How do I improve my egg shell quality?

1 Feb

Effect of ageing on shell quality

Eggs are a healthy source of high quality protein, vitamins and minerals. One of the major challenges in egg production is hen aging, which has a detrimental impact on egg shell quality as well as the numbers of eggs laid.

A farmed hen is now bred with the ability to produce up to 100 weeks of age under commercial conditions. During this time she will produce 26kg of eggs, about 14 times her bodyweight. This quality of eggs will include 3kg of egg shell and more than 1kg of calcium. This cycle of daily egg production can be challenging to the physiology and metabolism of the hen, particularly with respect to bodyweight and bone density of the hen. Excessive laying or unbalanced diets can results in thin birds and thin bones (osteoporosis).

It is also more common for egg shell issues to become more prevalent as the hen ages. Deterioration in egg shell quality such as increased microcracks or thin shells, can result in an increased risk of egg breakage (in the oviduct and in the nest) and of bacterial contamination entering the egg. If the egg breaks in the oviduct, this can result in delayed egg laying or create a blockage, which can potentially predispose to salpingitis and even egg bind, both of which can be life threatening to the hen.

What are egg shells made of?

Egg shell consists of 96% calcium carbonate and 4% organic framework. Each egg shell contains 2-2.5g of calcium . Calcium is sourced by the hen from its food but at night whilst the egg shell continues to be formed, calcium is resorbed from the skeleton, which acts as a reservoir. Vitamin D3 (VitD3) regulates calcium metabolism. D3 in the diet is absorbed from the intestines and is activated in the liver to 25-OHVitD3 (scientific name 25-hydroxy cholecalciferol). This product is then further metabolised in the kidneys to 1,25-OHVit D3, which is the active form of VitD3.

What kind of Vitamin D supplements help?

Egg shell quality and bone density, particularly in aging hens can be improved by VitD3 supplements. If straight VitD3 is used, the hen needs to have a stable intestinal function to absorb the D3 and a healthy liver and kidneys to metabolise the VitD3 to the active 1,25OHVitD3. If hens are unwell, have an intestinal upset or older hens with possible reduced liver and kidney function, then supplementing with 25-OHVitD3 would be better or ideally supplementing with 1,25OHVitD3.

Dried, milled leaves from the waxy leaf nightshade plant contain naturally occurring 1,25OHVitD3.