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The beak's outer shell is made of hexagonal keratin tiles cemented together with an organic glue and piled in several staggered layers. Retrieved 21 May It is often absent in fast swimming fishes such as the tuna and mackerel families. The VeganZyme label indicates the activity per serving for ease of use. There are two different skeletal types: Functional morphology of raptor hindlimbs: I do know that kibble and raw digest at different rate.
Thank you for your time! Did the lab culture the pathogen? Did they give a possible cause? Personally, I think it is alway best to feed an animal food they are designed to eat. Doing this usually solves a host of problems. Thank you for your reply! I am going to take your recipe to my vet and talk to her about switching the diet…I agree that providing a more natural what she is designed to eat has got to be healthier than pumping her full of medicine and prescription food!
Sounds like a good idea but brace yourself for negative feedback. Many veterinarians are against homemade dog foods and have very little training in nutrition.
Ed, I definitely agree with your comment about vets and homemade food! But in all fairness to vets at least mine, whom I love they are NOT typically trained in nutrition and food. They also are a bit eager in my experience to prescribe antibiotics without knowing the underlying cause.
But I also find this to be true of human physicians as well. Feeding and caring for dogs for me is as important as feeding and caring for a child. My dogs ARE my children. And that includes their treats as well. The pet food industry is a huge money making machine, and unfortunately, we Americans are led astray by their advertising, their lack of information of contents and origin, and the lack of regulation of food processing.
I am stepping down. But I hope more dog owners will find your site and heed your comments. It is up to US the owners and care takers to get the best for our dogs. My best friend is a 13 year old female Rottie. When she does throw up, It comes up with very little effort or distress. Sometimes its undigested food, sometimes its white stuff…. Everything else about her seems fine. Gums are red, eyes are fine, personality is normal. She was, for a few weeks feed bread, by neighbor who was dog sitting…He meant no harm…but…bread is bad for dogs digestive systems, yes?
Hi Grace, I came in search of a possible solution to help my pup gain some weight and stumbled upon your question. The symptoms of your gal match the symptoms of the condition that my 10 month old pup is afflicted with. Another form of it is neurological. The nerves that tell the muscles of the esophagus to move food down cease to do so. I have to liquify my pups food and feed him on stairs so that gravity can help get his food into his stomach, but otherwise he leads a very normal life.
I started feeding her boiled chicken and rice and my once very fussy eater gobbled it up. Blood is gone, stools are becoming more solid. I want to try one of your diets — not sure if it should be raw or cooked; I want to stick to chicken at least at first because of the colitis.
Also, what about switching between chicken and beef — can you do that, or do you have to do the 24 hour fast? Switching between homemade dog food recipes does not require a fast. I just posted a chicken and rice dog food recipe that may work for you. Any other advice to make her more healthy and have more normal stools would be appreciated. Linda PS Sadie says thanks for the delicious recipe — no more fussy eating!
I feed him a liquid diet in an upright position 4 times per day and he gets LOTS of exercise. Thank you very much for your time and possible advice.
You may want to try the chicken and rice dog food recipe. Pass this through a blender and it should be ok. Dogs metabolize fat well. High carbohydrate content in kibble seem to be more responsible for weight gain. I have just start my research about raw foods. I have a 5 year old Great Pyrenees who is having difficulties having bowel movements. I have taken him to the vet multiple times and after many enemas and laxatives he seemed fine. However, they have told us to start putting metamucil on his food regularly as he would not eat the high fiber diet we started putting him on.
This worked for a couple of weeks, now he is back to the way he was backed up and we have to give him more laxatives. Someone mentioned to me that raw food may help with his digestion. Poor boy is in pain. Is the raw food diet good for this sort of thing? Thanks for your time. Have you ever tried probiotics to help his digestive tract? Yes, I started giving it to him when he started having problems. He is still having difficulties. I have been reading more about the raw food diet and I am becoming more nervous about it.
I read how if your not balancing the meals appropriately then you can cause more problems. Its so hard to tell what is legit. I will keep researching before I switch over. If I find anything I will also update you. If you are nervous about feeding raw dog food then just feed him cooked. Try feeding the chicken and rice dog food recipe or the easy cooked dog food recipe.
