Progress 10/01/00 to 09/30/04
Outputs
In experiment 1, sixteen yearling Quarter Horses were used in a split-plot designed experiment to determine the effects of exercise on bone metabolism. Horses were blocked by sex and BW and then randomly assigned to either the exercised (EX) or non-exercised (NEX) treatment. Radiographs of the third metacarpal were taken on d 0, d 45 and d 90 for determination of radiographic bone aluminum equivalence (RBAE). Although no differences between treatments were found in RBAE within days measured, a significant decrease in RBAE was observed between d 0 and 90 for the NEX horses. This decrease in bone optical density throughout the duration of the trial would indicate that stalling and lack of exercise may result in a greater loss of bone mineral content as compared to the horses forced to exercise. In experiment 2, this study examined the effect of phytase supplementation on dry matter and phosphorus digestibility in mature horses. Four mature sedentary Quarter Horse geldings
were used in a 4x4 Latin square design experiment. The treatments were as follows: 1) control (0) with no phytase added to the basal ration, 2) 300 FTU/kg added to the basal ration, 3) 600 FTU/kg added to the basal ration, and 4) 900 FTU/kg added to the basal ration. Phosphorus digestibility was not improved with the addition of supplemental phytase (P>.05). In experiment 3, Eight Quarter Horse yearlings were used in a split-plot designed experiment to estimate fecal output (FO) and dry matter digestibility (DMD) using different methods of chromic oxide (Cr2O3) administration. The two methods of Cr2O3 application were: 1) mixed with the concentrate during pelleting (mixed diet) and 2) top-dressed on the concentrate prior to feeding (top-dressed diet). Calculated FO was greater in the mixed diet versus the top-dressed. Consequently, DMD was lesser in the mixed diet versus the top-dressed. However, measured FO did not differ between treatments. Within the mixed diet, calculated FO was
greater than the measured FO. It appears from these data that the use of Cr as an external marker may result in an overestimation of fecal output and subsequent underestimation of dry matter digestibility. In experiment 4, fifteen yearling Quarter Horses were used in a split-plot designed experiment evaluate the response of calcium (Ca) metabolism to varying concentrations of Ca in the diet. Diets were formulated to contain Ca levels at 115% (high, H), 100% (basal, B), and 85% (low, L) of NRC requirements. The 25-week trial consisted of three 72-hour collection periods at day 0 (period I, 12 months of age), day 90 (period II, 15 months of age), and day 180 (period III, 18 months of age) during which complete urine and fecal collections were taken. Results from this study demonstrate an increased Ca retention with increased intake during the first two periods. During period III however, horses consuming diets at or below NRC recommendations, as a percentage of the total diet,
experienced an increased absorption, retention, and digestibility of Ca during this time of increased growth rate.
Impacts
Data from this trial may better aid in defining the exercise requirements for young, growing horses in order to optimize bone growth and integrity.
Publications
- J.C. Henry, S.R. Cooper, D.W. Freeman and J.R. Kropp. 2003. Effects of Exercise on Bone Metabolism in Yearling Horses. Prof. Anim. Sci. 19: 435-438.
- D.P. Patterson, S.R. Cooper, D.W. Freeman, R.G. Teeter. 2002. Effects of phytase supplementation on dry matter and phosphorus digestibility in horses. J. Equine Vet. Sci 22:456-459.
- D.P. Patterson, S.R. Cooper, D.W. Freeman, R.G. Teeter. 2002. Estimation of fecal output and dry matter digestibility using various chromic oxide marker methods in the horse. Prof. Anim. Sci. 18:176-179.
- A.D. Moffett, S.R. Cooper, D.W. Freeman and H.T. Purvis. 2002. Response of yearling quarter horses to varying concentrations of dietary calcium. Prof. Anim. Sci. 18:277-281.
|
Progress 10/01/02 to 09/30/03
Outputs
Sixteen yearling Quarter Horses were used in a split-plot designed experiment to determine the effects of exercise on bone metabolism. Horses were blocked by sex and BW and then randomly assigned to either the exercised (EX) or non-exercised (NEX) treatment. Diets were formulated to meet or exceed NRC requirements for yearlings in moderate growth. Diets were fed at 2.5% of BW which consisted of a pelleted concentrate, prairie grass hay, and alfalfa cubes in a 50:30:20 ratio, respectively. Radiographs of the third metacarpal were taken on d 0, d 45 and d 90 for determination of radiographic bone aluminum equivalence (RBAE). Blood was taken every 14d throughout the trial to measure serum ICTP and PICP concentrations. Although no differences between treatments were found in RBAE within days measured, a significant decrease in RBAE was observed between d 0 and 90 for the NEX horses. This decrease in bone optical density throughout the duration of the trial would indicate
that stalling and lack of exercise may result in a greater loss of bone mineral content as compared to the horses forced to exercise. Consequently, the EX horses may be better prepared for future mechanical stresses placed upon them.
