Avian Nutrition Flashcards
What accounts for the cause of up to 75 % of all medical problems in birds?
Up to 75% of all medical problem in pet birds have a
nutritional background
What would an unbalanced diet in birds lead to?
An unbalanced diet in birds would lead to malnutrition,
obesity, impaired immune function, poor reproductive
success and more
What can birds be categorized by?
Birds can be categorized by their diet
- There are 23 groups of birds according to their diet
There are very many species of birds even within similar
groups- for example 9000 species of psittacine
- Some psittacines feed primarily on high fat nuts (macaws for example)
- Others feed on a much lower fat vegetation (Amazons)
What are the groups of vegetarian birds and what do they eat?
- Frugivore (eats primarily fruit) - Granivore (eats grains)
- Nectarivore (feeds on flower nectar)
- Palynivores (feed on pollen)
What are the groups of carnivorous birds and what do they eat?
- Avivorous birds: eat birds
- Carnivorous birds: eat meat
- Insectivorous birds: eat insects
- Molluscivorous: feed on mollusks
- Piscivorous: feed on fish
What is the water requirements of birds?
Water: Avian water requirements change in different species
- Australian and other desert birds have lower water requirements
- Water requirements are highest in neonates
- Water should be fresh and clean, without supplements
What changes in terms of requirements when birds are molting?
Molting (replacing feathers) requires specific nutrients, and has higher energy costs
- The energy is needed for the production and maintenance of feather pulps
- It can increase by 3-20% (at peak molt)
What changes the amount of saliva during eating? What is the crop?
- The amount of saliva differs between species according
to diet (less in fish eating birds, more in birds that eat grain/seed) - The crop is an enlargement of the esophagus, cranial to
the thoracic inlet (not present in gulls, penguins) - The crop can be palpated in a physical exam
- The crop can become impacted with dry food in a
dehydrated bird
When does the crop store food? what occurs while the food is within the crop? What are the two main parts of the stomach? What occurs in each?
The crop stores food when the gizzard is full
- The food softens and swells with water
- No chemical digestion in the crop/esophagus
- The stomach has two main parts- the proventriculus or the
glandular stomach, and the muscular stomach (gizzard)
- Proventriculus: The glandular cells secrete acid and pepsin
- The gizzard physically grinds the food
What occurs in the birds small and large intestines?
The small intestines:
- Bile and pancreatic secretions are transported into the distal duodenum and help with digestion of carbohydrate, protein and
fat
Large intestines:
- The large intestines consists of paired caeca and a short straight
intestines
- The caeca are a site of fermentation and lymphatic tissue
- The straight intestine ends in the cloaca, along with the
urogenital tract
What can be seen about nutritional status during physical exam of a bird?
- Visual inspection can suggest fat deposition
along the pectoral region - Body condition score in birds is best appreciated by assessing the musculature and
fat coverage in the pectoral region - Crop palpation: is important to make sure there is no impaction or stasis of food in the crop.
- Visual inspection of the plumage can also suggest malnutrition. For example, this bird should be bright green and not dark
- The oropharynx should be inspected Most birds would have a choanal slit and choanal papilae
- The overall skin, feet, and feathers may all be indicators of malnutrition
What change in weight would indicate / warrant further assessment
An acute decrease of 5% bodyweight, or a chronic
decrease of 10% warrant further assessment
What is a backyard flock? What are the two rules to remember?
Pets, or used for eggs and
meat or a combination
Two rules to remember:
- A chicken will only grow
and perform to the
extent it receives proper
nutrition
- A chicken cannot grow
beyond its maximum
genetic potential
Why is nutrition variable between backyard flocks and large scale commercial facilities?
- Nutrition for small flocks and backyard poultry tends to be
more variable than nutrition for egg laying hens or meat
birds in a large-scale production setting - Diet can affect the health of the bird or affect productivity
- When animals are used for production, feed is a major
expense of the overall investment
Is there a correlation between water intake and food intake? What is a few ways to ensure the bird drinks?
Don’t forget the water!
- There’s a direct correlation between amount of water consumed and amount feed consumed
- If a chicken stops drinking it will stop eating soon after
- Water should be kept at appropriate
temperature and freshness
- Always provide at least two or three additional drinkers in excess of the estimated water consumption
What is important to remember about feed quality for birds?