Your dog will love either and both are very nutritious. This is my first time on your website and I love that easy recipe with the eggshell and all! Now I put the used eggshell in my stale bread, cracker mix for the birds as they need it for digestion but I never thught you could do that for dogs.
Thanks for letting other animal lovers know about the positive benefits of a natural food diet for our beloved pets. I mean really, if the commercial dog food is all that great and healthy then why does it say NOT fit for human consumption? Hmmm, now I have an issue with that! Treat our furry critters as we want to be treated also! Thank you so much and my 3 APBT just love their natural food fare!
They whine like your 2 didin the video but they are so healthy and happy and just full of energy. Yes they love fish especially salmon. What a life they have! God Bless you and yours. I have an 8 month old Cavachon. She started having diarrhea here and there about 6 weeks ago. We had her poop tested at the vet but no parasites. She had been eating Diamond Puppy. We switched to chicken and rice and diarrhea got better. Interesting note, on chicken and rice, she no longer ate her poop.
Whenever we tried to put her back on Diamond Puppy, diarrhea would come back. So, back to chicken and rice. During that time, she ate part of a yard ornament and was given meds to make her vomit. After that, she had diarrhea even staying on chicken and rice. The vet gave her antidiarrheal meds for 10 days and it finally went away.
Meanwhile, she was still on only chicken and rice. After several days with nodiarrhea, I tried to give her a little Diamond Puppy again mixed in with chicken and rice and it started to come back again. I came across your cooked dog food recipe.
I ordered Dinovite and Licochops. Before making the full recipe, I gave her a little Dinovite in her chicken and rice for the past 3 days. The remaining tissue consists of endocrine cells called islets of Langerhans. These clusters of cells look like grapes and produce hormones that regulate blood sugar and regulate pancreatic secretions. A healthy pancreas produces the correct chemicals in the proper quantities, at the right times, to digest the foods we eat. The pancreas contains exocrine glands that produce enzymes important to digestion.
These enzymes include trypsin and chymotrypsin to digest proteins; amylase for the digestion of carbohydrates; and lipase to break down fats.
When food enters the stomach, these pancreatic juices are released into a system of ducts that culminate in the main pancreatic duct. The pancreatic duct joins the common bile duct to form the ampulla of Vater which is located at the first portion of the small intestine, called the duodenum. The common bile duct originates in the liver and the gallbladder and produces another important digestive juice called bile.
The pancreatic juices and bile that are released into the duodenum, help the body to digest fats, carbohydrates, and proteins. The endocrine component of the pancreas consists of islet cells islets of Langerhans that create and release important hormones directly into the bloodstream. Two of the main pancreatic hormones are insulin , which acts to lower blood sugar, and glucagon , which acts to raise blood sugar. Maintaining proper blood sugar levels is crucial to the functioning of key organs including the brain, liver, and kidneys.
Each disorder may exhibit different symptoms and requires different treatments. So far there is no evidence that defensive behavior in terrestrial prey species takes advantage of the above escape directions to lower rates of predator success.
However, birds seem to adjust their defensive tactics in the vertical domain by taking-off at a steep angle, thus moving diagonally toward the direction of an approaching aerial predator. These preliminary findings warrant further studies in Barn Owls and other predators, in both field and laboratory settings, to uncover fine predator head movements during hunting, the corresponding defensive behavior of the prey, and the adaptive significance of these behaviors. Barred Owl primary - leading edge below and trailing edge above.
The silent flight of owls -- Noise is generated by vortices produced when air flows over a bird's wing and larger vortices produce more noise. Wings with small saw-toothed projections vortex generators , like those on the leading edge of owl wings, generate many small vortices instead of large vortices and produces less aerodynamic noise.
In addition, the fringe feathers at the trailing edge of the wing with fewer hooklets at the ends of the barbs help to break up the sound waves that are generated as air flows over the top of their wings and forms downstream wakes, and the soft down feathers located elsewhere on the wings and legs of owls absorb the remaining sound frequencies above 2, hertz and make owls completely silent to their prey. As a bonus, with high angles of attack and at slow speeds, vortex generators stick out of the stagnant air near the surface of the wing, and into the freely moving air outside the boundary layer.