Impacts
Data from this trial may better aid in defining the exercise requirements for young, growing horses in order to optimize bone growth and integrity.
Publications
- J.C. Henry, S.R. Cooper, D.W. Freeman and J.R. Kropp. 2003. Effects of Exercise on Bone Metabolism in Yearling Horses. Prof. Anim. Sci. 19: 435-438.
|
Progress 10/01/01 to 09/30/02
Outputs
Sixteen yearling Quarter Horses were used in a split plot designed experiment to determine the effect of exercise on bone metabolism. Horses were blocked by age and weight, and then randomly assigned to either the exercised (EX) or non-exercised (NEX) treatment. Diets were formulated to meet or exceed NRC requirements for yearlings in moderate growth. Diets consisted of a pelleted concentrate, prairie grass hay, and alfalfa cubes fed in a 50:30:20 ratio at 2.5% of body weight. The 90-d trial consisted of three 72-h collection periods on d 0 (period I), d 45 (period II), and d 90 (period III) during which total fecal collections were performed. Radiographs of the third metacarpal were also taken at this time. Body weight and skeletal parameters were measured every 7-d and blood was taken every 14-d for determination of serum ICTP and PICP concentrations. Although no differences between treatments were found in RBAE within periods, changes in RBAE across periods
demonstrated a tendency for decreased bone density in both the EX and NEX horses between periods II and III. Furthermore, the significant decrease in bone density observed in the NEX horses throughout the duration of the trial would indicate that stalling and lack of exercise may result in a greater loss of BMC as compared to the forced exercise horses. Consequently, EX horses may be better prepared for the future mechanical stress placed upon them.
Impacts
Data from this trial may aid in better defining the exercise requirements for young, growing horses in order to optimize bone growth and integrity.
Publications
- J.C. Henry, S.R. Cooper, D.W. Freeman and J.R. Kropp. 2002. Effects of Exercise on Bone Density, Growth Parameters and Biochemical Markers of Bone Metabolism in Yearling Quarter Horses. Okla. Agr. Exp. Stat. Res. Rep. http://www.ansi.okstate.edu/research/rr.htm
|
Progress 10/01/00 to 09/30/01
Outputs
Exp.1 Four mature sedentary geldings were used in a 4x4 Latin square design experiment to study the effects of Phytase on phosphorus availability and mineral balance. Results from this trial found that phosphorus digestibility and balance were not significantly enhanced through the addition of phytase to the diet. Exp.2 Fifteen yearling Quarter Horses were used in a split-plot design experiment to evaluate the response of calcium metabolism, bone density and parameters of growth to varying calcium concentrations in the diet. Horses were on trial from 12 to 18 months of age and were fed diets containing 115%, 100% and 85% of NRC requirement for calcium. Results from this trial demonstrate an increased calcium retention with increased intake. However, no difference was detected between dietary treatments in bone density or parameters of growth. These data therefore support current NRC recommendations for dietary calcium in yearling horses.
Impacts
Data from these trials may aid in the revision of the current NRC for Horses (1989) by better defining calcium and phosphorus requirements for young, growing horses.
Publications
- A.D. Moffett, S.R. Cooper, D.W. Freeman and H.T. Purvis. 2001. Response of yearling Quarter Horses to varying concentrations of dietary calcium. Proc. 17th Equine Nutr. Physiol. Symp. Lexington,KY.62-68.
- D.P. Patterson, S.R. Cooper, D.W. Freeman and R.G. Teeter. 2002. Effects of varying levels of phytase supplementation on nutrient digestibility in horses fed a common textured ration. J. Equine Vet. Sci. (Submitted).
|
Progress 10/01/99 to 09/30/00
Outputs
This project was new October 2000 and there is no progress to report this period.
Impacts
(N/A)
Publications
- No publications reported this period
|
|