| Popis: |
Summary In a switchback experiment, six mature Quarter Horse and Thoroughbred geldings weighing approximately 495 kg and in average body condition score of 5.4 were fed two diets and exercised daily. Horses were randomly assigned to a conventional diet or alfalfa:corn plant cubes as an exclusive diet. During the 21-day adaptation period, level of work increased daily digestible energy requirements to approximately 1.75 times maintenance. Sweat production was estimated on days 0, 7, 14 and 21. A 4-day digestion trial was conducted on days 17, 18, 19 and 20. Horses performed a standardized exercise test on day 21 by galloping 18 minutes at a heart rate of 150 beats per minute followed by 2 minutes at 200 beats per minute. Venous blood samples, heart rates, respiration rates and rectal temperatures were taken before exercise, immediately after and throughout recovery from the test. Then, the horses were abruptly switched to opposite diets and the procedures were repeated. No noticeable digestive disturbances occurred as a result of the abrupt introduction of diets to horses. Furthermore, no “cribbing” problems or apparent cases of choking were observed throughout the study. Horses consumed the cubed diet slower (P .1) between diets. Only slight increases (P>.05) in body condition were observed at the end of each period. Heart rate, respiration and rectal temperature increased (P |
