Calcium is vital for laying hens. Whereas most animal diets contain less than 1% calcium, layer diets must contain substantially more. Indeed, such diets contain from 3 to 4%, only because the formation of each eggshell requires two grams of calcium (in the form of about 5.5 grams of calcium carbonate)1.
Five laying hens problems caused by a lack of calcium
Laying hens have a high demand for calcium, especially during peak egg production when calcium output is at its greatest. Hypocalcaemia occurs when a chicken’s blood-calcium levels are dangerously low. It is a significant problem in hens, especially ex-battery hens and breeds known for having excessive egg production traits. This is because egg-laying requires calcium to form the eggshell, resulting in depletion of it from her own body. Clinical signs include of low calcium includes2:
Decreased egg production
A hen needs calcium not only to form the shell around each egg laid but also to produce the contractions that help her to lay that egg3.
Thin eggshells and broken eggs
The quality of the eggshells they produce depends on their calcium intake. Thin or poorly formed eggshells can lead to breakages and lost production.
A deficiency of either calcium or phosphorus results in a lack of normal skeletal calcification. Rickets is seen in growing birds, while calcium deficiency in laying hen’s results in reduced shell quality and osteoporosis4. This depletion of bone structure causes a disorder that is commonly referred to as “cage layer fatigue.” When calcium is mobilized from bone to overcome a dietary deficiency, the cortical bone erodes and is unable to support the weight of the hen.
Rickets is frequently associated with a deficiency of calcium5. The condition is most likely to arise in situations of vitamin D deficiency Osteoporosis results from calcium being removed from the bone to meet other needs, and this causes porous and brittle bones. Some birds mobilize large amounts of calcium from their skeleton during the laying period, and the bones may become so demineralized that the birds are unable to stand and appear paralyzed. The sternum and rib bones are frequently deformed, and all bones are easily broken6.
Weak bones and Bone Fractures
Bones function as a temporary reserve of available calcium being able to contribute no more than about 2,000 mg. Drawing more than that harms the structural integrity of the bones, causing leg problems7. Calcium is essential for egg formation as the medullary bone is a woven bone that acts as a labile source of calcium for eggshell formation8.
Low blood calcium
For growing pullets calcium deficiency can result in increased general activity and environmental pecking9. Increased pecking can be a significant welfare problem, as well as having economic consequences. The pullet’s requirement for calcium is low during the growing period, but the bird still needs phosphorous and calcium in its diet.
The Solution: Dietary Calcium
Including the right amount of calcium in the diet will help to minimize the percentage of broken eggs and bone problems, which, consequently, will result in superior performance rates and high-quality eggs. Calcium can be supplied to hens from a range of different sources including natural products like Morgan Agro’s seashells.
How Much Calcium is Needed?
To lay quality, healthy eggs, a hen must receive an average of 4-5 grams of calcium per day10.
Calcium requirements (%) in layers. Adapted from Rostagno11, 2017
The quality of the eggshells produced depends on hens’ calcium intake. If a hen does not have access to free-choice calcium, and thus cannot properly form eggshells, she may become egg-bound or lay eggs with soft shells.
Where can I get seashells?
Calcium is essential for laying hens, and seashells are a great natural source that can help prevent weak bones, shells and other problems due to the lack of calcium.
Morgan Agro supplies the highest quality seashells from the Caspian Sea. If you are a poultry farmer, feed manufacturer or supplier, interested in what our product can do to improve laying hen performance and nutrition then contact us for samples or more details.
- Ioannis Mavromichalis, ‘In Layer Diets, Limestone Is Not Just Calcium Carbonate’, Feed Strategy, 2015 <https://www.feedstrategy.com/poultry-nutrition/in-layer-diets-limestone-is-not-just-calcium-carbonate/> [accessed 26 March 2021].
- Poultry DVM, ‘LOW BLOOD CALCIUM LEVEL’, 2021.
- Fresh Eggs Daily, ‘What Causes Soft Shelled Chicken Eggs?’, 2021 <https://www.fresheggsdaily.blog/2014/04/soft-shelled-or-rubber-eggs-causes-and.html>.
- Growel Agrovet Private Limited, ‘Mineral Deficiencies in Poultry.’, 2015 <https://www.growelagrovet.com/mineral-deficiencies-in-poultry/> [accessed 24 December 2021].
- farmhealthonline.com, ‘Calcium and Phosphorus Deficiency in Poultry’, 2018 <https://www.farmhealthonline.com/disease-management/poultry-diseases/ca-and-p-deficiency/> [accessed 8 December 2021].
- Nick Dale, ‘National Research Council Nutrient Requirements of Poultry — Ninth Revised Edition (1994)’, Journal of Applied Poultry Research, 3.1 (1994) <https://doi.org/10.1093/japr/3.1.101>.
- Ioannis Mavromichalis, ‘Calcium Digestibility Remains Key in Layer Hen Nutrition’, Feed Strategy, August 2021 <https://www.feedstrategy.com/blog/calcium-digestibility-remains-key-in-layer-hen-nutrition/>.
- C. C. Whitehead, ‘Overview of Bone Biology in the Egg-Laying Hen’, in Poultry Science, 2004 <https://doi.org/10.1093/ps/83.2.193>.
- B. O. Hughes and D. G.M. Wood-Gush, ‘An Increase in Activity of Domestic Fowls Produced by Nutritional Deficiency’, Animal Behaviour, 21.1 (1973) <https://doi.org/10.1016/S0003-3472(73)80035-1>.
- Coopcrate, ‘How to Prevent Calcium Deficiency in Your Chickens’, 2020 <https://www.coopcratechickens.com/calcium-supplements-for-your-chickens/> [accessed 24 December 2021].
- Rostagno, Horacio Santiago et al. 2017. Tablas Brasileñas Para Aves y Cerdos. Composición de Alimentos y Requerimientos Nutricionales. 4th ed. ed. Horacio Santiago Rostagno. Universidad Federal de Viçosa, Departamento de Zootecnia.