I think diet has a big impact. Just from observation, the eggs from my friends free-roaming, spoiled pet chickens are different from regular store bought eggs. The shells are thicker and the yolks are a much darker orange color. Closest grocery brand I can find are Nellie’s. Would love to see if anyone found a study.
It is a combination of natural levels + diet.
“Compared to eggs of the caged hens, pastured hens’ eggs had twice as much vitamin E and long-chain omega-3 fats, 2.5-fold more total omega-3 fatty acids, and less than half the ratio of omega-6:omega-3 fatty acids (P<0.0001).”
I loved getting duck eggs from my local farm. So much that it’s a goal for me personally. Their diet absolutely impacts every part of their ovum. It also affects their offsprings development should the eggs be fertilized. I’d scour the web to see if there were any nutrient profile studies done. I also believe method of slaughter affects cortisol building up in the tissues of the animal
Well to comment about wild boar vs domesticated piggy. Wild boars also literally have to run all day and scour for food, food sources do vary for the boar but its lifestyle is also extremely different than his domesticated cousin wilbur.
In part the feed matters greatly. But unlike ruminate animals who have bacteria & digestion system capable of converting to saturated fat, mono gastric animals do not. So poultry & pork, the feed matters.
the fats in chicken and pork are a reflection of the fats in their diets (coming from soy, corn, etc). For ruminants this isn’t true as the bacteria in their guts coverts those plant fats to more saturated fats that are preferred by mammals. If you raise chickens at home and can include some saturated fats in their diet then the fat in their meats will reflect that