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Tres protocolos reproductivos fueron evaluados: 1) PG: inyección de PGF2α en el día 50 posparto e inseminación (IA) en base a detección del estro. 2) OVS (Ovsynch: día 0, GnRH; día 7, PGF2α; día 9, GnRH; día 10, IA); y 3) ROV (GnRH + Ovsynch: día- 7, GnRH; día 0, GnRH; día 7, PGF2α; día 9, GnRH; día 10, IA). Además, el efecto de la somatotropina (bST) a la IA, sobre la fertilidad al primer servicio posparto (FERT), y la tasa de preñez a 99 días posparto (PP). FERT fue similar en ROV y OVS (36.2 vs 36.6 %) (P>0.05); y mayor a PG (27.3 %) (P0.05). PG y sin bST (22.5 %) fue menor que OVS con (38.5 %), y sin bST (33.7 %); y que ROV con bST (37.0 %) y sin bST (36.1 %); y PG con bST (32.9 %) (P

This paper summarizes the current archaeological, physiographic, demographic, molecular, and bioarchaeological understanding of the initial peopling and subsequent population dynamics of South America. Well-dated sites point to a colonization by relatively few broad-spectrum foragers from northeastern Asia between ~13,000 and 12,000 cal BC via the Panamanian Peninsula. By ~11,500–11,000 cal BC, a number of regional, specialized bifacial technologies were developed, with evidence for the seasonal scheduling of resources and the colonization of extreme environments. Restricted mobility, landscape modification, and the cultivation of domesticates were underway by ~8000 cal BC. The early migration routes followed by colonists resulted in a broad east-west population structure among ancient South Americans. Genetic, demographic, and skeletal morphological data indicate that a subsequent demographically driven dispersal into South America largely replaced preexisting central Andeans ~5000 BC, due to increased fertility associated with the shift to agriculture. Beyond the Andes, however, there is little evidence of impact of these later expansions on foragers and horticulturists of the Amazon and Southern Cone who were largely descended from Paleoindians and early Holocene populations.

Previous studies on settlement patterns have suggested that the prehistoric farmers who inhabited the Peruvian north-central coast during the transition between the Middle and Late Formative Periods (500–400 B.C.) experienced considerable population growth. In this study we assess the mean weaning age of the population recovered at the Quebrada Chupacigarro cemetery in the middle valley of Supe (2739–2153 cal B.P.), using stable isotopes, to test if weaning practices are compatible with this scenario. Stable nitrogen (δ15N) isotopes from bone collagen of 34 individuals (18 subadults and 16 adults) were analyzed by age using a cross-sectional approach with the WARN (Weaning Age Reconstruction with Nitrogen isotope analysis) method. Furthermore, stable carbon (δ13C) isotopes were assessed to identify age-related dietary differences between juveniles and adults. The results show that the introduction of supplementary foods occurred around 6 months of age (95‰ CI: 0.0–1.2 years; 65‰ CI: 0.1–0.9 years), while complete weaning was likely achieved at 2.6 years (95‰ CI: 1.2–4.2 years; 65‰ CI: 1.9–3.5 years). The findings suggest a relatively late age of end of weaning, not necessarily compatible with higher fertility rates. The resultant increased fertility in Quebrada Chupacigarro is plausible only under the hypothetical failure of postpartum infertility mechanisms, modulated by other potential factors from the context, such as culture-driven weaning practices. Estudios previos de patrones de asentamiento sugieren que los agricultores prehistóricos que habitaron la región de la Costa Nor-Central del Perú durante la transición entre los períodos Formativo Medio y Formativo Tardío (500–400 a.C.) experimentaron considerable crecimiento poblacional. Utilizando isotopos estables, en este estudio se investiga la edad promedio de destete de una población exhumada del cementerio Quebrada Chupacigarro (2739–2153 cal A.P.), localizado en el valle medio de Supe, para comprobar si las prácticas de lactancia materna y destete son compatibles con este escenario. Isotopos estables de nitrógeno (δ15N) obtenidos de colágeno óseo de 34 individuos (18 subadultos y 16 adultos) fueron analizados según edad usando un abordaje seccional cruzado con el programa WARN. Además, isótopos estables de carbono (δ13C) fueron utilizados para identificar diferencias dietéticas intrapoblacionales y/o dietas especiales entre subadultos y adultos. Los resultados indican que la introducción de la dieta suplementaria ocurrió alrededor de los 6 meses (IC95‰: 0.0–1.2años; IC65‰: 0.1–0.9 años), mientras el destete final ocurrió a una edad promedio más probable de 2.6 años (IC95‰: 1.2–4.2 años; IC65‰: 1.9–3.5 años). Nuestros resultados sugieren una edad de destete relativamente tardía, no necesariamente compatible con una alta tasa de fertilidad. El incremento resultante de fertilidad en Quebrada Chupacigarro es plausible apenas bajo la hipotética falla de los mecanismos de infertilidad postparto, modulada por otros factores del contexto como hábitos de lactancia materna y destete culturalmente mediados.

This study explores how armed conflict relates to contraceptive use in Colombia, combining data from the Uppsala Conflict Data Program and Demographic and Health Surveys 1990-2016. Our study is the first systematic effort to investigate whether and how violent conflict influences women's contraceptive use, using nationally representative data across all stages of women's reproductive careers. With fixed effects linear probability models, we adjust for location-specific cultural, social, and economic differences. The results show that although modern contraceptive use increased over time, it declined according to conflict intensity across location and time. We find no evidence that this relationship varied across socioeconomic groups. Increased fertility demand appears to explain a small portion of this relationship, potentially reflecting uncertainty about losing a partner, but conflict may also result in lack of access to contraceptive goods and services.

