Eggs: the uncracked potential for improving maternal and young child nutrition among the world's poor

Periodic cooking of eggs

Egg cooks are challenged by the two-phase structure: albumen and yolk require two cooking temperatures. Separation or a compromise temperature to the detriment of food safety or taste preference are the options. In the present article, we find that it is possible to cook albumen and yolk at two temperatures without separation by using periodic boundary conditions in the energy transport problem. Through mathematical modeling and subsequent simulation, we are able to design the novel cooking method, namely periodic cooking. Comparison with established egg cooking procedures through a plethora of characterization techniques, including Sensory Analysis, Texture Profile Analysis and FT-IR spectroscopy, confirms the different cooking extents and the different variations in protein denaturation with the novel approach. The method not only optimizes egg texture and nutrients, but also holds promise for innovative culinary applications and materials treatment.

Prevalence and predictors of short stature in children aged 3-18 years in Hainan Province, China: a cross-sectional study

Background

Short stature is a global health-related problem and remains to be evaluated in children in Hainan Province. The present study was conducted to investigate the associated factors with short-stature in children.

Methods

This cross-sectional study was conducted using a staged, cluster random sampling method. A total of 26,189 children aged 3-18 years, originating from 18 cities and counties in Hainan Province, to determine the prevalence of short stature. Additionally, these children were selected for a thorough analysis of associated factors.

Results

The crude prevalence of short stature was 2.88%, and the standard prevalence was (after adding weights) 3.01%. Children's short stature was significantly related to seven factors: area, birth weight, body mass index z score (BAZ), maternal education, family income (RMB per year), frequency of bean intake and frequency of egg intake. A nomogram model of factors associated with short stature was constructed. The area under the curve (AUC) of the receiver operating characteristic (ROC) curve was 0.698 (95% CI: 0.679-0.716).

Conclusions

Our findings demonstrated that birth weight, BAZ, dietary habits, and family-related factors were strongly correlated with short stature in children in Hainan Province.

Unveiling the Nutritional Quality of Terrestrial Animal Source Foods by Species and Characteristics of Livestock Systems

Background. It is well-established that a range of macronutrients, micronutrients and bioactive compounds found in animal-source foods play unique and important roles in human health as part of a healthy diet. Methods. This narrative review focuses on terrestrial animal source foods (TASFs). It particularly analyzes five groups: poultry eggs, milk, unprocessed meat, foods from hunting and wildlife farming, and insects. The objectives were as follows: (1) examine the nutrient composition of TASFs within and across livestock species, drawing on the country and regional food composition databases; (2) analyze the influence of intrinsic animal characteristics and production practices on TASF nutritional quality. Results. TASFs are rich in high-quality proteins and fats, as well as micronutrients such as vitamin B12, iron or zinc. This study found differences in the nutritional quality of TASFs by livestock species and animal products, as well as by characteristics of livestock production systems. Our findings suggest that there may be public health opportunities by diversifying TASF consumption across species and improving certain aspects of the production systems to provide products that are both more sustainable and of higher quality. Conclusions. Future research should adopt a more holistic approach to examining the food matrix and the dietary patterns that influence TASF digestibility. It is necessary to include meat from hunting and wildlife farming and insects in global food composition databases, as limited literature was found. In addition, scarce research focuses on low- and middle-income countries, highlighting the need for further exploration of TASF food composition analysis and how intrinsic animal characteristics and livestock production system characteristics impact their nutritional value.

Modeling of cooking and phase change of egg white using computational fluid dynamics

This study proposes simulating the cooking of eggs by modeling fluid egg products as phase-change materials (PCMs) within a computational fluid dynamics (CFD) model. A simplified physical prototype was built to conduct experiments to tune a simpler version of the mathematical model. The information was later used to build a complete mathematical model of a real egg that was compared with experimental data. Phase transition temperature ranges, and the energy required to initialize the transition were specified. Heat transfer coefficients were estimated for both models. Experiments for thermal processing and phase change were conducted at temperatures between 90 and 100 °C. The real egg model was validated with experimental data reported elsewhere. The simulations assess the time required to cook an egg (800-1200 s), demonstrating a homogeneous increase in temperature and phase transition. However, potential overestimation in simulations was observed, likely due to differences in quantifying techniques and non-uniform cooking processes.

Minimum dietary diversity is associated with lower risk of childhood underweight: Evidence from the 2019/2021 National Family Health Survey of India

A lack of consumption of a diversified diet is associated with poor physical and cognitive development in children. Evidence on the relationship between minimum dietary diversity (MDD) and childhood malnutrition remains inconclusive in India. We hypothesized that children aged 6 to 23 months on a diversified diet (five out of eight defined foods and beverages) are less likely to be malnourished (stunting, wasting, and underweight) compared to their counterparts who are not on a diversified diet. This cross-sectional study was based on the 2019-2021 National Family Health Survey of India, comprising a weighted sample of 57,714 children aged 6 to 23 months. Multilevel logistic regression was conducted for data analysis. The results showed a significant protective effect of dietary diversity on underweight (odds ratios [OR] = 0.91; 95% confidence intervals [CI]: 0.86-0.96). In addition, children who did not consume eggs (OR = 1.09; 95% CI; 1.03-1.15), dairy products (OR = 1.22; 95% CI: 1.17-1.27), or fruits and vegetables (OR = 1.11; 95% CI: 1.06-1.17) were more likely to be underweight than children who did. Children who did not consume dairy products, fruits, and vegetables were also more likely to be stunted and wasted. However, we did not find significant associations of MDD with wasting and stunting. Nutritional interventions promoting daily consumption of dairy products, eggs, fruit, and vegetables are recommended to address the growing problem of childhood malnutrition in India. Regions with higher rates of malnutrition and those lacking MDD, such as Uttar Pradesh and Rajasthan, should be prioritized.

The Egg Hub Model: A Sustainable and Replicable Approach to Address Food Security and Improve Livelihoods

Background

Despite progress in improving living standards and reduced poverty, food insecurity and malnutrition remain a significant issue worldwide. Childhood is a critical time for the intake of protein to support physical and cognitive growth, including animal-source foods like eggs which can effectively mitigate stunting in low- and middle-income countries. In Malawi, high malnutrition rates among women and children represent a significant public health challenge, but high-quality sources such as eggs remain costly, scarce, and rarely consumed by children in Malawi. The Egg Hub model, identified and piloted by local agri-food entrepreneurs and the Sight and Life Foundation in Malawi, tackles the obstacles faced by smallholder farmers, working to increase egg production, enhance availability, and improve consumption within rural communities by supporting small-scale farmers transition from unsustainable and unproductive backyard rearing to small-scale farm through access to high-quality inputs, training, loans, and a guaranteed market for their eggs.

Objectives

This paper provides a detailed account of the implementation of the pilot of the Egg Hub Model in Malawi including the demand creation process, the impact of the model on producers, consumers, and operators, and the social, economic, and environmental sustainability aspects of the model.

Methods

Qualitative and quantitative surveys (n = 217 consumers) were used for demand creation and qualitative surveys were used with 15 retailers to determine egg sales. With 16 farmers and the egg hub operator, business metrics, including profits and loss records, were analyzed.

Results

The pilot of the Egg Hub model in Malawi supported 85 farmers to triple their egg production, allowing their communities to purchase eggs at prices reduced by 40%, benefiting an estimated number of 180,000 rural poor. Egg consumption among the target population increased from an average of 2 to 9 eggs/month and led to reduced egg wastage and better biosecurity, reducing the risk of children's exposure to chicken feces and infections. The achievements of this Egg Hub in Malawi allowed the model to be replicated in Ethiopia, Peru, and Brazil, producing 40 million eggs annually and benefiting more than half a million consumers.

Conclusion

The Egg Hub model is a comprehensive and scalable solution to increase egg supply, address malnutrition and food insecurity, and improve livelihoods. The advantages include centralizing key activities through a community-centered approach, empowering female farmers, increasing access to a highly nutritious food, and economic benefits for farmers and their communities.

Text messages to improve young child diets: Results from a cluster-randomized controlled trial in Kanchanpur, Nepal

The objective of this study was to test whether adding a text message campaign about the importance of eating eggs and other nutrition-related behaviours to an on-going package of large-scale, diverse social and behaviour change interventions would improve four types of nutrition-related knowledge and behaviour outcomes: child diets (egg consumption as the primary outcome), maternal diets, maternal nutrition knowledge, and maternal participation in additional interventions. The cluster-randomized controlled trial involved a repeat cross-sectional design, recruiting families with children 12-23 months of age at baseline and endline in one plains district of Nepal. Throughout the 1000-day period, 51 text messages were sent to each household at specific time points to reinforce ideal diets and other nutrition-related practices and promote engagement with community health workers and other intervention platforms. The primary outcome was egg consumption and dietary diversity among young children. We found no population-level effect. Some evidence supports that for those who received and opened the SMS intervention, it improved child egg consumption (odds ratio [OR]: 1.41, 95% confidence interval [CI]: 1.03-1.93), child minimum dietary diversity (OR: 1.36, 95% CI: 1.07-1.73), child dietary diversity scores (β: 0.15, 95% CI: 0.01-0.24), as well as maternal IYCF knowledge (β: 0.21, 95% CI: 0.08-0.35), participation in health mothers' group meetings (OR: 3.03, 95% CI: 1.91-4.84) and Bhanchhin Aama listenership (OR: 1.36, 95% CI: 1.07-1.73). This study highlights the importance of more research to understand the effectiveness of emerging digital interventions for behaviour change among specific populations, to facilitate nuanced targeting to those who can best benefit from these investments. Registered at clinicaltrials.gov with identifier NCT03926689.

