Okay. This is actually a lovely picture of a probably Buff Orpington Rooster. And as you can see here, unless he's hiding just a lot of feathers under there, this man might be a little bit over conditioned. So it's a good example. So let's jump into some egg production disorders in which we will also talk about calcium needs. 

Okay. So the first thing we're going to talk about is molting. I would like to say here, preface this molting is a natural physiology aspect of birds. It is not a pathology. So doesn't mean we need to be concerned about, but it is something that we can control. It does change egg laying behavior. Most of the things that we see as egg production disorders in the field can be controlled using our knowledge of good management and physiology. And, you know, a lot of these owners might just need education from you, their vet about these different aspects. So molting is something that I see a lot of people panicking with their first flock, you know? Oh, they're losing all their feathers. No one's laying an egg. And you notice around the time of year it's November, December in the northern hemisphere, we're starting to see shorter day lengths. This is a normal behavior. It's called molting. It's a seasonal decrease in egg production. It's healthy. It's natural. Poultry lay eggs in response to lengthening or long daylight. You can go into how that works in the pineal gland, etc.. But the reason they do that is because they want to lay eggs to have chicks. And you want to have chicks in the spring summer when food is most abundant. So in the winter, it's kind of an off switch for reproductive physiology. It allows the bird to sort of reset everything, recoup some of her nutritional balances and regrow some of those feathers that she might have been putting off doing because she's spending all of her energy on laying eggs. In fall, birds will stop laying eggs and may lose and regrow their feathering. You can see a picture of this molting hen. She has various stages of feather regrowth. She's doing a really good job, though. You can see all of these lovely feathers coming in. This blue area, is that folded up feather within the the shaft is just going to start branching out and sort of blooming like a flower at the end. Really lovely. She's doing a really good job. She's going to be very well feathered after this molt. You can mitigate molting behavior, though, in your small backyard clients if they would like to by providing more than 12 hours of light per day. So that might mean that if you bring your birds in before nightfall, which is recommended to decrease predation, you're going to have just the light on a timer in their house that keeps it at about daylength brightness until, you know, 12 hours has hit since the sun came up. Then that's something you might have to just keep adjusting as day length wanes and waxes, but it's something you can definitely do. It's what we do in the commercial industry to make sure we have eggs all year round. 

Alrighty. Egg production is also heavily impacted by nutrition, and I would say that any nutritional deficiency will cause a decrease in lay. This is because this is a very metabolically taxing activity. You're providing everything a new chick needs to grow into an egg as well as its protective coating. It takes up a lot of energy, takes up protein, takes up a lot of micronutrients. So anything that you do to mess up the nutrition will cause a decrease in lay and it's always worth looking at that management aspect. Calcium deficiency is probably the most common nutritional deficiency affecting lay, however. Laying rations have higher levels of calcium and often a vitamin D as well to aid in eggshell formation. You want to make sure you supplement that to these birds with a laying ration because you don't want them just to draw from their own bone reserves. And they will to lay these eggs. If you have a calcium or vitamin D deficiency, if you're not getting enough in your diet and you've just been running through your own body supplies, eventually you're going to reach a level where you're going to start having soft or thin shelled eggs laid. This can also affect coordinated nerve conduction because we know that calcium is very important in nerve conduction, which can lead to an inability to physically lay the egg because it takes a lot of coordinated muscle contractions to actually expel an egg from the cloaca. So what we're going to do here is we're going to ensure the diet is four layers. That means it's going to have more calcium and it's likely going to have more vitamin D, it's going to be balanced for that growth stage. Eggshell deposition, also this is a physiology fact, occurs in the very early morning. So we know that eggs take just about a day, kind of rule of thumb, 24 to 26 hours to produce, is going to occur in the very early morning in the shell gland. So before the sun comes up. Large particle calcium supports this process because she's going to need to mobilize calcium into her bloodstream to actually deposit onto that eggshell before the sun comes up, before she's eating. So she needs to already have it in her body. Large particle calcium will break down over time in their gizzards, or their mechanical stomach, and constantly just be infusing her body of then necessary calcium versus small particle calcium. So things like the little tiny itty bitty crumbles sort of like the dust, like calcium we might use to supplement crickets for our reptile friends, that is going to be absorbed more rapidly, and it's not going to give her that long term effect overnight. So feeding an oyster shell, which is actually sort of limestone or broken up seashells or even sometimes eggshell chunks, can be very helpful for that. Most laying rations will have those. But if you start seeing thinner shelled eggs, you can add a little bit of those top dress over the top until you see a return to normal eggshell quality. This is a photo of an egg with a very thin shell. You can see that he's kind of pinching it and it's like giving a little bit like a jelly egg. This can be a soft or thin shelled egg from a calcium deficiency, but it could also indicate disease. So we need to look at both our nutrition as well as potential diseases when we see this type of issue. More frequently with calcium deficiencies, you'll just see a very thin shelled egg. So you'll go to pick up the eggs in the morning and they'll already have cracks in them. If you're cracking them in your own kitchen, you'll notice they'll just crumble away. You might be able just to pinch it and crack it, which, you know, is not a normal thing for a regular egg. 

