Why no washing/disinfecting eggs?

[BlacksheepCardigans]

I've spent about a week reading everything I can on bacterial infections and egg hatching. I got interested because it seems like everybody just says "Oh well, blood ring," or "Oh well, didn't pip," and that's that. It seemed to me that it shouldn't be OK for lots of chicks to be dying due to bacterial stuff.

What I find is interesting - every piece of research says that the whole "eggs are perfect inside as long as you leave the bloom on" idea is completely false. Eggs are immediately vulnerable to bacteria and they are full of salmonella and e. coli inside the egg within minutes of exposure.

And - EVERYTHING I find says that you're supposed to disinfect the eggs. Every study examining hatchability says disinfecting the shells improves hatch rate.

In the commercial and university hatcheries, they won't even attempt to hatch anything visibly dirtied or smeared. They will only accept visually perfect eggs. And they're STILL disinfecting every single one, and consider it vital to getting a good hatch.

I have to say, this has 1) made me really wary of any egg with smears on it, 2) made me determined to change nest box materials very frequently, and 3) made me wonder why in the world we're not dipping/spraying/washing hatching eggs as a matter of course.

Any thoughts?

 

[SarahIrl]

Ooooooooooh, I am trying to be very 'on the fence' here but washing with hot water would be my least favourite practice, you can damage the membranes doing that. They heat and thicken, making air exchange through the shell very difficult. This is essential for a healthy chick to grow. I patched an egg this year (see pic below) as it had a cracked shell but intact membranes, and it is now the lovely big baby roo pictured under it. Nobody expected it to work. I used candle wax and though as nealry 50% of the shell was covered, it would suffocate. I scraped off as much as I could when locking down at day 18 and it was fine, none te worse for wear. Good to know candle wax isn't toxic to chicks!!

and candled

brahma roo

 

[BlacksheepCardigans]

We keep them unnaturally, though. I think we keep them ethically, but certainly not in the way that their bodies and eggs evolved to live. In the wild the egg would not be anywhere near someone else's poop, nor would the hen poop near them herself. She wouldn't have soiled feet, either. She'd choose a nest location that was not shared, far from any established travel corridors, and they'd be as untouched by bacteria as it's possible to get in the real world. In a coop, even a really big/nice coop, they're exposed to bacteria at a concentration that they'd never be in the wild. So you can't really use the "the hen wouldn't" argument, because once you're keeping them out of the wild the hen is doing about a thousand things she wouldn't.

 

[CallyB57]

Oh my...heavens to mergatroid! This might sound like it has nothing to do with washing or not washing eggs, but here is the deal.
All my life I have heard scientists and experts spout of statistics, only to turn around a year later and say - well....new research shows blah blah blah, which of course if in direct contradiction to what they were declaring the previous year. Not too many years ago the perfect and nutritious egg was touted as a cholesterol-filled heart clogger. Now it is okay to eat an egg a day - heart okay.

Take Vitamin E - no don't take it.

C prevents colds - there is no evidence that C prevents colds.

Hormones are great for women and prevent osteoporosis and mustaches - OH MY - stop taking hormones as there is a link between hormones and breast cancer.

I'll say it again - heavens to mergatroid.

Either wash your eggs or don't wash them. I don't wash mine and a couple have fonky looking smudges on them, but one of the ones with a fonky looking smudge looks like it is rocking back and forth and I heard tap tap tapping from it. Also, I have free ranging banty hens and one of them dug a hole in the ground next to a fence that was slightly damp and had bits of pine straw in it. The eggs were absolutely filthy and they all hatched and followed the hen around everywhere. Hawks got some of them - now I have one little hen and 3 roosters left but they are healthy and feisty and quite beautiful.

The point is, no matter what anybody else says, including the experts, nothing is certain, absolutely NOTHING. (if you don't include taxes and death)

 

[PunkinPeep]

Quote:
This is a good point. It is also kind of why i don't necessarily apply hatchery methods to my own methods. Just the same way that my birds/eggs are exposed to more bad bacteria than a wandering flock in the woods/jungle - my back yard chickens in their little house, with a big yard and clean nest boxes, are not exposed to the same (or i imagine, even comparable) levels of bad bacteria and variables and possibilities for contamination that are expected/protected against in big hatchery operations.

The big chicken meat producing operations also clean the meat in bleach water because the FDA can't think of a better way to combat the horrifying unsanitary conditions in which the birds are processed. That doesn't mean that i'm going to do that at my house. I'm going to process my meat birds under clean conditions, so i don't have to bleach my meat before i can safely eat it.

My point is that the big operations are dealing with staggering variables, and while i can learn from their research, their methods aren't necessarily for me. Especially considering that many of us produce in our back yards because we don't like the methods used by the big operations.

In my very small home operation, i'm averaging about 92% hatch rates. Fifty percent is definitely not o.k. with me. I don't put filthy eggs in the 'bator, and i don't sanitize the eggs. A certain amount of good and bad bacteria helps to make our chickens stronger and more resistant to disease. I really think this starts in the egg. If one egg doesn't hatch because there was poop in the vicinity, i think i just made my flock stronger, not weaker.

