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Discussing Healthy Hens on World Egg Day

Updated: Oct 1, 2022

8th of October is the annual World Egg Day. Celebrated by many, the humble egg has been a staple in millions of households, providing familiar tastes and satiation for many alike. Eggs are savored so much worldwide that we are still seeing a continuous increase in global egg production, after a linear growth throughout the last two decades.

Data provided by (Global Egg Production Continues to Grow - International Egg Commission, accessed on the 6th October 2021)

We would like to highlight the birds behind the ever so popular animal product - the layer hens. The increased demand for eggs offsets high egg-laying rates of modern layer strains, resulting in the total number of hens not decreasing with time despite more effective genetic selection and farming practices. Chickens are the most numerous farmed land animal, totaling at around 26 billion worldwide, of which layer hens constitute a third.

Although consumers are increasingly perceiving the need to improve animal welfare in modern agriculture, layer hens sometimes slip through the cracks in our attention. Many factors including but not limited to the housing system, nutrition, animal genetics and general farming practices play a key role in the overall life quality of a layer hen. Recent advances in transitioning towards cage-free farming operations and the banning of beak trimming have shown that the well-being of these birds cannot be ensured by improving just these aspects of commercial egg farming. As the data visualized below indicates, most pain and suffering experienced by birds housed in higher welfare systems is in the form of bone fractures. High impact collisions were recently shown not to be an adequate explanation for why layer hens continue experiencing bone fractures despite the increased levels of exercise and bone strengths offered by the transition to cage-free systems.

Data provided by (Transition to cage-free systems – Welfare Footprint Project, accessed on the 6th of October, 2021 Code to embed the table)

There is a high risk that the health metrics currently used in the field of animal science correlate much better with productivity and farming economics than the well-being of the individual hens. Due to constant egg-laying, layer hens have high physiological demand for nutrients - particularly calcium, phosphorus and vitamin D, all of which are equally needed for them to build and maintain skeletal integrity. Therefore, the feed provided for their consumption must contain sufficient amounts of nutrients that could be both ingested and effectively utilized by the birds to replenish stores, accommodate for the exaggerated dietary needs, and reduce the risk for bone fractures.

Currently, there are no global standards for layer feed. There are guidelines and minimum requirements in certain countries, as a good example, Nigeria recently approved new legislation for poultry feed in 2018, but for the most part the industry sets the standard. As farmers move from productivity to welfare/sustainability, we have an opportunity to set those standards to ensure better health status for hens, and simultaneously, produce a better egg.

Calcium levels are key in the development of an egg. During the egg formation process, bone can be mobilized to provide roughly 40% of calcium in the eggshell. With hens producing 250-300 eggs a year, there is a high chance of calcium depletion from their bones leading to osteoporosis. Several studies have shown that increasing calcium levels in feed to 4% and higher, allows hens to develop stronger bones and a stronger egg–decreasing cases of osteoporosis, and limiting cracked eggs. Phosphorus also plays an important role in egg development and in a 2003 study, conducted by Keshavarz, supplementing feed with 0.45% non-phytate phosphorus resulted in higher bone ash content in white layers. Vitamin D3 is also directly tied to the absorption of calcium. Increasing vitamin D3 to levels of 3000 IU and higher, is shown to have two outcomes: stronger tibia bones and an increase of vitamin D3 found in the egg. In a 2004 study, conducted by P Mattila et al., they found that, “ [vitamin D3 enriched eggs] would deliver about 1.9 to 2.8 µg of vitamin D3, which is equivalent to 2 to 3 times more than the intake from typical eggs.” This would allow farmers to promote their product as “designer” eggs, which consumers gravitate towards and are willing to pay more for–an example of this is the recent trend of omega 3 eggs. There are many other nutrients that can be optimized to increase hen heath and egg quality.

Our new organization, Healthier Hens, intends to research and pilot a study that will increase nutrients to optimal levels in order to determine if they positively benefit the hen’s welfare without compromising production. This is our first World Egg Day as an organization and within a year we hope to choose a country of operation and run a proof-of-concept pilot with four farms. This would include 2 cage free farms and 2 caged farms, so we can test our theory across different housing systems and see where the impact of fortification would be most significant. We will also explore and evaluate three intervention models (i.e., feed production, collaboration with mills, subsidizing the purchase of supplements) by conducting in-country research (expert interviews, data gathering, etc.), and run a cost effectiveness analysis for each model.

We hope you can join us today in celebrating World Egg Day and acknowledging the central role of egg-laying hens. Please reach out to via our contact form below with any questions or opportunities to collaborate, and join our newsletter to stay up-to-date with our progress.


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