revision week 1

• Biosecurity

  All procedures implemented to reduce the risk and consequences of infection with a disease causing agent
• How do you know a calf in drinking successfully?

  Calf will bunt at the udder

  Wag tail
• In a calf what part of the stomach does milk bypass cus its small?

  Rumen
• When is the maximum production of forage

  Late spring/ early summer
• Maize (corn)

  Doenst grow in low tempe (grows may-sept)

  Harvested when above 25% DM
• Roots

  Grown in autunm

  Fed to animals later part of autunm to winter
• Silage

  Cut in may, july, august/sept
• Nutitional targets for grass silage

  Aim for 30% DM

  The wetter it is the lower the pH needs to be
• Storing farm food

  Clamp must be sealed otherwise if air gets in = oxygen gets it = fungi can become toxic = microtoxins so can poison qnimal
• Advantages of hay over silage

  More palatable

  Small volumes can be made

  Easy to store and transport

  Less likely to get contaminated
• Haylage

  Horse

  Higher water content than hay

  Lower nutrient content than most silages

  Plastic wrapping allows some fermentation

  PH will drop to 4.5-5 within 3 weeks

  More expensive then hay

  Probe to spoilage
• Straw

  Dried stems of wheat, barley and oats

  Low nutritional value

  Used as bedding and forage

  Barley and oat slightly more palatable

  Given on high concentrates to ruminants
• Concentrates

  Higher in protein than forages

  Need to balance with roughage to avoid acidosis
• Why do horses need forage

  Gi stability

  Nutritional requirement

  Behavioural need
• What vitamin do dogs have a dietary requirement for

  D
• What dietary fatty acids are essential for dogs

  Polyunsaturated fatty acids linoleic acid

  Alpha linolenic acid
• innate immune system

  Been there for ever

  Fast to act

  Non specific

  Pathogen associated molecular proteins (PAMPs)

  Damage associated molecular proteins (DAMPs)
• Physical barriers of innate immune system

  Skin, hair, cilia

  Mucous and chemical substances

  Digestive enzymes

  Stomach acids
• Internal barriers of innate immune system

  Inflammation

  Phagocytosis

  Natural killer cells

  Antigen presenting cells
• Adaptive immune system

  Specific recognition

  B cells (produce antibodies)

  T cells (cytotoxic cells and helper cells)

  Takes days

  Memory
• Innate immune system- phagocytes

  Macrophages, neutrophils, dendritic cells

  First line of defence
• Macrophages

  Phagocytosis and activation of bactericidal mechanisms

  Antigen presenting
• Neutrophils

  Phagocytosis and activation of bactericidal mechanisms

  Have 3 mechanisms for attacking microorganisms:

  Phagocytosis

  Degranulation

  Nets- neutrophil extracellular traps

  First responders to inflammation
• Eosinophils

  Killing of antibody-coated parasites
• Mast cells

  release granules containing histamine and active agents --> triggers inflammation --> responsible for mediating allergic reactions
• basophils

  rare

  promotion of allergic responses and augmentation of anti-parasitic immunity
• natural killer cells


  viruses spend most of their life inside infected cells --> produce inflammatory mediators like cytokines --> trigger NK cells to kill infected cells
• dendritic cells

  antigen presenting cells

  expresses many receptors to capture/respond to microbes

  present mainly antigen to T-lymphocyte

  express high levels of MHC molecules
• B-lymphocytes

  bone marrow derived

  product antibodies 9immunoglobulins)

  memory --> humeral response (responds to things outside of cell so blood and tissue)
• T-lymphocyte

  thymus derived

  responsible for cell mediated immune response of adaptive immunity

  responds to things inside the cell
• List the different types of antibody isotopes

  IgG

  IgM

  IgA

  IgE

  IgD
• IgM

  produced early in immune response

  provides short term protection until IgG is produces, then it decreases

  Has mu chains
• IgG

  most common in blood and bodily fluids

  good at binding to toxins and microbes

  binds to and immobilises the pathogen

  coats pathogen surface with antigens so phagocytic cells can recognise it

  activates complimentary pathway causing release of immune proteins involved in eliminating pathogens

  then b ends to toxin and neutralises it

  has gamma chains
• IgA

  main antibodies in secretions coating mucosal surfaces

  1st line of defence against pathogens
• IgD

  found o B-cell surfaces

  they won't be found floating around in blood
• IgE

  main function is to assist with allergic reactions and parasitic infections

  eosinophils will respond to IgE
• Types of T-cells

  CD4 and CD8
• CD4

  MHCII

  coordinate the adaptive immune response, don't directly eliminate pathogens

  (Th1, Th2, Th17)

  Treg= regulatory
• CD8

  MHCI

  cytotoxic --> kills cells
• what activates innate immune cells

  pattern recognition receptors

  activation of receptors for antibodies that are produced as part of the adaptive immune response