Colostrum Flashcards
What does colostrum contain?
High in fat and sugars
High IgG, IgM, IgA
Neutrophils and macrophages
Why is colostrum so important in farm animals?
all maternal IgG transferred via colostrum, none is transferred in utero
Why is colostrum important to neonates?
Gut health - stimulates neonates immature digestive system
Nutrition
Immunity
Prevent hypothermia - neonates have low % of adipose tissue so cannot thermoregulate properly
What is the role of the immunoglobulins found in colostrum?
IgG:
- only Ig that can cross placental barrier
- absorbed across GIT to provide systemic protection
IgA:
- mucosal protection by prevention of pathogen attachment
IgM:
- first to interact with pathogens and cause agglutination
Describe the absorption of colostral IgG
By pinocytosis:
- Cells engulf IgG from intestinal lumen and transfer across lymphoreticular system
- enter bloodstream
2 isoforms:
- IgG1 and IgG2
- IgG1 is re-secreted into GIT lumen
‘gut closure’ at 24h of age as pinocytotic cells die
what is passive transfer?
the process by which a neonate acquired immunity via absorption of immunoglobulins
What are the possible sources of colostrum?
Dam
Fresh but different dam
Stored colostrum
Replacer - not supplement
Different animal species
What are the 5 important factors for colostrum management?
Quality
Quantity
Quickly
Quite clean
Quantify
Describe the storage of colostrum
Refrigeration
Frozen (do not thaw quickly as high temps will denature immunoglobulins)
Pasteurisation
What happens as a result of passive transfer?
Health advantages
Reduces pre and post weaning mortality due to infectious disease
Increases daily live weight gain
Breeding animals have better fertility
Increased milk production in 1st and 2nd lactations
What are the implications of failure of passive transfer
short and long term health problems
Impacts on longevity
Increased risk of disease e.g., sepsis, neonatal scours
Increased risk of mortality
Stunted growth and development
What are the methods of measuring colostrum quality
Colostrometer:
- measures specific gravity
- directly related to Ig content
- >50 mg/ml is good quality
Brix refractometer:
- measures protein fraction
- 22% brix = good quality
Why is it bad to give small amount of colostrum and wait to give the rest?
Initial amount can stimulate epithelial lining of SI to close so rest of colostrum cannot be absorbed correctly
How can we measure colostral antibody transfer?
Brix refractometer used to measure protein fraction from neonates serum sample
Foal IgG snap tests (ELISA)
How can failure of passive transfer be corrected?
Serum transfusion:
- blood from healthy adult spun to harvest serum (containing antibodies)
- serum is transfused into neonate