This work is a reply to the comment by Edinborough et al. (2021) on our recently published paper (Penezic et al., 2020). In our original paper we presented the results based on the tooth cementum annulation analysis that show that the Neolithic females had higher levels of physiological stress than the Mesolithic females in the Central Balkans. We proposed the hypothesis that this was caused by differences in fertility. In their comment on our paper, Edinborough et al. (2021) question: 1) the accuracy and precision of the TCA analysis as the age estimation method 2) that pregnancies leave traces in the tooth cementum 3) our interpretation of the results. In this reply we argue: 1) that the TCA is a reliable method for age estimation 2) that the reflection of pregnancies in the tooth cementum was established by independent and previously published research and 3) we clarify that our interpretation - that the increased fertility in the Neolithic period may be the cause of the observed patterns - is a hypothesis that needs to be further tested rather than the final conclusion of our original paper.

We explore whether a 1990 Japanese educational reform that eliminated gender-segregated and gender-stereotyped industrial arts and home economics classes in junior high schools led to behavioral changes among these students some two decades later when they were married and in their early forties. Using a Regression Discontinuity (RD) design and Japanese time-use data from 2016, we find that the reform had a direct impact on Japanese women's attachment to the labor force, which seems to have changed the distribution of gender roles within the household, as we observe both a direct effect of the reform on women spending more time in traditionally male tasks during the weekend and an indirect effect on their husbands, who spend more time in traditionally female tasks. We present suggestive evidence that women's stronger attachment to the labor force may have been driven by changes in beliefs regarding men' and women's gender roles. As for men, the reform only had a direct impact on their weekend home production if they were younger than their wives and had small children. In such relationships, the reform also had the indirect effect of reducing their wives' time spent in weekend home production without increasing their labor-market attachment. Interestingly, the reform increased fertility only when it decreased wives' childcare. Otherwise, the reform delayed fertility.

The aim of this research was to investigate the influence of duck variants and addition of vitamins into muscovy duck semen on fertility and fertile period of duck eggs after artificial insemination. Semen was collected from five muscovy ducks and divided into 3 treatment groups: without vitamin supplementation (A0), supplementation of 400 μg/mL vitamin C (A1), and supplementation of 80 μg/ml vitamin E (A2). Each semen was inseminated into female ducks of Magelang (B1) and Mojosari (B2) variants. Complete Random Design was used with 3x2 factorial. The results showed that vitamins and duck variants had no significant interaction (P0.05) with fertility and fertile period. The duck variant had no effect (P0.05) on fertility and fertile period, while the addition of vitamins significantly affected (P0.01) the fertility and fertile period. The addition of 400 μg/mL vitamin C increased fertility by 22.28±0.20% but reduced the fertile period by 7.8±3.5 days, whereas 80 μg/mL of vitamin E increased fertility by 11.57±2.47% but reduced fertile period by 12.3±0.9 days. It can be concluded that the addition of 400 μg/mL of vitamin C and 80 μg/mL of vitamin E in Muscovy duck semen increased fertility but shortened fertile period of duck eggs after artificial insemination.

Up to 80% of patients undergoing bariatric surgery are women and most of them are in childbearing age. Weight loss in those patients results in increased fertility in a short time postoperatively. Although women after bariatric procedure have an improved maternal and fetal outcome during pregnancy and in the postpartum period compared to women with untreated obesity, conceiving during the time of rapid weight loss is associated with higher rates of nutritional deficiencies and obstetric complications. Therefore women who receive surgical treatment for obesity are advised not to conceive for the following 12–18 months both to ensure optimal weight loss and to begin pregnancy with optimal nutritional and vitamin status. Before choosing a contraceptive method, both safety and efficacy in the pre– and post–weight loss period should be considered. The UK Faculty for Sexual and Reproductive Health advises using long-acting reversible contraceptives for the first 2 years after surgery.

Variations in wheat yield are largely explained by changes in grain number per m2 which is linked to the number of fertile florets at anthesis. This, in turn is the outcome of developmental processes which control floret initiation and mortality. Earliness ‘per se’ (Eps) genes are involved in fine-tuning time to anthesis in wheat (and other cereals) but their effect on development prior to anthesis is less well studied. We aimed to determine effects of Eps genes on spike fertility, quantifying aspects of floret developmental which influence this trait. Field experiments were carried out to record floret primordia generation/degeneration dynamics in near isogenic lines (NILs) with contrasting Eps alleles (late flowering vs early flowering alleles; Eps-late and Eps-early, respectively) derived from the Avalon x Cadenza (AxC) cross with the Eps gene on either chromosome 1D or 3 A and from the Spark x Rialto (SxR) cross with the Eps gene on chromosome 1D. Eps NILs varied in spike fertility: Eps-late alleles increased fertility. Although the effect was in general slight, the magnitude was affected by the particular alleles and the cross used to produce the NILs. Differences in the number of fertile florets were explained by differences in the dynamics of floret development. NILs with Eps-late alleles improved the development of a small number of labile florets allowing them to complete their development to become fertile florets instead of dying, as in lines carrying early alleles. Thus, these alleles improved floret fertility mainly through reducing the rate of floret mortality with no influence on the dynamics of floret primordia initiation or in maximum number of floret primordia. Therefore, Eps genes could be exploited in wheat breeding not only to fine-tune time to anthesis but also to improve spike fertility.