An Egg Intervention Improves Ponderal But Not Linear Growth Among Infants 6-12 mo of Age in Rural Bangladesh

BACKGROUND

Animal source foods are rich in multiple nutrients. Regular egg consumption may improve infant growth in low- and middle-income countries.

OBJECTIVES

To assess the impact of daily egg consumption on linear growth among 6-12-mo olds in rural Bangladesh.

METHODS

We conducted a 2 × 4 factorial cluster-randomized controlled trial allocating clusters (n = 566) to treatment for enteric pathogens or placebo and a daily egg, protein supplement, isocaloric supplement, or control. All arms received nutrition education. Here, we compare the effect of the egg intervention versus control on linear growth, a prespecified aim of the trial. Infants were enrolled at 3 mo. We measured length and weight at 6 and 12 mo and visited households weekly to distribute eggs and monitor compliance. We used linear regression models to compare 12-mo mean length, weight, and z-scores for length-for-age (LAZ), weight-for-length, and weight-for-age (WAZ), and log-binomial or robust Poisson regression to compare prevalence of stunting, wasting, and underweight between arms. We used generalized estimating equations to account for clustering and adjusted models for baseline measures of outcomes.

RESULTS

We enrolled 3051 infants (n = 283 clusters) across arms, with complete 6 and 12 mo anthropometry data from 1228 infants (n = 142 clusters) in the egg arm and 1109 infants (n = 141 clusters) in the control. At baseline, 18.5%, 6.0%, and 16.4% were stunted, wasted, and underweight, respectively. The intervention did not have a statistically significant effect on mean LAZ (β: 0.05, 95% confidence interval [CI]: -0.01, 0.10) or stunting prevalence (β: 0.98, 95% CI: 0.89, 1.13) at 12 mo. Mean weight (β: 0.07 kg, 95% CI: 0.02, 0.11) and WAZ (β: 0.06, 95% CI: 0.02, 0.11) were significantly higher in the egg compared with control arms.

CONCLUSIONS

Provision of a daily egg for 6 mo to infants in rural Bangladesh improved ponderal but not linear growth.

TRIAL REGISTRATION NUMBER

NCT03683667, https://clinicaltrials.gov/ct2/show/NCT03683667.

Unravelling taboos and cultural beliefs associated with hidden hunger among pregnant and breast-feeding women in Buyende district Eastern Uganda

BACKGROUND

Food taboos and cultural beliefs among pregnant and breast-feeding women influence their food consumption patterns and hence the health of women and unborn children. Cognizant of their neglect in programs aimed to ameliorate hidden hunger among pregnant and breast-feeding women in Buyende and other resource-poor communities in sub-Saharan Africa, we opted for a study to unravel them to inform program design.

METHODS

We documented food taboos and beliefs amongst pregnant and breast-feeding women from six sub-counties of Buyende district in Eastern Uganda. A mixed-methods approach was used, which was comprised of questionnaire interviews with 462 women, eight focus group discussions with 6-10 participants in each and a total of 15 key informant interviews.

RESULTS

The present study revealed that 129 (27.9%) of the respondents practice food taboos and adhere to cultural beliefs related to their dietary habits during pregnancy and breast-feeding that are fuelling the prevalence of hidden hunger. The most tabooed foods during pregnancy were sugarcane (17.8%), fishes which included lung fish, catfish and the Lake Victoria sardine (Rastrineobola argentea) (15.2%), oranges (6.6%), pineapples (5.9%), eggs (3.3%), chicken (3.3%) and cassava, mangoes and Cleome gynandra (each at 3%). Most foods were avoided for reasons associated with pregnancy and labour complications and undesirable effects on the baby. Most women learnt of the taboos and beliefs from the elders, their own mother, grandparents or mother-in-law, but there was also knowledge transmission in social groups within the community.

CONCLUSIONS

The taboos and cultural beliefs in the study area render pregnant and breast-feeding women prone to micronutrient deficiency since they are denied consumption of a diversity of nutritious foods. There is a need to educate such women about consumption of nutrient-rich foods like fish, eggs, fruits and vegetables in order to improve their health, that of the unborn and children being breast fed. Additionally, culturally appropriate nutrition education may be a good strategy to eliminate inappropriate food taboos and beliefs with negative impact on the health of pregnant and breast-feeding women.

Formulation and acceptability of local nutrient-dense foods for young children: A formative study for the Child Health, Agriculture and Integrated Nutrition (CHAIN) Trial in rural Zimbabwe

Stunting affects almost one-quarter of children globally, leading to reduced human capacity and increased long-term risk of chronic disease. Despite intensive infant and young child feeding (IYCF) interventions, many children do not meet their requirements for essential nutrients. This study aimed to assess the feasibility of implementing an IYCF intervention utilizing nutrient-dense powders from egg, biofortified sugar beans and Moringa oleifera leaf in rural Zimbabwe. A mixed-methods formative study was conducted comprising the following: (i) a recipe formulation trial, (ii) trials of improved practices to assess acceptability of the intervention, and (iii) a participatory message formulation process to develop counselling modules for the IYCF-plus intervention. Twenty-seven mother-baby pairs were recruited between November 2019 and April 2020. Key domains affecting IYCF practices that emerged were time, emotional and physical space, cultural and religious beliefs, indigenous knowledge systems and gender dynamics. Household observations and sensory evaluation indicated high acceptability of the new ingredients. Recipe formulation and participatory message formulation by participants instilled community ownership and served to demystify existing misconceptions about the new food products. Families noted the potential for intervention sustainability because the foods could be grown locally. Supplementing complementary foods with nutrient-dense local food ingredients as powders has the potential to sustainably address nutrient-gaps in the diets of young children living in rural lower- and middle-income countries. Comprehensive IYCF counselling utilizing a gender-lens approach, family support and indigenous knowledge systems or resources are key elements to support positive behaviour change in complementary feeding interventions.

High Dietary Folic Acid Supplementation Reduced the Composition of Fatty Acids and Amino Acids in Fortified Eggs

AIMS

The study aimed to evaluate the effects of dietary folic acid (FA) on the production performance of laying hens, egg quality, and the nutritional differences between eggs fortified with FA and ordinary eggs.

METHODS

A total of 288 26-week-old Hy-Line Brown laying hens (initial body weights 1.65 ± 0.10 kg) with a similar weight and genetic background were used. A completely randomized design divided the birds into a control group and three treatment groups. Each group consisted of six replicates, with twelve chickens per replicate. Initially, all birds were fed a basal diet for 1 week. Subsequently, they were fed a basal diet supplemented with 0, 5, 10, or 15 mg/kg FA in a premix for a duration of 6 weeks.

RESULTS

Supplementation of FA could significantly (p < 0.05) enhance the FA content in egg yolks, particularly when 10 mg/kg was used, as it had the most effective enrichment effect. Compared to the control group, the Glu content in the 10 and 15 mg/kg FA groups showed a significant (p < 0.05) decrease. Additionally, the contents of Asp, Ile, Tyr, Phe, Cys, and Met in the 15 mg/kg FA group were significantly (p < 0.05) lower compared to the other groups. Adding FA did not have significant effects on the levels of vitamin A and vitamin E in egg yolk, but the vitamin D content in the 5 and 10 mg/kg FA groups showed a significant (p < 0.05) increase. Furthermore, the addition of FA did not have a significant effect on the levels of Cu, Fe, Mn, Se, and Zn in egg yolk. The dietary FA did not have a significant effect on the total saturated fatty acids (SFA) and polyunsaturated fatty acid (PUFA) content in egg yolk. However, the total monounsaturated fatty acid (MUFA) content in the 5 and 10 mg/kg groups significantly (p < 0.05) increased. These changes in nutritional content might be attributed to the increased very low-density lipoprotein (VLDL) protein content. The significant decrease in solute carrier family 1 Member 1 (SLC1A1), solute carrier family 1 Member 2 (SLC1A2), and solute carrier family 1 Member 3 (SLC1A3) gene expression compared to the control group appeared to be the reason for the decrease in amino acid content in egg yolk within the dietary FA group.

CONCLUSION

The findings suggest that the appropriate addition of FA can enhance the levels of MUFA and vitamin D in egg yolks, thereby improving their nutritional value. Excessive intake of FA can decrease the effectiveness of enriching FA in egg yolk and impact the enrichment of certain amino acids. The yolk of eggs produced by adding 10 mg/kg of FA to the feed contains the optimal amount of nutrients. This study informs consumers purchasing FA-fortified eggs.

Maternal and household factors affecting the dietary diversity of preschool children in eastern Ethiopia: a cross-sectional study

OBJECTIVE

Investigate the association between the dietary diversity of preschool children and proximate factors including household food insecurity, maternal food choice, preferences, khat use, and levels of depressive symptoms.

DESIGN

Cross-sectional survey of randomly selected households.

SETTING

Haramaya Health and Demographic Surveillance site in Eastern Ethiopia, predominantly smallholder farming households.

PARTICIPANTS

678 preschool children (24-59 months) and their mothers.

METHODS

The key outcome, the adequacy of dietary diversity of preschool children, was calculated using a 24-hour parental dietary recall. Binary logistic regression was then used to identify maternal and household factors associated with dietary adequacy versus inadequacy.

