Milk yield per cow has more than doubled in the previous 40 years and many cows now produce more than 20,000 kg of milk per lactation. The increase in production should be viewed with concern because: i) the increase in milk yield has been accompanied by declining fertility, increasing leg and metabolic problems and declining longevity; ii) there are unfavourable genetic correlations between milk yield and fertility, mastitis and other production diseases, indicating that deterioration in fertility and health is largely a consequence of selection for increased milk yield; and iii) high disease incidence, reduced fertility, decreased longevity and modification of normal behaviour are indicative of substantial decline in cow welfare. Improving welfare is important as good welfare is regarded by the public as indicative of sustainable systems and good product quality and may also be economically beneficial. Expansion of the Profitable Lifetime Index used in the UK to include mastitis resistance and fertility could increase economic response to selection by up to 80%, compared with selection for milk production alone. In the last 10 years, several breeding organisations in Europe and North America followed the example of Nordic Countries and have included improving fertility and reducing incidence of mastitis in their breeding objectives, but these efforts are still timid. A multi-trait selection programme in which improving health, fertility and other welfare traits are included in the breeding objective, and appropriately weighted relative to production traits, should be adopted by all breeding organisations motivated in their goal of improving welfare.

To alleviate the imbalance in demographics, the Chinese government initiated the universal two-child policy nationwide in 2016, which has comprehensively impacted society, especially females. Our study investigates whether this policy has negatively affected workforce employment and income among women in urban areas. Based on the DID (difference-in-differences) method and the Heckman Two-Step Estimation, reliable empirical evidence shows that the universal two-child policy has significantly reduced women’s employment by 4.06% and decreased their labour income by 10.43%. Surprisingly, this policy has decreased the employment among women under 25 years old by 23.99% and has reduced the income of higher educated females by 29.59%. Furthermore, we find that the influence of the universal two-child policy on female employment has gradually increased from 2016 to 2018, and its impact on income has presented an evident time lag.

Trypanosoma rangeli is a protozoan that infects triatomines and mammals in Central and South America. Although it does not cause disease to humans, this parasite produces different levels of pathogenicity to its invertebrate host, mainly in species of the genus Rhodnius. In this study, we followed T. rangeli-infected and uninfected pairs throughout their adult lives and measured the amount of blood ingested, number of eggs laid, number of eggs hatched and proportion of infertile eggs, as well as female life expectancy. We found that all reproductive parameters were drastically decreased during infection, mainly due to the reduced amount of blood the infected insects ingested throughout their lives. Reproductive parameters were also affected by the reduction of the life expectancy of infected females, as survival was positively correlated with the number of eggs laid. The strategies used by the parasite to be transmitted are discussed in view of the pathological effects it causes in the insect.

Smutgrass is an invasive weed species that can quickly outcompete bahiagrass because of its aggressive growth, prolific seed production, and rhizomatous nature. Total renovation of bahiagrass pastures or hayfields is generally not a feasible or economically viable option for most producers. Therefore, controlling the continual spread of smutgrass will require an integrated weed management (IWM) plan that incorporates multiple strategies. The objective of this study was to test the interactions of herbicides and fertilizers on smutgrass control in bahiagrass and determine the most efficacious and economical IWM plan for low-input bahiagrass systems. This research was conducted on a mixture of ‘Tifton 9’ and ‘Pensacola’ bahiagrass at the Alapaha Beef Station in Alapaha, GA. The study design was a randomized complete block with a three-by-four factorial treatment arrangement with six replications. Fertility treatments included 56 kg N ha–1 (ammonium nitrate, 34% N) + 56 kg K2O ha–1, 56 kg N ha–1, and an unfertilized control. Smutgrass was reduced to <15% ground coverage when a postemergent herbicide was applied. The addition of a preemergent herbicide and/or fertilizer further reduced the coverage of smutgrass (P < 0.01). As smutgrass declined, the bahiagrass ground coverage increased; other vegetation and dead material did not differ by treatment. Generally, herbage accumulation and crude protein were only affected following the second N application (P < 0.01). Treatments that included preemergent (indaziflam) and postemergent (hexazinone) herbicides in addition to N and K2O resulted in an improved bahiagrass stand as timely weed suppression removed competition, while fertilizer provided essential nutrients for optimum growth to fill in the gaps. Combining herbicide and fertilizer is a more economical option for producers when compared to a complete bahiagrass renovation.

Mate preferences and mating-related behaviours are hypothesised to change over the menstrual cycle to increase reproductive fitness. Recent large-scale studies suggest that previously reported hormone-linked behavioural changes are not robust. The proposal that women's preference for associating with male kin is down-regulated during the ovulatory (high-fertility) phase of the menstrual cycle to reduce inbreeding has not been tested in large samples. Consequently, we investigated the relationship between longitudinal changes in women's steroid hormone levels and their perceptions of faces experimentally manipulated to possess kinship cues (Study 1). Women viewed faces displaying kinship cues as more attractive and trustworthy, but this effect was not related to hormonal proxies of conception risk. Study 2 employed a daily diary approach and found no evidence that women spent less time with kin generally or with male kin specifically during the fertile phase of the menstrual cycle. Thus, neither study found evidence that inbreeding avoidance is up-regulated during the ovulatory phase of the menstrual cycle.