As to the discussion about research studies giving results that are often reversed......
while i think that it pays to pay attention to research, i think we have to consider that the researchers are often looking at only one variable and often don't pay attention to a lot of other factors that would be common sense to most of us. There is value in "what works for me," because if the researchers say that "eggs are bad for you; they cause high blood pressure and high cholesterol," and i watch my father eat two fried eggs a day for the length of my life, and i find out that he has abnormally low blood pressure and low cholesterol, i can conclude that the researchers might not have considered all the variables. And i can do this without being a scientist or finding out what they missed, and i can still be correct. Because i saw that "what works for me" fully defied "the research."

 

[BlacksheepCardigans]

Quote:
Sure - before I post the studies, let me say that my signature refers to the fact that before this summer I hadn't had poultry for about eight years. Before that I had birds ranging from cockatiels to cayugas every year of my life since I was two. I grew up across the road from a prominent pheasant and waterfowl fancier, figured that everybody had black-necked swans in their backyard. I've personally raised and bred chickens (LF and bantam), ducks (runner and cayuga), geese (Pilgrim and African), guineas, house birds of all types, etc. I don't show poultry, because I have no way to quarantine, but I have shown rabbits, Saanens, horses, and now dogs. I have a biology degree and was the teaching assistant who ran the embryology lab (based on chicken eggs and embryos). 90% of a theology master's, too, though that's not necessarily apropos to the discussion

. So no, I'm not new to this.

Here are the studies:

http://edis.ifas.ufl.edu/ps018 is a very good overview of the reasons for disinfecting
http://www.ncbi.nlm.nih.gov/pubmed/1906612 - using hydrogen peroxide; note that dead embryos were significantly reduced when compared to unwashed eggs
http://www.ncbi.nlm.nih.gov/pubmed/2356172 - using quat; again notice that hatchability is improved over untreated
http://www.ncbi.nlm.nih.gov/pubmed/2196048 - the fact that even touching dry litter contaminated with salmonella contaminates the egg in 60% of UNWASHED eggs; if the eggs have moist contamination (as in touching feces), the rate is 100%
http://www.jstor.org/pss/1592082 - chicks hatching from eggs with salmonella quickly infect the other chicks in the same brooder
http://japr.fass.org/cgi/content/abstract/8/4/499 - bacteria easily penetrate egg shells - note "the natural defenses of the egg are generally not adequate" http://japr.fass.org/cgi/reprint/8/4/499.pdf is the full-text PDF of the same article, and is critical to read through; note that by the time the egg has dried in the nest, whatever it was sitting in has been drawn through the pores already.
http://japr.fass.org/cgi/reprint/3/3/234.pdf - e. coli on hatching eggs; disinfection will improve hatchability
There's a great study by Sparks (1985) called "Bacterial penetration of the recently oviposited shell of hens' eggs" showing that the riskiest time was right after the egg was laid, while it was cooling

And before anybody says that backyard flocks don't have to worry about salmonella, yes they do. Salmonella is everywhere - got chickens? You've got a very high chance of having salmonella bacteria out there. http://www.jstor.org/pss/1592033 is a study that isn't easily available in full-text, but they tested a bunch of flocks and found that 100% of their positive s. pullorum results came from backyard flocks. The commercial flocks also had salmonella, of course, but the backyard birds were far from sterile.

I have, seriously, about a hundred more, but the above are some of the most useful and direct.

 

[Klukkin Ken]

Take this with a grain of salt as I have never hatched any eggs and I am not wanting to sound bad by saying this, but that seems a little ridiculous to me. How would a hen disinfect her own eggs when she sits on them naturally? I'm sure the hen has plenty of bacteria on her feathers.

 

[blefky]

Just brainstorming here, as I'm relatively new, but as with any research, I would want to know who conducted it, how it was conducted, etc. Any research is only as good as the researcher's methods. If the bloom passed to chicken eggs was not, at the very least, somewhat capable of protecting the egg's contents would wild fowl not have died out? And, as a matter of course, nestboxes should be kept clean - that's just good maintenance. It doesn't surprise me that any information coming from commercial operations are in favor of disinfecting eggs as, from my own bits of research, their operations seem largely filthy and therefore the high levels of bacteria might be more of an issue than for a relatively "clean" backyard set up. Again, just thinking out loud, but I also wonder if, given the use of prophylactic antibiotics, many commercial operations aren't now dealing with resistant strains of bacteria. That's a whole different ball game.
One last thought, the reason I'm not in favor of dipping or disinfecting eggs is that avoiding that nastiness is one of the main reasons I began keeping laying hens in the first place. I think that you will find many, many people on BYC who have good hatch rates without disinfecting.

 

[blefky]

I'll be interested to read what the more experienced have to offer.

 

[SarahIrl]

I wouldn't put liquid on an egg to clean it as the surface is porous and it will get inside the egg. Hence the idea that washing them is bad as it draws in the liquid used to wash them and also any surface waterbourne bacteria. If you boil an egg in food dyed water, the surface of the white will also be coloured. So, I simply brush off the worst bits of mud/muck/straw from bedding ( remember this happens in clean beds too as eggs are wet when first laid and will get bits stuck to them naturally) and for the more stubborn bits take a soft nail board and work off the rest. Any dried dust/muck that won't come off by hand/dry cloth/nail board, stays on. I have had spotless eggs get blood rings/stop developing/not hatch and filthy dirty smudged ones hatch out perfect chicks. However, I do not wash them or allow ANY liquids on my eggs for hatching, and if I order eggs request tehy are not wet in any way. Works ok for me - average 75-80% hatch rate, including shipped eggs.