RESULTS

The majority (80.53%) of surveyed children had low dietary diversity (mean Dietary Diversity (MDD)) score of 3.06±1.70 on a 7-point scale). Approximately 80% of households exhibited food insecurity. Households with greater food security (adjusted OR (AOR)=1.96, 95% CI 1.19 to 3.23), healthier maternal food choice (AOR=2.19, 95% CI 1.12 to 4.31) and broader maternal food preferences (AOR=4.95, 95% CI 1.11 to 21.95) were all associated with higher dietary diversity of their preschool children (p≤0.05). Other covariates associated with adequate child dietary diversity included improved household drinking water sources (AOR=1.84, 95% CI 1.16 to 2.92) and family planning use (AOR=1.69, 95% CI 1.00 to 2.86). Despite predictions, however, maternal depression and khat consumption were not identified as factors.

CONCLUSIONS

The dietary diversity of preschool children is extremely low-a pattern observed in both food-secure and food-insecure households. Key factors include maternal selection of food for convenience and ease, preferences that do not include animal protein or healthier food choices, and lack of access to improved drinking water sources. Interventions around maternal food choice and preferences could improve preschool children's nutritional health.

Design of a generic model based on physiology for persistent organic pollutants in laying hens: Applications on chlordecone and chlorinated paraffins

A Physiology Based Pharmacokinetic (PBPK) model has been developed to predict the kinetics of Persistent Organic Pollutants (POPs) in laying hens. Different datasets have enabled the calibration of the model for chlordecone (CLD), an organochlorine pesticide used in the French West Indies between 1972 and 1993, as well as for chlorinated paraffins (CPs), widely used for various industrial applications worldwide. For this purpose, the sensitivity analysis showed that intake parameters, laying rate, partition coefficients of yolk, hepatic clearance, percentage of metabolism and age were key parameters. Applied to CLD and CPs, this model shows a good capacity for prediction, with 88 % of the experimental values ranging within 1.5-fold of the predicted value at steady state for CPs and 100 % for CLD. The fine modelling of the physiology and the laying process contributes to precision of the model and gives genericity, enabling the switch from one bird species to another. The model can be implemented with other POPs if the clearance and partition coefficient are known.

Eggs for Improving Nutrition, cognitive development and reducing linear growth retardation among Infants and young Children (ENRICH): protocol of an egg supplementation trial among children aged 9-18 months in Hyderabad, India

INTRODUCTION

Evidence on the impact of nutrient-rich animal source foods such as eggs for improving child growth and cognition is inconsistent. This study aims to examine the impact of an egg intervention in children, along with behaviour change communication (BCC) to the mother, on linear growth and cognition, and nutritional status in children aged 9-18 months.

METHODS AND ANALYSIS

A 9-month open-labelled randomised controlled trial will be conducted in three urban slums in Hyderabad, India, as a substudy of an observational cohort study (n=350) following pregnant women and their children until 18 months of age in a population at risk of stunting. The children born to women enrolled during the third trimester of pregnancy will be block randomised in a 1:4 ratio into the intervention (n=70) and control (n=280) groups. Children in the intervention group will be supplemented with one egg per day starting from 9 months until 18 months of age. BCC designed to enhance adherence to the intervention will be used. The control group will be a part of the observational cohort and will not receive any intervention from the study team. The primary outcome will be length-for-age z-scores, and the secondary outcomes will include cognition, blood biomarkers of nutritional status including fatty acid profile and epigenetic signatures linked with linear growth and cognition. Multivariate intention-to-treat analyses will be conducted to assess the effect of the intervention.

ETHICS AND DISSEMINATION

The study is approved by the Institutional ethics committees of ICMR-National Institute of Nutrition, Hyderabad, India and London School of Hygiene and Tropical Medicine, UK. The results will be published in peer-reviewed journals and disseminated to policy-makers. Findings will also be shared with study participants and community leaders.

TRIAL REGISTRATION NUMBER

CTRI/2021/11/038208.

Identification and functional analysis of ovarian lncRNAs during different egg laying periods in Taihe Black-Bone Chickens

Introduction: Long non-coding RNA (lncRNA) refers to a category of non-coding RNA molecules exceeding 200 nucleotides in length, which exerts a regulatory role in the context of ovarian development. There is a paucity of research examining the involvement of lncRNA in the regulation of ovary development in Taihe Black-Bone Chickens. In order to further investigate the egg laying regulation mechanisms of Taihe Black-Bone Chickens at different periods, transcriptome analysis was conducted on the ovarian tissues at different laying periods. Methods: This study randomly selected ovarian tissues from 12 chickens for RNA-seq. Four chickens were selected for each period, including the early laying period (102 days, Pre), the peak laying period (203 days, Peak), and the late laying period (394 days, Late). Based on our previous study of mRNA expression profiles in the same ovarian tissue, we identified three differentially expressed lncRNAs (DE lncRNAs) at different periods and searched for their cis- and trans-target genes to draw an lncRNA-mRNA network. Results and discussion: In three groups of ovarian tissues, we identified 136 DE lncRNAs, with 8 showing specific expression during the early laying period, 10 showing specific expression during the peak laying period, and 4 showing specific expression during the late laying period. The lncRNA-mRNA network revealed 16 pairs of lncRNA-target genes associated with 7 DE lncRNAs, and these 14 target genes were involved in the regulation of reproductive traits. Furthermore, these reproductive-related target genes were primarily associated with signaling pathways related to follicle and ovary development in Taihe Black-Bone Chickens, including cytokine-cytokine receptor interaction, TGF-beta signaling pathway, tyrosine metabolism, ECM-receptor interaction, focal adhesion, neuroactive ligand-receptor interaction, and cell adhesion molecules (CAMs). This study offers valuable insights for a comprehensive understanding of the influence of lncRNAs on poultry reproductive traits.

Quantification of toxic metals in chicken egg and chicken feed via SOM-artificial neural network

Poultry products such as meat and eggs are rich sources of proteins, vitamins, and minerals. It is a good indicator of healthy food. Keeping in view, the present study is designed to evaluate the prevalence of toxic heavy metals (lead, nickel, cadmium, and chromium) in chicken eggs and feed. For this purpose, five samples of egg and feed were collected from five different commercial markets in Skardu City. Each sample was prepared using the wet digestion method and analyzed using a flame atomic absorption spectrophotometer. The results showed that lead, nickel, and chromium were present in varying amounts in the feed and egg, with nickel being the most concentrated metal, followed by lead and chromium in egg samples, while the feed samples showed the highest concentration of chromium followed by lead and nickel. However, concentrations of selected heavy metals except cadmium were all above the permissible limit of the World Health Organization. The self-organizing map-artificial neural network is employed for the identification of patterns of heavy metals in chicken feed and egg samples. The lower left neurons of the maps showed higher heavy metal concentrations found in samples taken from Bazar, whereas the rest of the samples showed varied concentrations. A comparison of feed and egg concentrations showed that nickel concentration was lower in feed samples than in egg samples. The lead concentration decreased in eggs except in the Krasmathang feed sample. Chromium concentration presented a negative correlation due to the extremely high concentration found in the Bazar feed sample.

Egg consumption and growth in children: a meta-analysis of interventional trials

Introduction

Stunting and wasting are prevalent in low- and middle-income countries, putting children at risk for disease and disability. Eggs are a nutrient-rich food that can potentially facilitate growth.

Purpose

The aim of this meta-analysis was to evaluate the potential beneficial effect of egg supplementation on growth in children.

Methods

Following the PRISMA guidelines, PubMed and Healthline (Ovid) were systematically searched for interventional studies on egg supplementation for growth in children aged 6 months to 18 years, with no restrictions on date. Studies were evaluated for quality using Cochrane's GRADE technique. Data were pooled and reported as means and 95% confidence intervals.

Results

Seven studies reporting on 9 unique interventions in 3,575 male and female participants were included in the meta-analysis. Participants in the intervention groups experienced significantly greater increases in height/length (by 0.47 [0.13, 0.80] cm, p < 0.01) and weight (by 0.07 [0.01, 0.13] kg, p = 0.03) when compared to those in the control groups.

Conclusion

Eggs are an affordable, nutritious option for improving growth in children, though more studies with longer interventions are warranted.Systematic review registration: PROSPERO (CRD42021289609: https://www.crd.york.ac.uk/prospero/).

Comparison of the nutrient composition of eggs produced in the Guatemalan highlands during the wet and dry seasons

The potential of chicken eggs as a nutritionally complete protein and source of key micronutrients during the first 1000 days post-conception has been progressively recognized across the globe, particularly in resource-poor settings. Fluctuation of egg nutrient content by season is relatively unknown, which may influence international food composition databases and outcomes in intervention studies using egg supplementation. To better interpret the findings of The Saqmolo' Project, we conducted comprehensive nutrient analyses on eggs produced during the wet and dry seasons in the highlands of central Guatemala. We randomly collected 36 shell eggs from a local farm during both seasons, hard-boiled, and prepared them for transport to the United States, where they were pooled and assessed for their nutrient composition. Methods of the Association of Official Analytical Chemists, the American Oil Chemists Society, and the American Association of Cereal Chemists were utilized to determine total energy, moisture, ash, total protein, total fat, fatty acids, total carbohydrates, 12 vitamins, 11 minerals, and carotenoids, by season, in some instances with modifications. Differences in nutrient composition between de-shelled hard-boiled eggs collected between seasons were assessed using an analysis of variance (ANOVA) and Tukey's family error rate comparison test. Most nutrients in eggs produced in the highlands of central Guatemala differed negligibly (but statistically significantly) based on seasonality. Only vitamins A and E, folate, choline, and calcium fluctuated at clinically significant levels relative to the AI/RDA for infants 7-12 months. Total energy, protein, trans fatty acids, moisture, and vitamin D3 levels did not differ between seasons (p > .05). Further multi-year sampling is needed to examine how seasonal variation affects the nutrient composition of eggs. These data may be used to supplement existing national and regional food composition databases.

