Study tests former food products in layer diets without egg quality drop
Bottom line
A new study in Animals tested whether “former food products,” or FFPs, can be used in layer diets without hurting egg quality. Researchers fed 180 Lohmann Brown hens either a control diet or diets containing 20% or 40% FFPs, then evaluated eggs collected at 31 to 33 weeks of age for physical, chemical, and sensory traits. The study found most core egg quality measures, including egg weight, shape index, yolk and albumen weight, and edible portion, were comparable across groups, suggesting these recycled food-derived ingredients may be incorporated at meaningful levels without obvious quality penalties. The work adds to a growing body of literature positioning FFPs as a circular-economy feed ingredient that can reduce competition with human-edible cereals. (mdpi.com)
Why it matters: For veterinary professionals and poultry advisers, the findings support cautious interest in FFPs as a sustainability tool, but they don’t remove the need for tight formulation and quality control. Recent reviews note that FFP-rich diets can be limiting in key amino acids such as lysine, threonine, and methionine, and industry guidance on bakery by-products warns that variable composition, sugar load, fat quality, and storage stability can affect gut health, performance, and consistency if inclusion rates aren’t managed carefully. In other words, the concept looks promising, but success still depends on nutrient balancing, ingredient monitoring, and flock-level oversight. (tandfonline.com)
What to watch: Expect follow-up work on longer-term laying performance, nutrient variability, economics, and whether higher FFP inclusion rates hold up under commercial conditions. (tandfonline.com)
A study published in Animals adds fresh evidence that former food products, or FFPs, may be able to replace a meaningful share of conventional feed ingredients in layer diets without clearly compromising egg quality or sensory properties. In the trial, 180 Lohmann Brown hens were assigned to a control diet or diets with 20% and 40% FFP inclusion, and eggs collected between 31 and 33 weeks of age were assessed for quality traits. Based on the journal summary, the main physical egg measures remained broadly comparable among groups. (mdpi.com)
The study lands amid broader pressure on poultry systems to cut feed-related environmental impact. FFPs, which can include processed surplus foods and bakery-derived materials no longer intended for human consumption, have drawn attention because they can redirect food-chain leftovers into animal agriculture rather than waste streams. A recent minireview said interest in these ingredients is being driven by circular-economy goals and the need to reduce competition with human food resources, while also noting that more species-specific validation is still needed, especially around product quality, sensory outcomes, welfare, and sustainability claims. (pmc.ncbi.nlm.nih.gov)
That context matters because enthusiasm for alternative ingredients has often outpaced the evidence. The Animals paper is useful precisely because it focuses on the downstream product, not just bird performance. Egg quality and sensory acceptance are commercially important endpoints, and prior literature has repeatedly shown that hen diet can alter yolk color, flavor perception, texture, and consumer acceptance, depending on the ingredient and inclusion level. Reviews of sensory work in eggs have found that some alternative inputs have little practical effect, while others can shift color or off-flavor intensity enough to matter in the market. (pmc.ncbi.nlm.nih.gov)
Still, the bigger question for field use is consistency. A 2026 review on FFPs in poultry diets reported that these ingredients can partially replace conventional cereals without compromising performance, product quality, or welfare, provided diets are reformulated for amino acid balance, micronutrients, and energy density. That same review highlighted a recurring limitation: FFP-rich diets are often short in lysine, threonine, and methionine unless corrected. Separately, Hendrix Genetics’ technical review of bakery by-products in laying hens pointed to practical concerns around high sugar load, variable nutrient composition, oxidative rancidity, fine particle size, and possible gut microbial disruption when products are not well characterized. (tandfonline.com)
Expert reaction specific to this paper was limited in open sources, but the broader industry tone is cautiously supportive. The poultry nutrition literature increasingly frames former food products as a promising sustainability lever, while stressing that “promising” is not the same as plug-and-play. The minireview of recent findings called for more multidisciplinary in vivo work in laying hens at different inclusion levels and emphasized the need to understand consumer perception of animal products derived from these feeding strategies. (pmc.ncbi.nlm.nih.gov)
Why it matters: For veterinarians working with commercial poultry operations, this study is another signal that alternative feed streams are moving from concept to practical consideration. If egg quality and sensory properties can be maintained, FFPs could help producers manage feed costs, improve sustainability metrics, and diversify ingredient sourcing. But veterinary and technical teams will still need to watch the fundamentals: nutrient specifications, ingredient variability between suppliers and batches, storage quality, microbial risk, body condition, gut health, and shell and egg quality over time. The clinical and production question isn’t just whether hens can eat these diets, but whether flocks can stay stable on them across a full cycle. (mdpi.com)
There’s also a communication angle. As pet parents and food consumers pay closer attention to sustainability, egg-sector stakeholders may see more interest in circular feed ingredients. That makes evidence on product quality especially valuable, because acceptance will likely depend on whether sustainability gains can be demonstrated without creating concerns about taste, consistency, or food quality. The literature suggests that’s achievable, but only with careful formulation and monitoring. (pmc.ncbi.nlm.nih.gov)
What to watch: The next step is validation under commercial conditions, including longer-duration studies, standardized definitions of FFP composition, economic comparisons with conventional feedstuffs, and more detailed reporting on sensory and nutritional outcomes at higher inclusion levels. (tandfonline.com)
Common questions
Can former food products be used in layer diets without hurting egg quality?
In this study, hens fed diets with 20% or 40% former food products had egg quality measures that were broadly comparable to the control group, including egg weight, shape index, yolk and albumen weight, and edible portion.How many hens were studied, and what kind were they?
The trial used 180 Lohmann Brown hens.What egg traits did the researchers evaluate?
They assessed eggs collected at 31 to 33 weeks of age for physical, chemical, and sensory traits.What is the main caution about using former food products in poultry diets?
The article says these diets still need tight formulation and quality control, because FFP-rich diets can be limiting in amino acids such as lysine, threonine, and methionine, and ingredient composition can vary.