Okay, So after you have ruled out your nutritional causes, then you can then go looking for infectious disease causes. Typically, these are viral. Always rule out nutrition first because it's the easier one to tackle and frequently is the culprit here. Infectious bronchitis is a coronavirus of poultry, of chicken specifically. So this is not a turkey issue. This is causing bird, caused by bird to bird transmission and you're going to see clinical signs such as wrinkled eggs like the ones shown in the photo, but you can also see pale shells, you might see respiratory signs, so snicking, sort of sneezing, little cough noises, nasal discharge. You'll see a decrease in production and feed consumption. Decrease in production is probably related to the feed consumption drop. They're not feeling well. They're not eating. And we know that if you don't have enough nutrients, you're not laying eggs as well. For this, you're gonna want to submit choanal swabs for PCR at your local poultry diagnostic laboratory, and they'll be able to direct you to the specific methodology that they are going to use. Again, choanal swabs, you collect them, there's a cleft in the hard palate of poultry, you're just going to gently rub a sterile swab up there and put them into a baggie or into transport on, vial, depending on your labs preference. Another thing that you should be on the lookout for, this is happening in Pennsylvania where I live, which is why I am extra attuned to it now is egg drop syndrome. So this is something that we used to think was sort of a foreign disease to the U.S. but we've seen it now popping up for the past few years. We think it might be around here. It's an adenovirus. It's associated with ducks as well. So if you're having a backyard flock that's mixed with ducks and you start to see very soft eggs, this might be something to look into. You can have an infection that's related to duck content, duck contact directly from other infected birds are also fomites. So if you're walking around on a duck premises and then you come home and use those same shoes to look at your chickens in your own backyard, you might be bringing adenovirus back. Clinical signs here are going to be shell less or extremely thinly shelled eggs. So these are what we call like jelly eggs. They will almost have no shell at all, and it'll just be the membranes.  They're kind of spooky looking. You can also see pale egg shells or very rough egg shells. But I'm really going to encourage you for those to look think more along the lines of nutritional deficiency. If you see jelly eggs, though, go ahead and submit those, specifically shell less eggs, you can send in the whole egg in a bag, and also cloacal swabs for PCR. So go ahead and put that same sterile swab and just gently around the cloaca. You can also submit serology. Serology is useful here because these birds should never have been exposed to egg drop syndrome virus. So even if it's an exposure in the past and you're seeing clinical signs now, it's still something that would be a positive diagnostic for me. One note here, if you are seeing pale brown eggs, if you're having just a brown egg flock and you start seeing pale eggs, also, look for signs of bacterial disease, basically feel those birds. Any type of febrile condition in brown egg layers can reduce the color of a brown egg, in my experience. So be on the lookout for anything that could be causing them. 

Okay, sudden production drops. So it's sort of a very scary thing to see. It's something we all need to be aware of. Sudden drops in egg production without obvious causes can be a sign of serious disease, serious reportable disease. So if you have any doubts, if you're concerned, if you have a flock that's been laying an egg a day for the last however many months, and all of a sudden everyone is looking depressed and there aren't any eggs. Go ahead and call your poultry diagnostic laboratory, your state animal health official. It's better to be safe and overly protected than it is to let something go by if it was actually a reportable disease. But you're also going to want to rule out your management issues. So did you or have something happen that was just very drastic? Did all of their water run out overnight and no one refilled it the next day and they've had two days without water? Did they run out of feed and nobody noticed and they've not been eating feed. Those will cause them to lose ability to lay eggs because they have to start using their own body reserves to stay alive rather than to give you eggs. Did you accidentally induce molting? This happens, and this happens on a commercial scale and can cause a lot of panic if people don't realize why. This can be sudden dark periods. So if your birds are being kept inside because you're in a very cold part of the country during the winter and you haven't been out there in a day or two and everything else is going fine, but your light bulbs went out. You can induce molting that way accidentally. Also, if you have a drop in feed calories, if you bought a bag of feed and it's just terrible, you can induce molting that way. Also, check calcium deficiency. You can screen for diseases, though, and you should at the direction of your poultry diagnostic laboratory and your state animal health officials, especially for regulatory diseases that we'd be concerned about. So avian influenza, Newcastle disease, test for other pathogens, as indicated by clinical signs, as indicated by preference of your state animal health officials and more information about those viral diseases is in those past recorded lectures. I would say here that avian influenza and Newcastle disease are both very reportable. You cannot tell them apart by clinical signs. The clinical signs are absolutely identical, but they will depend on the pathogenicity of the strain. So if you have a mild strain come through, you might just see respiratory signs, decrease in production, feed consumption, just kind of poorly shelled eggs, abnormal eggs. But if you have a virulent disease, you're going to be seeing depression, mortality and that sudden absence of eggs in, well, like typically laying flocks. It's very important that you know about this, even if you're just seeing backyard and small flocks, because we in the U.S. and Canada are in an ongoing issue of periodic highly pathogenic avian influenza outbreaks. In the U.S. In 2022, we had a huge, huge issue with avian influenza. I would say think about 60% of those cases, if you're just looking at the numbers were in small or like noncommercial flocks. So this is something that is getting into these birds and it's getting in because of wild bird contact. So even just, you know, a duck poop from 10,000 feet above your backyard can get in there and cause this disease, which is why it's so great to keep those feed and water sources contained whenever possible. To diagnose these things, we're going to submit choanall swabs for PCR. And if you're looking at waterfowl, you're going to submit a cloacal swab. Then you're going to send serology also to your state laboratory. You cannot diagnose highly pathogenic avian influenza definitively without the National Veterinary Services Laboratory. The USDA actually saying what it is because it is a disease of regulatory importance. 

