Dietary protein and fat effects on protein status in Arabian horses during interval training and repeated sprints

This study tested the hypothesis that decreasing dietary protein quantity while increasing protein quality may reduce the undesired effects of excess protein without risking protein deficiency in exercising horses. Twelve horses were assigned to a 2 × 2 factorial experiment: 2 fat levels, 3% low-fat (LF) or 13% high-fat (HF), and 2 protein levels, 7.5% low-protein (LP) or 14.5% high-protein (HP) crude protein (CP). Horses were fed the diets for a 4-week period, then underwent a standardized exercise test (SET). Horses were then trained for 11 weeks, and then underwent another SET. Blood samples were taken every 2 weeks and during SETs. Plasma concentrations of albumin, total protein, urea nitrogen, and creatinine were determined.