Serum ferritin, serum iron, and erythrocyte values in foals.

The research study investigated the changes in serum ferritin, serum iron, and erythrocyte values in healthy Thoroughbred and Quarter Horse foals from birth up to one year of age, tracking how iron supplementation affected these values.

Study details and methodology

• The team enlisted 21 healthy foals, both Thoroughbred and Quarter Horse breeds for this study. These foals were studied from their birth until they reached an age of one year.
• The foals were given access to iron-supplemented creep feed even before they were weaned. Post weaning, at 4 months of age, they were included an iron-supplemented concentrate in their diet
• At the time of birth, before nursing began, the initial blood samples were taken from the foals for testing.

Key findings

• The researchers observed that total iron-binding capacity, serum iron concentration, and packed cell volume (PCV) all decreased within the first 24 hours of a foal’s life. For example, the serum iron concentration fell from a mean of 446 micrograms/dl at birth to roughly 105 micrograms/dl at 3 days old.
• The serum ferritin concentration, on the other hand, increased from an average of 85 ng/ml at birth to approximately 159 ng/ml after only one day. Beyond this point, the researchers noticed the ferritin concentration gradually decreased, hitting a low of about 61 ng/ml at three weeks of age. From the six-month mark onwards, ferritin levels rose to match those typically found in adult horses.
• The study also revealed that the content of ferritin in colostrum at birth was significantly higher, at around 354 ng/ml, compared to just 25 ng/ml in milk a day later.
• The scientists noticed a correlating increase and decrease in total iron-binding capacity and serum ferritin concentration.
• Finally, the mean PCV decreased slowly until it reached a minimum at three months of age. This dip was found to be associated with a rising count of microcytes, as ascertained with a cell-size distribution analyzer.