Publications by authors named "Brian D Nielsen"

The 2007 Horse NRC reduced cobalt (Co) requirements from 0.1 ppm to 0.05 ppm in dietary dry matter, though preliminary research suggested increasing dietary-Co enhanced fiber digestion in horses.

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Article Synopsis
  • The study investigated the effects of the bisphosphonate clodronate disodium (CLO) on bone health in juvenile sheep over 165 days, analyzing factors like bone turnover, density, and microstructure.
  • Forty juvenile sheep were divided into four treatment groups, including a control and three that received CLO at different times, while they were exercised regularly and monitored for physical changes.
  • Results showed no significant effects of CLO on the sheep's skeleton, with minor changes in serum bone biomarkers attributed to time and exercise, suggesting the need for further research on low-dose bisphosphonates in active juvenile populations.
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Studies have attempted to demonstrate the benefits of silicon on bone health using a wide range of Si amounts-provided in the diet or through supplementation-and several different animal species. Previous studies in humans have also demonstrated a positive correlation between Si intake and bone health measures. The aim of the current review is to determine the effective levels of Si intake or supplementation that influence bone health to better inform future study designs and guidelines.

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Background: Pathological fractures have been reported in equids with pituitary pars intermedia dysfunction (PPID) but their prevalence and pathogenesis is unknown.

Objectives: 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.

Study Design: Case-control study: five PPID equids and six aged and four young PPID control horses.

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Objective: To establish an orthopedic, preclinical, ovine model of controlled exercise using an equine walker.

Animals: 20 Dorset-Polypay sheep.

Procedures: Sheep underwent 11 weeks of exercise, 4 days per week.

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Objective: To determine the single-dose pharmacokinetics of clodronate disodium (CLO) in juvenile sheep and the plasma protein binding (PPB) of CLO in juvenile sheep and horses.

Animals: 11 juvenile crossbred sheep (252 ± 6 days) for the pharmacokinetic study. Three juvenile crossbred sheep (281 ± 4 days) and 3 juvenile Quarter Horses (599 ± 25 days) for PPB analysis.

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The effects of gait and diameter have been studied independently, but rarely together in equine circular exercise studies. This study aimed to determine the impact of diameter (10-m or 15-m) at various gaits (walk, trot, and canter) on stride frequency or forelimb stance duration. Nine mature horses were outfitted with Tekscan™ Hoof Sensors on their forelimbs during circular and straight-line exercise at various gaits on a clay and sand arena surface.

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Much research has been conducted in an attempt to decrease skeletal injuries in athletic horses. The objective of this literature review is to compile the findings of over three decades of research in this area, make practical recommendations, and describe how research can develop over the years. An initial study investigating the role of bioavailable silicon in the diets of horses in race training produced the unexpected finding of decreased bone mineral content of the third metacarpus subsequent to the onset of training.

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Racehorses are often supplemented extra iron with the expectation that the iron will improve overall performance and health. A survey of 120 U.S.

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Objective: To determine the effects of clodronate disodium (CLO) on control and recombinant equine interleukin-1β (IL-1β)-treated equine joint tissues.

Study Design: In vitro experimental study.

Sample Population: Cartilage explants, chondrocytes, and synoviocytes (n = 3 horses).

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Osteoclasts are unique and vital bone cells involved in bone turnover. These cells are active throughout the individual's life and play an intricate role in growth and remodeling. However, extra-label bisphosphonate use may impair osteoclast function, which could result in skeletal microdamage and impaired healing without commonly associated pain, affecting bone remodeling, fracture healing, and growth.

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Keeping horses outdoors on pasture full-time with free access to shelter holds numerous advantages over housing in stalls, promoting both better mental and physical health. One reason for these benefits is the potential for increased physical activity in horses outdoors on pasture versus those confined to stalls. However, it is not guaranteed the horse will take advantage of this opportunity for greater movement.

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Circular exercise is used in many equestrian disciplines and this study aimed to determine if circle diameter impacts juvenile animal forelimb bone and joint health. On day 0, 24 calves at 9 weeks of age were assigned the following exercise treatments: small circle (12 m clockwise), large circle (18-m clockwise), treadmill, or non-exercised control. Exercise was initiated at 1.

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The main factors influencing speed in athletes are stride length (SL) and stride rate (SR). However, conflict remains whether SL or SR is the key determinant of higher speeds. Quarter Horses (QH) generally reach higher speeds in their races than do Thoroughbreds (TB).

