Ca concentration was affected by treatment (P<.003) and time (P<.001). Mean serum P concentration was affected by the interaction of time and treatment (P<.001). Mean apparent daily Ca balance was affected bythe interaction of time, treatment, and age (P<.03). Mean apparent daily P balance was affected by treatment (P<.02) and time (P<.001). Biochemical and radiographic data from this experiment suggest that bone remodeling as well as Ca and P balance and serum concentrations are affected by age, inactivity, and exercise in mature horses.  相似文献   

5.
Seven untrained Standardbred horses were used in a training programme of 6 weeks to evaluate the effects of exercise and training on bone metabolism. The horses were exercised on a treadmill according to a standardized exercise test (SET 1: six incremental steps, 5 min duration each; start 5 m/s, increase 1 m/s). SET 1 was followed by a training programme of 6 weeks. In alternating order: high-speed exercise (HSE): 15 min duration, start at VLa4, continuous increase in speed every 60 s by 0.3 m/s (14 incremental steps); low-speed exercise (LSE): constant velocity at VLa2.5, duration: approximately 60-90 min (total training programme: eight HSE and eight LSE sessions). SET 2 finished the training programme and a deconditioning period of 12 weeks followed. Blood samples for lactate, total plasma protein (TPP), osteocalcin, and ICTP (cross-linked C-telopeptide of type I collagen) were collected. ICTP increased during SET 1 and SET 2, whereas osteocalcin decreased to below resting concentration 24 h after SET 1. A rise in ICTP was observed during LSE 1 and LSE 8, which was followed by a drop 24 h after exercise. No changes in osteocalcin were noted during LSE 1, but 24 h after LSE 1 osteocalcin dropped to below pre-exercise levels. LSE 8 resulted in an increase in osteocalcin, followed by a drop 24 h after LSE 8. Osteocalcin and ICTP were not affected by HSE. Baseline osteocalcin levels dropped during the course of training. The acute response of biochemical bone markers indicates a direct influence of a single bout of exercise on bone metabolism.  相似文献   

6.
Although previous research suggests that short bouts of high-speed exercise will increase bone mass in horses, little research has been conducted to determine the impact of endurance exercise on bone. Although many in the equine industry believe that months of slow training will increase bone strength, we hypothesized that endurance training would not alter bone mineral content as determined through optical density. Eleven 2-year-old Arabians were split into two groups, Exercised (E, 6 geldings) or Control (C, 5 fillies), with radiographs taken on day 0 for estimation of bone mineral content by radiographic bone aluminum equivalence (RBAE). The E horses were then trained on a high-speed treadmill for 90 days; training consisted of walking (1.6 m/second), trotting (4 m/second) and cantering (8 m/second) at increasing distances until the target of 60 km/day was met. On day 90, E horses were confined to 9 × 14 m dry lots and placed on a regular exercise schedule, including a 60-km endurance test once every 3 weeks. The C horses remained on pasture throughout the study. On day 162, radiographs were made again on all 11 horses. No differences between treatments, days, or interactions were noted in any cortex or the total RBAE, suggesting that endurance exercise does little to alter bone optical density compared with free-choice exercise on pasture.  相似文献   

7.
This experiment was conducted to determine if additional mineral supplementation during early training would increase mineral retention and improve the strength of bone as indicated by the mineral content of the third metacarpal. Twelve previously untrained Quarter Horse geldings were randomly divided into two groups, broke to ride, trained to gallop on the track and maintained in training for four 28-day periods. One group of four horses served as controls and was fed a ration averaging 28.3 g of Ca/day and 21.9 g P/day while in training. Eight other horses were fed a ration averaging 34.9 g Ca/day and 26.4 g P/day while in training. Feed, feces and urine were analyzed to determine mineral balance. Radiographs were taken of the left front leg to examine bone density as indicated by radiographic bone aluminum equivalence (RBAE). The high mineral treatment group retained more Ca than controls (P<.05) at days 56 and 84. An increase in Ca retention would prove beneficial in facilitating the bone remodeling process and overall skeletal growth. Additionally, the high mineral group had a greater increase in total RBAE (P<.05) when compared to the control group. Hence, it appears that benefit was derived from feeding the greater amount of Ca to the young racehorse at the onset of training.  相似文献   

