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Flashcards in Biology & husbandry of lab animals Deck (10)
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1
Q

Distribution of animals used in lab research:

A
  • rodents - 70-85% of all vertebrate lab animals

- non-human primates + dogs + sheep, pigs, goats, etc = 3% of vetebrates

2
Q

Mus musculus general

A
  • > 400 inbred genetically defined strains
  • heart rate: 300-800/min
  • respiration rate: 100-200
  • body temp: 36.5-38
  • chromosomes: 40 (2n)
  • dental: each half of each jaw contains 1 incisor & 3 molars. Incisors keep growing and are kept short by chewing
  • sex is determined by comparing the anogenital distance, which is twice as long in males than in females (in females this area is also hairless
  • breeding age: 8-10 weeks
  • oestrus cycle - 4 (2-9) days
  • duration of pregrancy - 19 (18-21) days
  • litter size: 6-12
  • temperature regulation achieved by sweating from foot pads and vasodilatation of the tail (same in rats)
3
Q

Mus musculus housing

A
  • establish social hierarchies
  • males housed together may become aggressive
  • more aggressive after having lived alone
  • less aggressive if litter mates housed together from weaning
4
Q

coprophagy/caecophagy

A
  • consumption of feces
5
Q

Antimicrobial treatments of drinking water:

A
  • acidification (to pH 3.0)
  • chlorination (0.2-0.5ml free Cl per L)
    both inhibit microbial growth without affecting water consumption
6
Q

Mus musculus reproduction

A
  • polyoestrous females
  • more regular cycles when individually housed
  • females in groups without males tend to become anoestorus
  • Whitten-effect: introducing a male into an anoestrous colony will lead to synchronization of the oestrous cycles
  • Bruce effect: if female is housed with a second male within 24 hours of successful mating, implantation of fertile egg cells will not take place and no pregnancy will occur
    (both Bruce and Whitten effects are induced by pheromones present in the urine of male mice)
  • 12-24 hour coagulation plug after mating (secreted by the accessory glands in the male genital tract)
  • weaning 3 weeks after birth
7
Q

Ratus norvegicus

A
  • > than 200 genetically defined inbred strains of rats
  • ca. 50 outbred strains on record
  • first rats for research developed at the Wistar Institute in Philadelphia
  • within the eye socket - Harderian gland - produces brown-red secretions which contain porphyrins; removed by grooming; presence of reddish secretion around the eyes and nose indicates diminished well-being
  • temp control as in mice. In addition, rats have been known to cover their body with saliva in an effort to reduce body temp.
8
Q

Ratus norvegicus housing

A
  • groups housed rats have higher plasma corticosteroid concentrations
  • social behavior of grouped animals changes when a solitary housed rat is introduced to the group
  • overcrowding can cause a rise in body temperature
9
Q

Ratus norvegicus reproduction

A
  • comparable to mouse
  • NO Bruce effect
  • no oestrous synchronization due to male pheromones
10
Q

Oryctolagus cuniculus

A
  • European wild rabbit
  • most common breeds: Dutch breed (<2kg) and the New Zealand White (2-5kg); few inbred strains
  • ca. 30% react abnormally to atropine
  • resting rabbits breathe through their diaphragm, causing the abdomen to move in and out
  • toe nails must be clipped regularly
  • males get territorial and aggressive when housed together
  • high concentration of crystals in urine make cleaning difficult (use descalants)
  • pellet food should be supplemented with hay to prevent intestinal disturbances and obstructions caused by hairballs
  • no real oestrous cycle with spontaneous ovulation in does;
  • after mating pituitary secretes luteinising hormone which induces ovulation ca. 10 hours later
  • when induction of ovulation is not followed by fertilization, pseudopregnancy occurs and lasts for 16-18 days