Interventions to improve the nutritional status of children under 5 years in Ethiopia: a systematic review

OBJECTIVE

To conduct a systematic review of experimental or quasi-experimental studies that aimed to improve the nutritional status of children under 5 years of age in Ethiopia.

DESIGN

Embase, MEDLINE/PubMed, Cumulative Index to Nursing and Allied Health Literature (CINAHL), PsychINFO, and Academic Search Database were used to locate peer-reviewed studies, and Google Scholar and Open Dissertation were used to locate grey literatures. All searches were conducted between 2000 and November 2022.

SETTING

Ethiopia.

PARTICIPANTS

Pregnant women and mothers with children aged 0-59 months.

RESULTS

Ten cluster randomised controlled trials (RCT), six quasi-experimental studies and two individual RCT were included. Out of the identified eighteen studies, three studies targeted pregnant mothers. Our findings showed that almost two-thirds of published interventions had no impact on childhood stunting and wasting, and more than half had no impact on underweight. Some behaviour change communication (BCC) interventions, food vouchers, micronutrient supplementation and quality protein maize improved stunting. Similarly, BCC and fish oil supplementation showed promise in reducing wasting, while BCC and the provision of quality protein maize reduced underweight. Additionally, water, sanitation and hygiene (WaSH) interventions provided to pregnant mothers and children under 2 years of age were shown to significantly reduce childhood stunting.

CONCLUSION

Future childhood nutritional interventions in Ethiopia should consider adopting an integrated approach that combines the positive effects of interdependent systems such as BCC, food supplemental programmes (e.g. boosting protein and micronutrients), health interventions (e.g. strengthening maternal and childcare), WaSH and financial initiatives (e.g. monetary support and income schemes).

Effects of egg as an early complementary food on growth of 6- to 9-month-old infants: a randomised controlled trial

OBJECTIVE

To assess the effect of daily egg consumption for six months on linear growth (primary outcome), weight-for-age, weight-for-length, mid-upper arm circumference-for-age, head circumference-for-age Z-scores, gross motor milestones development, anaemia and iron status (secondary outcomes) in a low socioeconomic community.

PARTICIPANTS

Infants aged 6 to 9 months living in the peri-urban Jouberton area, in the Matlosana Municipality, South Africa.

DESIGN

A randomised controlled trial with a parallel design was implemented. Eligible infants were randomly allocated to the intervention (n 250) receiving one egg/day and the control group (n 250) receiving no intervention. The participants were visited weekly to monitor morbidity and gross motor development, with information on adherence collected for the intervention group. Trained assessors took anthropometric measurements, and a blood sample was collected to assess anaemia and iron status. There was blinding of the anthropometric assessors to the groups during measurements and the statistician during the analysis.

RESULTS

Baseline prevalence of stunting, underweight, wasting, overweight and anaemia was 23·8 %, 9·8 %, 1·2 %, 13·8 % and 29·2 %, respectively, and did not differ between groups. Overall, 230 and 216 participants in the intervention and control groups completed the study, respectively. There was no intervention effect on length-for-age, weight-for-age, weight-for-length Z-scores, gross motor milestone development, anaemia and iron status.

CONCLUSIONS

Daily egg intake did not affect linear growth, underweight, wasting, motor milestones development, anaemia and iron status. Other interventions are necessary to understand the effect of animal-source food intake on children's growth and development. This trial was registered at https://clinicaltrials.gov/ (NCT05168085).

Food Insecurity is Associated with Low Dietary Diversity in Rural Women in Mexico: Results from the Mexican National Health and Nutrition Survey, ENSANUT 2018

Rural women suffer greater vulnerability to food insecurity (FI) compared to their urban or male counterparts. We analyzed the association between food security (FS) status and dietary diversity (DD) in rural women through data from the Mexican National Health and Nutrition Survey (ENSANUT) 2018 from 2,099 rural women. DD was measured using a semi-quantitative food frequency questionnaire. FS was measured using the Latin America and Caribbean Food Security Scale (ELCSA). The prevalence of any level of FI was 70.1%. Mean DD score was 3.8. Mild FI was associated with low DD (OR 1.49, 95% CI 1.06, 2.10). Results highlight the need for government strategies targeted to this population sector to improve their diet quality.

Minimum dietary diversity and consumption of ultra-processed foods among Brazilian children 6-23 months of age

The study aimed to estimate the prevalence of minimum dietary diversity (MDD) and consumption of ultra-processed foods in children 6-23 months of age according to sociodemographic variables. Three indicators of complementary feeding of 4,354 children from the Brazilian National Survey on Child Nutrition (ENANI-2019) were built based on a questionnaire about food consumption on the day before the interview: MDD, consumption of ultra-processed foods, and MDD without the consumption of ultra-processed foods. The prevalence and 95%CI were calculated, stratified by macroregion; race/skin color, education and work status of the mother or caregiver; enrollment in the Brazilian Income Transfer Program; household food security; sanitation; and child enrollment in daycare/school. The overall prevalence of MDD was 63.4%, with lower prevalences among children who lived in the North Region (54.8%), whose mothers or caregivers had 0-7 years of education (50.6%), and lived under moderate or severe food insecurity (52.6%). Ultra-processed foods were consumed by 80.5% of the children, with the highest prevalence in the North Region (84.5%). The prevalence of MDD without ultra-processed foods was 8.4% and less prevalent among children with black mothers or caregivers (3.6%) and among those whose mother or caregiver had 8-10 years of education (3.6%). The most frequently consumed food groups from the MDD indicator were grains, roots and tubers (90.2%), dairy products (81%) and those from ultra-processed food were sweet or salty cookies/crackers (51.3%) and instant flours (41.4%). The ubiquitous presence of ultra-processed foods in the diets of Brazilian children and the low frequency of diversified foods, especially among the most vulnerable populations, indicate the need to strengthen policies and programs to ensure adequate and healthy infant nutrition.

Effects of an integrated poultry value chain, nutrition, gender and WASH intervention (SELEVER) on hygiene and child morbidity and anthropometry in Burkina Faso: A secondary outcome analysis of a cluster randomised trial

Nutrition-sensitive agriculture programmes have the potential to improve child nutrition outcomes, but livestock intensification may pose risks related to water, sanitation and hygiene (WASH) conditions. We assessed the impact of SELEVER, a nutrition- and gender-sensitive poultry intervention, with and without added WASH focus, on hygiene practices, morbidity and anthropometric indices of nutrition in children aged 2-4 years in Burkina Faso. A 3-year cluster randomised controlled trial was implemented in 120 villages in 60 communes (districts) supported by the SELEVER project. Communes were randomly assigned using restricted randomisation to one of three groups: (1) SELEVER intervention (n = 446 households); (2) SELEVER plus WASH intervention (n = 432 households); and (3) control without intervention (n = 899 households). The study population included women aged 15-49 years with an index child aged 2-4 years. We assessed the effects 1.5-years (WASH substudy) and 3-years (endline) post-intervention on child morbidity and child anthropometry secondary trial outcomes using mixed effects regression models. Participation in intervention activities was low in the SELEVER groups, ranging from 25% at 1.5 years and 10% at endline. At endline, households in the SELEVER groups had higher caregiver knowledge of WASH-livestock risks (∆ = 0.10, 95% confidence interval [CI] [0.04-0.16]) and were more likely to keep children separated from poultry (∆ = 0.09, 95% CI [0.03-0.15]) than in the control group. No differences were found for other hygiene practices, child morbidity symptoms or anthropometry indicators. Integrating livestock WASH interventions alongside poultry and nutrition interventions can increase knowledge of livestock-related risks and improve livestock-hygiene-related practices, yet may not be sufficient to improve the morbidity and nutritional status of young children.

Understanding household and food system determinants of chicken and egg consumption in India

Poultry is one of the fastest-growing agricultural sectors in India and its demand is said to be rising. There is a perception that higher incomes, growing population, urbanisation, and increased productivity in the industry have influenced Indian poultry consumption. However, consumer surveys have shown that the average poultry consumption in India has remained low. With this in mind, the paper analysed household determinants of chicken and egg consumption within the Indian population, using two rounds of National Sample Survey data (1993-1994 and 2011-2012). By conducting a spatiotemporal analysis of household consumption and expenditure survey and by using truncated Double Hurdle and Unconditional Quantile regressions (UQR) models, this study explored socio-economic and food system determinants of chicken and egg consumption in India. Key results highlight that while consumption has increased marginally over twenty years, supply-side determinants, such as price and poultry production concentration, influenced heterogenous consumption patterns in India. We also find evidence that historically marginalised groups consumed more chicken and eggs in comparison to non-marginalised groups and preliminary evidence suggests how household gender dynamics influence different consumption patterns. Adequate consumption of poultry is important to improve nutrient-deficient diets of vulnerable groups in India. Our findings on demand side determinants of poultry products are crucial to support consumer tailored actions to improve nutritional outcomes along with the Indian poultry sector policy planning.