- Feed should not be stale, rancid, or moldy
- Feed storage: dry cool area (away from direct sunlight,
moisture or heat) - Do not use/buy feed that is not fresh
- vitamins may degrade
What is mash feed? Peletized feed? Crumbled feed?
- Mash feed consists of all ingredients ground into particles and mixed loosely together
- Pelletized feed is mash that is held together with a binder and then heat-treated, extruded, and cut into various lengths and diameters
- Crumbled feed consists of pelletized feed broken down into smaller pieces
- Scratch should only be given as a snack.
- Chickens can forage around for bugs and greens but always provide them with appropriate formulated balanced feed.
What can foraging be used for? How can you have foraging occur?
- Foraging can be used as enrichment and can improve
the performance of many avian species including chickens - Foraging can be achieved by allowing to have free
access to a natural environment or to with foraging
tools or toys
What are the benefits of feeding pellets or crumbles vs. Mash? What is the cons?
Pros:
- Feed is compacted in pellet form
- the bird is able to consume and metabolize a greater amount of feed
- Pelleted feeds are a complete unit of feed
- Birds are unable to pick out different ingredients
- This form of feed also makes it possible for producers to formulate high-energy, high-protein diets that aid in maximizing the amount of
feed used to produce a pound of meat
- Some mash feeds are extremely dusty and difficult to handle
Cons:
Added cost to conversion of mash to crumble/ pellet
what is the benefit of complete feeding?
Complete feed does not require additional supplements - Easiest and simplest method of feeding
- Downside: Usually a bit more expensive, so can be mixed with grain (v/v) to reduce cost
- Its important to feed the animals according to their
respective life stage
- A laying hen mash is too high in calcium for a growing bird
as it can cause orthopedic disease
What kind of feed should meat type birds receive? What will this improve? What about diet for starting broilers? What about egg laying birds?
- Feed for all meat-type birds will be pelleted
- This results in 4% improvement in feed efficiency - Diets for starting broilers will be a “crumble”
- Feed for egg-laying birds most often comes as a mash (no pelleting process)
What can be used to encourage feeding during hotter months? What about scratch feed?
- Crumbled diets can be used to encourage feed intake during hotter months.
- Scratch feed should not be considered a complete feed for any type of bird
- It should only be thrown out as an occasional treat
What is the largest component of poultry diets? What is it provided by? What fibers are included? What is the concern with excessive fiber?
Carbohydrates. It is usually provided by grains.
Includes fibers such as cellulose which is indigestible by the bird but can support gi health.
Excessive fiber can decrease digestibility and decrease production
What determines fat content in avian diets? What are the kcal/kg content of diets for meat type birds, will it contain more or less fat? When may it be beneficial to use lower fat diets and why?
- Fat content may differ according to the bird and the goals
(meat/egg/pet) - Diets for meat-type birds, for example, will contain over 3,000 kcal per kilogram and are higher in fat
Higher fat and lower protein diets may be used in the summer as less heat is produced by fat metabolism
What fat sources can change the fatty acid composition of the egg yolk in birds?
Use of certain fat sources such as fish meal, flaxseed, corn and various oils can change the fatty acid composition in the egg yolk
What are the protein sources for birds? What is needed for complete protein in birds. What may need to be supplemented in avian diets?
- Protein can come from plants or animal protein (such as protein
meals) - Several plant proteins are needed to provide a complete protein (legume + grain may come close)
- Lysine and methionine may be deficient but are available as a supplement
What additional amino acids to chickens require ?
proline and histidine
What can increased urea production caused in birds? When are protein requirements are high? What is the general trend of protein digestibility and bird species?
- Increased urea production can also increase smell and airway irritation if excrements are not cleaned
- Protein digestibility differs between species according to their natural diet
- Protein requirements during egg laying are high, especially in chickens that lay many eggs. Also higher during growth.
What is grit? What does it do? How frequently should it be made available to birds? What about calcium grit?
- Hard insoluble granite grit should be available to the birds
- It helps food digestion in the ventriculus
- Should be made available 2-3 days a month
- Calcium grit can be provided but it does not last long as the calcium dissolves and absorbed
What are coccidiostats? What are they labeled by? What may be a reason they need to be removed from the diet?
- A coccidiostat (antiprotozoal agent, for example, Amprolium) is generally added to the diets of pullets and meat birds that are raised on the ground
- Feed manufacturers label feed according to the type and age of poultry (for example: starter, grower, layer) with appropriate instructions for use
- Some coccidiostats need to be withdrawn if the animal or its products are used for food ( not for human consumption, egg laying birds of meat birds cannot be on coccidiostats)
What can cause vitamin A deficiency in birds?
