Animal hygiene deck II Flashcards
particulate matter quantitites are higher in which season?
slightly higher in winter (rooms often closed, ventilation
rate lower)
Highest dust concentration detected in ?
aviaries and pig farms, less dust can be found in cattle and sheep housing.
The approximate dust amount (airborne particles in total) in
conventional animal facilities is often measured in the range of
0.25 - 25 mg/m3.
Note: these are measured at times but are NOT safe. Dust content exceeding 10 mg/m3 seriously damages any living organism.
The size of dust particles ranges greatly but is between
0.2 - 100 μm.
The size of the majority of the dust particles ranges between
0.3 - 20 μm.
Indirect impact of dust: (5)
enhances condensation of humidity;
inhibits the effect of sunlight, especially UV radiation;
accumulates on windows’ glass;
affects the work of the ventilation system;
serves favourable environment for the development of microbes and mould
fungi.
Direct impact of dust: (3)
skin: itching, skin inflammation, disorders in thermoregulation, the
protective function of the skin and skin sensitivity decreases;
eyes: irritant effect, conjunctivitis;
respiratory tract (especially <5 μm, originating from excreta!).
Most respiratory reactions in pigs are
allergic (antibodies in blood).
Pneumoconiosis
The pneumoconioses are a group of lung diseases caused by the lung’s reaction inhaling certain dusts.
What can dust inhalation cause in birds?
Acute alveolitis
What common bacterial infection can horses contract via dust inhalation?
Rhodococcus equi in horses: bacteria lives on the ground → horses inhale
it with the dust → zoonotic pneumonia (mainly foals).
Commonish airway disease in horses
Horses → Recurrent airway obstruction (RAO), 2 forms.
Dust allergic effect:
respiratory hypersensitivity to antigens
(AID)
Dogs → Allergic inhalant dermatitis (AID) – genetic disposition to produce IgE antibodies to inhaled allergens (frequent cause of dermatitis).
Dust content exceeding ? seriously damages any living organism.
10 mg/m3
Most air microflora are
harmless saprophytes.
However, Fungi spores may also disseminate without anchoring to a substrate.
Favourable factors in a farm for air microflora include: (3)
no direct solar radiation, indoor humidity exceeds outdoor humidity preventing drying, enough nutrients.
The highest bacteria and fungi concentrations in
broiler and pig houses.
Examples of diseases that spread via wet carrier (droplet infection): (4)
Foot-and-mouth disease,
bovine spongiform encephalopathy,
tuberculosis,
glanders and strangles in horses, etc.
Examples of diseases that spread via dry carrier (dust infection): (3)
Anthrax,
tuberculosis,
aspergillosis, etc.
(spores!)
Biological aerosols consist of
living and non-living airborne biological particles and their fragments (e.g. endotoxins, i.e. lipopolysaccharides.
Bioaerosols are formed by suspension of particles of biological origin in the air.
Bacteria are most numerous in what species’ housing?
poultry housing.
The prevention and control of bioaerosols’ exposure is based on the three levels of intervention:
elimination of the source;
controlling the source;
controlling exposure.
Lipopolysaccharides originate from?
from the outer membrane of gram-negative bacteria
CFU
colony-forming unit
Harmful gases in the air of farms (6)
CO (carbon monoxide)
CO2 (carbon dioxide)
N2O (nitrous oxide)
NH3 (ammonia)
H2S (hydrogen sulfide)
CH4 (methane)