Thanks a lot, this sounds really interesting. Do you have any sense, why producers are not already fortifying feed with at least some of the nutrients? If deficiencies contribute significantly to the mortality of the hen, wouldn’t it be in their self-interest to do so?
Hi Tobias, thanks for your questions! My sense is that the producers are fortifying the feed a little bit, but to maximize production rather than for better welfare. What is optimal for those two goals diverges. A couple of reasons for that:
Feed cost is the largest single item in poultry production and accounts for 60 to 75% of the total production cost. So producers fortify the minimum amount possible that will still make the calculation of cost and benefits positive for them to make a profit, but not necessarily what would make a hen more healthy and happy.
There is also sometimes a lack of knowledge about optimal feeding, because producers only learn about something if a feed company has an incentive to market it. Since there’s no money to be made in e.g. changing calcium timing / particle size, that knowledge doesn’t get passed from the scientific literature to producers.
What is optimal for profit doesn’t equal what is optimal for welfare, and we see a difference in current nutrients and what we found to be optimal. More specifically, we looked at optimal for welfare vs current fortification of calcium, phosphorus, and vitamin D3 standards of the top five egg-producing countries. This table shows the difference between their nutrient standards and the optimum nutrient levels (all sources can be found in Supplement B of our full report, section 2.2.):
Perhaps more important than the mortality is that bone fractures are a leading source of chronic pain for hens, and keel bone fractures aren’t visible to the naked eye. Producers probably fortify their feed enough to keep a sufficient number of the hens alive (again to maximize profit, because some mortality rate is just assumed to always happen and is written into the cost-benefits of production). Mortality may be low enough that the costs of them dying vs the expense of feed isn’t worth it.