Serum folate levels in horses, with particular reference to the English thoroughbred.

The research investigates the folate levels in the serum of different types of horses, such as thoroughbreds in training, thoroughbred mares at stud, and crossbred ponies at grass. The study finds that intensive exercise significantly decreases serum folate levels and increases levels of bilirubin and PCV.

Investigation of Folate Levels

• The research primarily examined the levels of folate in the serum of various types of horses. These included thoroughbreds undergoing race training, pregnant thoroughbred mares kept at stud, and crossbred ponies that live permanently at grass.
• Folate is a type of B vitamin that is important for the formation of red and white blood cells in the bone marrow, the conversion of carbohydrates into energy, and the production of DNA and RNA. Therefore, understanding its levels can provide insight into the health and performance potential of these horses.

Comparison of Folate Levels

• The study found that thoroughbreds in active training, showing no apparent haematological or clinical irregularities, had lower serum folate levels (mean 3.3, ranging from 1.5 to 6.1 micrograms per litre).
• These levels were found to be lower compared to pregnant thoroughbred mares at stud (mean 10.6, range 6.4 to 15.8 micrograms per litre) and crossbred ponies at grass (mean 10.9, ranging from 7.4 to 16.6 micrograms per litre).

Effect of Intensive Exercise

• According to the research, engaging in intensive exercise for a six-month period significantly reduced serum folate levels (P < 0.001).
• Along with this, intensive exercise also considerably increased the concentrations of bilirubin (P < 0.0001) and packed cell volume (PCV) (P < 0.0002) in a group of 30 thoroughbred racehorses over the study period. Bilirubin is an orange-yellow pigment formed in the liver by the breakdown of hemoglobin and excreted in bile, while PCV is a measure of the volume percentage of red blood cells in blood.
• However, the levels of haptoglobin, a protein produced by the liver that the body uses to bind free hemoglobin, showed no notable changes during the period of intensive exercise.