Feeding too much omega-3 fatty acids in layer diets can negatively impact egg production, according to a recent Penn State research study.
The study was conducted using oil from microalgae to supplement layer diets with omega-3 fatty acids. The specific microalgae used contains a high level of docosahexaenoic acid (DHA), which is a very long-chain (VLC) omega-3 polyunsaturated fatty acid (PUFA).
“When feeding the hens heart-healthy omega-3s to enrich their eggs, if the level of supplementation is too high, the birds’ egg production will be severely curtailed and some will stop laying eggs,” stated Robert Elkin, research lead and professor emeritus of avian nutritional biochemistry at the university’s College of Agricultural Sciences.
“That’s because egg yolk is essentially derived from compounds made in the liver and transported to the ovary. Omega-3s are known to inhibit the secretion of these yolk precursors — mainly triglyceride-rich very low-density lipoproteins — from the liver.”
Microalgae oil was selected for the dietary supplement because it is high in DHA, which has been proven to positively impact cardiovascular disease, cancer risk, eye health and cognitive function in older, healthy adults.
The research
In the recently published study, 56 white leghorn hens were fed various dietary treatments of the microalgae oil supplement for 28 days. Over half of the birds receiving the highest level of supplementation, 40 grams of oil/ kilogram of feed, stopped laying eggs or had significantly reduced yolk weights.
The highest microalgae supplementation resulted in an average of 266 milligrams of VLC omega-3 PUFAs per egg. According to the Dietary Guidelines for Americans 2015-2020, this is more than half of the daily recommendation for healthy adults.
The research team recommends a dietary inclusion of the microalgae not exceeding 20 g/kg, or 2% of the diet, to allow for fatty acid egg yolk enrichment without affecting layer performance.
Additionally, the research team observed that hens co-fed an oil rich in oleic acid, combined with the high level of microalgae, had the negative effects reversed. According to Elkin, the oleic acid-based oil is not commercially feasible due to its cost but is important for understanding fatty acid nutrition and metabolism in layer hens.