The main aim of this study was to analyse fertility change in Ovamboland (North-Central Namibia) (1927–2010) and the Kavango region (North-East Namibia) (1935–1979) in Northern Namibia. According to the results, the fertility change was quite similar in both areas: fertility declined during the 1950s compared to the preceding period, 1935–1949. We can assume that the main reason for this early fertility decline was changes in the number of migrant workers (out-migration), which caused changes in both the marriage age and birth intervals. In both Ovamboland and in the Kavango region, fertility increased from the late 1950s into the early 1960s and the fertility transition started at the end of the 1970s. In both areas, the increase in fertility during thelate 1950s and early 1960s was probably due to the improved health situation. Fertility transition started at the end of the 1970s, but mortality had already started to decline before that. The main causes of this declining fertility at the end of the 1970s and during the 1980s were improved access to modern methods of contraception and probably also the increased level of education. As a result of the HIV epidemic, mortality increased in Ovamboland at the end of the 1990s and early 2000s. The declining fertility in the same period was probably linked to this increased mortality due to AIDS, while the increased fertility after 2008 is, in turn, probably linked to management of the HIV epidemic.

The objective of this study was to assess the efficacy of a single injection of Prostaglandin F2α (PGF2α) combined with or without GnRH before initiation of a Heatsynch protocol (GnRH-7d- PGF2α-2d-EB-1d-AI) on ovarian response and fertility in lactating Holstein cows. A total of 252 cows with a corpus luteum (CL; ≥10 mm) were assigned to one of three synchronization groups; 1 - Control (n=84), cows received two injections of PGF2α 14 days apart; 2 - Heatsynch with GnRH (PGH, n=88) the cows received PGF2α followed by GnRH four days later and then a Heatsynch protocol was initiated eight days after GnRH treatment; and 3 - Heatsynch without GnRH (PH, n=80) cows received a single injection of PGF2α followed by a Heatsynch protocol initiated 12 days after PGF2α. Cows detected in estrus were inseminated approximately 12 h after onset of estrus. Ovarian response and pregnancy diagnosis were determined by ultrasonography during the synchronization protocol and 30 days after AI, respectively. Results showed the percentage of cows with plasma P4≤0.4 ng/mL at AI were greater in PGH group compared to other groups (90.3 vs. 75.0%, P=0.03). The percentage of cows that ovulated in response to the GnRH injection of Heatsynch was affected (P

Male parental investment can contribute to the fitness of both sexes through increased fertility and child survivorship. The level and intensity of parental investment are dependent upon ecological variations: in harsh and demanding environments, the need for biparental care increases. Moreover, when environmental pressures increase, uncertainty over paternity may lead to favoring stricter mate-guarding practices, thus directing males to invest more effort toward controlling and guarding their mates from infidelity. In this paper, we test the hypothesis that religious veiling, as a social and cultural practice which regulates and restricts sexuality, will be more important in harsher environments. Our results show that harsh and demanding environments are associated with the importance of religious veiling and the level of religiosity, providing a link between cultural practices such as religious veiling and ecological variation.

Simple Summary The goals of this study were to advance first mating in ewe lambs and to shorten the period ranging from weaning to first lambing. Sarda ewe lambs (n = 400) were separated into four groups of 100 and exposed for a 50-day breeding period to fertile, adult rams as follows: (1) RMR (Rams–Melatonin–Replacement) group: exposed to melatonin-treated rams which were replaced every 10 days; (2) RM (Rams–Melatonin) group: exposed to melatonin-treated rams which were not replaced; (3) RCR (Rams–Controls–Replacement) group: exposed to untreated rams which were replaced every 10 days; and (4) RC (Rams–Controls) group: exposed to untreated rams which were not replaced. In each group, lambing dates, fertility rate, litter size, and distance in days from ram introduction to lambing (DRIL) were recorded. The RMR group showed the highest fertility rate, whilst shorter DRIL and higher number of ewes that lambed in a shorter time frame were recorded both in RM and RMR groups, compared to controls. The findings highlighted that melatonin treatment in rams and their replacement allowed advancing first mating, increasing fertility rate, and improving lambing concentration. Abstract This study aims to find reliable strategies for advancing first mating and shortening the period from weaning to first lambing in ewe lambs. Sarda ewe lambs (n = 400) were selected from two farms and allocated into four separated groups of 100, all of which were exposed to fertile, adult rams over the course of a 50-day breeding period. The first treatment group (RMR) was exposed to four melatonin-treated rams which were replaced every ten days, whilst the second treatment group (RM) was exposed to four melatonin-treated rams which were not replaced. Alternatively, the first control group (RCR) was exposed to four untreated rams which were replaced every ten days, whilst the second control group (RC) was exposed to four untreated rams which were not replaced. In each group, lambing dates, fertility rate, litter size, and distance in days from ram introduction to lambing (DRIL) were recorded. The highest fertility rate was recorded in the RMR group (p ≤ 0.05). Shorter DRIL (p ≤ 0.01) and higher lambing concentrations were recorded in the RM and RMR groups as compared to the controls. The findings indicate that melatonin treatment of rams and their replacement at 10-day intervals results in earlier onset of first mating, increased fertility rate in ewe lambs, and a higher number of ewes that lambs in a shorter time frame.

The beef cattle industry recorded progressive growth in the last two decades. Despite this growth, suppliers are having difficulty to meet the domestic demand for beef. Continued strong growth of beef cattle production capacity depends on supplier profitability, which in turn will be influenced by primarily on availability of feedstuffs that constitutes a large proportion of the cost of production. The policy design and management of beef cattle production systems in Malaysia is challenging since imported beef is much more profitable. To this end, the research has applied systems approach that can be used to study and understand the behavior of a complex system over time which is characterized by interdependence, mutual interaction, information feedback and circular causality. The results indicate that low beef price and feed cost ratio would worsen beef cattle production. However, development of grazing and fodder area and genetic improvement boost the beef cattle production significantly by 2020. The results of this research support the idea that the best policies to obtain the targeted self-sufficiency level is through importation of animal for breeding, minimized rate of beef cattle mortality, increased fertility and the conduct of training in feed efficiency management.

