In the previous articles were mentioned different methods to measure the internal quality of the egg as is the case of Haugh Units. However, it is also extremely important to know the factors that result in low Haugh Units values.

The factors can be pre-set or post-set, the former being a result or reflection of the state of the hen (age, management, diet and diseases).

– Age: Haugh Units are reduced with the age of hens, and this is independent of the time of year.

– Handling: Light programs with increased cycle length decrease the height of the albumen, resulting in lower UH values. However, the performance of a forced molt is a favorable factor for the improvement of albumen quality. This is due to the involution and subsequent regeneration of the magnum that involves forced molting. Renewed tissue is more efficient in the production of albumen.

– Diseases:

One of the major diseases that can affect egg quality is Infectious Bronchitis, affecting both the shell and the albumen. This is due to the destruction of the magnaum cells. This problem is persistent so a good vaccination program should be done along with the use of immunostimulants.

– Feeding: Different authors have pointed out that Haugh Units may vary according to protein sources. It has been observed that the incorporation of beans and the use of meat meal may increase the values ������and the use of sunflower or rapeseed can have a negative effect on the quality of the albumen. The incorporation of more lysine in the diet may also favor the results.

It is also important to note that contamination by metals such as vanadium (10 ppm) or excess magnesium can modify the consistency of the albumen. However, it has been observed that the use of ascorbic acid could counteract the effects of vanadium contamination.

As for the protein concentration of the feed Cava and Hamilton (1982), they observed that a reduction of the protein rations of 15.6%, 14.8% and 14.0% respectively increased the values ������of the Haugh Units in Leghorn birds. The opposite effect was observed with increasing protein inclusion in the rations. A reduction of the same has a positive effect on the consistency of the albumen, as it increases Haugh Units, while the opposite effect is observed with increasing the level of inclusion of protein in the diet.