UK Egg Research Articles

Openness is sperm and egg donor conception: improving support for donors and their families

This brief discusses the policy implications of the findings of a recent large scale study of UK egg and sperm donors. Since 2005, UK sperm and egg donors must consent to being identifiable to people conceived from their donation(s), should they request that information at age 18. There has been much speculation, but limited empirical research, on how donors might feel about this change. The Curious Connections study, which included interviews with donors, their relatives and professionals who work with them, examined how donors and their families experience donation in the context of increased openness. The study found that contemporary sperm and egg donors were overwhelmingly supportive of the move to “identity-release” donation. However, current UK policies do not fully reflect the range of ways in which donors and their families experience and understand what it means to donate egg or sperm. The authors recommend a range of policy and practice changes, including increased flexibility regarding information sharing between donors and recipient parents, the provision of long-term support for donors and their families, enabling children of donors to register with the Donor Sibling Link, creating a voluntary register of donor conceptions arranged outside of licensed clinics, and increased support for known donor conception.

The experience of counselling for UK egg providers

AbstractObjectiveThe aim of this study was to address current gaps in knowledge regarding the appropriateness and quality of counselling provided to egg donors in the UK.MethodsThe present study used a cross‐sectional, qualitative design. Semi‐structured interviews were carried out with 29 UK egg donors to explore their experiences of egg donation and the counselling received.ResultsOf the 29 participants, 24 had received counselling. The remaining five did not receive counselling because they were either not accepted as a donor (n = 4) or were offered, but chose not to take up the session (n = 1). The findings are presented in relation to five themes: feeling supported via counselling; feeling well‐informed; welcoming an individualised approach; the counselling setting; and thinking about the future.ConclusionEgg donors in this study had varying experiences of counselling offered to them as part of the egg donation process in the UK.ImplicationsThe findings indicate that there are some aspects of counselling in the UK that could be improved, including the routine offering of counselling throughout the egg donation process and the tailoring of counselling to meet egg donors' individual needs.

Good eggs

Good eggs

Homocysteine and female fertility, pregnancy loss and offspring birthweight: a two-sample Mendelian randomization study.

Observational studies link elevated homocysteine concentrations (Hcy) with female fertility, pregnancy loss, and low offspring birthweight. Maternal rs1801133, a functional variant in MTHFR strongly associated with lifelong elevated Hcy, is associated with recurrent pregnancy loss and offspring birthweight in Asian women. We investigated if genetically elevated Hcy is associated with fertility, pregnancy loss, and offspring birthweight in European women. We performed a two-sample Mendelian randomization (MR) study using publicly available data. We obtained 18 genetic variants (five involved in Hcy metabolism) explaining up to 5.9% of the variance in Hcy from a genome-wide association meta-analysis of 44,147 European individuals (82% women). We investigated fertility (including age at menopause), pregnancy loss, and offspring birthweight in the UK Biobank (N = 194,174), EGG (N = 190,406), and ReproGen (N = 69,360-252,514) consortia using summary statistics. We calculated inverse-variance weighted, and several sensitivity MR regression statistics. rs1801133 was associated with a 7.45 months (95% CI: 4.09, 10.80) increase in age at menopause and 29.69 (12.87, 46.51) g decrease in offspring birthweight per SD increase in Hcy in the UK biobank, and confirmed in EGG and ReproGen. MR for Hcy metabolism alone (five variants in MTHFR, MTR, CBS) showed similar results for offspring birthweight across consortia. However, using all 18 variants resulted in no association for any of the outcomes across consortia. Hcy and suggestively vitamin B variants are most likely the drug targets for folate supplementation in pregnant women on the offspring birthweight, while Hcy variants related to renal function or diabetes are not involved.

Health and Welfare

Jane Howorth is the organizer of Britain’s biggest hen party, a group of 900 volunteers dedicated to improving the lives of millions of chickens employed in the UK egg industry. They seek out new homes for birds destined for the slaughterhouse at the end of their productive careers, and work to improve understanding of hen health and welfare. Jane set up the British Hen Welfare Trust in 2005 and talks to Companion about their plans to support clinical research on the common diseases affecting backyard poultry.