Objective Although recent research has begun to examine the impact of elevated anxiety on evolutionary fitness, no prior research has examined anxiety across a continuum. Such research is important as the effect of traits across a continuum on fertility hold important implications for the levels and distribution of the traits in later generations. Method In a three-generational sample (N = 2657) the linear and quadratic relationship between anxiety and the number of children, grandchildren, and great-grandchildren 15 years later was examined. Results The findings suggested that anxiety had a positive quadratic relationship with the number of children, grandchildren, and great-grandchildren 15 years later. These relationships were not significantly moderated by sex. Moreover, most of the variance between anxiety and the number of great-grandchildren was explained by anxiety's influence on the number of children and grandchildren, as opposed to anxiety having an independent direct impact on the number of great-grandchildren. Conclusion These findings suggest that extreme values from the mean anxiety are associated with increased evolutionary fitness within the modern environment.

La endometriosis es una de las enfermedades más enigmáticas de la ginecología y en general de la profesión médica. Su patogénesis sigue siendo desconocida. La forma de presentación es bizarra, ya que hay mujeres que tienen endometriosis y presentan dolor y/o infertilidad y hay mujeres que teniendo endometriosis no presentan ni dolor ni infertilidad. Asimismo, muchos aspectos de su manejo continúan siendo controversiales, y el tratamiento del endometrioma no escapa a esta situación. Diversos tratamientos tanto médicos como quirúrgicos han sido propuestos con resultados variados, pero quizás el aspecto más controversial es el relacionado con el tratamiento quirúrgico del endometrioma ovárico. Siempre ha sido manifiesta la relación entre el endometrioma y la infertilidad, y el tratamiento de elección siempre ha sido el quirúrgico, más aún con la evidencia de un incremento de la fertilidad después de la cirugía. Pero, con el advenimiento de la fertilización in vitro (FIV) aparecieron dudas con respecto al real beneficio de la cirugía para mejorar la fertilidad en mujeres con endometrioma, ya que fueron apareciendo algunos estudios que refirieron el impacto negativo de la cirugía en la reserva ovárica al remover tejido ovárico sano junto con la cápsula del endometrioma, en el momento de la cirugía. Pero, es importante resaltar que el endometrioma no solamente genera infertilidad sino que muchas veces la molestia más prevalente es el dolor, y que muchas de estas pacientes no son infértiles. Por esto, el objetivo de esta revisión de las controversias es tratar de establecer a la luz de las evidencias el estado actual del manejo del endometrioma en general y el impacto del tratamiento quirúrgico en la fertilidad en lo particular.

The aim of this study was to estimate genetic parameters for estrus-related traits that could improve selection for increased fertility due to improved ability of the cow to return to cycling and go into heat after calving. We compared the time from calving to first insemination (CFI) to 3 physical activity traits: the interval from calving to first high activity (CFHA), estrus duration (ED), and estrus strength (ES). We calculated CFI based on data from commercial Holstein herds that included the insemination dates for 11,363 cows. The CFHA, ED, and ES traits were derived from electronic activity tags for 3,533 Holstein cows. Estimates of heritability were 0.07 for CFI, 0.16 for CFHA, 0.02 for ED, and 0.05 for ES. We found a strong genetic correlation between CFI and CFHA (0.96). Genetic correlations between ED and CFI and CFHA were −0.37 and −0.68, respectively. Genetic correlations between ES and CFI and CFHA were −0.50 and −0.58, respectively. The heritability of CFHA and its strong genetic correlation with CFI suggest that including CFHA in the genetic evaluation of female cow fertility could improve the effectiveness of selection, because CFHA reflects the ability to return to cyclicity and go into heat after calving.

Objective: The Okhotsk people were sedentary hunter–gatherer–fishers who lived and prospered in Sakhalin, Hokkaido, and the Kurile Islands during the 5th to 13th centuries AD. They expanded rapidly along the northeastern coast of Hokkaido. We reconstructed infant feeding practices of the Moyoro population of the Okhotsk culture in eastern Hokkaido, Japan. Methods: Stable isotope ratios in 58 subadult human skeletons were measured. Results: The results suggest that complementary foods with a relatively low carbon isotope ratio were consumed during and after weaning, as observed in ethnographic descriptions of northern human populations such as the Ainu and isotopically suggested in ancient northern hunter–gatherer–fisher populations. Nitrogen isotope ratios of subadults showed that the age at the end of weaning in the Moyoro population was 1.8 (1.4–2.2 in 95% credible interval) years, which is earlier than that in other northern hunter–gatherer–fisher populations. Conclusions: Because weaning age is one of the most important determinants of fertility, a shorter breastfeeding period suggests increased fertility. Furthermore, better nutrition would further promote the population increase, and thus populations of the Okhotsk culture could expand into new regions. These findings are consistent with recent emerging evidence of great contributions of the Okhotsk to the formation of later Ainu populations and culture. Am J Phys Anthropol 157:544–555, 2015. © 2015 Wiley Periodicals, Inc.

