Menopause and Reproductive Senescence in Comparative Context

2008 ◽  
pp. 4-16 ◽  
Author(s):  
Joseph M. Erwin ◽  
Patrick R. Hof
Keyword(s):  
Reproductive Senescence

Role of ovarian failure in reproductive senescence in aged red deer (Cervus elaphus) hinds

Reproduction ◽  
2000 ◽  
Vol 120 (2) ◽  
pp. 211-216 ◽  
Author(s):  
M. Fisher ◽  
B. McLeod ◽  
D. Heath ◽  
S Lun ◽  
P. Hurst
Keyword(s):  
Cervus Elaphus ◽  
Red Deer ◽  
Ovarian Failure ◽  
Reproductive Senescence

A longitudinal study of senescence in a pinniped

2002 ◽  
Vol 80 (3) ◽  
pp. 395-401 ◽  
Author(s):  
Pierre A Pistorius ◽  
Marthán N Bester
Keyword(s):  
Longitudinal Study ◽  
Adult Female ◽  
No Reduction ◽  
Marion Island ◽  
Mirounga Leonina ◽  
Elephant Seals ◽  
Reproductive Senescence ◽  
Southern Elephant Seals ◽  
Female Survival ◽  
Breeding Seasons

To measure the prevalence of senescence in southern elephant seals (Mirounga leonina Linn.) at Marion Island, changes in adult-female survival and breeding probabilities with age were quantified. Mark–recapture data that had been collected over a 17-year period were analysed using recently developed software to obtain likelihood estimates of survival and capture probabilities. With recapture effort constant over the study period, capture probabilities during the breeding seasons were used as indices of breeding probabilities. Longevity in the population was assessed from the resighting of tagged and hence known-age individuals. Less than a 1% difference between prime-age survival and post prime age survival was found over 8 cohorts of marked females. In addition, no reduction in survival of very old individuals was detected, suggesting the absence of senescence in terms of reduced survival in southern elephant seals. No evidence of reproductive senescence in terms of reduced breeding probability with age was detected. Mortality throughout the population therefore resulted in no individuals surviving to the age where physiological decline would become a mortality agent or result in failure to breed. Five percent of female southern elephant seals survived to age 10 and 0.5% to age 17.

The impact of dietary protein:carbohydrate balance on lifespan and reproduction in Protaetia brevitarsis (Coleoptera: Scarabaeidae: Cetoniinae)

2021 ◽  
pp. 1-8
Author(s):  
S.-H. Kim ◽  
H. Park ◽  
W. Kim ◽  
J.-H. Song ◽  
S.J. Roh ◽  
...  
Keyword(s):  
Reproductive Performance ◽  
Egg Production ◽  
Detailed Knowledge ◽  
Reproductive Senescence ◽  
Egg Hatchability ◽  
Edible Insect ◽  
Age Related ◽  
Medicinal Value ◽  
Egg Production Rate ◽  
The Impact

The establishment of efficient and sustainable production of industrially important insects necessitates the detailed knowledge of the optimal mixture of macronutrients required for maximising their performance and fitness. The white spotted flower chafer, Protaetia brevitarsis (Coleoptera: Scarabaeidae: Cetoniinae), is one of the most important edible insects in East Asia with high nutritional and medicinal value. Here, we report how the ratio of protein to digestible carbohydrate (P:C) in the diet influenced lifespan and reproductive performance in the adults of P. brevitarsis. Throughout their lifespan, beetles were fed ad libitum one of five diets with differing P:C ratio (0:1, 3:7, 1:1, 7:3, 1:0). Both lifespan and the number of eggs produced over the lifetime were maximised at the P:C ratio of 3:7 and declined as the ratio deviated away from this optimal P:C composition. Beetles fed a diet containing only protein (P:C 1:0) not only had the shortest lifespan but also exhibited substantially reduced lifetime egg production compared to those fed the other diets. However, the effects of dietary P:C ratio on daily egg production rate and egg hatchability were marginal. The number of eggs produced at each age stage peaked at the age of week 2 and then gradually declined with increasing age, showing the sign of reproductive senescence. Age-specific egg production was higher in beetles confined to three intermediate P:C ratios (3:7, 1:1, 7:3) than those confined to two extreme P:C ratios (0:1, 1:0) throughout their lifespan. The speed of age-related decrease in reproductive performance was the slowest at P:C 3:7. Our data have implications for optimising the production of this edible insect with emerging economic importance.

