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Where do farm animals get their protein?

  1. Apr 30, 2004 #1

    ShawnD

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    Humans eat cows so we can grow (you need protein to grow). If cows are just eating grass all the time, how are they able to grow? Many people in third world countries are sick because they don't have enough protein in their diet. Cows don't eat meat at all but they don't have that problem.

    What's going on here?
     
    Last edited: Apr 30, 2004
  2. jcsd
  3. Apr 30, 2004 #2
    How animals convert grass protein into meat protein

    This is why humans raise and hunt animals -- to convert relatively useless vegetable amino acids into usable amino acids. The cow does this by having more than one stomach. One of the cow's stomachs is called a rumen (hence the name ruminant for hoofed animals with rumens and hence the word ruminate
    since the food sits in the rumen for a while as it ferments). In the rumen, special bacteria ferment the vegetable protein (amino acids) and convert it into proteins that are usable by animals.

    Other animals also do this -- deer, goats, pigs -- the animals with hoofs. These are called ruminants and humans use them, either by domesticating them or by hunting them (or with a combination -- migratory herding), in order to convert grasses into food.



    Main Entry: ru£men
    Pronunciation: *r*m*n
    Function: noun
    Inflected Form: plural rumi£na \-m*n*\ ; or rumens
    Etymology: New Latin, from Latin, gullet * more at RUMINATE

    : the large first compartment of the stomach of a ruminant from which food is regurgitated for rumination and in which cellulose is broken down by the action of bacterial and protozoan symbionts : PAUNCH; broadly : the first three compartments of the ruminant stomach — distinguished from abomasum; compare OMASUM, RETICULUM
     
    Last edited: Apr 30, 2004
  4. Apr 30, 2004 #3
    How whitetail deer survive in a foraging environment

    Here is an article about how the whitetailed deer survives on grasses:



    • THE STOMACH consists of four chambers. The largest is (1) the rumen, which stores food until it is regurgitated and rechewed. Reswallowed food ferments in the rumen and the second chamber, (2) the reticulum. Then it passes to the (3) omasum and (4) abomasum, which absorb water and minerals and break down proteins.

    • Heat produced by the digestive process affects deer behavior. Hot weather, along with the heat of digestion, reduces their activity; they seek cover in a cool, shady spot. On winter nights, the rumen acts like a furnace. Except in the coldest weather, deer can stay bedded without losing so much heat that they have to get up and move around.

      Digestion is very efficient; only about 5 percent of the food cannot be digested and is expelled as hard, relatively dry pellets.




    BTW, because ruminants eat grasses and they have to eat a large amount to satisfy their nutritional needs they tend to concentrate radiofallout such as strontium 90 (which looks to the body like calcium, and so concentrates in milk and in the teeth and bones) and cesium 237.
     
  5. Apr 30, 2004 #4

    ShawnD

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    Neat, thanks.
     
  6. Apr 30, 2004 #5

    iansmith

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    I remember disecting pig and they only have one stomach and they are not ruminants (http://www.ncbi.nlm.nih.gov/Taxonom...id=91561&lvl=3&lin=f&keep=1&srchmode=1&unlock).

    Technically the microflora does not convert protein into other protein, they degraded into amino-acid and other by product which can be used by the animal.

    Also to note, cattle are also feed soya which as a higher pourcentage of protein than the average plant. Also, farm animal used to be feed animal flour which contain proteins too. It was band about some years ago but producer still used it.
     
  7. Apr 30, 2004 #6
    Biosynthesis of amino acids by rumen microflora

    Thanks. My understanding was that cloven hooves and rumens go together, but that is evidently not the case:



    • Ruminant, even-toed animal that regurgitates and masticates its food after swallowing. The majority of ruminants have four nipples; they usually have sweat glands only on the muzzle and between the toes. Most species bear horns that may be permanent or may be shed periodically. The division includes three subdivisions: Tragulina, containing the chevrotains and characterized by a stomach with three chambers; Tylopoda, consisting of the camel, dromedary, llama, alpaca, guanaco, and vicuña, and characterized by a stomach with three distinct chambers; and Pecora, containing all sheep, goats, antelope, deer, gazelles, giraffes, and domestic cattle, and characterized by the presence of a distinct four-chambered stomach. Pecoran animals are known as true ruminants. Between the esophagus and the intestine, the stomach chambers of a true ruminant are the rumen, the reticulum, the omasum, and the abomasum, or rennet bag.

      Microsoft® Encarta® Encyclopedia 2002. © 1993-2001 Microsoft Corporation. All rights reserved.



    I think you are wrong here. My understanding is that the rumen's microflora do biosynthesize amino acids not present in the feed.
     
  8. Apr 30, 2004 #7

    Moonbear

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    Right, pigs are not ruminants. They also happen to be omnivores, not herbivores. Cattle, goats, deer, sheep are all ruminants, and as mentioned above, extract protein from plants much more efficiently than humans do because of the ruminal bacteria. It's also worth noting they don't actually have 4 stomachs, but 4 chambers of their stomach. Monogastric (single stomach) herbivores, such as horses and rabbits, have a large cecum (believed to be homologous to our appendix) that serves a similar purpose of maintaining a bacterial population that assists in converting plant material into protein the animal can use. Humans don't have either of these (we have an appendix, but it's not developed to be useful, and some people, due to surgical intervention, don't even have one), so we don't utilize plant protein as efficiently as the herbivores. That's why we need animal protein in our diet.
     