The objective was to compare fertility in cows using an Ovsynch protocol starting on day 6 of first postpartum estrous cycle with an Ovsynch protocol initiated at random stages of the estrous cycle during heat stress (temperature-humidity index (THI)=77–83). Cows ( n =459) at the beginning of the lactation period were randomly assigned to time-of-ovulation synchronization treatments: (1) control, Ovsynch (first GnRH treatment, PGF2α treatment 7 days later, second GnRH treatment 56h later, and TAI 16h later), initiated at random stages of the estrous cycle (40±2days postpartum, n =224) and (2) Ovsynch initiated on day 6 of first postpartum estrous cycle (estrus=day 0) based on detection of the first estrus after day 30 postpartum (O6, 35±2 postpartum, n =235). Statistical analyses were conducted using SAS. The percentage of cows responding to the initial GnRH injection using the Ovsynch protocol was greater with the O6 treatment compared to the control treatment (60.4% compared with 52.6%). The percentage of cows having a corpus luteum (CL) on the day of the PGF2α injection was not different among treatments (control=87.0% and O6=90.2%, respectively). Also more cows in the O6 treatment group responded to the second GnRH injection of the Ovsynch protocol compared with control treatments (82.5% compared with 75.8%). Treatment affected the percentage of cows diagnosed pregnant at 32±0.7days and 60±3days after the resynchronized timing of AI but pregnancy losses (5.3% compared with 6.8%) did not differ between treatment groups. It is concluded that initiating the Ovsynch protocol 6 days after estrus during the first 40 days postpartum resulted in a greater pregnancy rate at the synchronized estrus and increased fertility compared with control cows during heat stress.

In many developed countries, fertility rates are in decline and longevity is increasing. While greater longevity is cause for celebration, a growing elderly population increases the overall demand for expanded social security programs, particularly those pertaining to long-term care services. By considering and measuring the care burden per capita, we show that an increase in the fertility rate can improve household utility, even though it reduces the wage rate. The findings of this analysis imply that improvements in the fertility rate are desirable, as it eases burdens relating to long-term care services, as well as those relating to public pension plans.

Consanguinity of human populations can but does not have to be associated with increased fertility. A recent study involving communities of Northeast Brazil revealed increased levels of endogamy.Data from 20 451 interviewed couples and their 74 289 children were analysed.The present study aimed to compare fertility between consanguineous and unrelated couples of these communities.Consanguineous and unrelated couples of the 39 communities had an average of 4.3 (SD = 0.9) and 3.5 (SD = 0.8) children (p 0.0001), respectively. Average offspring number of consanguineous couples varied from 3.9 (SD = 1.1) to 5.6 (SD = 3.4) for couples related at the level of third cousins and double first cousin/uncle-niece, respectively (p 0.005). The correlation coefficient between Human Development Index and fertility was -0.38 (p = 0.0179) and -0.23 (p = 0.17) for unrelated and related couples, respectively.Results indicated an overall positive association between consanguinity and fertility. Fertility tended to be increased, for closely related couples, compared to those related more distantly.

It is generally thought that females can receive more of the material benefits from males by increasing mating frequency and polyandry can lead to greater reproductive success. The cabbage beetle, Colaphellus bowringi Baly (Coleoptera: Chrysomelidae), is a highly promiscuous species, in which females or males can readily mate repeatedly with a given partner or multiple partners at a very high frequency. In the present study, the effect of mating frequency (number of matings) and mating pattern (polyandry vs. monogamy) on female reproductive fitness was investigated by measuring fecundity, fertility, and female longevity. The results indicated that increased female mating frequency with the same male did not result in variation in lifetime fecundity, but significantly increased fertility and decreased female longevity. Moreover, five copulations were sufficient to acquire maximal reproductive potential. Female lifetime fecundity also did not differ between polyandrous and monogamous treatments. However, monogamous females exhibited a significant increase in fertility and significant prolongation of longevity compared with polyandrous females, further demonstrating that monogamy is superior to polyandry in this beetle.

I study the impact of a universal child benefit on fertility and maternal labor supply. I exploit the unanticipated introduction of a sizable child benefit in Spain in 2007. Following a regression discontinuity-type design, I find that the benefit significantly increased fertility, in part through a reduction in abortions. Families who received the benefit did not increase consumption. Instead, eligible mothers stayed out of the labor force longer after childbirth, which led to their children spending less time in formal child care. (JEL I38, J13, J16, J22)

The use of stallion frozen semen minimizes the spread of disease, eliminates geographic barriers, and preserves the genetic material of the animal for an unlimited time. Significant progress on the frozen thawed stallion semen process and consequently fertility has been achieved over the last decade. These improvements not only increased fertility rates but also allowed cryopreservation of semen from "poor freezers." This article reviews traditional steps and new strategies for stallion semen handling and processing that are performed to overcome the deleterious effects of semen preservation and consequently improve frozen semen quality and fertility.

Current industry recommendations are to mate gilts on their second or third oestrous cycle (heat) to ensure that they have reached sufficient maturity and have adequate body reserves in order to sustain reproductive performance over subsequent parities. Delaying breeding has the financial implications of increased non-productive days and extra feed costs. However, these could be offset by increased fertility and/or increased lifetime productivity. The aim of this study was to investigate the effect of heat number (oestrous cycle number) on which gilts where mated on first litter and lifetime performance. In total, 157 gilts born between 2002 and 2006 were mated on either their 1st, 2nd, 3rd, 4th or 5th observed standing oestrus. Litter and reproductive data were collected on a continual basis until all animals had completed their commercial reproductive life. Sows were culled as of normal commercial practice and reason for culling was classified into groups. There was no effect (P > 0.05) of oestrus number at first service on first litter performance (numbers of piglets born alive, dead, total born, average birth weight or pre weaning mortality). There was also no effect (P > 0.05) on sow performance in the first lactation (feed intake during lactation, weight change during lactation or weaning to service interval). However, over their lifetime, gilts served on their fourth and fifth oestrus had significantly fewer numbers of piglets born alive (P 0.05) of oestrus number at first service on the total weight of piglets born alive, dead or weaned over the sow's lifetime. There was no significant effect (P > 0.05) of oestrus number at first service on reason for culling but there was on the culling rates of the sows between parities (P