Salpingitis is also super common and causes egg production issues. This is, I think, probably the most common cause, whatever we would call egg binding in chickens. So when people are saying, Oh, my chicken is egg bound, it sort of just means that they're unable to lay an egg. There's a lot of different reasons for that. They might have an issue that's been causing them to lay internally. They could have, you know, calcium deficiencies. They could have an egg that's too large. But salpingitis can also cause this. The pathophysiology of this is interesting. So as a normal part of the laying process, if you ever watch a chicken lay an egg really up close and personal, the cloaca and the chicken vagina will temporarily avert slightly. So you're going to actually see like pink mucosal tissue actually go out as the egg is expelled and stay out for just a little while. And that's normal because she's resetting all those nerve impulses to bring everything back inside. However, while it's outside, environmental contamination can cause ascending infections via this route. And these are usually enteric bacteria that are present in the lay environment or in the nest box, especially if those chickens have been pooping in their nest boxes. This can be compounded by dirty coop conditions. If you have a lot of stuff going on in there and it's dusty and dirty and you know it. Any pathology, though, that lengthens that time that that tissue is spent outside the body, such as obesity, it can be harder for those birds to actually pull everything back in because there's increased pressure internally from the amount of mass that they have. Or excessive egg size. If your birds are laying really, really large eggs, all of a sudden that can be an issue. Bacterial infection. Once it is up there and it ascends through the oviducts. So we see this nice diagram. It's going to come up through the cloaca. It can actually cause an egg mixture, of caseous bacterial material all through this area that can plug the oviduct shut and it almost looks like a little blob. It's going to be yellow. It's going to sometimes form to the actual confirmation of the oviduct. 

So you can see one here. This is in a pullet. She's pretty young, so that oviduct hasn't actually developed very much yet. This was an experimental bird, but I thought it was a great example. You can see it's just tracking all the way up her oviduct right there. Clinical signs here is going to be that lack of egg production, depression, decreased feed intake. They're going to be feeling dumpy. They don't feel good. Gross lesions on necropsy. If you have the ability to do that, occasionally you can feel a palpably enlarged abdomen if it's been going on for some time and really accumulating material. But more often it's going to be internal only you're going to see that caseous egg material in the oviduct, occasionally causing oviductal rupture and peritonitis. So it actually gets to be too large, it'll just rip through and all of that bacteria can go around and cause infection elsewhere in the celum. Treatment here often unrewarding because we're actually trying to treat an infection that's in a lumen that connects to the exterior space. So we're not going to be able to feed systemic antibiotics in and have it make it necessarily into the lumen of the oviduct. Humane euthanasia is unfortunately often necessary for these girls. So again, it's super important that we keep these coops very clean as much as possible. 

So to control this, we're going to make sure our hens are properly conditioned. So we want to manage obesity. We want to make sure that the ration provides adequate calcium and vitamin D levels so that she is able to conduct those nerve impulses to pull all of her tissues back in in a prompt and timely manner. We make sure our coops are sanitary. This is a picture of a really nice sanitary coop. I actually love a coops that are handcrafted like this with straw in there, because what you can do is you, after you're collecting eggs, you can just reach in and take the straw and put it into your trash and put a new handful of straw in there that is unsoiled and clean. You're also going to muck out regularly, which means if you have a buildup of feces and just dirt and debris and stuff from your birds in that coop, just dig it up, replace it with new litter, get rid of it so it's not in your birds environment. Keep your litter dry to maintain bacterial populations below the necessary threshold for causing other infections and keep those nest boxes visibly clean. If you have nest pads, go ahead and actually wash and sanitize those. Some people have the plastic ones. You can spray those down. Please do make sure that they're clean, they don't clean themselves. And then ensure your hens have adequate space. This will decrease the likelihood that other hens will peck at that adverted tissue and directly inoculate bacteria. But it will also allow them to distribute the bacteria that they naturally produce throughout their area. The more animals you have in contact right up close together, the more issues you will always have with disease. So having adequate space is going to be good for not only animal behavior, but also disease prevention. All righty.