Dietary Strategies for Complementary Feeding between 6 and 24 Months of Age: The Evidence

Suboptimal complementary feeding practices remain highly prevent. This review aims to comprehensively synthesize new emerging evidence on a set of topics related to the selection and consumption of complementary foods. We synthesized evidence related to five key topics focused on nutritional interventions that target the complementary feeding period, based on four systematic reviews that include updated evidence to February 2022. While there have been many studies examining interventions during the complementary feeding period, there is an overall lack of relevant information through which to draw conclusions on the ideal feeding schedule by food type. Similarly, few studies have examined the effects of animal milk versus infant formula for non-breastfed infants (6-11 months), though those that did found a greater risk of anemia among infants who were provided cow's milk. This review highlights a number of interventions that are successful at improving micronutrient status and anthropometry during the complementary feeding period, including fortified blended foods, locally and commercially produced supplementary foods, and small-quantity lipid-based nutrient supplements. Complementary feeding education for caregivers can also be used to improve nutrition outcomes among infants in both food secure and insecure populations.

Impact of a Homestead Food Production program on poultry rearing and egg consumption: A cluster-randomized controlled trial in Bangladesh

Women and children in Bangladesh face high levels of micronutrient deficiencies from inadequate diets. We evaluated the impact of a Homestead Food Production (HFP) intervention on poultry production, as a pathway outcome, and women's and children's egg consumption, as secondary outcomes, as part of the Food and Agricultural Approaches to Reducing Malnutrition cluster-randomized trial in Sylhet division, Bangladesh. The 3-year intervention (2015-2018) promoted home gardening, poultry rearing, and nutrition counseling. We randomly allocated 96 clusters to intervention (48 clusters; 1337 women) or control (48 clusters; 1368 women). Children < 3 years old born to participants were enrolled during the trial. We analyzed poultry production indicators, measured annually, and any egg consumption (24-h recall), measured every 2-6 months for women and their children. We conducted intention-to-treat analyses using mixed-effects logistic regression models with repeat measures, with minimal adjustment to increase precision. Poultry ownership increased by 16% points (pp) and egg production by 13 pp in the final intervention year. The intervention doubled women's odds of egg consumption in the final year (Odds Ratio [OR]: 2.31, 95% CI: 1.68-3.18), with positive effects sustained 1-year post-intervention (OR: 1.58, 95% CI: 1.16-2.15). Children's odds of egg consumption were increased in the final year (OR: 3.04, 95% CI: 1.87-4.95). Poultry ownership was associated with women's egg consumption, accounting for 12% of the total intervention effect, but not with children's egg consumption. Our findings demonstrate that an HFP program can have longer-term positive effects on poultry production and women's and children's diets.

Quantitative lipidomic analysis of chicken egg yolk during its formation

BACKGROUND

The accumulation of lipids in egg yolk during its formation represents a knowledge gap between food science and animal science research to which researchers in either field have not paid sufficient attention. Therefore, the egg yolk samples during different periods of formation (yellow follicle, YF; small hierarchical follicles, SF; and the largest hierarchical follicle, LF) were prepared, and their fatty acid compositions and lipidomes were quantitatively compared.

RESULTS

The fatty acid profiles and lipidomes of egg yolks at the three stages of formation were significantly different. The relative content of oleic acid and palmitic acid were increased, but that of the main polyunsaturated fatty acids (linoleic acid, linolenic acid and docosahexaenoic acid) was decreased in the SF period to the LF period. Among the 786 lipid molecular species identified, 150 and 46 differentially abundant lipids (DALs) were identified in the pairwise comparison of YF/SF (early stage of egg yolk formation) and SF/LF (late stage of egg yolk formation), respectively. Triglycerides and diglycerides, represented by TG(14:0/18:1/20:1) and DG(18:1/18:1/0:0), were decreased, whereas free fatty acids (especially free unsaturated fatty acids) were greatly increased during yolk formation. The changes in phospholipids were complex; the relative abundance of phosphatidylcholine [represented by PC(18:0/22:5)] decreased, whereas phosphatidylethanolamine [represented by PE(18:0/18:0)] increased. In addition, the relative abundance of lysophosphatidylcholine [represented by LPC(18:1/0:0)] was increased during egg yolk formation.

CONCLUSION

The transport and accumulation of lipids into the egg yolk is dynamically adjusted during its formation, and the transport and timing of different lipid molecular species are different. © 2022 Society of Chemical Industry.

Plasma mineral status after a six-month intervention providing one egg per day to young Malawian children: a randomized controlled trial

Mineral deficiencies are common in children living in low-resource areas. Eggs are a rich source of essential nutrients and have been shown to improve growth in young children, although little is known about their impact on mineral status. Children aged 6-9 months (n = 660) were randomized to receive either one egg/day for 6-months or no intervention. Anthropometric data, dietary recalls, and venous blood were collected at baseline and 6-months follow-up. Quantification of plasma minerals (n = 387) was done using inductively coupled plasma-mass spectroscopy. Difference-in-difference mean plasma mineral concentrations was determined from baseline and follow-up values and assessed between groups by intention-to-treat using ANCOVA regression models. Prevalence of zinc deficiency was 57.4% at baseline and 60.5% at follow-up. Mean difference (MD) of plasma magnesium, selenium, copper, and zinc levels were not different between groups. Plasma iron concentrations were significantly lower in the intervention compared to the control group (MD = - 9.29; 95% CI: - 15.95, - 2.64). Zinc deficiency was widely prevalent in this population. Mineral deficiencies were not addressed with the egg intervention. Further interventions are needed to improve the mineral status of young children.

The Impact of Processing and Extraction Methods on the Allergenicity of Targeted Protein Quantification as Well as Bioactive Peptides Derived from Egg

This review article discusses advanced extraction methods to enhance the functionality of egg-derived peptides while reducing their allergenicity. While eggs are considered a nutrient-dense food, some proteins can cause allergic reactions in susceptible individuals. Therefore, various methods have been developed to reduce the allergenicity of egg-derived proteins, such as enzymatic hydrolysis, heat treatment, and glycosylation. In addition to reducing allergenicity, advanced extraction methods can enhance the functionality of egg-derived peptides. Techniques such as membrane separation, chromatography, and electrodialysis can isolate and purify specific egg-derived peptides with desired functional properties, improving their bioactivity. Further, enzymatic hydrolysis can also break down polypeptide sequences and produce bioactive peptides with various health benefits. While liquid chromatography is the most commonly used method to obtain individual proteins for developing novel food products, several challenges are associated with optimizing extraction conditions to maximize functionality and allergenicity reduction. The article also highlights the challenges and future perspectives, including optimizing extraction conditions to maximize functionality and allergenicity reduction. The review concludes by highlighting the potential for future research in this area to improve the safety and efficacy of egg-derived peptides more broadly.

The Global Association between Egg Intake and the Incidence and Mortality of Ischemic Heart Disease-An Ecological Study

The relationship between egg consumption and ischemic heart disease (IHD) remains controversial as there is still no clear answer regarding the relationship, with research limited to a few geographical regions. In the current study, we conducted a longitudinal analysis of the association between egg intake and IHD incidence (IHDi) and mortality (IHDd) using 28 years of international data from 1990 to 2018. Egg intake (g/day/capita) by country was obtained from the Global Dietary Database. Age-standard IHDi and IHDd rates per 100,000 subjects in each country were obtained from the 2019 Global Burden of Disease database. The analysis included a total of 142 countries with populations of at least one million, for which all data were available from 1990 to 2018. Eggs are consumed worldwide, and regional differences in consumption are also shown. Utilizing IHDi and IHDd as objective variables and egg intake as an explanatory variable, the analysis was conducted using linear mixed models, which controlled for inter- and intra-country variation from year to year. The results showed a significant negative association between egg intake, and IHDi (-0.253 ± 0.117, p < 0.05) and IHDd (-0.359 ± 0.137, p < 0.05). The analysis was carried out using R 4.0.5. The results suggest that adequate egg intake might suppress IHDi and IHDd on a global scale.

Prolonged Egg Supplement Advances Growing Child's Growth and Gut Microbiota

Protein-energy malnutrition still impacts children's growth and development. We investigated the prolonged effects of egg supplementation on growth and microbiota in primary school children. For this study, 8-14-year-old students (51.5% F) in six rural schools in Thailand were randomly assigned into three groups: (1) whole egg (WE), consuming 10 additional eggs/week (n = 238) (n = 238); (2) protein substitute (PS), consuming yolk-free egg substitutes equivalent to 10 eggs/week (n = 200); and (3) control group (C, (n = 197)). The outcomes were measured at week 0, 14, and 35. At the baseline, 17% of the students were underweight, 18% were stunted, and 13% were wasted. At week 35, compared to the C group the weight and height difference increased significantly in the WE group (3.6 ± 23.5 kg, p < 0.001; 5.1 ± 23.2 cm, p < 0.001). No significant differences in weight or height were observed between the PS and C groups. Significant decreases in atherogenic lipoproteins were observed in the WE, but not in PS group. HDL-cholesterol tended to increase in the WE group (0.02 ± 0.59 mmol/L, ns). The bacterial diversity was similar among the groups. The relative abundance of Bifidobacterium increased by 1.28-fold in the WE group compared to the baseline and differential abundance analysis which indicated that Lachnospira increased and Varibaculum decreased significantly. In conclusion, prolonged whole egg supplementation is an effective intervention to improve growth, nutritional biomarkers, and gut microbiota with unaltered adverse effects on blood lipoproteins.

An Egg Intervention Improves Dietary Intakes but Does Not Fill Intake Gaps for Multiple Micronutrients among Infants in Rural Bangladesh

BACKGROUND

Eggs are nutrient-rich. Strengthening evidence of the impact of egg consumption on dietary quality can inform complementary feeding guidance.

OBJECTIVES

We aimed to assess the effect of an egg intervention on dietary intakes among infants aged 6-12 mo in rural Bangladesh.