Approximately 113,000 bariatric procedures are conducted yearly. From 1998 to 2005, 83% of those having bariatric surgery in the 18 to 45-year-old age group were women. Reproductive implications are ideally addressed when surgery is planned, including the possibility of increased fertility after surgery, appropriate contraception, and the interval from surgery to pregnancy. Maternal and neonatal outcomes post bariatric surgery have generally been found to be positive and are often improved over those seen in obese women without a history of bariatric procedures. However, surgical complications have been reported, as well as nutritional deficits. Some studies have suggested an increase in small for gestational age (SGA) newborns and increased cesarean section rates, while others have not found these relationships. Neonatal complications have also been reported. Pregnancy care for women with a history of bariatric surgery includes screening for and managing nutritional deficits, careful assessment to rule o...

Despite debate regarding the magnitude of the impact, immigrant inflows are generally understood to depress wages and increase employment in immigrant-intensive sectors. In light of the overrepresentation of the foreign-born in the childcare industry, this article examines whether college-educated native women respond to immigrant-induced lower cost and potentially more convenient childcare options with increased fertility. An analysis of U.S. Census data between 1980 and 2000 suggests that immigrant inflows are indeed associated with native women’s increased likelihoods of having a baby, and responses are strongest among women who are most likely to consider childcare costs when making fertility decisions—namely, married women and women with a graduate degree. Given that native women also respond to immigrant inflows by working long hours, this article concludes with an analysis of the types of women who have stronger fertility responses versus labor supply responses to immigration.

Background Small scale trials of male hormonal contraception have produced encouraging results. Attitudes to, and beliefs about, a proposed male pill may affect uptake. Methods This paper examines attitudes towards a proposed ‘male contraceptive pill’ among a self selected sample of 54 men and 134 women, living in a non-metropolitan centre in the East of England, United Kingdom who were already users of contraception. Thirty four respondents were also interviewed and their views on the male pill were qualitatively analysed. Results The acceptability of a male pill was high, with just under half (49.5%) of the respondents indicating that they woud use it. Gender, length of relationship, age and educational achievement did not affect the reported acceptability. However, 42% of respondents expressed concerns that men would forget to take a male pill. Women were significantly more likely to express this concern than men. Furthermore, 26% of respondents expressed health concerns. Willingness to take a male pill was associated with expressing the view that increased protection against pregnancy would be an advantage of such a method. Those unwilling or undecided were more likely to express concerns about the effect of a pill on future fertility. Conclusions A male pill was accepted as a potential aid to increased fertility control by a large proportion of a convenience sample of contraceptive users in the East of England. If a male pill were to be marketed in the UK this study suggests that concerns about effects on future fertility and health risks may need to be addressed.

Fuel prices have fluctuated wildly in the last several years, and faced with unpredictable or rising fuel costs, growers often lower temperature set points to decrease fuel use. However, plant growth and development are influenced by lower temperatures and may actually cause increases in fuel use as a result of longer production times. Alternative strategies to efficient crop production are needed. Fertility, light, and CO2 are other environmental factors that can be manipulated within a greenhouse but how all three interact together on growth and development are surprisingly not well known. Petunia ×hybrida Vilm. were grown in controlled environments in a 2 × 2 × 2 factorial study investigating how light, fertility, and CO2 influence growth and development, including shoot partitioning, nutrient uptake, and carbohydrate concentration. Generally, light enhanced flowering, both mass and fraction of total biomass, whereas increased fertility was detrimental to the proportion of biomass allocated to flowers. The influence of CO2 was complex with high CO2 suppressing flowering and enhancing leaf growth, but only midway through the 7-week experiment. Carbohydrate concentration remained high in elevated CO2, even when light and fertility were not limiting. This suggests a sink limitation, so even in high light and fertility, crop response to enhanced CO2 was low. Although CO2 had no size effect late in growth, CO2 suppressed nutrient concentrations. Together, these data suggest strategies that growers may have in controlling their crop growth and development and indicate that enhanced growth (leaf and steam mass) may be at the detriment of development (flowering mass and allocation).

This thesis contributes to the limited demographic literature on Central Asia – the region through which led the great Silk Road – an ancient route of trade and cultural exchange between East and West. We focus on Kyrgyzstan and countries in its immediate neighborhood: Tajikistan and Uzbekistan. We analyze the dynamic interplay between marriage, childbearing, and migration, and examine fertility intentions and intentions to migrate as predictors of demographic outcomes. The thesis consists of four co-authored and one single-authored paper connected through a common theme of ethno-cultural differences in demographic behavior. In the first three studies, we explore the link between migration and family formation. We demonstrate that increased fertility of recent migrants is attributable to marriage-related resettlements. In paper four, we provide an analysis of intentions to move abroad. Our results suggest that ethnicity plays a significant role, independent of other factors, in determining migration plans and preferences, and detect ethnic-specific effects of marriage, childbearing, and social capital on the inclination to migrate. In paper five, we compare the fertility and fertility intentions of ethnic majority and minority groups in three neighboring countries of the region. We explain fertility differentials between ethnic groups in terms of the combined effects of their status in society, country-level differences in institutional settings, and historical and cultural factors.

