Rabbit and Rodent Nutrition N. Matthew Ellinwood, D.V.M., Ph.D. Spring 2010

Rabbits At least 45 breeds of rabbits Serve as: –pet animals –meat producers –fur and hide producers –research subjects Differ from rodents in having 2 sets of upper incisors

Rabbit GI Anatomy Non-ruminant herbivores with simple (glandular) stomach Shorter sm. intestine than most species Enlarged cecum for enhanced forage use –Don’t digest fiber well (15-17% optimal) –Do digest starch and recycle protein Lg. Intestine sorts food based on components & size –Fiber continues to colon for excretion –Fluids and soluble particles transferred back to cecum for further digestion

Rabbit digestive tract

Coprophagy/Cecotrophy Ingestion of feces (“normal”) –Hard and soft feces produced –Soft feces ingested directly from the anus as excreted in early morning (night feces) –Not a problem if housed on wire cages –Similar to rumination due to path: cecum mouth stomach…a “recycler” –Provide vitamins B and K and increase forage use

Feedstuffs Hay –Alfalfa--high in protein and calcium –Most forages are low in phosphorus –High fiber (cellulose) will have limited digestion by cecal fermentation or coprophagy –Grass--significantly lower in protein and digestibility –Timothy--now being seen as basis of pelleted diets

Feedstuffs Garden vegetables –Good sources of vitamins –High in moisture/low in dry matter –Fibrous materials--help with digestive function –Not exceptionally good sources of protein –Enrichment

Feedstuffs Grains –Generally good sources of energy and phosphorus –Poor sources of calcium and fiber –Grain byproducts also acceptable –Prefer oats and barley to corn

Feedstuffs Protein supplements –Commercial pelleted diet ~ 15-19% CP –Plant based –Oil content increases energy –Generally only needed for max. growth

Feeding Tips Pelleting common –Reduces feed sorting/wastage –Cereal grains utilized…especially oats Avoid moldy feeds Often nocturnal feeders Avoid overfeeding calories –Use higher forage/vegetable matter formula –Meal feed superior to “free choice”

Feeding Tips cont’d Atony and hairballs reduced with 22% fiber in diet –Rabbits unable to vomit Concern: although fermentation followed by coprophagy is significant, dietary essential amino acid requirements still exist Fat addition common for grower rabbits Gnawing toys also good

Nutrient Recommendations Fiber -Reduces hairballs -Reduces chance of obesity -Helps w/ GI function

Special Considerations Calcium –Very efficient absorption... and excretion –Alfalfa higher in calcium than other grasses –Leads to: cloudy urine, urine sludge, bladder calculi Enteritis/enterotoxemia –Major problem with high concentrate diets –Clostridial organisms flourish in presence of overconsumption of energy…especially in young rabbits Also a concern with antibiotic administration

Chinchillas Originated in S. America Desire for pelts nearly led to extinction Longer life span than other pet rodents Require dust baths for coat quality Generally eat at night Monogastric herbivore w/ large cecum--“hind gut” fermenters

Chinchillas Normally coprophagic Susceptible to constipation –Prevented by having adequate crude fiber Susceptible to dietary changes (diarrhea) –Make changes slowly Absolute requirements not known –Most commercial diets are higher in fiber and lower in protein than conventional rodent diets Enjoy veggies, fruits, and grains as treats (limit to one to two raisins per day)

Guinea Pigs Domesticated in S. America; some wild cavies still found there today Produce large amount of feces Females must be bred before 7 mo. of age

Guinea Pigs Food preferences established early Normally coprophagic Provide free-choice timothy hay Green veggies make great snacks and supplement Vit C requirements Like rabbits, subject to antibiotic induced enterotoximia

Guineas & Vitamin C Must have diet formulated for Guinea pigs or otherwise supplemented with Vit C –Most diets fortified with Vit C (ascorbic acid) –Approx half of initial amt. of Vit C is oxidized within 90 days of mixing 15-25mg / day required Clinical signs (joint bleeds) can occur as soon as 2 weeks on Vit C deficient diet Scurvy caused by Vit C deficiency is leading cause of death in guineas

Gerbils More active than hamsters If escape cages, often return to them Excessive burrowing and tunneling Prone to stress induced epileptic seizures

Gerbils Standard rodent diet acceptable –4-5% fat –16% protein –Generally block-style pellets If fed seed diets –Will select more palatable, fatty seeds Ex: Sunflower seeds (low calcium and high fat relative to requirements) –Provide seeds only as a treat Do NOT practice coprophagy

Hamsters Nocturnal Least hardy of all small rodents High metabolic rate due to small size Will chew on most everything Possess cheek pouches and utilize them frequently when feeding Classified as granivorous

Hamsters Normally coprophagic Higher protein requirement than standard rodent chow –17-23% Susceptible to Vit E deficiency –Fresh milled diet (< 6 months) –Muscle weakness

Rats relatively intelligent, but prone to obesity Mice exhibit Whitten and Bruce effect Standard rodent chow (block-style) will be sufficient Vigorous digestive tracts Diets well formulated due to extensive use as research animals Rats & Mice

Summary Characteristics AnimalCopr. CP Vit. Enrich Rabbits X 15-19% X Chinchillas X 12-14%C(?) X Guinea Pigs X 16-18% C X Gerbils16% X Hamsters X 17-23% E X Rats & Mice X 16% X

Inbred mice breeds Dr N.A Namvar Asl (D.V.M)