This surface layer is typically quite thin, but dramatically reduces speed of the airflow towards the rear of the wing. The vortex generators mix the free stream with the stagnant air to get it moving again, providing considerably more airflow at the rear of the wing and helping to prevent stalling.
This process is referred to as 're-energizing the boundary layer. Unpredictable predators -- The use of space by predators in relation to their prey is a poorly understood aspect of predator-prey interactions. Classic theory suggests that predators should focus their efforts on areas of abundant prey, that is, prey hotspots, whereas game-theoretical models of predator and prey movement suggest that the distribution of predators should match that of their prey's resources.
If, however, prey are spatially anchored to one location and these prey have particularly strong antipredator responses that make them difficult to capture with frequent attacks, then predators may be forced to adopt alternative movement strategies to hunt behaviorally responsive prey.
Roth and Lima examined the movement patterns of bird-eating Sharp-shinned Hawks Accipiter striatus in an attempt to shed light on hotspot use by predators. Their results suggest that these hawks do not focus on prey hotspots such as bird feeders but instead maintain much spatial and temporal unpredictability in their movements.
Hawks seldom revisited the same area, and the few frequently used areas were revisited in a manner consistent with unpredictable returns, giving prey little additional information about risk. But why wouldn't Sharp-shinned Hawks focus their hunting on the areas with the most potential prey bird feeders?
One possibility is that behaviorally responsive prey diminish the "hotspot" quality of feeders. Although feeder hotspots are sources of abundant prey, the individuals at such feeders generally benefit from group vigilance as a result of these higher densities. As a result, the vulnerability of the prey may actually be lower at feeders than at other locations.
In addition, unpredictable movement may reflect a sort of "prey management" by predators, whereby predators spread their hunting activity over multiple areas in an effort to avoid inflating the antipredator behavior of their prey. This hunting strategy may be effective when prey are anchored to high-resource areas such as feeders and use antipredator behaviors, such as high vigilance, that reduce a predator's attack success if it attacks frequently and predictably.
Seabirds are choking on ocean plastic video. The tongues of cormorants and other fish-eating species are small because these species swallow prey whole and tongues are not needed to manipulate or position food in the oral cavity. Dorsal view of the surface of the lower bill of a Great Cormorant Phalacrocorax carbo. Arrow shows the tongue with sharpened tip. Scale bar, 12 mm. Lateral view of the cormorant tongue. The tongue and the small anterior and posterior areas of the mucosa of the bill are covered by white keratinized epithelium.
Black arrow shows short base of the tongue. White arrow shows the median crest on the dorsal surface of the tongue. A, anterior; B, posterior. Scale bar, 3 mm Source: Detailed view of the horny tip left of the Guadeloupe Woodpecker tongue in vivo position Villard and Cuisin Dorsal view of the tongue of the Spotted Nutcracker Nucifraga caryocatactes. Arrows show two elongated processes of the apex. A, apex, B, body, R, root, LP, laryngeal prominence.
Scale bar, 3 mm. Lateral view of the tongue of the nutcracker. Arrow shows elongated processes, pointed diagonally, B, body, R, root. Hummingbird tongues are fluid traps, not capillary tubes -- Hummingbird tongues pick up a liquid, calorie-dense food that cannot be grasped, a physical challenge that has long inspired the study of nectar-transport mechanics.
Existing biophysical models predict optimal hummingbird foraging on the basis of equations that assume that fluid rises through the tongue in the same way as through capillary tubes. Rico-Guevara and Rubega found that hummingbird tongues do not function like a pair of tiny, static tubes drawing up floral nectar via capillary action. Instead, the tongue tip is a dynamic liquid-trapping device that dynamically traps nectar by rapidly changing their shape during feeding.
In addition, the tongue—fluid interactions are identical in both living and dead birds, demonstrating that this mechanism is a function of the tongue structure itself, and therefore highly efficient because no energy expenditure by the bird is required to drive the opening and closing of the trap.