Objectives To review religious and ethical considerations for health care professionals when discussing fertility preservation with young survivors. Data Sources Published research reports and articles, published guidelines, and web sites. Conclusion Although advances in assisted reproductive technology have increased fertility preservation options, not all treatments are acceptable or available for all young survivors. Implications for Nursing Practice The ongoing provision of information from health care professionals allows young survivors to make high-quality decisions about fertility across the survivorship continuum. Knowledge of the influence that religious beliefs and economics have on decisions help nurses to better understand and support patients during this difficult time.

Anecdotal evidence has suggested increased fertility rates resulting from catastrophic events in an area. In this paper, we measure this fertility effect using storm advisory data and fertility data for the Atlantic and Gulf-coast counties of the USA. We find that low-severity storm advisories are associated with a positive and significant fertility effect and that high-severity advisories have a significant negative fertility effect. As the type of advisory goes from least severe to most severe, the fertility effect of the specific advisory type decreases monotonically from positive to negative. We also find some other interesting demographic effects.

This study evaluated a novel presynchronization method, using Ovsynch prior to the Ovsynch-timed AI protocol (Double-Ovsynch) compared to Presynch-Ovsynch. Lactating Holstein (n=337) cows, were assigned to two treatment groups: (1) Presynch (n=180), two injections of PGF 14 d apart, followed by the Ovsynch-timed AI protocol 12 d later; (2) Double-Ovsynch (n=157), received GnRH, PGF 7 d later, and GnRH 3 d later, followed by the Ovsynch-timed AI protocol 7 d later. All cows received the same Ovsynch-timed AI protocol: GnRH (G1) at 68+/-3 DIM (mean+/-SEM), PGF 7 d later, GnRH (G2) 56h after PGF, and AI 16 to 20h later. Pregnancy was diagnosed 39-45 d after timed AI. Double-Ovsynch increased the pregnancies per AI (P/AI) compared to Presynch-Ovsynch (49.7% vs 41.7%, P=0.03). Surprisingly, Double-Ovsynch increased P/AI only in primiparous (65.2% vs 45.2%; P=0.02) and not multiparous (37.5% vs 39.3%) cows. In a subset of 87 cows, ovarian ultrasonography and progesterone (P4) measurements were performed at G1 and 7 d later. Double-Ovsynch decreased the percentage of cows with low P4 (1ng/mL) at G1 (9.4% vs 33.3%) and increased the percentage of cows with high P4 (or =3ng/mL) at PGF (78.1% vs 52.3%). Thus, presynchronization of cows with Double-Ovsynch increased fertility in primiparous cows compared to a standard Presynch protocol, perhaps due to induction of ovulation in non-cycling cows and improved synchronization of cycling cows. Future studies are needed, with a larger number of cows, to further test the hypothesis of higher fertility with Double-Ovsynch, and to elucidate the physiological mechanisms that underlie apparent changes in fertility with this protocol.

The interaction of the bacteria Azospirillum spp. with photosynthetic, single cell microalgae that are co-immobilized in alginate beads provides a significant shortcut for understanding the interaction of this plant growth-promoting bacteria (PGPB) with plants in general. This interaction is currently relevant for studying physiological, physical, biochemical, and molecular aspects. As an independent subfield of Azospirillum research, this interaction has some significant potential biotechnological applications, such as wastewater treatment, production of biofuel (ethanol and biodiesel), increased fertility of eroded soils combined with promoting growth of higher plants, production of pigments, and production of biomass. All of these applications have yet to be scaled up and evaluated for their true practical potential.

Fluctuating asymmetry (FA) is believed to reflect developmental stability and thus may serve as a marker of the biologic quality of individuals. To test the hypothesis that degree of FA is related to a woman's potential fertility, we measured finger length together with levels of estradiol in saliva samples collected daily for an entire menstrual cycle in 171 Polish urban and rural women. We show that women who are more symmetrical, as assessed by the degree of inequality in the fourth-digit length of their right and left hands, have 13% higher average levels of estradiol over the menstrual cycle than less symmetrical women (19.4 and 17.1 pmol/l, respectively; p =.0001). Among urban women, mid-cycle levels of estradiol were 28% higher in the symmetrical group than in the asymmetrical group. Because higher hormone levels in women may lead to a substantial rise in the probability of conception, low FA may therefore be associated with increased fertility.

This paper focuses on the agricultural transition in Portugal and on demography across this transition, concentrating on two key skeletal samples, the Mesolithic shell midden of Cabeco da Arruda and the Neolithic burial cave of Casa da Moura. It extends our previous work on the demography of the transition and the methodology surrounding its determination. We explain our method for determination of the number of individuals in samples where whole skeletons cannot be used. We then concentrate on the estimation of fertility, placing it within limits of biological feasibility, sample inadequacies, and vagaries of age assessment. From our analysis, which includes an examination of historical issues with the sites, we argue for regional population continuity between 8000 and 6000 cal BP, and suggest that Neolithic life-ways slowly intensified, founded on important elements deriving from the late Mesolithic, with changes that included increased fertility through shortening of the birth interval

Increased fertility of heterozygous women is one of the suggested processes maintaining balanced polymorphism of the hemoglobinopathies in some countries. In the present work we studied the fertility of 68 b-thalassemia trait (heterozygous AT) and 53 sickle cell trait (heterozygous AS) women married with normal hemoglobin husbands. The average number of children per heterozygous AT and AS women (2.7647 and 3.0755, respectively) did not differ significantly from those observed among their control sisters with normal hemoglobin (2.3778 and 3, respectively). In addition, it was not observed a significant difference between the proportion of married women without children between the heterozygous women and their control sisters. The results herein presented hence does not support the hypothesis of increased fertility of heterozygous women as being a homeostatic mechanism able to maintain the polymorphism of either b-thalassemia and hemoglobin S in Brazil.

