Herbivores have special adaptations for digesting cellulose

Cellulose is the principal organic compound in the diets of herbivores. Most herbivores, however, cannot produce cellu-lases, the enzymes that hydrolyze cellulose. Exceptions include silverfish (insects well known for eating books and stored papers), earthworms, and shipworms. Other herbivores, from termites to cattle, rely on microorganisms living in their digestive tracts to digest cellulose for them.

The digestive tracts of ruminants (cud chewers) such as cattle, goats, and sheep are specialized to maximize the benefits of their endosymbiotic microorganisms. In place of the usual mammalian stomach, ruminants have a large, four-chambered organ (Figure 50.17). The first two chambers, the rumen and the reticulum, are packed with anaerobic microorganisms that break down cellulose by fermentation. The ruminant periodically regurgitates the contents of the rumen (the cud) into the mouth for rechewing. When the more thoroughly ground-up vegetable fibers are swallowed again, they present more surface area to the microorganisms for their digestive actions.

The microorganisms in the rumen and reticulum metabolize cellulose and other nutrients to simple fatty acids, which become nutrients for their host. In addition, the microorganisms themselves provide an important source of protein for the host. A cow can derive more than 100 grams of protein per day from digestion of its endosymbiotic microorganisms.

50.17 A Ruminant's Stomach Bison, like their relatives domestic cattle, have a specialized stomach with four compartments that enables them to digest and obtain energy from protein-poor plant material.

Esophagus

Esophagus

Large Intestine Ruminant

The abomasum is the

"true" stomach, secreting HCl and proteases. The microorganisms are killed by the HCl, digested by the proteases, and passed on to the small intestine for further digestion.

The abomasum is the

"true" stomach, secreting HCl and proteases. The microorganisms are killed by the HCl, digested by the proteases, and passed on to the small intestine for further digestion.

The food leaving the rumen carries with it enormous numbers of cellulose-fermenting microorganisms. This mixture passes through the omasum, where it is concentrated by water absorption. It then enters the true stomach, the abomasum, which secretes hydrochloric acid and proteases. The microorganisms are killed by the acid, digested by the proteases, and passed on to the small intestine for further digestion and absorption. The rate of multiplication of microorganisms in the rumen is great enough to offset their loss, so a well-balanced, mutually beneficial relationship is maintained.

Some mammalian herbivores other than ruminants have microbial fermentation chambers in a branch off the large intestine, called the cecum. Rabbits and hares are good examples (see Figure 50.8). Since the cecum empties into the large intestine, the absorption of the nutrients produced by the microorganisms is inefficient and incomplete. Therefore, some of these animals re-ingest some of their own feces, a behavior known as coprophagy. Coprophagous species usually produce two kinds of feces, one consisting of pure waste (which they discard), and one consisting mostly of cecal material, which they reingest directly from the anus. As this cecal material passes through the stomach and small intestine, the nutrients it contains are digested and absorbed. In humans, the cecum has become the vestigial appendix, which serves no digestive function.

Essentials of Human Physiology

Essentials of Human Physiology

This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.