These results rule out previous conclusions from capillarity-based models of nectar feeding and highlight the necessity of developing a new biophysical model for nectar intake in hummingbirds. Hummingbird tongue tips twist to trap nectar. How the hummingbird tongue really works with videos. Close encounters with possible prey. You want to live 10—20 years. You are peering under leaves, poking into rolled ones, searching around stems, exploring bark crevices and other insect hiding places.
Abruptly an eye appears, 1—5 cm from your bill. The eye or a portion of it is half seen, obstructed, shadowed, partly out of focus, more or less round, multicolored, and perhaps moving. Now, a safe few meters away, are you going to go back to see whether that was food? Associated body patterns often suggest other head and facial features, which in turn enhance the eye-like nature of the spots. None of these patterns exactly matches the eyes or face of any particular species of predator; but, even when quickly and partially glimpsed, all give the illusion of an eye or face.
These false eyes are mimicking the eyes and faces of such predators of insect-eating birds as snakes, lizards, other birds, and small mammals, as perceived at close range by the insectivorous birds in their natural world. Note the distended throat of this American Kestrel.
Pigeons generally lay two eggs one day apart, which hatch 18 days after they are laid. A similar substance is produced by flamingos and male Emperor Penguins. The normal function of the crop is food storage. Pigeon 'milk' also contains IgA antibodies and antioxidants carotenoids. The avian stomach is divided into 2 parts:. Photomicrograph 50X of a cross section through the proventriculus showing folds of mucous membrane P ; deep proventricular glands GP ; capsule connective tissue around the glands arrow head ; muscle layer m ; serosa connective tissue with blood vessels S , and the lumen L From: Photomicrograph X of longitudinal section of the gizzard showing folds of mucous membrane lined by simple prismatic epithelium P ; simple tubular glands Gs in the lamina propria constituted by connective tissue Lp ; secretion of glands S that are continuous with the cuticle or koilin ; C , part of muscle layer m , interpersed with bundles of connective tissue Tc From: Photomicrograph X of the koilin of an Eclectus Parrot Eclectus roratus.
Note the regular, columnated structure of the koilin layer K and its association with the glandular epithelium E of the ventriculus From: De Voe et al. A, koilin, B, crypts, C, glands that secrete koilin, D, epithelial surface, E, desquamated epithelial cells, 2 Mucosa of the gizzard. A, koilin, B, secretion in gland lumens and crypts, and 3 Koilin layer.
A, secretion column, B, koilin-layer surface, C, horizontal stripe indicating a 'pause' in secretion of the koilin, D, cellular debris. Eglitis and Knouff Vultures of the seas -- Animals are primarily limited by their capacity to acquire food, yet digestive performance also conditions energy acquisition, and ultimately fitness.
Optimal foraging theory predicts that organisms feeding on patchy resources should maximize their food loads within each patch, and should digest these loads quickly to minimize travelling costs between food patches.
GPS-tracking of 40 Wandering Albatrosses from the Crozet archipelago during the incubation phase confirmed foraging movements of between — km, giving the birds access to a variety of prey, including fishery wastes.
Using miniaturized, autonomous data recorders placed in the stomach of three birds, the first-ever measurements of gastric pH and temperature in procellariformes were obtained.
Such low stomach pH gives Wandering Albatrosses a strategic advantage because it allows a rapid chemical breakdown of ingested food and rapid digestion. This is useful for feeding on patchy, natural prey, but also on fishery wastes, which might be an important additional food resource for Wandering Albatrosses. It is likely that this physiological characteristic evolved as a response to a diet largely composed of squid, and to a patchy distribution of this food resource resulting in large, infrequent meals.
The strategy of Wandering Albatrosses is to cover long distances rapidly and at low costs to increase the probability of encountering dispersed prey patches whose distribution is unpredictable. Knots with large gizzards consumed far more molluscs with shells than the birds with smaller gizzards. Birds with smaller gizzards simply couldn't feed fast enough. By allowing them to crush more shell per gizzard-full, larger gizzards gave birds the edge.
Thus, even though it is energetically costly for the knots to maintain a larger gizzard, when the bird needs to get the most out of its crunchy diet, it's a price worth paying. So, the birds' gizzards enlarge as they fatten for migration. Because the molluscs' shells stay the same size as the molluscs shrink, the amount of shell a bird must process to eat its fill also increases.