Polygyny can increase, decrease, or have no effect on fertility. Understanding how this can occur requires consideration of both the proximate determinants of fertility and the ultimate effects of polygyny as a female reproductive strategy. Several factors reduced the fertility of polygynous women in 19th century Utah, including marrying at an older age, marrying older men, and conflict between co-wives. Sterility did not explain the reduced number of children in polygynous women, nor is there evidence of a "dilution effect" from sharing a husband. If women could anticipate a reduction in their own fertility, why would they still choose polygyny? Evidence suggests that they chose it because the children of polygynous men had increased fertility, high enough to offset the low fertility of polygynous women themselves.

The aim of the present study was to evaluate the effects of L-arginine-HCl supplementation on ovulation rate, fertility, prolificacy, and serum VEGF concentrations in ewes with synchronized oestrus. Thirty Suffolk ewes with a mean body weight of 45 ± 3 kg and a mean body condition score (BCS) of 2.4 ± 0.28 were synchronized for estrus presentation with a progestin-containing sponge (20 mg Chronogest® CR) for 9 days plus PGF2-α (Lutalyse; Pfizer, USA) on day 7 after the insertion of the sponge. The ewes were divided into two groups; i.e., a control group (n = 15) that was fed on the native pasture (basal diet) and an L-arginine-HCl group (n = 15) that received 7.8 g of rumen-protected L-arginine-HCl from day 5 of the sponge insertion until day 25 after mating plus the basal diet. The L-arginine-HCl was administered daily via an esophageal probe between days 5 and 9 of the synchronization protocol and every third day subsequently. Blood samples were drawn from the jugular vein every 6 days throughout the entire experimental period. The results revealed that the L-arginine-HCl supplementation increased fertility during the synchronized estrus (P = 0.05). However, no effects were observed on the final BCS (P = 0.78), estrus presentation (P = 0.33), multiple ovulations (P = 0.24), prolificacy (P = 0.63), or serum VEGF concentration. In conclusion, L-arginine-HCl supplementation during the period used in this study increased fertility in sheep with synchronized estrus possibly due to improved embryo-fetal survival during early pregnancy.

We investigate empirically the impact of maternal mortality on the enrolment rate of girls and boys at the primary and secondary levels. We also examine whether the effect of maternal mortality on enrolment is strengthened or weakened by religion. Evidence shows that at both the primary and secondary levels, maternal mortality has a negative impact on the enrolment of girls and boys, with the negative greater for girls than for boys. For girls, the negative effect of maternal mortality is compounded by religion and increased fertility.

Total fertility rates were declining from peaks experienced by early 1930s cohorts for 20 successive cohorts. The decline ceased among the 1950s and 1960s cohorts, because fertility deficits of young women were compensated with increased fertility when women reached their late twenties and thirties. The relative stability of completed fertility of these cohorts is attributed to Nordic social policies. Fertility deficits of young women in 1970s cohorts are comparatively large. For their completed fertility to be similar to that of earlier ones, there is considerably more catching up to do. What remains an open issue is whether social policies will be sufficiently effective for couples born in the late 1960s and the 1970s to have births not born earlier in their lives.

A 27-year-old caucasian female with classical galactosaemia due to Q188R homozygous mutation is reported. At 18 years she had triplets and at 23 years a further pregnancy. All infants are well.

Summary The soil seed bank of limestone grassland plots was investigated after 6 years of manipulation of temperature, rainfall, fertility and disturbance. An inoculum of seeds of species alien to the site was also added to the experiment. The seed bank was largely made up of species that were native to the site and had small, persistent seeds. Large-seeded species, whether native or introduced, were rare or absent in the seed bank. Small-seeded species were generally more deeply buried than large-seeded species. Total seed density was comparable with that of other limestone grasslands. Significant climate effects were few, although the seed bank of the winter annual Arabidopsis thaliana was increased by summer drought and that of Cerastium fontanum was increased by winter heating. The density of seeds of native species declined in response to disturbance and increased fertility treatments, while that of introduced species increased. Changes in the seed bank lagged behind changes in the vegetation, with introduced species making up a higher proportion of the vegetation than of the seed bank after 6 years of manipulation.

This paper examines some of the determinants of fertility in three fairly homogenous states in northern India. The results show that scheduled tribe status—though not the scheduled caste status—has a substantial negative effect on fertility. The results also provide strong support for the view that improving the position of women through more equitable social and economic development will have a far greater impact on fertility reduction than will the provision of family planning services. Finally, the results provide indirect support for the view that increased income leads to increased fertility and that children are not “inferior goods.”

Singapore is promoting itself as a model for Asian development, citing its high growth rates and stable society. It contends that its approach differs dramatically from that of the West because of its solid value system regarding families and community. This paper examines the ways women and changing family policies have been critical components of Singapore's growth. It shows, however, that rather than having a long-term consistent view of appropriate family size and roles, the Singaporean government adopted strikingly different policies (particularly toward fertility) over the past three decades, as it attempted to affect the supply of labor in the short-run and over the longer term and thereby maintain growth rates. This sheds a different light on Singapore's claims regarding its stable approach to families, particularly since policy changes since the mid-1980s have placed intense demands on women's limited time by encouraging increased female labour force participation and increased fertility.