Reproductive senescence in free-ranging North American elk Cervus elaphus Cervidae

Mammalia ◽  
2019 ◽  
Vol 83 (6) ◽  
pp. 593-600 ◽  
Author(s):  
Louis C. Bender ◽  
Jessica R. Piasecke
Keyword(s):  
Age Structure ◽  
Cervus Elaphus ◽  
North American ◽  
Reproductive Senescence ◽  
Female Age ◽  
North American Elk ◽  
Age Related ◽  
Consistent Manner ◽  
Multiple Species ◽  
Free Ranging

Abstract Successful production of calves is necessary for growth of North American elk (Cervus elaphus Linnaeus 1758) populations, but few studies have evaluated age-related effects on both the conception and survival of a calf to weaning in multiple free-ranging populations. Conception and survival of calves to weaning were both affected by maternal age, with old (age 9 and older) females showing reproductive senescence as compared to prime-aged (ages 2–8) females despite achieving similar or greater size and condition. Reproductive senescence in our free-ranging populations ultimately resulted in old females weaning fewer calves (0.42 calves/female) than did prime-aged females (0.64 calves/female). Other factors, especially maternal size, also influenced conception and survival to weaning, and these interacted with age in a consistent manner, i.e. larger females or females in better condition were more likely to conceive and successfully wean calves within each age class. Female age structure receives less consideration in ungulate management than does male age structure, despite demonstrated impacts on population productivity of multiple species because of reproductive senescence. Because of the large proportion of individuals in senesced age classes in elk populations, low productivity in populations may simply reflect female age structure, rather than other frequently hypothesized factors.

Female Reproductive Senescence

2017 ◽  
pp. 77-103
Author(s):  
Richard W. Steger ◽  
William E. Sonntag ◽  
Joseph Meites
Keyword(s):  
Reproductive Senescence

scholarly journals Hormone Replacement Therapy: Risks and Benefits

2020 ◽  
Vol 7 ◽  
Author(s):  
Eriston Vieira Gomes
Keyword(s):  
Hormone Replacement Therapy ◽  
Replacement Therapy ◽  
Therapeutic Option ◽  
Hormone Replacement ◽  
Medical Practitioner ◽  
Clinical Approach ◽  
Vaginal Atrophy ◽  
Reproductive Senescence ◽  
Risks And Benefits

The climacteric is a physiological period of the female reproductive cycle characterized by a decrease in the levels of sex hormones, mainly estrogen. It consists of several phases, with amenorrhea as the initial clinical manifestation followed by long-term changes, such as vaginal atrophy. In this context, hormone replacement therapy (HRT) aims to improve the symptoms of female reproductive senescence, seeking to provide a comfortable physical and psychological condition during this period. However, as with any drug treatment, HRT has its risks and benefits, and it is up to the medical practitioner, in agreement with the patient, looking for the best therapeutic option, minimizing the risks and consequences resulting from this clinical approach.

Histological evidence of reproductive senescence in Atlantic herring (Clupea harengus)

2020 ◽  
Vol 98 (1) ◽  
pp. 73-78
Author(s):  
Hugues P. Benoît ◽  
Kadra Benhalima ◽  
Jenni L. McDermid
Keyword(s):  
Survival Rate ◽  
Relative Frequency ◽  
Natural Populations ◽  
Mortality Rates ◽  
Reproductive Period ◽  
Clupea Harengus ◽  
Atlantic Herring ◽  
Reproductive Senescence ◽  
Histological Evidence ◽  
Adaptive Explanation

Senescence is the age-specific decline in fitness of adult organisms principally associated with a decline in survival rate (actuarial senescence) and fecundity (reproductive senescence). Although common in natural populations of many taxa, there are few examples in fishes. A recent study found age-specific increases in the relative frequency of macroscopically non-reproductive Atlantic herring (Clupea harengus Linnaeus, 1758), consistent with reproductive senescence in a number of Canadian populations. However, a non-adaptive explanation for these patterns, unrelated to senescence, could not be definitively ruled out. Here, we present the results of histological examination of herring gonads undertaken to examine this and another hypothesis. The sample size of macroscopically senescent gonads was small (n = 4 females), a function of the low abundance of large, older, purportedly senescent, herring in these populations subjected to high mortality rates, and constraints on obtaining fresh samples. The results indicate that these fish were senescent and not merely skip spawning, providing further evidence of senescence and the occurrence of a post-reproductive period in herring in Atlantic Canada. Based on existing theory for the evolution of senescence, observations of actuarial senescence in Norwegian spring-spawning herring suggest that this population may also experience reproductive senescence and that the phenomenon may occur broadly in the species.

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