Flashcards in 13a Nutrition of Fish, Birds, Reptiles Deck (18):
Aquarium fish as pets.
- >5000 species kept in aquariums
- no detailed info about nutrient requirements
- extrapolation of data from aquaculture
- no need for so many different feeds
- examples: koi carp, coral butterfly
- few carnivorous, many omnivorous, many herbivorous
- major classifications: warm or cold temp, top bottom or middle feeding, night or day feeding, single or mixed population
Describe digestive physiology of fish.
- only few have teeth
- food eaten whole or in large particles
- stomach small (large in omnivores or herbivores)
- in small fish, no stomach and food passes directly to intestines (bite size is swallow size)
- pancreatic duct enters at proximal end of intestine where stomach would be
Describe energy requirements of fish.
- ectothermic fish do not maintain a constant body temperature 'cold blooded'
- live and carry out chemical reactions at the whim of the environmental temperature they live in
- major survival benefit -> require less energy to maintain normal life
- energy need is direct correlate of water temp
Describe nutrient requirements of fish
- rely more on amino acids than carbs
- higher protein turnover than mammals
- omnivorous and carnivorous fish can utilize starch (better in gelatinized form)
- herbivorous fish not adapted to large meals (3-4 small meals better)
Describe some special nutrient requirements of fish.
- do not need as much Ca and P as don't have hard bones. uptake and excretion regulated through gills
- high amounts of iron can interfere in oxygen transfer
- can cope with a range of mineral concentrations (sodium, potassium, chloride)
- water soluble vitamins quickly dissolved in water so feed often over supplemented
- vit C essential; deficiency leads to lordosis
- pigmentation due to carotenoids (astaxanthin and canthaxanthin); beta carotene can not be used by all fish so feed should contain specific carotenoid
- omega 3 and 6 fatty acids needed because of big changes in water temp; linolenic acid need to keep fish membranes fluids even with cool temps; saturated fats will solidify and clog digestive system
What are the 2 orders of ornamental birds?
- order Psittaciformes
- order Passeriformes
Describe the digestive physiology of birds.
- cecum and colon small or absent
- transit time <12h; budgies and finches 3-6 hours
- small birds suffer from starvation in less than 3 days so food must be available at all times
Describe the nutrient requirements of birds.
- main source of glucose: starch from variety of seeds
- many small ornamental birds can not use fibre because no cecum and colon, so do not feed many fresh fruit and veg
- berries, dark green or yellow veg, peas, kidney and pinto beans
- some large psitterines can use fibre as part of diet
- birds can also pick and choose which seeds to meet requirements
Describe life cycle feeding management
- growth very rapid
- body size increase ten fold in 10 days
- feather growth requires greater amounts of amino acids: proline, glycine, methionine and cysteine
- uric acid synthesis needs more energy to make than urea (increased energy requirement)
- urea synthesized from glycine and acetic acid so glycine essential amino acid for growing and reproducing birds
Describe feeding during moult
- replacement of feathers by new ones
- usually on annual basis in fall
- large amounts of well balanced amino acids especially methionine, cysteine and glycine
- good sources include canola seed and white millet
-overall increased protein and energy requirements
Describe general feeding management of birds.
- feed balanced diet
- provide mix of different types of seeds and vegetative parts to meet mineral and vitamin requirements
- birds learn feeding from their parents
- when weaning birds from one diet to another, offer in morning
Do we have lots of research on reptiles?
- nutritional research is limited
- dietary recommendations based on knowledge of natural diets and feeding histories, clinical experience and principles of comparative nutrition
- herbivorous, omnivorous and carnivorous
How are the GI tracts of omnivorous/ carnivorous and herbivorous reptiles different?
- cecum larger volume and greater relative length of herbivore hind gut
Describe reptilian digestion, metabolism and nutrition
- digestive system of herbivorous reptiles different than mammals (numerous fold and partitions to slow down passage and increase fermentation)
- herbivorous reptiles larger than carnivorous (more room for fermentation, habitat and optimal temp range also influence size, carnivorous need to move faster)
Describe water requirements of reptiles.
- water delivery must fit environment of animals, proper depth, smell and taste, proper humidity
- dehydration can cause gout or dyscedysis (drying of skin and inability to shed)
- too high humidity can cause hyperkeratinization
Describe energy requirement of reptiles
- ectothermic: too low temp causes decrease in food intake; too high temp causes excessive metabolism, decreased food intake and growth
- only require 1/4 of energy of mammals
- inverse relation between metabolic rate and body size
Describe protein requirement of reptiles
- carnivorous: 30-60%
- herbivorous: less than that
- high requirements os use animal proteins or high protein seeds and nuts