Get My Free Ebook


Responses

  • Andrea
    What adaptations do herbivores have for a celluloseheavy diet?
    7 years ago
  • cordelia mancini
    What adaptations do herbivores have to digest cellulose?
    7 years ago
  • mario
    How long is the small intestine of ruminant animal?
    7 years ago
  • Daniel
    Why is an earthworm a herbivore?
    7 years ago
  • haddas
    What anables herbivores to diggest cellulose?
    6 years ago
  • VERA
    Why herbivores have longerintestines?
    6 years ago
  • ROMAN MACLEAN
    Have have animals adapted to cellulose digestion?
    6 years ago
  • Efrem
    What adaptations herbivores possess to digest cellulose?
    5 years ago
  • estella
    Why don't domestic herbivores make enzymes to digest cellulose?
    4 years ago
  • anja ackerman
    What special adaptations do pigs have for digesting plants?
    4 years ago
  • Robert
    What adaptation do herbivores have that enables them to digest cellulose?
    3 years ago
  • shirley
    What are the adaptations of omasum for cellulose ?
    3 years ago
  • mathilda
    What are the adaptations of herbivores which enable then to digest cellulose?
    3 years ago
  • Aatifa
    What adaptations fo rodents have to digest cellulose?
    3 years ago
  • dennis
    What are the adaptations of herbivorous which enable the to digest cellulose?
    2 years ago
  • gloriana
    What are the two adaption of herbivores?
    2 years ago
  • vittorio
    Which special adaptation of this animal to digest cellulose is unique?
    2 years ago
  • valentino milano
    HOW ARE HERBIVORES ADAPTED TO DIGESTION OF VEGETATION KCSE?
    2 years ago
  • amethyst
    What is the adaptation method that allows ruminants to digest cellulose?
    2 years ago
  • RUDIBERT
    How digestive system of herbivore is adapted to digest cellulose?
    2 years ago
  • monika
    Which enzyme enable animals to digest cellulose?
    2 years ago
  • Kenneth
    Which special organ herbivore have to digest grass?
    1 year ago
  • yrj
    How herbivours adopted to digest cellulose?
    1 year ago
  • sancho
    How herbovores mammals digest cellulose?
    1 year ago
  • blake mcclellan
    How are the herbivores suited for digestion of cellulose?
    1 year ago
  • eric
    How adapted herbivore's food?
    1 year ago
  • alvaro napolitano
    How herbivores are adapted to their functions?
    1 year ago
  • Kian
    Which of the following adaptations allow herbivores to digest plants?
    1 year ago
  • Ulrich
    Where do cellulose digestion take place in herbivores?
    1 year ago
  • Kye
    Why herbivorous animals digest cellulose?
    1 year ago
  • niina
    How digestion in herbivires animals?
    1 year ago
  • jens
    How herbivores are adapted to digestion of cellulose?
    1 year ago
  • tyler campbell
    What are the three special adaptive features of herbivore for digestion of cellulose?
    1 year ago
  • ronnie
    Why hervivourse can digest plant?
    1 year ago
  • Kelly
    What adaptive feature enables the digestive system to carry out their functions?
    1 year ago
  • Vera Bass
    What Adaptive Features That Enables Digestion To Take Place?
    1 year ago
  • Annette Ford
    Do herbivore intestine have cellulase?
    11 months ago
  • mimosa took
    How is cellulose digested by herbivores?
    10 months ago
  • ted
    How do pigs break down cellulose?
    10 months ago
  • ines
    How to make pigs digest cellulose and fiber?
    10 months ago
  • april
    How stomach of.a ruminant.is adapted to cellulose?
    10 months ago
  • simone vogler
    How do herbivores adapt?
    9 months ago
  • Robinia
    How is the stomach of a ruminant herbivore adapted to carry out its function?
    8 months ago
  • blanco
    How does the stomach of a ruminant herbivore adapted to carry out his functions?
    8 months ago
  • Sirkka
    Which part of the herbivore's gut does digestion of cellulose takes place?
    7 months ago
  • Lucio
    Which region of the gut that promote digestion of cellulose in herbivorus animals?
    6 months ago
  • louis
    What are the adaptive features that help the ruminants to digest cellulose present in their food?
    6 months ago
  • SANCHO
    What are the adaptations of herbivores to deal with a large plants diet?
    5 months ago
  • negisti
    How Herbivore Are Adapted For Digestion Of Cellulose?
    3 months ago
  • torsten
    How do herbivores digest celluse?
    3 months ago
  • placido de luca
    How harbivores are adapted to digest cellulose?
    3 months ago
  • j
    Where is digestion of cellulose takes place in herbivorous?
    3 months ago
  • v
    Where digestion of cellulose in gut of herbivorous occurs?
    1 month ago
  • yohannes
    What are the three special adaptation that enables them digest cellulose?
    26 days ago
  • alexander
    What adaptation enable herbivore to digest cellolose?
    6 days ago

Post a comment