The Suckling Rat as a Model for Immunonutrition Studies in Early Life
Table 1
Physiological characteristics and logistical considerations of the three most used animal models for nutritional intervention in early life [10–15].
Mouse
Rat
Pig
Physiological characteristics
Pregnancy period (days)
18–21
21–23
110–118
Placenta type
Discoidal, hemoendothelial choroidea, decidual
Discoidal, hemoendothelial choroidea, decidual
Epitheliochorial
Litter size
6–12
6–15
11–16
Birth weight (g)
0.5–1.5
3–5
900–1600
Weaning weight male/female (g)
18–25/16–25
55–90/45–80
6000–8000
Suckling period (days)
21–28
21
28–49
Solid diet beginning (days)
10
12
12–15
Puberty male/female (wk)
4–6/5
6/6–8
20–28
Life expectancy (years)
1-2
2-3
14–18
Developmental maturity at birth1
*
*
**
Animal model logistical considerations2
Minimum enclosure size for mother and litter (cm2)
330
800
0.2–2.5 m2
Purchase and maintenance cost
*-**3
*
***
Availability
*-*****3
*****
***
Easily of pup’s manageability
**
*****
***
evelopmental maturity (i.e., gastrointestinal functions—nutrition and evacuation—thermoregulation, locomotion, etc.) related to adults from immature (*) to mature (*****). nimal model desirability factors evaluated from relatively low (*) to relatively high (*****). ost and availability differ depending on the particularities of the animal strain.