METHODS

We conducted a cluster-randomized controlled trial allocating clusters (n = 566) to enteric pathogen control or placebo treatment, with daily provision of a protein-rich meal, isocaloric meal, egg, or control. Nutrition education was provided to all arms. Our focus here is on the egg and control arms. Infants were enrolled at 3 mo. From 6 mo, we visited households weekly to distribute eggs and measure compliance. A semistructured feeding questionnaire assessed 24-h intake at 6, 9, and 12 mo. Assessments were repeated in ∼10% of subjects 2-29 d later. Using NCI SAS macros, we estimated usual intake distributions for energy, protein, fat, and 18 micronutrients and the proportion meeting intake recommendations. We compared the outcomes between the arms using clustered bootstrapping.

RESULTS

Data were available from 757 infants (137 clusters) and 943 infants (141 clusters) in the egg and control arms, respectively. In the egg arm compared with the control arm, the mean usual intakes were higher for energy (610 compared with 602 kcal/d, 9 mo; 669 compared with 658 kcal/d, 12 mo), crude protein (2.2 compared with 1.7 g/(kg·d), 9 mo; 2.4 compared with 1.9 g/(kg·d), 12 mo), available protein (2.0 compared with 1.6 g/(kg·d), 9 mo; 2.1 compared with 1.8 g/(kg·d), 12 mo), and for 13 and 14 micronutrients at 9 and 12 mo, respectively. The proportion meeting intake recommendations for most micronutrients was higher in the egg arm but remained <50% for 15 and 13 micronutrients at 9 and 12 mo, respectively.

CONCLUSIONS

Daily egg consumption improved dietary intakes among Bangladeshi infants, but was insufficient to meet multiple micronutrient intake recommendations, demonstrating the need to be coupled with other strategies.

The effectiveness of an egg-based intervention on improving the nutrition of poor school-age children in China: A quasi-experimental assessment

OBJECTIVES

Although egg-based interventions are effective in alleviating undernutrition for infants and toddlers, little is known regarding their effectiveness for children in remote and poor areas of China. For policy and intervention implications, the aim of this study was to examine the effects of offering one hard-boiled egg per school day to school-age children in less-developed areas of China.

METHODS

This analytical sample included 346 school-age children. Children in the treatment group received one egg per school day. Applying propensity score weighting to the difference-in-difference models, this study examined the effects of the egg intervention on child nutrition status measured in height-for-age Z score (HAZ), weight-for-age Z score (WAZ), and body-mass-index-for-age Z score (BMIZ).

RESULTS

After applying propensity score weighting, the average treatment effect (ATE) and the average treatment effects on the treated (ATT) estimations showed that the increase in HAZ scores from wave 1 to wave 3 for the program participants was 0.28 points higher compared with the increase in HAZ scores from wave 1 to wave 3 for the control group (P < 0.05). The ATE and the ATT estimations showed that the increase in WAZ scores from wave 1 to wave 3 for the program participants was 0.50 and 0.49 points higher compared with the increase in WAZ scores from wave 1 to wave 3 for the control group (P < 0.001). Regarding BMIZ score improvement from wave 1 to wave 3, the program participation had relatively larger effects by 0.57 and 0.55 points based on the ATE and ATT estimations (P < 0.001), respectively.

CONCLUSIONS

The egg intervention can be an effective intervention to improve child development in less-developed areas of China.

Sustainability and scalability of egg consumption in Burkina Faso for infant and young child feeding

Introduction

Malnutrition is a significant challenge to the health of women and children in Burkina Faso. Given the critical role of animal source food on the health of infants and young children (IYC), interventions continue to explore the potential for eggs to prevent malnutrition.

Methods

Using data from the Un Oeuf intervention, which significantly increased IYC egg consumption, combined with quantitative and qualitative data from endline and 3-month follow-up, we explore the barriers and facilitating factors to IYC egg consumption and the sustainability and scalability of the intervention.

Results

Child egg consumption was high at follow-up in the Control, Partial, and Full Intervention arms (83.3, 88.2%, and 100, respectively). The Full Intervention arm had the highest mean number of eggs consumed (2.9, 2.6, and 5.7), which reflected a slight reduction from endline (6.2). All participants owned chickens at follow-up (100%), however, flock size varied. The Full Intervention arm had more chickens (mean 8.8) than the Control (5.1) or Partial Intervention (6.2) arms, which was a 50% reduction in below endline (18.5 chickens). Qualitative results indicate that chicken ownership, education about the nutritional value of eggs, and spousal support facilitated IYC egg consumption. Barriers included egg production, cultural taboos, and animal health. Motivational factors reported included the observed improvement in child health, increased availability of mothers' time, and mothers' financial independence. Knowledge sharing within the Full and Partial Intervention groups was widely reported, and the sustainability of IYC egg consumption was reinforced by accountability among mothers and to community leaders, flipbooks distributed during the project, and high motivation.

Discussion

Main findings indicate that mothers who received the full Un Oeuf intervention were able to overcome barriers to feeding their child an egg daily, were able to improve their livelihood, were motivated to continue feeding their child eggs, and saw the addition of eggs into the child's diet as sustainable. Future nutrition sensitive agriculture interventions should consider tailoring this approach for other LMIC contexts. Future research is needed to explore a possible threshold in the number of household chickens necessary to continuously feed a child an egg a day.

Frequency of Infant Egg Consumption and Risk of Maternal-Reported Egg Allergy at 6 Years

BACKGROUND

Recent research suggests that early egg introduction during infancy may help to prevent egg allergy development. However, the infant egg consumption frequency that is sufficient to induce this immune tolerance remains uncertain.

OBJECTIVES

We examined the associations between the infant egg consumption frequency and maternal-reported child egg allergy at 6 y.

METHODS

We analyzed data of 1252 children from the Infant Feeding Practices Study II (2005-2012). Mothers reported the frequency of infant egg consumption at 2, 3, 4, 5, 6, 7, 9, 10, and 12 mo old. Mothers reported the status of their child's egg allergy at the 6-y follow-up. We used Fisher exact test, Cochran-Armitage Trend Test, and log Poisson regression models to compare 6-y egg allergy risk by the frequency of infant egg consumption.

RESULTS

The risk of maternal-reported egg allergy at 6 y significantly (P-trend = 0.004) decreased with infant egg consumption frequency at 12 mo: 2.05% (11/537) for infants not consuming eggs, 0.41% (1/244) for those consuming eggs <2 times per wk, and 0.21% (1/471) for those consuming eggs ≥2 times per wk. A similar but nonsignificant trend (P-trend=0.109) was observed for egg consumption at 10 mo (1.25%, 0.85%, and 0%, respectively). After adjusting for socioeconomic confounders, breastfeeding, complementary food introduction, and infant eczema, infants who consumed eggs ≥2 times per wk at 12 mo had a significantly lower RR of maternal-reported egg allergy at 6 y (confounder-adjusted RR: 0.11; 95% CI: 0.01, 0.88; P = 0.038), whereas those who consumed <2 times per wk (confounder-adjusted RR: 0.21; 95% CI: 0.03, 1.67; P = 0.141) did not have a significantly lower risk than those who did not consume eggs at all.

CONCLUSIONS

Consumption of eggs ≥2 times per wk in late infancy is associated with a reduced risk of developing egg allergy later in childhood.

Animal-source foods as a suitable complementary food for improved physical growth in 6 to 24-month-old children in low- and middle-income countries: a systematic review and meta-analysis of randomised controlled trials

Although animal-source foods are suitable complementary food for child growth in low- and middle-income countries (LMICs), their efficacy is still under discussion. This systematic review and meta-analysis was done to investigate the suitability of animal-source foods intake on child physical growth in LMICs. A systematic literature search was done using electronic databases and scanning the reference list of included studies, previous meta-analysis and systematic reviews. Paper selection was based on the PICO (ST) criteria. Papers were selected if based on 6 to 24-month-old children, if they were randomised controlled trials evaluating the effect of complementary animal-based food supplementation of any natural origin, if reporting at least a measure of body size and published after 2000. The PRISMA guidelines for reporting systematic review was followed in the paper selection. Fourteen papers were included in the systematic review and eight were considered for the meta-analysis. Animal-based food supplementation resulted in a higher length-for-age LAZ and weight-for-age (WAZ) Z-scores compared with the control group with random effect size of 0·15 (95 % CI 0·02, 0·27) and 0·20 (95 % CI 0·03, 0·36), respectively. Results were confirmed after influence analyses, and publication bias resulted as negligible. An increased effect on LAZ and WAZ was observed when the food supplementation was based on egg with effect size of 0·31 (95 % CI = -0·03, 0·64) and 0·36 (95 % CI = -0·03, 0·75), respectively. Animal-source foods are a suitable complementary food to improve growth in 6 to 24-month-old children in LMICs.

