Effect of extruded fodder on biochemical and haematological parameters of Standardbred horses under training conditions

The aim of this study was to examine whether feeding of extruded fodder can improve the energy metabolism of horses under training conditions. The experiment was performed on 12 clinically healthy Standardbred horses (6 horses in the control group and 6 horses in the experimental group). The diet of the horses was based on oats, barley, meadow hay, and a supplement of vitamins and minerals. The diet of the experimental group (6 horses) was supplemented with 1.25 kg of extruded fodder that replaced the corresponding dose of grain. Feeding doses were related to the rate of sub-maximal workload. Selected biochemical parameters of energy and protein metabolism, electrolytes, and haematological parameters were monitored at rest and 5 min after exercise at the beginning and at the end of the 10-week experimental period. The 10 weeks of the training period resulted in a significant decrease in serum glucose concentration, serum total proteins, and plasma creatinine concentration, and a significant increase in plasma urea concentration and haemoglobin in both groups of horses at rest. Post-exercise a significant increase in blood urea levels and a decrease in total proteins in both groups demonstrated that the proteins became sources of energy. A significant increase in the haemoglobin level together with a significant decrease in the creatinine level in the horses of both groups at the end of the experiment indicated an increased aerobic metabolism. Nevertheless, extruded fodder in the horses' diet did not have the anticipated effect.