A clean egg is important not only for the fresh-egg industry, but also for the hatchery sector, where dirty eggs reduce chances of producing viable chicks. There are many factors causing the appearance of dirty eggs in layers, but the major issues are hen health and nutrition; quite often interrelated. If certain nutrition principles are followed in feed formulation, the number of dirty eggs sticky or watery droppings will be significantly reduced.

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The first area of attention is, of course, that of ingredient selection. For example, certain cereals, with rye being the most offensive in this respect, contain high levels of non-starch polysaccharides that increase digesta viscosity. This invariably leads to sticky excreta and increase the incidence of dirty eggs. 

This issue can be easily resolved by reverting to less offensive cereals, such as maize or wheat, or by reducing the amount of 'offensive' cereals. In addition, there is some evidence suggesting a reduction in sticky droppings when certain non-starch polysaccharide enzymes are added in diets containing cereals that enhance digesta viscosity.

Another reason for dirty eggs is the problem of wet droppings (mild diarrhea). This is mostly caused by disease or environmental stress, but certain nutritional factors can aggravate (or alleviate) the situation. Feed or water high in mineral salts, and particularly sulphur salts, can cause excessive water secretion in the gut resulting in a high water concentration in the excreta. 

When certain ingredients high in simple sugars are used in formulation (for example, bakery meal can have up to 25 percent sucrose), then this can also lead to this problem. This is not pathogenic diarrhea and cannot be treated with medications, but it requires attention at the feed formulation level.

In addition, factors leading to high water intake, including high dietary protein levels, may also lead to wet droppings, especially during summer months. To counter such problem, it is often advisable to include fibrous ingredients with a high-water absorbing capacity (for example, sugarbeet pulp), but this will invariably lead to a slight increase to dietary crude fiber levels. In contrast, an absorbing clay can offer similar benefits without much dilution of dietary energy. Finally, certain osmoregulators that cause reversal of excessive water secretion from the gastrointestinal epithelial cells can be used. 

A combination of approaches works better than any single one alone. Fortunately, resolving this problem does not require an expensive intervention, and results are often satisfactory, unless the causative factor is disease, in which case veterinary attention is required.