Social and economic factors influencing intrahousehold food allocation and egg consumption of children in Kaduna State, Nigeria

Adequate intake of high-quality nutritious foods during infancy and early childhood is critical to achieving optimal growth, cognitive and behavioural development, and economic productivity later in life. Integrating high-quality and nutrient-dense animal source foods (ASFs), a major source of protein and micronutrients, into children's diets is increasingly considered essential to reducing the global burden of malnutrition in low- and middle-income countries. While eggs are an ASF that shows promise for mitigating child undernutrition, interventions promoting egg consumption among children have had mixed results in improving egg intake and child growth outcomes. As part of an evaluation of a demand creation campaign promoting egg consumption, qualitative research was carried out in September 2019 to assess sociocultural and household factors affecting egg intake among young children living in Kaduna State, Nigeria, where a thriving egg industry and childhood stunting rates of 50% exist. Methods included freelisting exercises (11), key informant interviews (11), in-depth interviews (25) and FGDs (4). Results illuminated cultural rules that restrict egg consumption among children living in low-income households. These rules and norms reflect social and economic valuations that foster male dominance in household decision-making and guide food purchasing and intrahousehold food allocation that allow men to consume eggs more regularly. Study results highlight sociocultural considerations when selecting food interventions to address child malnutrition in low-income contexts. Interventions encouraging increased consumption of ASFs, and specifically eggs in young children, should be informed by formative research to understand sociocultural norms and beliefs guiding egg consumption.

Effectiveness of the Eggs Make Kids demand-creation campaign at improving household availability of eggs and egg consumption by young children in Nigeria: A quasi-experimental study

Using a quasi-experimental design, our study aimed to determine the effectiveness of the 'Eggs Make Kids Sharp & Bright and Strong & Active' demand-creation campaign in Nigeria. The intervention arm received emotionally compelling radio and television advertisements about eggs, and was exposed to promotional activities and advertising about eggs at points of purchase, schools and health facilities; the comparison arm received no intervention. Children 6-59 months of age (intervention: n = 1359; comparison: n = 1485) were assessed 14 months apart. Intent-to-treat analyses with analysis of covariance method assessed the impact of the intervention on caregivers' behaviour towards eggs, caregivers' willingness to pay for eggs, availability of eggs in households, and consumption of eggs by children 6-59 months of age. Analyses were adjusted for possible confounders and perceived effects of COVID-19 on finances and food consumption. Compared to the comparison arm, the intervention arm showed a greater prevalence of household egg acquisition (odds ratio = 1.34, p < 0.0001), and larger improvements in caregiver self-efficacy (β = 0.242, p = 0.004) and intent to feed eggs to children (β = 0.080, p = 0.021). No effects were found on children's egg consumption or caregivers' reported willingness to pay for eggs. The lack of impact on child egg consumption despite increased acquisition of eggs and caregiver self-efficacy suggests that other barriers to child consumption may exist. Additional research should further investigate factors that may influence intrahousehold distribution of eggs and whether these may also influence other nutritious foods.

Determinants of egg consumption by infants and young children in Ethiopia

OBJECTIVE

To identify determinants of egg consumption in infants and young children aged 6-23·9 months in Ethiopia.

DESIGN AND SETTING

Data used were from the cross-sectional baseline survey of an egg campaign in Ethiopia implemented by the Global Alliance for Improved Nutrition.

PARTICIPANTS

Children aged 6-23·9 months (n 453) were sampled. Data on socio-demographic characteristics, economic resources, caregiver's behaviour, child health and feeding practices, and egg consumption in the last 7 d were collected using interviewer-administered questionnaires. Multivariable ordinal logistic regression was used to examine the association between explanatory variables and egg consumption in the last 7 d.

RESULTS

About half of children (53·4 %) did not consume eggs in the last 7 d. The odds of children consuming eggs were 4·33 (P < 0·002) times higher when their caregivers had some college education compared with no education. Wealth was positively (OR, 1·13, P = 0·029) and household food insecurity was negatively (OR, 0·96, P = 0·117) associated with child egg consumption. Purchasing eggs (OR, 9·73, P < 0·001) and caregiver's positive behavioural determinants (OR, 1·37, P = 0·005) were associated with child egg consumption. The associations of socio-demographic characteristics and economic resources with egg consumption provide evidence of partial mediation through caregiver behaviour and child health.

CONCLUSIONS

About half of children aged 6-23·9 months consumed eggs. Availability of eggs in households, mainly through purchase, was strongly associated with egg consumption. Education of caregivers and household heads and economic resources were associated with egg consumption and may operate through caregiver behaviour.

Advanced Practical Strategies to Enhance Table Egg Production

The global demand for table eggs has increased exponentially due to the growing human population. To meet this demand, major advances in hen genetics, nutrition, and husbandry procedures are required. Developing cost-effective and practically applicable strategies to improve egg production and quality is necessary for the development of egg industry worldwide. Consumers have shown a strong desire regarding the improvement of hens' welfare and egg quality. They also become interested in functional and designer foods. Modifications in the nutritional composition of laying hen diets significantly impact egg nutritional composition and quality preservation. According to previous scientific research, enriched egg products can benefit human health. However, producers are facing a serious challenge in optimizing breeding, housing, and dietary strategies to ensure hen health and high product quality. This review discussed several practical strategies to increase egg production, quality, and hens' welfare. These practical strategies can potentially be used in layer farms for sustainable egg production. One of these strategies is the transition from conventional to enriched or cage-free production systems, thereby improving bird behavior and welfare. In addition, widely use of plant/herbal substances as dietary supplements in layers' diets positively impacts hens' physiological, productive, reproductive, and immunological performances.

Infant age at egg introduction and malnutrition‐related child growth in the United States

To evaluate the relationship between infant age of egg introduction and malnutrition‐related growth outcomes in the United States, we analysed secondary data of 1716 mother–child dyads in the Infant Feeding Practices Study II and its Year 6 Follow‐Up Study. Malnutrition‐related growth outcomes included body mass index z‐score (BMIZ), obesity (weight‐for‐height z‐score [WHZ] ≥3 or BMIZ ≥ 2), WHZ, wasting (WHZ < −2), height‐for‐age z‐score (HAZ), and stunting (HAZ < –2). Infant age at egg introduction was analysed as a continuous variable. We used generalised estimating equations to estimate the mean difference in continuous outcomes and relative risk [RR]) for binary outcomes, adjusting for related maternal and child confounders. We also explored interactions with child sex, maternal race/ethnicity, maternal educational level, ever breastfeeding, and formula feeding. In the total sample, a later infant age at egg introduction was associated with a lower mean difference in HAZ (confounder‐adjusted mean difference = −0.08, 95% confidence interval [CI]: −0.12 to −0.03 per month) and a higher risk of stunting (confounder‐adjusted RR = 1.17, 95% CI: 1.03–1.33 per month) at 6 years. The associations between infant age at egg introduction and 12‐month growth outcomes differed by child sex. Among females but not among males, later introduction of eggs was associated with a lower mean WHZ (−0.06 [−0.12 to 0.00] per month) at 12 months. Later egg introduction during infancy was associated with a lower mean HAZ and a higher risk of stunting in 6‐year‐old children. Besides this, it was associated with a lower WHZ among females at 12 months.

This secondary data analysis evaluated the relationship between infant age at egg introduction and malnutrition‐related growth outcomes among young US children within the Infant Feeding Practices Study II and its Year 6 Follow‐up Study.

In the total sample, a later infant age at egg introduction was associated with a lower mean 6‐year height‐for‐age z‐score and a higher risk of stunting at 6 years.

The associations between infant age at egg introduction and 12‐month growth outcomes differed by child sex. Later introduction of eggs was associated with a lower mean weight‐for‐height z‐score among females. However, this association was not observed among males.

Association between Dietary Patterns and Physical Fitness among Chinese Children and Adolescents in Shaanxi Province

Background: This study aims to investigate the associations between dietary patterns (breakfast, egg, dairy products, and sugared beverage intake frequencies) and physical fitness among Chinese children and adolescents in Shaanxi Province. METHODS: Data were extracted from the Chinese National Survey on Students’ Constitution and Health (CNSSCH). The study ultimately included 7305 participants (48.4% male, 51.6% female) aged 6–22 in Shaanxi Province, China. Multiple linear regression was used to examine the association of the frequency of breakfast, egg, dairy product, and sugared beverage intakes with physical fitness. RESULTS: The frequency of breakfast, egg, and dairy product intakes were all independently and positively associated with the level of physical fitness. The frequency of sugared beverage intake was negatively associated with the level of physical fitness. CONCLUSION: Healthier dietary patterns (i.e., higher breakfast, egg, and dairy product intakes and lower sugared beverage intake) were associated with greater physical fitness. Specifically, maintaining a healthy dietary pattern of breakfast, egg, and dairy product intakes can positively affect the strength and endurance performance of children and adolescents. Increased dairy product intake plays a crucial part in boosting the physical fitness total scores of children and adolescents.

Potential of Egg as Complementary Food to Improve Nutrient Intake and Dietary Diversity

The original aim was to determine the effect of egg consumption on infant growth in a low socioeconomic community in South Africa in a randomized controlled trial. Enrolment was, however, prematurely stopped due to COVID-19 lockdown regulations. The resultant small sample (egg group n = 70; control group n = 85) was followed up to assess the feasibility of egg consumption for eight months in terms of dietary intake, egg usage and perceived effects of lockdown on child feeding. Egg consumption remained low in the control group, <10% consumed egg ≥4 days/week at the follow-up points. In the egg group, egg was frequently consumed at midpoint (daily 87.1%, 4−6 days 8.1%) and endpoint (daily 53.1%, 4−6 days 21.9%). At endpoint, dietary intake of cholesterol and vitamin D was higher, and intake of niacin and vitamin B6 lower in the egg group compared to the control group. Dietary diversity was low, 36.2% of the egg group and 18.9% of the control group (p < 0.05) achieved minimum dietary diversity at endpoint. No babies developed egg allergy or sensitization, and adjusted regression analysis showed that frequency of egg intake was not related with the incidence or duration of allergy-related symptoms. This study showed that frequent egg consumption can contribute safely to complementary food for babies, especially in low- and middle-income countries.