8.
Intermittent administration of parathyroid hormone (PTH) is an anabolic therapy for osteoporotic conditions in humans. This study evaluated the effects of equine PTH fragment (ePTH-1-37) administration on bone metabolism in 12 healthy horses. Six horses each were treated once daily for 120days with subcutaneous injections of 0.5μg/kg ePTH-1-37 or placebo. Blood was collected to determine ionized calcium (Ca(++)), total Ca (Ca(T)), inorganic phosphorus, serum equine osteocalcin (eOC), carboxy-terminal telopeptide of type I collagen (ICTP), bone-specific alkaline phosphatase, and carboxy-terminal cross-linked telopeptide of type I collagen. Bone mineral density (BMD) was determined with dual X-ray absorptiometry of the metacarpus and calcaneus. Significantly higher blood Ca(++) and plasma Ca(T) concentrations were measured 5h after ePTH-1-37 administration compared to placebo. Higher serum eOC concentrations were found for ePTH-1-37 treatment at days 90 (P<0.05) and 120 (P=0.05). Significantly higher serum ICTP levels were observed with ePTH-1-37 treatment at days 60 and 90. For both study groups, BMD increased significantly in the calcaneus. Long-term use of ePTH-1-37 seemed to have no negative effects on bone metabolism in healthy horses. The absence of undesirable side effects is the premise to ensure safety for further clinical investigations in horses with increased bone resorption processes.  相似文献   

9.
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 levels. There was a very marked individual effect on serum levels of osteocalcin and alkaline phosphatase (p less than 0.01). This effect was present for phosphate levels but not significant for total calcium. The individual effect was lower and time effect was higher for serum osteocalcin if the subjects were divided into two age groups, one of horses of five years or less (n = 4) and a second group older than five years (n = 5). In both groups a circadian rhythmicity was observed. Serum osteocalcin showed a biphasic pattern. Levels were constant during daytime (light period) and underwent significant variations during the night (dark period), going through a nadir at 2000 h and through a maximum peak at 0500 h. It was concluded that in normal horses the blood osteocalcin level follows a circadian variation. Also daytime (light period) seems to be the more appropriate period for blood sampling.  相似文献   

10.
The purpose of this study was to investigate, if different Ca concentrations in diets have an influence on bone mineral metabolism in growing goats and sheep. Twelve growing goats and sheep were divided into two groups. The two control groups received 6.1 g calcium/day (nG) and 6.7 g calcium/day (nS) for goat and sheep respectively. The other two groups were fed 17.7 g calcium/day (hG) and 18.5 g calcium/day (hS). Blood samples were taken 2, 4, 5 and 6 weeks after the start of the experiment. In serum Ca and vitamin D were determined and bone metabolism was measured using crosslinked carboxyterminal telopeptide of type I collagen (ICTP), crosslaps, bone-specific alkaline phosphatase and osteocalcin (OC). Bone mineral density (BMD) was quantified using quantitative computed tomography. Bone resorption marker (ICTP) concentrations were significantly different between both groups control sheep/control goat and hS/hG, but no significant differences were evident in the different feeding groups within one species. OC concentrations showed a similar course to ICTP. The goats had significantly higher concentrations compared with sheep. The 1,25 dihydroxyvitamin D (VITD) concentrations in both hCa groups were significantly lower than in the control groups. BMD increased in the hCa groups compared with the control groups with the time, but significant differences were only evident in sheep in week 2. The hCa diet did not induce differences between the groups within one species for all bone markers. The control Ca diet seems to improve the active Ca absorption via VITD whereas the hCa diet leads to a higher amount of Ca apparently digested. Higher BMD was only observed in group hS compared with nS.  相似文献   

