As we continue to push layer genetics for lower body weight (to save on feed maintenance costs), large and more eggs in a single cycle, we should not forget that we also need to refine layer nutrition beyond additives.
Eggshell quality remains a problem, if not a bigger one, with modern genetics. Here, the role of macro minerals is paramount. However, traditional nutrition for these animals has focused only on calcium metabolism, but even here we need to update our thinking. The only problem that I foresee in pursuing such research endeavors is the lack of funding as the sources for most macro-minerals are inexpensive and bring about very low margins. However, this is of no interest to the layer, and it is something that I would urge egg producers to consider funding through their organizations.
For example, do we know the digestibility of even calcium among raw materials? The same goes for the several sources of calcium such as mono- and dicalcium phosphate. We know much about phosphorus digestibility/availability, but this is thanks to the advent of commercial phytase. The same cannot be said for potassium. But, as some nutritionists continue to lower inclusion levels of soybean meal, total potassium in the final diet is frequently lowered as well. And although the old and outdated NRC gives very low figures for potassium requirements, this may no longer be the case – at least in my experience in the field.
I base this not only on my own work, but on research reports about magnesium that has been shown to improve eggshell quality at levels much higher than those reported in the NRC back in the 1990s. And to take things even further, in areas reporting higher temperatures (heat stress) due to climate change, the interplay between chloride and sodium needs to be re-evaluated as the length of heat stress periods appears to increase with each passing year.