UK egg company cracks plastics bio-filler breakthrough

UK egg company cracks plastics bio-filler breakthrough

Being an identity-release donor: a qualitative study exploring the motivations, experiences and future expectations of current UK egg donors

The objective of this study was to examine the motivations, experiences and future expectations of identity-release egg donors in the UK following the removal of donor anonymity and the increase in financial compensation for egg donation. This exploratory, in-depth qualitative study comprised semi-structured interviews with 11 women who had attended an egg donation screening appointment at a UK clinic during a four-month period in 2014. Interviews were conducted two to six weeks after the woman had donated or had withdrawn/been rejected from the donation process. Participants’ primary motivation for donating was to help infertile women have their ‘own child’, and the recent increase in financial compensation did not seem to play a significant role in their decision. All were happy to be identifiable and contacted by children born as a result of their donation. However, some were hesitant about providing non-identifying information about themselves for these offspring and wished for further information about the recipient(s) of their eggs and the outcome of their donation. Whilst this study was limited due to the small sample size, it is the first study of UK egg donors following the rise in donor compensation and suggests that other strategies may be more effective in increasing donor numbers.

Phylogenetic structure of European Salmonella Enteritidis outbreak correlates with national and international egg distribution network.

Outbreaks of Salmonella Enteritidis have long been associated with contaminated poultry and eggs. In the summer of 2014 a large multi-national outbreak of Salmonella Enteritidis phage type 14b occurred with over 350 cases reported in the United Kingdom, Germany, Austria, France and Luxembourg. Egg supply network investigation and microbiological sampling identified the source to be a Bavarian egg producer. As part of the international investigation into the outbreak, over 400 isolates were sequenced including isolates from cases, implicated UK premises and eggs from the suspected source producer. We were able to show a clear statistical correlation between the topology of the UK egg distribution network and the phylogenetic network of outbreak isolates. This correlation can most plausibly be explained by different parts of the egg distribution network being supplied by eggs solely from independent premises of the Bavarian egg producer (Company X). Microbiological sampling from the source premises, traceback information and information on the interventions carried out at the egg production premises all supported this conclusion. The level of insight into the outbreak epidemiology provided by whole-genome sequencing (WGS) would not have been possible using traditional microbial typing methods.

The greenhouse emissions footprint of free-range eggs

Eggs are an increasingly significant source of protein for human consumption, and the global poultry industry is the single fastest-growing livestock sector. In the context of international concern for food security and feeding an increasingly affluent human population, the contribution to global greenhouse-gas (GHG) emissions from animal protein production is of critical interest. We calculated the GHG emissions footprint for the fastest-growing sector of the UK egg market: free-range production in small commercial units on mixed farms. Emissions are calculated to current Intergovernmental Panel on Climate Change and UK standards (PAS2050): including direct, indirect, and embodied emissions from cradle to farm gate compatible with a full product life-cycle assessment. We present a methodology for the allocation of emissions between ruminant and poultry enterprises on mixed farms. Greenhouse gas emissions averaged a global warming potential of 2.2 kg of CO2e/dozen eggs, or 1.6 kg of CO2equivalent (e)/kg (assuming average egg weight of 60 g). One kilogram of protein from free-range eggs produces 0.2 kg of CO2e, lower than the emissions from white or red meat (based on both kg of meat and kg of protein). Of these emissions, 63% represent embodied carbon in poultry feed. A detailed GHG emissions footprint represents a baseline for comparison with other egg production systems and sources of protein for human consumption. Eggs represent a relatively low-carbon supply of animal protein, but their production is heavily dependent on cereals and soy, with associated high emissions from industrial nitrogen production, land-use change, and transport. Alternative sources of digestible protein for poultry diets are available, may be produced from waste processing, and would be an effective tool for reducing the industry's GHG emissions and dependence on imported raw materials.

Comparing the environmental impacts of alternative protein crops in poultry diets: The consequences of uncertainty

