Estrous Cycles of Nine Species of Muroid Rodents

1977 ◽  
Vol 58 (1) ◽  
pp. 89-92 ◽  
Author(s):  
D. A. Dewsbury ◽  
D. Q. Estep ◽  
D. L. Lanier
Keyword(s):  
Estrous Cycles ◽  
Muroid Rodents

THE DURATION OF THE BREEDING SEASON OF FOUR BREEDS OF SHEEP

1974 ◽  
Vol 54 (3) ◽  
pp. 389-392 ◽  
Author(s):  
J. J. DUFOUR
Keyword(s):  
Sexual Activity ◽  
Breeding Season ◽  
Estrous Cycles ◽  
Progressive Decline ◽  
Daily Exposure ◽  
Almost All

Three breeds of sheep (Dorset, Leicester, and Suffolk) and a crossbred line from these breeds (DLS) were observed throughout 1 yr to determine their sexual activity by daily exposure of the ewes to vasectomized rams. The DLS and Dorset ewes exhibited their first estrus earlier in the year (P < 0.01) and stopped cycling later than the Leicester and Suffolk ewes (P < 0.01). The duration of the breeding season in the DLS ewes was 20 days (P > 0.05) longer than in the Dorsets and 70 and 115 days (P < 0.01) longer than in the Leicester and Suffolk ewes, respectively. The percentage of Dorset and DLS ewes showing one or more estrous periods increased progressively from June to reach 100% in September for both breeds. The Suffolk and Leicester ewes commenced to cycle in late August and by September almost all ewes had shown an estrous period. The progressive decline in estrous activity became evident first with the Suffolk in January, then with the Dorset and Leicester in February and with the DLS in March. The Dorset, DLS and Leicester ewes had longer estrous cycles than the Suffolk ewes. Within ewes, length of estrous cycles was highly repeatable for all breeds. False estrus and silent estrus occurred in 1.0 and 3.9% of the estrous periods, respectively. Over successive estrous cycles, length of estrous cycles increased significantly.

scholarly journals Exploration strategies map along fast-slow metabolic and life-history continua in muroid rodents

2009 ◽  
Vol 23 (1) ◽  
pp. 150-156 ◽  
Author(s):  
V. Careau ◽  
O. R. P. Bininda-Emonds ◽  
D. W. Thomas ◽  
D. Réale ◽  
M. M. Humphries
Keyword(s):  
Life History ◽  
Muroid Rodents

scholarly journals Diurnal patterning of eight activities in 14 species of muroid rodents

1980 ◽  
Vol 8 (2) ◽  
pp. 322-330 ◽  
Author(s):  
Denis J. Baumgardner ◽  
Susan E. Ward ◽  
Donald A. Dewsbury
Keyword(s):  
Muroid Rodents

Rejuvenating effects of 10-week underfeeding period on estrous cycles in young and old rats

1987 ◽  
Vol 8 (3) ◽  
pp. 225-232 ◽  
Author(s):  
K. Quigley ◽  
R. Goya ◽  
J. Meites
Keyword(s):  
Estrous Cycles ◽  
Old Rats

Electromorphs and Phylogeny in Muroid Rodents

1985 ◽  
pp. 671-683 ◽  
Author(s):  
Francois Bonhomme ◽  
Djoko Iskandar ◽  
Louis Thaler ◽  
Francis Petter
Keyword(s):  
Muroid Rodents

Interactive effects of food deprivation and exercise on reproductive function in female hamsters

1994 ◽  
Vol 267 (1) ◽  
pp. R185-R190 ◽  
Author(s):  
J. B. Powers ◽  
A. E. Jetton ◽  
G. N. Wade
Keyword(s):  
Food Deprivation ◽  
Reproductive Function ◽  
Hormonal Treatment ◽  
Estradiol Benzoate ◽  
Interactive Effects ◽  
Combined Effects ◽  
Inhibitory Effects ◽  
Estrous Cycles ◽  
Running Wheels ◽  
Estrous Behavior

Two experiments evaluated the combined effects of food deprivation and runningwheel access on estrous cycles and estrous behavior of female hamsters. In experiment 1, food deprivation on days 1 and 2 of the estrous cycle disrupted the next expected ovulation, and this effect was more, rather than less, robust in females allowed to exercise in running wheels while they were deprived. In experiment 2, a similar protocol was used except the females were ovariectomized and received sequential injections of estradiol benzoate (EB; 5 micrograms) and progesterone (P; 200 micrograms) separated by 48 h to induce lordosis, which was tested 4-5 after P. Food deprivation concomitant with hormonal treatment diminished lordosis durations, but this effect was significant only among the females that were permitted to run in activity wheels. Previous findings demonstrated that access to running wheels attenuated the inhibitory effects of short photoperiod exposure on hamster estrous cycles. In contrast, the present results indicate that this same manipulation exaggerates rather than diminishes the inhibitory effects of food deprivation on estrous cycles and hormone-induced behavioral estrus.

Pregnancy initiation in postpartum estrus in three species of muroid rodents

1979 ◽  
Vol 13 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Donald A. Dewsbury ◽  
Robert L. Evans ◽  
Daniel G. Webster
Keyword(s):  
Muroid Rodents ◽  
Postpartum Estrus
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