11.
Twelve Quarter Horses, 18 to 24 mo of age and having an average body weight of 460+/-12 kg, were randomly assigned to one of two exercise treatments (control and exercise) to study the effect of initiation of exercise training in young horses on vitamin K status. The control treatment consisted of hand-walking the horses 7 min/d and 5 d/wk for 180 d. Exercise consisted of the following treadmill exercise regimen: 2 min at 4.5 to 5.4 m/s, 3 min at 13.4 to 14.3 m/s, and 2 min at 4.5 to 5.4 m/s on 5 d/wk for 180 d. Both groups were allowed free access to brome grass hay (273 mg of phylloquinone/100 g) individually. Additionally, the exercise group was fed .45 kg of a grain-mix concentrate (40 mg of phylloquinone/100 g) on the days they were exercised. Jugular venous blood samples were collected at d 0, 30, 60, 90, 120, 150, and 180. Blood samples were analyzed for total serum osteocalcin and vitamin K status via the hydroxyapatite binding capacity of serum osteocalcin calculated as follows: Hydroxyapatite binding capacity of serum osteocalcin = [(total serum osteocalcin - serum osteocalcin following extraction of serum with hydroxyapatite)/total serum osteocalcin] x 100. All horses were killed with an overdose of sodium pentobarbital on d 180. Computed tomographic osteoabsorptiometry was used to measure relative bone density distribution on the surface of the distal radial carpal bone, proximal third carpal bone, and the distal third metacarpal condyle. Relative bone density distribution was measured in Hounsfield units and categorized as low-, medium-, and high-density bone corresponding to 800 to 1,199, 1,200 to 1,299, and 1,300 to 3,000 Hounsfield units, respectively. Carpal and metacarpophalangeal joints were assigned a score of 0 (normal) to 3 (severe) that reflected the presence and severity of joint lesions. Hydroxyapatite binding capacity of serum osteocalcin and serum osteocalcin were unchanged over the 180-d period in both groups. Exercised horses had a higher percentage of high density bone (P < .01) and a lower percentage of low density bone (P < .01) on the surface of the third metacarpal condyle and a higher cumulative gross lesion score (P < .01) in the metacarpophalangeal joint than controls. There were no differences between treatments in relative bone density distribution in the carpal bones, or cumulative gross lesion score of the carpal joints. No significant correlation was present between the serum measures, osteocalcin and hydroxyapatite binding capacity of serum osteocalcin, and the bone measures, relative bone density distribution and joint gross lesion score.  相似文献   

12.
This study was conducted to determine physiologic responses reflective of bone metabolism during the onset of training and to relate those responses to the mineral requirements of young racehorses. Ten previously untrained Quarter Horse geldings were put into race training. They were fed a diet balanced to meet NRC recommendations for young horses in training. Feed, feces and urine were collected, weighed and analyzed over the experiment to determine mineral balance. Radiographs were taken of the left front leg to determine mineral content of a cross-sectional area of the third metacarpal. Blood samples were taken to determine osteocalcin, parathyroid hormone, 25-hydroxyvitamin D, Ca and inorganic P concentrations. Horses were gentled to ride, trained to gallop on the track and maintained in training for four 28-day periods. Blood serum was collected every 14 day, while radiographs and 72-hr total collections of urine and feces were taken every 28 d. Radiographs demonstrated that mineral content was lowest at day 56 in the dorsal, palmar and medial cortices of the third metacarpal. Urinary Ca declined dramatically from day 0 to day 28, then remained constant to day 56, before decreasing at day 84. Fecal Ca peaked at day 28 and remained elevated above day 0 amounts until day 112. calcium retention was negative at day 0, became slightly positive by day 28 and increased through day 112. Phosphorus and Mg balance remained relatively unchanged throughout the duration of the study. This study demon-strated changes in the mineral content of the third metacarpal and Ca balance during early training and suggests that further studies be performed.  相似文献   

