L.A. Baker

THE DIGESTIBILITY AND MINERAL AVAILABILITY OF MATUA, BERMUDA GRASS, AND ALFALFA HAY IN MATURE HORSES

Summary Six mature stock-type geldings, 10 to 14 yr of age, were assigned treatments within two simultaneous 3 x 3 Latin square design experiments to determine the digestibility and mineral availability of Matua (M), Coastal Bermuda grass (B) and alfalfa (A) hay. Horses were fed equal amounts of hay twice daily at 2% BW/d. Bermuda grass contained less (P

THE EFFECT OF CALCIUM AND PHOSPHORUS SUPPLEMENTATION, INACTIVITY, AND SUBSEQUENT AEROBIC TRAINING ON THE MINERAL BALANCE IN YOUNG, MATURE, AND AGED HORSES

Abstract A randomized complete block design experiment was conducted to determine the effect of Ca and P supplementation, inactivity, and subsequent aerobic exercise on Ca and P serum concentrations, and balance and digestibilities in young, mature, and aged horses. Twelve stock-type geldings were blocked into three age groups: 2 and 3, 7 to 11, and 15 to 21 years of age. Two groups of six horses were randomly assigned to either control (C) or mineral supplemented (T) diet. Horses consuming C received about 133% of National Research Council (NRC) requirements for Ca and P, while horses consuming T received about 275% of NRC requirements for Ca and P. The trial consisted of eight 21-d periods. During periods I, II, and III, all horses were inactive, and during periods IV, V, VI, VII, and VIII, all horses performed an ascending aerobic exercise regimen. Serum samples were taken at the beginning of period I and at 21-d intervals thereafter for determination of serum Ca and P. Total fecal and urine collections were taken for 72 h at the beginning of period I and at 21-d intervals thereafter for determination of Ca and P balance. Overall mean apparent Ca balance was affected by treatment (P

The effect of calcium and phosphorus supplementation on bone metabolism in young, mature, and aged horses during inactivity and subsequent aerobic training

Abstract 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