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Mlac:WR and Mlac:SD

 
Common name Mlac:WR and Mlac:SD
Scientific name Rattus norvegicus
Strain

Wistar and Sprague Dawley

Source Denmark
Coat color  Albino
Biological Data  
Adult body weight

Male 250 – 300 g, Female  180-220 g

Average life span 2-3 years
Age at start mating

Male 8-10 weeks, Females 8-10 weeks

Estrous cycle 4 - 5 days
Duration of estrus

9 - 20 hours

Gestation period 19-22 days
Weaning age 19-22 days
Litter size 9-11 pups
Normal birth weight 5-6 g
Weaning weight 45-65 g
Food consumption 15-30 g/day (Adult)
Water consumption

20-45 ml/day (Adult)

Eyes open

10-14 days

Ears open

12-14 days

Hair coat 8-9 days
Nipples

10, 3 Pairs on the thorax, 2 Pairs on the abdomen.

The two outbred strains of  Rat , Wistar and Sprague Dawley strains are maintained at NLAC breeding facility. Differences between the two rat strains are Wistar rats possess wider head, long ears, and the tail length always shorter than that of the body length. And in Sprague -Dawley rats, they have longer and narrower in head , longer tail, which may equal or be longer than the body length.

Growth  rate  
Husbandry  

Breeding system
            Maximum avoidance of inbreeding mating system is applied in Wistar and Sprague Dawley rats strains for maintenance in foundation stock and random mating system is used for production in production stock.
 

Environment
           The rats are housed in controlled environment. The ventilation, temperature and humidity are controlled by HVAC (Heating, Ventilating, Air conditioning) system. They are controlled at :

- Temperature range of about 24 ± 2

- Relative humidity range of about 55 + 10%

- Air changes per hour 10-15 ACH

- Light: dark cycle 12:12 hours

- The rat are sensitive to noise so the noise level should be maintained less than 85 db.


Provision of Feed and water
           The rats are fed on commercial diet (No. CP 082) produced by Perfect companion group co. Ltd. The manufacturer which milled the feed according to our requested specifications. Food is provided ad libitum in stainless steel wire- bar lid feeders. The chlorinated RO Water is provided as drinking water (chlorine concentration 10-12 ppm) which is  free from Pseudomonas aeruginosa. Water provided to animals by bottles with sipper tubes.
 

Bedding 
          Hard wood chips (or shaving) is used for mice as bedding material. The same bedding is used in shipping containers. Dried bedding is packed in brown paper bags and sterilized by autoclave at 135 C for 7 minutes before used.

Equipment  

       

               Various sizes of cages are used in different purpose of breeding process.

Dimensions of Enclosure(inches)

Maximum Number Animals/ Enclosure

Types of Enclosure
And  Description

12×11×7.5

3 animals (pregnant 1 wk)/cage

Stainless steel cages with
Stainless steel wire-bar lid

10×7×10

1 animal (pregnant 2-3 wks)/cage

Stainless steel cages with
Stainless steel wire-bar lid

10.5×13.5×6.5

1 animal (Lactating female)/cage

Polycarbonate cages with
Stainless steel wire-bar lid

10×16×7

1 animal (Lactating female)/cage

Stainless steel cages with
Stainless steel wire-bar lid

14×29×6

1 animal/cage

Stainless steel cages with
Stainless steel wire-bar lid


Mlac:ICR | Mlac:WR | Mlac:SD | Mlac:DH | Mlac:NZW |
ICR Mouse(Free Hydronephrosis)|ICR Mouse Hydronephrosis BALB/cMlac | C3H/HeMlac | C57BL/6Mlac | DBA/2Mlac |BALB/cMlac-nu

Last updated : 14-11-2557 11:15:00