Conjugated linoleic acid (CLA) is a mixture of positional isomers of linoleic acid found in ruminant products and meat. The diet supplementing with CLA is an emerging area, requiring studies to elucidate its effects on animals and human reproduction, as well as its side effects. Therefore, the aim of this study was to evaluate the effects of CLA gastric administration, during the pregestational and gestational period in biometric and reproductive parameters, as well as in ovarian morphophysiology. Animals were distributed in three groups: (1) control (n = 10); (2) fish oil (n = 10); and (3) CLA (n = 10), that daily received, by gavage, phosphate-buffered saline, fish oil and CLA, respectively, carried out over 50 days (before mating, mating and pregnancy). There was an increment in the nasoanal distance and Lee index of the CLA and fish oil-treated groups during the first weeks (P > 0.05). CLA administration did not affect the ovarian follicle mobilization (P > 0.05), the number of follicles (P > 0.05) and the integrated density of lipid content of oocytes included in antral follicles (P > 0.05). There was no effect of CLA administration on the litter weight (P > 0.05; F2 and F3), however, an increment (P < 0.05) in the number of pups per litter (F2) was observed. Overall, this study demonstrated the absence of side effects of the CLA gastric administration on mice reproductive performance and suggests that this treatment would transgenerationally enhance fertility in this species.

The decline in fertility, rapid urbanization and the increase in women’s education levels in Turkey are simultaneous transformations. The coexistence and interaction of these transformations is the focal point for the interpretation of fertility trajectories in Turkey. This article explores Turkey’s heterogeneous fertility structure by examining the fertility trajectories of women between 1949 and 1978 cohorts. It also examines changes in these trajectories in light of Turkey’s fertility decline and interprets those changes through comparisons of women whose fertility behaviors are similar. Using three waves (1998, 2008 and 2018) of the Turkey Demographic and Health Survey data, we employed sequence analysis to calculate fertility trajectories and form clusters from these trajectories. The background similarities of women in the same fertility clusters were investigated with distance analysis, and we calculated predicted probabilities from multinomial logistic regression results and predicted cluster membership. The heterogeneous nature of fertility in Turkey during the demographic transition period shaped the transition process and it can be predicted that such heterogeneity will shape post-transition fertility. The behavior of having two children became the norm during this period, and greater spacing between births or even stopping after the first child became a preferred option among educated women who grew up in cities. For women who grew up in rural areas and uneducated women, we observed a transition from higher parities to three-norm.

We used the 2016 Hong Kong Census data and the diagonal reference model to investigate the effects of partners' educational pairings on fertility in Hong Kong. Our findings suggest a negative relationship between couples' educational achievements and their fertility. Moreover, males' educational attainment is more consequential of whether having children or not and both males' and females' educational attainments are determinants of the number of children to raise. In addition, the more educated a wife is relative to her husband, the less likely the couple is to have children. Once these educationally hypogamous couples have at least one child, they tend to have fewer children than their homogamous counterparts. By contrast, couples with a relatively more educated male are more likely to have children and tend to rear more children than those in educationally homogamous marriages.

Hairy galinsoga (Galinsoga quadriradiata Cav.) is a troublesome weed in lettuce (Lactuca sativa L.) and other low-growing crops. Many troublesome weed species are more responsive to fertilizer than major crops, and hence potentially more competitive under fertile conditions. This study examined the responses of G. quadriradiata and lettuce, in monoculture or competition with each other, to nitrogen and phosphorus. A greenhouse experiment assessed the biomass and flower production of G. quadriradiata grown in 16 nutrient treatments. The nutrient treatments were arranged in a phosphorus series, in which phosphorus varied, while nitrogen was either low or high, and a nitrogen series, in which nitrogen varied, while phosphorus was either low or high. A field experiment examined G. quadriradiata biomass, flower production, and competition with lettuce using the same nutrient treatments as the greenhouse experiment. Galinsoga quadriradiata dry biomass increased with phosphorus addition, especially when nitrogen was abundant. In the phosphorus series at high nitrogen, G. quadriradiata produced more biomass when competing with lettuce than in monoculture. Nutrient addition generally increased flower production per unit mass. Lettuce fresh biomass increased with phosphorus, but lettuce dry biomass was largely unaffected by fertility. Lettuce fresh and dry biomass were sometimes decreased by competition from G. quadriradiata, relative to intraspecific competition. We conclude that high phosphorus rates increase the productivity of G. quadriradiata and may increase its competitiveness. Therefore, high phosphorus rates should be avoided unless good weed control can be assured.

It is widely recognized that dizygotic twinning (DZT) runs in families, but estimates of heritability from twin and family data are remarkably scarce and vary considerably. Here, we traced seven large, sometimes historical, multigeneration pedigrees from West Africans, fin de siècle French Jews, Canadians (two pedigrees), and the French royal family, in which twin births were recorded. We estimated heritability of twinning (of all types) as zygosity information was not available, diluting the true DZT heritability by a third or so. The estimates in the range 8−20% are remarkably consistent across time (8−19 generations) and ethnicities and also consistent with twin and family estimates.