Chemotactic and phagocytic function of peripheral blood polymorphonuclear leucocytes in newborn foals.

This study analyzed the ability of white blood cells in newborn foals (young horses) to move towards and consume unwanted particles both before and after consuming colostrum, or first milk. The results indicate that while these cells are mature at birth, their functionality improves significantly after the foal consumes colostrum.

Examining Foals’ White Blood Cells

• The researchers studied the movement and consumption, or phagocytic function, of polymorphonuclear leucocytes (PMNLs) – a type of white blood cell – in newborn foals.
• The study involved 11 foals and the PMNLs from their peripheral blood, or circulating blood, were analyzed both immediately after birth (pre-colostral) and at different times after the foals ingested colostrum.

Testing Chemotaxis and Phagocytosis

• The study examined the number of foal PMNLs that had migrated in response to chemical signals (chemotaxis) and the number of yeast particles each PMNL consumed (phagocytosis).
• The researchers found that both chemotaxis and phagocytosis were significantly lower in tests conducted before the foals had consumed colostrum than in tests conducted four or more days after they had ingested colostrum.

Impact of Colostrum on PMNL Function

• The results suggest that the PMNLs in newborn foals are functionally mature at birth.
• However, the study also suggests that the expression of the PMNLs’ chemotactic and phagocytic functions improves with the ingesting of colostrum.
• The findings also imply that the humoral origin of chemical and opsonic factors, or substances that enhance phagocytosis, has an impact on PMNL function.

Comparisons to Adult Horses

• The study also found the PMNLs from newborn foals responded normally to plasma from adult horses, emphasizing the physiological maturity of these cells at birth, but also the impact of additional factors from colostrum on their functionality.