8.1 - Rabbits

rabbits

monogastric herbivores

lagomorphs

• are their own order

  • pikas, hares, rabbits

• order based on their physiology

• non-ruminant herbivores

non-ruminant herbivores

• consume diet primarily of forage (high fiber, low energy)

• fiber is critical

  • fiber can’t vary too much without risk of problems

• unique circadian rhythm for digestion

circadian rhythm

• nervous system alters GIT activity

• during day: normal microbial activity→ normal rabbit fecal pellets

• during night hours: tract motility changes (slows)

  • bacteria in cecum & colon make cecotropes

    • rabbits can capture more nitrogen through cecotrophy of protein rich cecotropes, improving efficiency

teeth

part of the specialized digestive system

• sharp teeth

  • allow for cutting of forage

  • rabbits have a wide variety of foods to choose from, even when no fresh forage is available

challenge with incisor teeth

• need constant work to maintain ideal size/length

• forage keeps teeth in shape

• if diet its not appropriate, teeth need to be trimmed

jaw structure

• upper & lower biting incisors

• large gap to accommodate long forages

• sharp broad grinding teeth

  • allows for mastication of rough plant material

GIT

• up to the large intestine, GIT similar to that of horse

• system looks different & changes the digestive physiology

cecum

• full of anaerobic, cellulytic bacteria

  • bacteria breaks down plant cell walls to cellulose, and converts the cellulose to glucose

  • glucose is formed to provide energy for microbial growth

• excess VFAs absorbed through cecal wall → provide energy for rabbit

cecotropes

fecal pellets with enriched populations of microbes

• microbes that grow using fiber in digestive tract build up in greater concentration because of slower motility during night hours

• when excreted, cecotropes are more concentrated in crude protein & are lower in fiber

  • most of the fiber is digested by the microbes

cecotrophy

rabbit consuming cecotropes

• digest like any other food source → are able to take advantage of the microbial protein

• utilize bacteria produced by amino acids

• rabbits can survive in environments with low-protein plants

  • due to recycling & capture of bacterial protein in cecotropes

• must provide sufficient forage in diet

  • allows for normal digestive motility

  • provides fiber for cecal microbes to use

development of cecotropes / rabbit stomach

digestion takes place, get to cecum (cecotropes develop here) → are excreted

• cecotropes remain separate from other feed material

  • maximizes potential for protein utilization

suckling

• usually only allowed to suckle a few times per day

  • evolutionary advantage — are prey species, need to stay quiet and hide the litter

• mother may ignore litter for long periods of time — NORMAL

• normal suckling behavior is best protocol for feeding the litter

weaning of kits

• done gradually so digestive tract can adapt

• provide small amounts of high-quality forage — preferably green forage (if not possible, dry hay is acceptable)

• provide small amounts of balanced grower pellets

*don’t want to provide large amounts of forage/hay/pellets → milk is still primary source of energy

nutrition after weaning

• fed high quality forage and small amount of grower pellet

  • grower pellets provides minerals & vitamins, supplements the forage, and supplies high quality protein & energy

• want to avoid overfeeding

  • check for excess fat and provide regular exercise

growth: forage

optimal nutrients for optimal growth → protein, energy, vitamins, & minerals for normal growth and development

• forage should be primary source of nutrients

  • 12-16% crude fiber

    • providing most fiber as forage is best for teeth development & normal GIT physiology

  • 16-18% crude protein

maintenance

• majority of lifespan spent here

• basic bodily functions, temperature, & voluntary activity

• requirements depend on environment (indoor vs outdoor)

  • same feed should be fed, but in different proportions

cat or dog food as feed source

inadequate for rabbits

• provides too much energy & protein, and not enough fiber

size of litter

4-10 kits/litter

length of gestation

32 days

nutritional requirements during gestation

• don’t increase significantly until ~15-20 days

• at ~3 weeks, addition of supplement for growth & lactation can be slowly introduced → ensures proper level of vitamins, minerals, & high quality protein

• energy requirements increase by 10-25% (depending on size of litter)

  • small increase in grain may be offered, but watch weight

• during last trimester (3 weeks), rabbit should be consuming primarily forage with high quality supplement available as needed

nesting behavior

begins 2-4 days prior to kindling

• proper nesting box/space should be provided

lactation

• feed intake decreases 24-48 hours prior to kindling

• after kindling, lactation begins & all nutrient requirements increase rapidly

  • provide free-choice forage, but allow intake of complete supplement as needed

• be observant of dam

  • if always hungry & losing weight while lactating, allow her to eat larger amount

geriatric rabbits

• loss of teeth may occur

  • results in:

    • reduced ability to forage

    • reduced ability to chew long forage

  • high qualiert balanced pellets should be fed

    • may need to be moistened if too hard

over feeding

• leads to obesity (an additional challenge associated with aging)

  • reduced drive to forage

  • decrease in exercise

  • may lead to: heart disease/weakness, kidney & skin problems

  *consider feed options related to not being able to gather forage, process it, or being unwilling to gather it

what happens if high-fiber, low-energy diet is NOT fed

• digestive physiology changes

  • passage of nutrients through GIT slowed down

effect of fiber on saliva production

fiber consumption increases saliva production

• saliva helps move material through the intestines at proper rate, allowing for normal fiber amount to reach large intestine

diet with too much grain/starch

• starch builds up in small intestine & saliva production is reduced

• when alive production decreases, less fiber is delivered to lower GIT

• as digestive motility slows, tract may become impacted with large bolus of undigested feed

  • results in life threatening conditions: animal can be in intense pain + starving

without a high-fiber, low-energy diet:

passage of nutrients slowed → decreased saliva consumption → starch build up in small intestine → less fiber gets to cecum → boluses of undigested feed cause an impact → results in life threatening condition

when sufficient fiber in diet:

• rabbits frequently groom themselves

  • lots of hair in GIT

  • normally saliva production stimulated by fiber intake

  • saliva keeps hair & digesta moving through & out of GIT

if intestinal motility is slowed

may lead to GI stasis

• happens when too much grain, too little fiber is in diet

• hair & other material in gut builds up into a trichobezoar (hair ball)

• usually occurs in stomach

trichobezoars

• rabbits can’t vomit → trichobezoars can’t be forcefully removed

• feed & water intake decreases

  • waste dropping become smaller

  • refuse pellets, chew cage

• become lethargic & depressed

• if caught:

  • rehydrate, mineral oil, increase gastric motility, feed fiber

• usually too late by the time someone figure it out

where does the hairball come from?

grooming activity:

• hair mixed with stomach contents

• dehydration leaves largest particles behind, including hair

• turns into solid, tightly adhered mass

• long hair breeds can have excessive hair — important to brush them

without a high-fiber, low-energy diet

• cecotropes not formed

• chronic soft stools

  • not useful to animals

  • animals cannot meet nutritional requirements

regular exercise

• usually a larger mobile enclosure that allows to grazing & movement

• gives them the ability to:

  • graze

  • induces normal intestinal motility

  • reduces risk of problems associated with low fiber diets & gastric stasis

summary

• non-ruminant herbivores with unique adaptions

  • jaw, teeth, & GIT structured for forage consumption

  • production of cecotropes to reprocess products (primarily protein) of fermentation in cecum

• without forages (fiber), & with grooming activity, things can back up

• trichobezoars can be fatal

• feed forages first