  9. May 1, 2004 #8

    iansmith

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    I should of been more specific, the by-products are usually derive from the amino-acid of the protein that were degredaded such as organic acids, other amino acid not present in the protein. If you read the second paper in the google search, the researchers found out that Asp can be biosynthesised from other amino acid.


    The caecum is not as efficient as the rumen due to the positioning of the caecum. Some monogastric herbivores like the rabbit and the koala have the good habit of ingesting their feces to absorb the lost nutrient.
     
  10. May 1, 2004 #9
    The first part is true. The last part is false. Plant proteins can easily meet all our needs (especially soy protein, unless you're allergic). We may not be as efficient as the ruminants and other herbivores, but we can still easily flourish on plant food. Check out the American Dietetic Association's position paper on vegetarian diets (scroll down to the section on protein): http://www.eatright.org/Public/GovernmentAffairs/92_17084.cfm
     
  11. May 2, 2004 #10
    Animals in the rumen

    If you linked the correct study, it says that arginine (Arg), not aspartate , is synthesized:


    • Biosynthesis of arginine from citrulline and related compounds by mixed ruminal bacteria, protozoa and their mixture in vitro


    Earlier you referred to the lifeforms in the rumen as microflora, but actually there seems to be a combination of microflora and microfauna in the rumen since protozoa are animals.
     
  12. May 2, 2004 #11
    From dictionary.com, an animal is:

    "A multicellular organism of the kingdom Animalia, differing from plants in certain typical characteristics such as capacity for locomotion, nonphotosynthetic metabolism, pronounced response to stimuli, restricted growth, and fixed bodily structure."

    Protozoans are single-celled, correct? Then they do not fit the established criterion for being animals. Instead of microflora, microorganisms would have fit the bill.
     
  13. May 2, 2004 #12
    Protozoa are animals or not

    From the M-W Unabridged 3.0:

    • Main Entry: pro·to·zoa
      Pronunciation: ,prOd.ð'zOð, -Otð-
      Function: noun plural
      Usage: capitalized
      Etymology: New Latin, from prot- + -zoa

      : a phylum or subkingdom of animals that have an essentially acellular structure though varying from simple uninucleate protoplasts (as most amoebas) to cell colonies (as volvox), syncytia (as pelomyxa), or highly organized protoplasts (as various higher ciliates) far more complex in organization and differentiation than most metazoan cells, that consist of a protoplasmic body either naked or enclosed in a test, fixed to the substrate or free, and immobile, creeping by means of pseudopodia or protoplasmic flow, or freely motile by cilia or flagella, that are similarly varied in physiological characteristics with nutrition holophytic, saprophytic, or holozoic, with reproduction asexual involving nuclear division usually by more or less modified mitosis associated with cytoplasmic binary fission or with multiple fission or exogenous or endogenous budding or sexual by means of conjugation, of isogamous or anisogamous hologamy or of processes approaching the fertilization processes of metazoans, and with a life cycle simple (as in an amoeba) or extremely complex (as in many sporozoans), that are represented by one form or another in almost every kind of habitat (as fresh or salt water, soil, sewage, the latex of plants, and the bodies of living animals), and that include parasitic forms which are among the gravest plaguers of man and his domestic animals — compare MALARIA PARASITE, TRYPANOSOME; CILIOPHORA, PLASMODROMA; EIMERIA, METAZOA, PARAZOA, PROTISTA

    • Main Entry: ¹an·i·mal
      Pronunciation: 'anðmðl
      Function: noun
      Inflected Form: -s
      Etymology: Latin, from animale, neuter of animalis animate, from anima breath, soul, + -alis -al - more at ANIMATE

      1 : an organism of the kingdom Animalia being characterized by a requirement for complex organic nutrients including proteins or their constituents which are usually digested in an internal cavity before assimilation into the body proper and being distinguished from typical plants by lack of chlorophyll and inability to perform photosynthesis, by cells that lack cellulose walls, and usually by greater mobility with some degree of voluntary locomotor ability, by greater irritability commonly mediated through a more or less centralized nervous system, and by the frequent presence of discrete complex sense organs

    So, according to this, protozoa is a "phylum or subkingdom of animals" -- meaning it is within the kingdom of animals -- though I suppose it might be considered an atypical example of animalia -- and animals are distinguished in part by "cells that lack cellulose walls." Maybe they are making an exception for "acellular" protozoa.
     
    Last edited: May 2, 2004
  14. May 2, 2004 #13

    Moonbear

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    Standard dictionaries are a poor reference for defining biological terms. They often lead to confusion because lay terminology is used that has different nuances of meaning from the technical view.

    Depending on who you ask, there are currently 5 or 7 kingdoms. In the 5 kingdom system, there are: plants, animals, fungi, protists, monera. Protozoa are in the Kingdom Protista, not Animalia. Thus they are neither plant nor animal. I don't know what further kingdoms have been added to generate 7, but I think discussion had been that it was the monera that was too broadly defined and should be split into multiple kingdoms. But one shouldn't get bogged down by the classification of organisms. Classification is a convenience, not a guaranteed reflection of evolutionary relatedness (as indicated by the number of classification schemes in use).
     
  15. May 2, 2004 #14

    iansmith

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    Microflora is usually used to describe microbial residents of any particular habitat or biosystem.
     
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