Age of onset of puberty and breeding life
|
|
Rat
|
Mouse
|
Guinea pig
|
|
Sexual maturity in weeks (male)
|
6-10
|
6-8
|
10-12
|
|
Sexual maturity in weeks (female)
|
8-12
|
6-8
|
10-12
|
|
Breeding life in months (male)
|
9-12
|
9
|
24
|
|
Breeding life in months (female)
|
9-12
|
9
|
24
|
Female reproductive cycles
|
|
Rat
|
Mouse
|
Guinea pig
|
|
Estrous cycle length (days)
|
4-5
|
4-5
|
16
|
|
Estrus duration (hr)
|
10-20
|
10-20
|
6-11
|
|
Estrus onset to ovulation (hr):
|
8-11
|
2-3
|
10
|
|
Fertilization life of ovum (hr):
|
10-15
|
15
|
8-26
|
|
Fertilization life of sperm in female tract (hr)
|
14
|
6
|
20-22
|
|
Presence of copulatory plug in female tract (hr)
|
12-24
|
18-48
|
9-18
|
|
Ovulation rate (egg number)
|
10-20
|
6-10
|
3-4
|
|
Pseudopregnancy (days)
|
12
|
12
|
none
|
Daily sperm production and epididymal sperm reserves of growing, sexually rested Wistar rats. Although there is a small daily sperm production by 40 to 50 days it is not until 75 days that there are optimum production and sperm reserves.
|
|
Age in days
|
|
|
40
|
45
|
50
|
75
|
100
|
|
Weight body (g)
|
201
|
228
|
298
|
399
|
499
|
|
Weight testes (g)
|
1.7
|
2.0
|
2.8
|
3.5
|
3.7
|
|
Daily sperm production 106/g testis
|
2.0
|
10
|
15
|
24
|
24
|
|
Daily sperm production 106/g rat
|
3.5
|
19
|
40
|
80
|
85
|
|
Sperm reserves epididymis head and body (106)
|
1
|
22
|
256
|
282
|
|
|
Sperm reserves epididymis tail (106)
|
1
|
3
|
267
|
422
|
|
Male copulatory patterns
|
|
Rat
|
Mouse
|
Guinea pig
|
|
Mounting time in seconds
|
5-10
|
15-20
|
5
|
|
Pre-ejaculatory intromissions
|
10-20
|
5-20
|
1-13
|
|
Ejaculations per mating
|
7
|
1-3
|
1
|