But with their larger gizzards, the birds can still make the most of even the crunchiest winter diet! Within 14 days, they showed a doubling of the size of their gizzards. Red Knots have strong muscular gizzards for feeding on molluscs. A shift back to a mussel diet induced about a doubling in gizzard mass in just a few days. As the knots were fed progessively smaller mussels day 22 to day 46 that are easier to crush, gizzard mass again declined.
A switch back to a soft food pellet diet caused a further decline in gizzard mass. Finally, a switch back to a mussel diet again cause a rapid increase in gizzard mass From: Piersma and Drent Ostrich Struthio camelus stomach.
Note how particle size of material in the gizzard ventriculus is smaller than in the proventriculus due to the grinding action of the muscular walls plus small pebbles gastroliths.
The capacity to reduce particle size is related to the metabolic demands of a species. Therefore, particle size reduction is often considered the key digestive difference between ecto- and endotherms that allows endotherms to rely on shorter digesta retention times without losing digestive efficiency, and hence facilitate the high level of food intake necessary to meet their increased metabolic requirements.
In contrast, adaptations for chewing intrinsically increase the weight of the head. The use of the gizzard system has the potential advantages that intake rate is not limited by chewing, that no investment in dental tissue is necessary, and that dental wear is not a determinant of senescence as observed in mammals. The absence of age-dependent tooth wear might even be a contributing factor to the slower onset of senescence in birds as compared to mammals.
On the other hand, the use of a gizzard requires the intake of suitable grit or stones—an action that represents, in the few studies where this has actually been quantified in birds, a relevant proportion of feeding time Fritz et al.
Gastrointestinal tracts of a carnivorous hawk, an omnivorous chicken, and 4 herbivorous birds. Note larger size of crop in omnivore and herbivores, and particularly in hoatzin. Ceca are small in hawks and relatively large in grouse. Although ceca are relatively small in Hoatzins , Emus, and Ostriches, an expanded foregut Hoatzins , a much longer midgut Emus , or a much longer colon Ostriches compensates for this From: Stevens and Hume Over-reliance on the passive pathway provides metabolic advantages and ecological constraints.
It does provide birds with an absorptive process that can deal with rapid and large changes in intestinal sugar concentrations. The passive pathway is also energetically inexpensive to maintain and modulate.
However, passive absorption through the paracellular pathway is dependent on concentration gradients. In the absence of a transport system that selects which materials to absorb, this non-discriminatory pathway may also increase vulnerability to toxins, and thus constrain foraging behavior and limit the breadth of the dietary niche of the birds. Another problem is that when luminal sugar concentrations are lower than those in plasma, glucose may diffuse back into the lumen.
Cross-section of the intestine ileum of a Spotted Tinamou Nothura maculosa. Villi are lined with columnar epithelium EP , including goblet cells arrows that secrete mucus. The muscle layer includes longitudinal fibers MI on the perimeter, circular fibers Mc , and additional longitudinal fibers at the base of the villi muscularis muscosae; MM From: Chikilian and de Speroni Blue-headed Parrots at clay lick.
Meyer-Rochow and Gal determined that the pressures involved could be approximated if they knew the 1 distance the feces traveled, 2 density and viscosity of the material, and 3 shape, aperture, and height of the anus above ground. How penguins choose the direction of defecation, and how wind direction factors into that decision, remain unknown.
Avian Pancreas tissue Source: The Avian Digestive Tract. Avian geophagy and soil characteristics in southeastern Peru. Luminal morphology of the avian lower intestine: Histological aspects of the stomach proventriculus and gizzard of the Red-capped Cardinal Paroaria gularis gularis. Comparative study of the digestive system of three species of tinamou. Crypturellus tataupa, Nothoprocta cinerascens , and Nothura maculosa Aves: Journal of Morphology Journal of Experimental Zoology Rictal bristle function in Willow Flycatcher.
Dysplastic koilin causing proventricular obstruction in an Eclectus Parrot Eclectus roratus. Journal of Avian Medicine and Surgery Anatomy and physiology of the digestive system in fowl. Pages in Proc. An histological and histochemical analysis of the inner lining and glandular epithelium of the chicken gizzard.