The statistical significance of the effects of including different protein sources in poultry diets on the environmental impacts Global Warming Potential (GWP), Eutrophication Potential (EP) and Acidification Potential (AP) of typical UK broiler meat and egg production systems was quantified using the Life Cycle Assessment (LCA) method combined with an uncertainty analysis. The broiler and layer diets compared in the study were either standard soya-based, or alternative diets based on European-grown protein crops, including field beans, field peas, sunflower meal and whole rapeseed. Different methods for accounting for land use change (LUC) in feed crop production were applied, including (1) a weighted average of “new” and “mature” agricultural land used for soya production (“best estimate” scenario), (2) assuming no LUC in the production of soya used in these diets (“sustainable soya” scenario) and (3) including indirect LUC for all arable crop production (“top-down” scenario). Monte Carlo simulations were used to quantify uncertainties in predicted impacts and to perform statistical comparisons between the effects of different diet compositions. The results showed that when included at relatively high levels in the diets (10–30% by mass), peas, beans and rapeseed could slightly reduce the simulated mean value of GWP (up to 12%) of broiler meat and egg production. However, when uncertainties in the data were taken into account, these reductions were not statistically significant. Furthermore, the reduction in GWP strongly depended on the method of LUC accounting applied in the analysis. With the “sustainable soya” and “top-down” scenarios, only small, non-significant differences between the different diets were found. In the case of EP, only small non-significant changes could be achieved with the alternative protein sources. For AP, a significant reduction of more than 20% could be achieved if the crude protein content of the broiler diet was reduced by using peas in combination with pure amino acids. This study demonstrates the importance of a holistic approach, coupled with Monte Carlo uncertainty analysis, to evaluate the environmental impacts of livestock systems. It takes into account the environmental burdens related, for example, to feed production and transport and differences in emissions from housing and the end use of the manure. Furthermore, due to the systematic uncertainty analysis, the statistical significance of the effects of different feeding scenarios can now be evaluated.

Position Statement on the Provision and Procurement of Human Eggs for Stem Cell Research

The nature of compensation for women who donate eggs (oocytes) for research remains a contentious issue internationally. This position paper lays out the arguments for, and discusses the arrangements in which, a modest payment might be ethically justifiable.

Egg-share donors’ and recipients’ knowledge, motivations and concerns: clinical and policy implications

This paper reports the results of a survey study examining the knowledge, motivations and concerns of egg-share donors and recipients, and assesses the clinical and policy implications of these findings. The survey, combining quantitative and qualitative items, was completed by 48 donors and 38 recipients who took part in an egg-sharing scheme at the London Women's Clinic between 2007 and 2009. Although the most important motivation for all egg-sharers was to have a baby, both donors and recipients displayed multiple motivations, including elements of self-interest and altruism. Many viewed egg-sharing as a reciprocal process in which two women with different needs help one another. The results are reassuring from an ethical and policy perspective: they suggest that if information about egg-sharing was more widely available (especially through general practitioners), more women may consider becoming egg-share donors, gaining swift access to their own treatment and reducing the UK's egg donor shortage.

Predicting the environmental impacts of chicken systems in the United Kingdom through a life cycle assessment: Egg production systems

The aim of this study was to apply a life cycle assessment (LCA) method, from cradle to gate, to quantify the environmental burdens per 1,000 kg of eggs produced in the 4 major hen-egg production systems in the United Kingdom: 1) cage, 2) barn, 3) free range, and 4) organic. The analysis was based on an approach that applied a structural model for the industry and mechanistic submodels for animal performance, crop production, and nutrient flows. Baseline feeds representative of those used by the UK egg production industry were used. Typical figures from the UK egg production industry, feed intake, mortality of birds, farm energy, and material use in different systems were applied. Monte Carlo simulations were used to quantify the uncertainties in the outputs and allow for comparisons between the systems. The number of birds required to produce 1,000 kg of eggs was highest in the organic and lowest in the cage system; similarly, the amount of feed consumed per bird was highest in the organic and lowest in the cage system. These general differences in productivity largely affected the differences in the environmental impacts between the systems. Feed production, processing, and transport caused greater impacts compared with those from any other component of production; that is, 54 to 75% of the primary energy use and 64 to 72% of the global warming potential of the systems. Electricity (used mainly for ventilation, automatic feeding, and lighting) had the second greatest impact in primary energy use (16-38%). Gas and oil (used mainly for heating in pullet rearing and incineration of dead layer birds) used 7 to 14% of the total primary energy. Manure had the greatest impact on the acidification and eutrophication potentials of the systems because of ammonia emissions that contributed to both of these potentials and nitrate leaching that only affected eutrophication potential. The LCA method allows for comparisons between systems and for the identification of hotspots of environmental impacts that could be subject to mitigation.