13.
Bone responds to exercise with changes in bone (re-)modelling, which might be monitored non-invasively with biochemical bone markers. The aim of this study was to evaluate the influence of exercise on serum osteocalcin and serum carboxy-terminal cross-linked telopeptide of type I collagen generated by matrix metalloproteinases (CTX-MMP) concentration in young racehorses. Seventy-one 2 to 4-year-old Thoroughbreds were included in this prospective infield study. Blood sampling was performed six times (i.e. six sampling cycles) during a 9-month period. Serum samples were analysed with commercial osteocalcin and CTX-MMP radioimmunoassays. Two-year-old racehorses had higher serum osteocalcin and CTX-MMP values than 3-year-old horses. Gender and training amplitude did not significantly influence serum osteocalcin and CTX-MMP values. Two-year-old horses showed an increase in osteocalcin values between cycles 2 and 3 and an increase in serum CTX-MMP values between cycles 1 and 2. Serum osteocalcin and CTX-MMP concentrations decreased between cycles 4 and 5, and 5 and 6. Three-year-old horses showed an increase in serum osteocalcin levels between cycles 3 and 4 and an increase in serum CTX-MMP concentrations between cycles 1 and 2, and 3 and 4. Serum osteocalcin levels decreased between cycles 5 and 6, whereas serum CTX-MMP levels decreased between cycles 4 and 5, and 5 and 6. Two- and three-year-old horses showed a decreased osteocalcin/CTX-MMP ratio between cycles 1 and 2. Moreover, 2-year-old horses showed an increase in the osteocalcin/CTX-MMP ratio between cycles 2 and 3. Sore shin formation did not significantly influence serum osteocalcin and CTX-MMP values. Serum osteocalcin and CTX-MMP are promising bone markers for monitoring exercise induced changes in equine bone metabolism.  相似文献   

14.
A safe, non-invasive method for the accurate measurement of bone mineral content in the third metacarpal bone of the horse is described. The technique involves scanning the bone with a single photon beam from an Americium-241 source. Data were obtained from the excised metacarpal bones from both forelimbs of 50 normal and seven lame horses. Measurements were made in vivo on eight normal and seven lame horses and on one experimental horse with osteopenia induced by partial weightlessness in a flotation tank. In the normal horses bone mineral content altered with age, particularly in the first six months of life. There were also differences according to the site of scanning on the metacarpus. The contribution of the splint bones to the total bone mineral content was less than 2 per cent distal to the mid-point of the metacarpus, but in the proximal shaft it increased to 12 per cent. No significant differences were noted either between right and left limbs, or between male and female animals. A reduction in bone mineral content was demonstrated in the affected leg of horses with chronic lameness and with osteopenia induced by weightlessness. The bone mineral content (g/cm) correlated well with the ash content (mg/100 mg dry bone weight), the specific gravity and the apparent transverse velocity of ultrasound (m/sec) through the bone. A measure of bone mineral density (g/cm3) was calculated from the bone mineral content and cross sectional area of the bone to overcome the individual differences in size of the metacarpus.  相似文献   

15.
Concentrations of the cross-linked carboxyterminal telopeptide of type I collagen (ICTP) and osteocalcin (OC) have been determined in the serum of one hundred clinically healthy adult Draught or Warmblood horses. The correlation between these two markers has been evaluated and the influence of gender, age and type of horse described. No significant variations were observed between animals of different sex, but a significant inverse correlation (P<0.0001) with age was observed for both measured parameters. After correction for age, serum levels of OC were found to be lower in Draught [adjusted least square mean (LSM)=6.612μg. L−1] than in Warmblood horses (adjusted LSM=8.596μg.L−1), whereas levels of ICTP were higher in Draughts (adjusted LSM=8.035pg.L−1) than in Warmbloods (adjusted LSM=6.643μg.L−1). A significant correlation (P<0.0001) was observed between OC and ICTP. This correlation was stronger if the type of horse was taken into account in the statistical model. The ratio OC:ICTP was independent of gender and age. A higher OC:ICTP ratio in Warmbloods compared to the Draught horses might reflect a higher bone remodelling level of horses submitted to regular daily work. It was concluded that ICTP and OC are influenced by the type of horse, and probably reflect a physiological difference in bone remodelling between these animals.  相似文献   