The Health Benefits of Egg Protein

Once the general public accepts that dietary cholesterol is not a concern for cardiovascular disease risk, foods that have been labeled as high-cholesterol sources, including eggs, may be appreciated for their various other dietary components. One of the nutrients in eggs that deserves further discussion is egg protein. Egg protein has been recognized to be highly digestible and an excellent source of essential amino acids, with the highest attainable protein digestibility-corrected amino acid score. Egg protein has been shown to decrease malnutrition in underdeveloped countries, possibly increase height in children, and protect against kwashiorkor. Egg protein has been demonstrated to be important to skeletal muscle health and protective against sarcopenia. Egg protein also can decrease appetite, resulting in a reduction in the caloric intake from the next meal and weight reduction. Other protective effects of egg protein addressed in this review include protection against infection as well as hypotensive and anti-cancer effects.

Impacts of COVID-19 Pandemic on Dietary Consumption among Chinese Residents: Evidence from Provincial-Level Panel Data

The COVID-19 pandemic has profoundly affected people’s daily lives, including their dietary behaviors. Using a panel data set of 31 provinces from 2015 to 2020, this study employed two-way fixed effects (FE) models to examine the impacts of the COVID-19 pandemic on dietary consumption among Chinese residents. The results showed that the COVID-19 pandemic positively affected residents’ consumption of grain, eggs, dairy, and white meat (poultry and aquatic products), while it had a negative effect on individuals’ red meat consumption in both urban and rural areas. These results were robust to different measures of the COVID-19 pandemic, including the number of confirmed cases, suspect cases, and dead cases. Comparatively, the changes in food consumption induced by the COVID-19 pandemic were more prominent for Chinese residents who lived in rural areas than urban areas. In addition, compared to their counterparts, the dietary consequences of the pandemic were more pronounced for residents living in the eastern region and regions with a high old-age dependency ratio and low illiteracy rate. Furthermore, the estimation results of the quantile regression model for panel data suggested that the COVID-19 pandemic had relatively larger impacts on the dietary consumption of Chinese residents at lower quantiles of food consumption compared with those at higher quantiles. Overall, the results of this study suggested that Chinese residents had a healthier diet after the outbreak of the COVID-19 pandemic. We discussed possible mechanisms, including health awareness, income, food supply and prices, and other behavioral changes during COVID-19 (e.g., physical activity and cooking). To further improve residents’ dietary behaviors and health, our study proposed relevant measures, such as increasing residents’ dietary knowledge, ensuring employment and income, and strengthening the food supply chain resilience during the pandemic.

Performance evaluation of a laboratory-developed light-initiated chemiluminescence assay for quantification of egg white-specific IgE

Background

Specific IgE (sIgE) testing has become one of the most important tools for diagnosing IgE‐mediated food allergy. Enzyme‐linked immunosorbent assay (ELISA) and dot‐enzyme‐linked immunosorbent assay (Dot‐ELISA) have been used to measure sIgE in clinical widely. Light‐initiated chemiluminescence assay (LICA) is a new method for measuring allergen‐sIgE. We aimed to establish a LICA method for quantitative detection of egg white‐sIgE and evaluate its performances.

Methods

The best chemibeads coupling method in detecting egg white‐sIgE was selected, and a LICA method for quantitative detection of egg white‐sIgE was established. The precision study was performed according to Clinical and Laboratory Standards Institute (CLSI) EP5‐A2. Detection capability which contains limit of blank (LoB), limit of detection (LoD), and limit of quantitation (LoQ) was evaluated according to National Health Commission of the People's Republic of China (NHC) WS/T 514–2017. Linear range was evaluated according to CLSI EP6‐A. All data were analyzed using SPSS software.

Results

Precision contains repeatability and intermediate precision. The CV of repeatability ranged from 2.72% to 7.29%, and the CV of intermediate precision ranged from 4.93% to 8.64%. The LoB, LoD, and LoQ of the assay were 0.000 kUA/L, 0.053 kUA/L, and 0.076 kUA/L. The assay linear range was 0.076–34.125 kU_A/L (r = 0.9979 ≥ 0.9900).

Conclusion

This laboratory‐developed LICA method can detect egg white‐sIgE, and performance meets clinical requirements. This method shows rapid turnaround cycles and high sensitivity. It can be used as an alternative method for clinical detection of egg white‐sIgE.

The Effects of 1 Egg per Day on Iron and Anemia Status among Young Malawian Children: A Secondary Analysis of a Randomized Controlled Trial

Background

Young children with diets lacking diversity with low consumption of animal source foods are at risk of iron deficiency anemia (IDA).

Objectives

Our objectives were to determine the impact of supplementing diets with 1 egg/d on 1) plasma ferritin, soluble transferrin receptor (sTfR), body iron index (BII), and hemoglobin concentrations and 2) the prevalence of iron deficiency (ID), anemia, and IDA.

Methods

Malawian 6-9-mo-old infants in the Mazira trial (clinicaltrials.gov; NCT03385252) were individually randomly assigned to receive 1 egg/d for 6 mo (n = 331) or continue their usual diet (n = 329). In this secondary analysis, hemoglobin, plasma ferritin, sTfR, C-reactive protein (CRP), and α-1-acid glycoprotein (AGP) were measured at enrollment and 6-mo follow-up. Iron biomarkers were corrected for inflammation. Ferritin, sTfR, BII, and hemoglobin were compared between groups using linear regression. Prevalence ratios (PRs) for anemia (hemoglobin <11 g/dL) and ID (ferritin <12 µg/L, sTfR >8.3 mg/L, or BII <0 mg/kg) between groups were compared using log binomial or modified Poisson regression.

Results

A total of 585 children were included in this analysis (Egg: n = 286; Control: n = 299). At enrollment, the total prevalence of anemia was 61% and did not differ between groups. At 6-mo follow-up, groups did not differ in geometric mean concentration of hemoglobin [mean (95% CI); Egg: 10.9 (10.7, 11.1) g/dL; Control: 11.1 (10.9, 11.2) g/dL] and inflammation-adjusted ferritin [Egg: 6.52 (5.98, 7.10) µg/L; Control: 6.82 (6.27, 7.42) µg/L], sTfR [Egg: 11.34 (10.92, 11.78) mg/L; Control: 11.46 (11.04, 11.89) mg/L] or BII [Egg: 0.07 (0.06, 0.09) mg/kg; Control: 0.07 (0.05, 0.08) mg/kg]. There were also no group differences in anemia [Egg: 46%; Control 40%; PR: 1.15 (95% CI: 0.96, 1.38)], ID [PR: 0.99 (0.94, 1.05)], or IDA [PR: 1.12 (0.92, 1.36)].

Conclusions

Providing eggs daily for 6 mo did not affect iron status or anemia prevalence in this context. Other interventions are needed to address the high prevalence of ID and anemia among young Malawian children. This trial is registered at http://www.clinicaltrials.gov as NCT03385252.

Discriminant Analysis of the Nutritional Components between Organic Eggs and Conventional Eggs: A 1H NMR-Based Metabolomics Study

The difference of nutrient composition between organic eggs and conventional eggs has always been a concern of people. In this study, ¹H nuclear magnetic resonance (NMR) technique combined with multivariate statistical analyses was conducted to identify the metabolite different in egg yolk and egg white in order to reveal the nutritional components information between organic and conventional eggs. The results showed that the nutrient content and composition characteristics were different between organic and conventional eggs, among which the content of glucose, putrescine, amino acids and their derivatives were found higher in the organic eggs yolk, while phospholipids were demonstrated higher in conventional eggs yolk. Organic acid, alcohol, amine, choline and amino acids were higher in conventional eggs white, but glucose and lactate in organic egg were higher. Our study demonstrated that there are more nutritive components and higher nutritional value in organic eggs than conventional eggs, especially for the growth and development of infants and young children, and conventional eggs have more advantages in promoting lipid metabolism, preventing fatty liver, and reducing serum cholesterol. Eggs have important nutritional value to human body, and these two kinds of eggs can be selected according to the actual nutrient needs.

Ovarian Transcriptomic Analysis of Ninghai Indigenous Chickens at Different Egg-Laying Periods

Egg production is an essential indicator of poultry fertility. The ovary is a crucial organ involved in egg production; however, little is known about the key genes and signaling pathways involved in the whole egg-laying cycle of hens. In order to explore the mechanism of egg production at different stages of the egg-laying process, ovarian tissues from four chickens were randomly selected for transcriptome analysis at each of the three ages (145 d, 204 d, and 300 d in the early, peak, and late stages of egg laying). A total of 12 gene libraries were constructed, and a total of 8433 differential genes were identified from NH145d vs. NH204d, NH145d vs. NH300d and NH300d vs. NH204d (Ninghai 145-day-old, Ninghai 204-day-old, and Ninghai 300-day-old), with 1176, 1653 and 1868 up-regulated genes, and 621, 1955 and 1160 down-regulated genes, respectively. In each of the two comparison groups, 73, 1004, and 1030 differentially expressed genes were found to be co-expressed. We analyzed the differentially expressed genes and predicted nine genes involved in egg production regulation, including LRP8, BMP6, ZP4, COL4A1, VCAN, INHBA, LOX, PTX3, and IHH, as well as several essential egg production pathways, such as regulation adhesion molecules (CAMs), calcium signaling pathways, neuroactive ligand–receptor interaction, and cytokine–cytokine receptor interaction. Transcriptional analysis of the chicken ovary during different phases of egg-lay will provide a useful molecular basis for study of the development of the egg-laying ovary.