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A current trend in equine research is technology development to minimize the subjective nature of gait analysis. One such technology is the Tekscan Hoof System, which records force and area loaded by the hooves during motion. The objective of this study was to determine the test-retest reliability of the Tekscan Hoof System between two sessions, and the recordings within those sessions.

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Circular exercise can be used at varying gaits and diameters to exercise horses, with repeated use anecdotally relating to increased lameness. This work sought to characterize mean area, mean vertical force, and mean pressure of the front hooves while exercising in a straight line at the walk and trot, and small (10-m diameter) and large circles (15-m diameter) at the walk, trot, and canter. Nine mature horses wore Tekscan Hoof Sensors on their forelimbs adhered with a glue-on shoe.

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Digital radiographs are common for estimating bone mineral content (BMC) in horses with radiographic bone aluminum equivalents (RBAE). Processing algorithms are used to produce clearer images of digital radiographs in clinical settings, but this distorts RBAE. This study compared RBAE from digital radiographs to BMC from bone ash, and physical and digital morphology measurements.

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Short sprints performed during growth can increase bone strength, mineral density, and cortical widths, but their impact on joint health is not fully understood. Some studies have found joints of young animals are damaged by forced sprints, while others found confinement hindered joint development. This study aimed to determine the impact of short sprints on synovial fluid neopeptide collagenase cleavage of type I and II collagen (C1,2C) and cartilage glycosaminoglycan (GAG) content.

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Many forage types are available, typically divided into cool or warm season grasses and legumes, which can be fed as fresh pasture or after preservation. Testing for nutrient content confirms what should be supplemented to make up shortfalls. Although testing is recommended, it is not always practical.

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Conflicting research and anecdotal evidence have created disagreement among equestrians as to whether two-year-old horses should be trained and raced. The objective of this literature review is to evaluate epidemiological studies, as well as physiological data on equine bone, articular cartilage, and tendons to better determine the impact of training and racing two-year-old horses. The evaluation of numerous studies on the topic provides evidence that a horse which is trained or raced as a two-year-old has a lower risk of injury and better adapted tissues for the rigors of racing.

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Because leg injuries produce welfare concerns and impact production for broilers, numerous interventions have been suggested as potential solutions. One mineral which may affect bone quality is silicon. The objective of this study was to determine if supplementing bioavailable silicon could affect bone morphology, mineralization, and strength without negatively influencing welfare and meat quality.

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As osteoarthritis is a major cause of lameness in horses in the United States, improving collagen health prior to onset and increasing collagen turnover within affected joints could improve health- and welfare-related outcomes. Through its positive effects on bone mineral content and density and its role in increasing collagen synthesis, silicon (Si) may slow the development and progression of osteoarthritis, thereby reducing lameness. This study evaluated the hypothesis that Si supplementation would increase cartilage turnover through increased collagen degradation and formation markers, as well as bone formation markers, resulting in reduced lameness severity when compared with controls.

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Owing to selection for rapid growth and heavy muscle, bone deformities and injuries in broiler chickens are common and present a welfare concern. Recently, clinical quantitative computed tomography scans (QCTs) have been used for laying hens with significant, strong correlations between QCT-generated bone mineral content (BMC), bone ash, and analytical calcium. The objectives of this study were to determine if QCT-generated bone mineral density of tibias and femurs correlated to fat-free ash and if analytical Ca could be correlated to bone ash and digitally calculated density in immature broilers.

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While beneficial in rehabilitation, aquatic exercise effects on cartilage and bone metabolism in young, healthy horses has not been well described. Therefore, 30 Quarter Horse yearlings (343 ± 28 kg; 496 ± 12 d of age) were stratified by age, body weight (BW), and sex and randomly assigned to 1 of 3 treatments for 140-d to evaluate effects of aquatic, dry, or no exercise on bone and cartilage metabolism in young horses transitioning to an advanced workload. Treatments included nonexercise control (CON; n = 10), dry treadmill (DRY; n = 10), or aquatic treadmill exercise (H2O; n = 10; water: 60% wither height, WH).

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Previous research documented that furosemide negatively impacted calcium balance for 3 days but did not determine when calcium balance returned to baseline. This study hypothesized that furosemide's impact on calcium would return to control values before 7 days post-administration. Ten mature geldings were assigned to either control (CON, n = 5) or treatment (FUR, n = 5) for the first of two 8-day total collections in crossover design.

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