A healthy start in life

Question 1

Immunity in chicks

Answer 1

Maternal immunity comes into yolk

Albumen is ingested - IgA and IgM

IgM & IgA from oviducts

IgG in yolk absorbed into blood

Question 2

How to optimise immunity in young?

Answer 2

1. Vaccinate the mother (ruminants 1 month before)
2. Good plane of nutrition of mum (makes sure she has substance in colostrum)
3. Mother & young pair up: Clean environment for birth, low pathogen load, rotation of pasture, drench and vaccinate animals etc.
4. Vaccinate young after maternal immunity declines
5. Give a booster vaccination
6. Low stress to reduce premature birth
7. Breeding “good mothers” - select for this trait

Question 3

Main antibody transferred to young in ruminant milk

Answer 3

IgG (75%)

IgA & IgM in much smaller amounts

Non-ruminants is mostly IgA

Question 4

Transfer of maternal immunity - T cell lymphocytes

Answer 4

In colostrum

Survive in intestine and penetrate intestinal wall and reach mesenteric lymph nodes

Enhance protection from e.g. E.coli

Question 5

Failure of passive transfer of maternal immunity in colostrum

Answer 5

1. Young not suckling
2. Immunocompromised mother
3. Deformity of teat/udder
4. Mother malnutrition
5. Poor mothering ability
6. Competition i.e. lots of young (large litter size)
7. Absorption failure

etc.