Causes:
- vitamin A deficiency can result when the level in the diet is inadequate or the vitamin added to the diet is oxidized by rancid fat in
the diet
- Vitamin A deficiency may also occur as a result of neomycin, a common antimicrobial that reduces its absorption
- Inadequate fat content would also cause vitamin A deficiency
What are the clinical signs of vitamin A deficiency?
Clinical signs:
- Cheese-like, but odorless, discharge from one or more eye
- Extremely thin birds (i.e., emaciation)
- Weak and/or uncoordinated birds
- Ruffled feathers
- Eyelids stuck together (referred to as sicca) - Water discharge from the throat (referred to as roup), nostrils or eyes
- Egg production and hatchability decrease in adults
(Looks like it has pinkeye)
What are the 3 main disorders seen in chicks deficient in vitamin E?
The three main disorders seen in chicks deficient in vitamin E are encephalomalacia, exudative diathesis (=accumulations of blood plasma under the skin), and muscular dystrophy
What is crazy chick disease?
Chicks with neuro signs. This results from hemorrhage and edema within
the granular layers of the cerebellum
What are the signs of rickets in birds? How can you prevent rickets?
- Young broilers and turkey poults can exhibit lameness at ~10–14 days of age
- Rickets is not a failure in the initiation of bone mineralization. But an impairment of the early maturation of this process.
- Young birds have limited ability to digest saturated fats
- Undigested compounds can complex with calcium to form insoluble soaps leading to an induced deficiency of
calcium and low absorption of vitamin D3
25(OH)D is more bioavailable and is now popular in us in lieu of vitamin D3
- There is often an enlargement of the ends of the long bones, with a widening of the epiphyseal plate
- Prevention- vitamin D3 supplementation
- A diet with sufficient fat to facilitate fat soluble vitamin absorption
What is tibial dyschondroplasia? Where is it seen? What is its cause? What are the clinical signs? How can it be prevented?
- A disease that is characterized by an abnormal cartilage mass in the proximal head of the tibiotarsus
- Likely genetic + nutritional background
- Mostly in fast growers
- Signs can occur early but more usually are not initially seen until 14–25 days of age
Signs: Pain, Decreased ambulation, Stiff gait
Prevention: Can be preventable by slowing down growth rate and a balanced diet with respect to calcium, phosphorus and vitamin D3
What is cagelayer fatigue? Who is it seen in? How can it be preventted?
- Can result in neurological signs due to hypocalcemia or even spinal fractures due to poor bone mineralization
- The condition is rarely seen in floor-housed birds, suggesting that reduced activity within the cage is a predisposing factor
- Diets must provide adequate quantities of calcium and phosphorus to prevent deficiencies
- Providing calcium carbonate or limestone can help as it will remain in the gizzard and slow-release calcium
What is occuring in this picture?
Hepatic lipidosis
How do you diagnosis birds with hepatic lipidosis?
DIAGNOSIS Serum liver enzymes and bile acids
Radiographs/ultrasound
Liver biopsy/aspirate (with pathology review)
How yan you diagnosis secondary nutritional hyperparathyroidism?
Examination and palpation
CBC, Plasma biochemistries, ionized calcium (Low Ca++ in chem) (increased ionized calcium)
Radiographs to evaluate general bone density -Fractures, bone deformities, poor bone density
What are the clinical signs of hypervitaminosis A?
CLINICAL SIGNS
▪ Sinusitis/upper respiratory disease
▪ Recurring bacterial infections
▪ Blunted choanal papillae
▪ White nodular plaques in the oral cavity
▪ Hyperkeratosis of skin
▪ Gout and renal failure if ureters affected
▪ Decreased reproductive success
What nutritional deficiency can cause lesions like this?
Hypovitaminosis A
What is likely causing the pododermatitis seen in this picture?
Hypervitaminosis A
What can be seen in an iodine deficiency? What bird is classic for presenting with this? How would it be diagnosed? What is the suggested therapy/ treatment?
▪ Classic disease of budgerigars
▪ Swelling in clavicular region, voice changes, dyspnea, and regurgitation
▪ Diagnosis via history, physical exam, and response to therapy
▪ CT scan would be diagnostic for enlarged thyroid
▪ Therapy is oral iodine supplementation