16.
Serum markers of bone metabolism were analyzed in Arabian horses from birth through 2 yr. The marker of bone formation utilized was osteocalcin (OC), and the marker for degradation was carboxy-terminal pyridinoline cross-linked telopeptide region of type I collagen (ICTP). Blood samples were taken via jugular venipuncture the day of birth, d 15, d 30, d 45, d 60, and every 30 d thereafter through d 720. Serum was obtained and analyzed for OC and ICTP. Osteocalcin concentrations increased immediately after birth, were variable, and returned to baseline by d 300. By d 330, concentrations of OC began to decrease from d 0 and stayed at this lower concentration through d 510. From d 540 through 720, OC concentrations were similar to baseline. A decrease from baseline (d 0) in ICTP concentrations was seen on d 60, and ICTP continued to decline in concentration through d 720. Therefore, concentrations of OC and ICTP decreased over time as previously reported, and this study characterizes those changes on a monthly basis. Variability and general concentrations for OC and ICTP obtained in this study will provide valuable information for future experimental design and use of these markers in young horses and will aid researchers in determining treatment effects without being confounded by changes in concentrations caused by growth.  相似文献   

17.
Three experiments were conducted to evaluate serum osteocalcin concentrations in normal weanling and yearling Quarter Horses. In Experiment 1, jugular blood samples were taken at 3 hr intervals for 24 hr to evaluate diurnal changes in serum osteocalcin concentration of foals (n=3) and yearlings (n=5). In Experiment 2, twelve Quarter Horse foals were weaned at 4 months of age to determine the influence of sex, weaning and method of weaning of serum osteocalcin concentration. The third experiment utilized fifteen yearling Quarter Horses (7 geldings, 8 fillies) in a two-phase trial to evaluate normal peripheral osteocalcin concentration in sedentary and exercising horses. In Experiment 1, there was no detectable variation (P>.05) in serum osteocalcin concentration during the 24 hr sample period in either age group. In Experiment 2, colts had greater (P<.05) osteocalcin concentrations than fillies at weaning. Method of weaning did not alter mean serum osteocalcin concentration (P>.1). Serum osteocalcin concentrations declined (P<.05) in all horses following weaning but returned to preweaning levels within one week. In Experiment 3, sedentary horses had similar (P>.1) osteocalcin concentrations on d 0, 45 and 90. Serum osteocalcin concentrations of sedentary horses were not affected by sex (P>.1). During exercise, fillies had greater (P<.05) osteocalcin concentrations than geldings. Serum osteocalcin concentrations of all horses declined linearly (P<.0001) during the 90 d exercise period. Osteocalcin may be useful as a tool to assess bone metabolism during growth and physical conditioning in horses. However, variability in serum osteocalcin concentrations due to age, sex and level of activity suggest that these factors must also be considered.  相似文献   