Estimating the benefits of farm animal welfare legislation using the contingent valuation method

This paper presents the method and findings of a contingent valuation (CV) study that aimed to elicit United Kingdom citizens’ willingness to pay to support legislation to phase out the use of battery cages for egg production in the European Union (EU). The method takes account of various biases associated with the CV technique, including ‘warm glow’, ‘part-whole’ and sample response biases. Estimated mean willingness to pay to support the legislation is used to estimate the annual benefit of the legislation to UK citizens. This is compared with the estimated annual costs of the legislation over a 12-year period, which allows for readjustment by the UK egg industry. The analysis shows that the estimated benefits of the legislation outweigh the costs. The study demonstrates that CV is a potentially useful technique for assessing the likely benefits associated with proposed legislation. However, estimates of CV studies must be treated with caution. It is important that they are derived from carefully designed surveys and that the willingness to pay estimation method allows for various biases.

Development of pecking damage in layer pullets in relation to dietary protein source

1. In recent years, the UK egg industry has become increasingly dependent on plant protein sources, in particular soyabean meal, and it has been suggested that this trend (and/or the concomitant absence of animal protein in layer diets) might be causally related to increased feather pecking and cannibalism. 2. This study examined the development of pecking damage in relation to dietary protein source, by rearing 12 groups of 12 layer pullets to 24 weeks of age on diets based on 'animal' (fishmeal) or 'plant' (soyabean meal) protein. 3. Damaging pecking began at 6 weeks of age, in three groups (one plant and two animal). Injurious pecking began at 18 weeks of age, and affected four groups (two plant and two animal). 4. Greater numbers of vigorous pecks/pulls were observed in plant protein groups throughout the experiment, although they were significantly higher only between 13 to 16 weeks of age. Pecking damage scores did not differ between treatments. 5. Dietary protein source did not affect plasma oestradiol, progesterone or egg production. 6. These results do not support the notion that inclusion of fishmeal in laying hen diets prevents or alleviates feather pecking and cannibalism.

Have lessons been learned from the UK bovine spongiform encephalopathy (BSE) epidemic?

History is full of examples of public health, commerce and politics in conflict. In recent years attempts to protect UK egg producers, after the discovery of Salmonella enteritidis (phage type 4) in hens' eggs, strained previously good working relationships between medical and veterinary epidemiologists and ended the political career of a government minister who spoke out in defence of the public health. Against the background lessons of earlier high profile public health problems in the UK conflict should have been avoided when bovine spongiform encephalopathy (BSE) started. It might have been expected that its significance for human health could have been recognized and researched earlier. Public announcements about it could have been timely and clear. Unfortunately this was not the case and it looks as though similar mistakes are going to be repeated over genetically modified foods.

Segmenting the UK egg market: results of a survey of consumer attitudes and perceptions

Despite the long‐term decline in per capita consumption, eggs remain an important staple in the British diet. Having recovered from the salmonella scare in 1989, the image of eggs has suffered in recent years due to the growing awareness of (and concern over) diet and health, and bird welfare. Reports the results of a recent consumer survey and concludes that there is a polarization of egg consumers, with free‐range consumers at one extreme, largely influenced by bird welfare, and battery consumers at the other, for whom functional properties (size and shell) and value for money are the major factors determining egg purchasing behaviour.

Persistence, seasonality and trend in the UK egg production

This paper discusses the time-series properties of UK egg production in order to provide an empirical analysis of the possible long-run impact of the shock on the industry following the recent incidence of salmonella poisoning. Our analysis shows that although the short-run properties of the UK egg production are consistent with the presence of persistent shocks, a shock duration is unlikely to have large long run efefcts. This result is remarkably robust to the choice of the persistence measure obtained.

IRREVERSIBLE SUPPLY FUNCTIONS REVISITED

This paper presents a successful application of an irreversible supply model to the UK egg sector. The model has been developed to overcome the problems that the conventional approaches to irreversible supply modelling face when used with a partial adjustment framework. The results indicate that the supply response to price changes under excess capacity is less than a third of that under non‐excess capacity, but that the long‐run response is symmetric, as required by the underlying theory. Furthermore, the long‐run elasticity from a conventional, symmetric, partial‐adjustment model is some 40% larger than that of the asymmetric model, implying that the importance of the asymmetric specification extends beyond an interest in the short‐run adjustment path.

An econometric model of the UK EGG market

An econometric model of the UK EGG market