Week 10- Failure of Passive Transfer Flashcards
Are foals born with a fully functional immune system?
No
What term describes the state of a foal’s immune system at birth?
Immunocompetent but immunologically naïve
What do foals rely on for immune protection early in life?
Colostrum and non-specific defense mechanisms
Which immune cells in neonatal foals have reduced pathogen killing ability?
Phagocytes
What is the effect of colostrum on innate immune factors like complement and lactoferrin?
Increases their levels after transfer
What is the limitation of antigen presentation in neonatal adaptive immunity?
Decreased capacity
When is IgGb detected in foals?
After 63 days
Why can’t foals receive antibodies via the placenta?
Because horses have an epitheliochorial placenta
How do foals absorb immunoglobulins from colostrum?
Through pinocytosis in the gut
How long after birth does passive transfer of immunity occur?
Only in the first 6–12 (up to 36) hours
At what age is immunoglobulin absorption most efficient in foals?
At birth
How much immunoglobulin is absorbed at birth?
50–60%
When is there little absorptive capacity for colostrum left?
After 12 hours
What prevents breakdown of colostral proteins in the GI tract?
Trypsin inhibitor in colostrum
What is the peak timing for IgG levels in foal blood?
18–24 hours
Name three immunoglobulins found in colostrum.
IgG
What percentage of adult complement activity is present at birth?
0.13
What type of immune cells from the mare can be found in the foal’s blood?
T lymphocytes
What IgG level is considered adequate for passive transfer?
> 8 g/L
What is the half-life of colostrally derived antibodies?
20–30 days
When does the antibody trough typically occur?
Between 6–12 weeks of age
Why should mares be kept at the foaling site before foaling?
To ensure local disease-specific antibody development
What are the two main causes of FTPI?
Insufficient intake and poor-quality colostrum
What IgG level defines complete failure of passive transfer?
<4 g/L