18.
OBJECTIVE: To report tissue gentamicin concentrations after intraosseous (IO) perfusion in standing horses. STUDY DESIGN: In vivo study. ANIMALS OR SAMPLE POPULATION: Twelve horses. METHODS: Sedated horses had a cannulated cortical bone screw inserted into the dorsolateral aspect of the treated metacarpus and a tourniquet applied proximally. Gentamicin (2.2 mg/kg) diluted in sterile saline solution (0.1 mL/kg) was infused through the screw. Two horses were euthanatized at each time interval: 0, 2, 6, 12, 24, and 36 hours. Synovial fluid and bone samples were collected distal to the screw from both forelimbs. Gentamicin concentrations were measured using fluorescence polarization immunoassay. RESULTS: The highest synovial fluid gentamicin concentrations were 385+/-273 microg/mL (mean+/-SD) in the metacarpophalangeal joint, 225+/-205 microg/mL in the proximal interphalangeal joint, 215+/-205 microg/mL in the distal interphalangeal joint, 382+/-195 microg/mL in the digital flexor tendon sheath, and 206+/-161 microg/mL in the navicular bursa. The highest bone concentrations of gentamicin were 55+/-30 microg/g in the distal metacarpus, 34+/-27 microg/g in the proximal, 16+/-15 microg/g in the middle, and 16+/-2.2 microg/g in the distal phalanges, and 27+/-17 microg/g in the proximal and 24+/-11 microg/g in the distal sesamoid bones. CONCLUSION: Standing IO perfusion of gentamicin resulted in local antibiotic concentrations in the synovial structures and bones of the distal aspect of the limb that exceed the reported minimum inhibitory concentration of pathogens commonly implicated in equine orthopedic infections. CLINICAL RELEVANCE: Standing IO perfusion of gentamicin in the distal aspect of the limb should be considered for treatment of orthopedic infections of this region in horses.  相似文献   

19.
An inquiry was carried out to assess the concentrations of plasma metabolites related to bone remodelling in 21 saddle horses of Warmblood breed aged 4-26 years, five draught horses of Ardennes breed aged 4-10 years, and 10 Ardennes foals aged 9-11 months. They were fed according to normal feeding practice in Belgium. The changes in some bone remodelling plasma metabolite concentrations were studied when an unbalanced diet was offered and later corrected for four Warmblood horses. Bone formation was evaluated by bone alkaline phosphatase (BALP), total alkaline phosphatase (TALP) and osteocalcin (bone gla-protein, OC). Bone resorption was assessed by hydroxyproline (HYP). Total calcium, ionized calcium, phosphorus (P) and 25-hydroxyvitamin D3 [25-(OH)D] concentrations were more or less constant. The comparison of four bone remodelling factors between the Ardennes and Warmblood horses showed higher concentrations in the Ardennes breed. Bone marker concentrations decreased according to age. The correction of the unbalanced Ca : P diet induced inconsistent effects at plasma level. The interpretation of the different bone parameters appeared to be difficult if not associated with other parameters such as a complete anamnesis and clinical examination of the animal in addition to dietary evaluation.  相似文献   

20.
In this study, blood-borne biochemical markers were used to track comparative rates of bone turnover in horses fed differing amounts of Ca, P and Mg. Bone turnover was tracked by serum osteocalcin; bone resorption by the carboxyterminal telopeptide of type I collagen (ICTP); and bone formation by the carboxyterminal propeptide of type I procollagen (PICP). Twenty-one longyearling Quarter Horses were blocked by gender and age, randomly assigned to one of four diets and subjected to 128 d of race training. The study was conducted in 32-d periods, each consisting of 28 d of race training followed by a 4-d fecal and urine collection, or a 4-d rest period. Blood samples were taken weekly during the training period. Serum and plasma samples were analyzed for biochemical markers of bone activity using RIA procedures. Onset of training resulted in elevated blood concentrations of ICTP, PICP and osteocalcin. Concentrations of ICTP and PICP were greater during the first 64 d of training, indicating increased bone activity during the first half of the training period. Horses with the greatest intake of minerals exhibited greater concentrations of PICP (bone formation marker) and lesser concentrations of ICTP (bone breakdown marker). Further, ICTP, PICP and osteocalcin concentrations decreased dramatically following 4-d of confinement and relative inactivity. Therefore it appears that feeding minerals at levels greater than current NRC recommendations provided a protective effect on the developing skeleton of the young racehorse. Additionally, the biochemical markers used in this study were sensitive enough to track daily changes in bone activity resulting from daily changes in stress to the skeleton.  相似文献   

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