Steven George wrote:
Do chickens really eat snakes?
Mike Jay wrote:I've read about 10 chicken books this winter getting ready for our first batch. Some of them suggested not feeding them fish, garlic or onions since it could pass flavors on to the eggs. Suckers may be a bland enough fish that it doesn't impart much flavor though? I believe they do need greens and grains as well as protein in their diet.
Nicole Alderman wrote:Here's what I understand so far. The fishy taste and smell comes from trimethylamine, which is caused by the oxidization of choline. When a fish rots--and it's choline oxidizes--the lovely rotten fish smell of trimethylamine comes about. Foods that contain high amounts of Omega 3 fatty acids--such as oils and meals derived from fish, linseed, camelina, and rapeseed--also have choline. And, when a bird digests that choline via bacterial fermentation in their guts, trimethylamine is created. Many (most?) poultry can convert the trimethylamine in their livers into a nonodorous form. Others, such as 5-10% chickens that lay brown eggs, and supposedly my ducks as well, cannot convert the trimethylamine in their livers. So, that delightful off flavor is passed onto my duck eggs (and meat as well). In the case of the chickens (couldn't find anything about ducks), there is actually a gene responsible for their ability/inability to transform the trimethylamine, and you can actually get your chicken tested to see if it has the desirable gene or not. You can also, supposedly, smell their breath. Those with fishy breath cannot do the transformation.
There's also things that can make it more difficult for poultry's livers to process the trimethylamine. The tannins in rapeseed and linseed interfere with the liver's ability to transform it to it's nonodorous form. Wheat, barley and leguminous plants help the gut ferment more choline into trimethylamine.
ASIDE from the trimethylamine issue, the fishy-flavor can be caused simply by polyunsaturated acids (such as linseed and fish oil).
Here's the sources I used for wrapping my brain around this: Wikipedia on Trimethylamine, Omega 3 Fatty Acid Research, pages232&233, ISA Genetics, "'Fishy' Taint in Brown Eggs ", and Do Your Eggs Taste Fishy, Curse of the Omegas