<p style="text-align: justify;"><span id="result_box" lang="fr"><span class="hps">Le cheval</span> <span class="hps">est</span> <span class="hps">techniquement</span> <span class="hps">considéré comme un</span> <span class="hps alt-edited">"fermenteur du</span> <span class="hps alt-edited">gros intestin"</span><span>.</span> <span class="hps">Les herbivores</span> <span class="hps">qui sont</span> <span class="hps alt-edited">fermenteurs du</span> <span class="hps alt-edited">gros intestin</span> <span class="hps alt-edited">sont caractérisés par</span> <span class="hps atn">le développement d'</span><span>une</span> <span class="hps">ou plusieurs</span> <span class="hps">grandes chambres</span> <span class="hps">de fermentation</span> <span class="hps">dans les parties</span> <span class="hps">distales de</span> <span class="hps">leur</span> <span class="hps">tube digestif.</span> <span class="hps">Chez le cheval</span> <span class="hps">à la fois le</span> <span class="hps">caecum et</span> <span class="hps">le côlon</span> <span class="hps">sont utilisés comme</span> <span class="hps">chambres de fermentation</span><span>.</span></span></p>
<p>&nbsp;</p>
<p style="text-align: justify;"><span id="result_box" lang="fr"><span class="hps">Le</span> <span class="hps">caecum</span> <span class="hps">est un sac</span> <span class="hps">aveugle</span> <span class="hps alt-edited">commençant au point</span> <span class="hps">où</span> <span class="hps">l'iléon</span> <span class="hps alt-edited">se déverse dans le</span> <span class="hps alt-edited">gros intestin</span><span>.</span> <span class="hps alt-edited">Il mesure environ</span> <span class="hps">1</span> <span class="hps">m de long et</span> <span class="hps">contient</span>, <span class="hps alt-edited">chez un</span> <span class="hps">cheval</span> <span class="hps">de taille moyenne</span><span>,</span> <span class="hps">30 litres de</span> <span class="hps">digesta</span><span>.</span> <span class="hps">Le</span> <span class="hps alt-edited">côlon</span> <span class="hps">a</span> <span class="hps">une anatomie</span> <span class="hps">complexe et</span> <span class="hps">passe</span> <span class="hps alt-edited">par une</span> <span class="hps alt-edited">forme de</span> <span class="hps alt-edited">double</span> <span class="hps">fer à cheval</span> <span class="hps">de la jonction avec</span> <span class="hps">le caecum</span> <span class="hps">vers</span> <span class="hps">le foie</span> <span class="hps alt-edited">dans</span> la <span class="hps">partie avant</span> <span class="hps">de la cavité abdominale</span>. <span class="hps">Ensuite, il</span> <span class="hps alt-edited">continue vers</span> <span class="hps">la</span> <span class="hps">flexion</span> <span class="hps alt-edited">pelvienne</span> <span class="hps">à l'arrière de</span> <span class="hps">la cavité abdominale,</span> <span class="hps">puis</span> <span class="hps">de nouveau</span> <span class="hps">vers l'avant</span> <span class="hps alt-edited">pour se vider</span> <span class="hps">enfin</span> <span class="hps">dans le rectum.</span></span><br /><br /></p>
<p style="text-align: justify;"><span id="result_box" lang="fr"><span class="hps">Les</span> <span class="hps">chambres de fermentation</span> <span class="hps">ont une population</span> <span class="hps">dense en</span> <span class="hps alt-edited">microorganismes</span> <span class="hps atn">(</span><span>bactéries et protozoaires</span><span>, tableau 5)</span> <span class="hps">qui digèrent</span> <span class="hps">les glucides</span> <span class="hps">fibreux tels</span> <span class="hps">que la cellulose</span><span>,</span> <span class="hps">l'hémicellulose et</span> <span class="hps">pectines</span> <span class="hps alt-edited">aucun d'eux</span> <span class="hps alt-edited">n'étant découpés</span> <span class="hps">dans l'intestin grêle</span><span>.</span> <span class="hps">Le cheval</span><span>,</span> <span class="hps">comme tous les autres</span> <span class="hps">animaux herbivores</span><span>,</span> <span class="hps">dépend</span> <span class="hps">des enzymes microbiennes</span> <span class="hps">pour extraire</span> <span class="hps">l'énergie</span> <span class="hps">de ces</span> <span class="hps">hydrates de carbone fibreux</span><span>.</span> <span class="hps alt-edited">Aucune</span> <span class="hps">digestion de la cellulose</span> <span class="hps alt-edited">ne pourrait avoir lieu</span> <span class="hps">dans un</span> <span class="hps alt-edited">gros intestin</span> <span class="hps">stérile.</span></span><br /><br /><strong>pH<span id="result_box" lang="fr"><span class="hps alt-edited">,</span> <span class="hps">concentration en ammoniac</span><span>,</span> <span class="hps alt-edited">et nombre de</span> <span class="hps">microbes dans</span> <span class="hps">le</span> <span class="hps">digesta</span> <span class="hps">dans</span> <span class="hps">différentes parties du</span> <span class="hps">tube digestif</span> <span class="hps">d'un cheval</span> <span class="hps">sur</span> <span class="hps">une</span> <span class="hps">ration</span> <span class="hps">de</span> <span class="hps alt-edited">foin </span><span>:</span></span> <br /></strong></p>
<table style="width: 453px; height: 160px;" border="1">
<tbody style="text-align: left;">
<tr style="text-align: left;">
<td style="text-align: left;">Intestin grêle</td>
<td style="text-align: left;">Caecum</td>
<td style="text-align: left;">Côlon</td>
<td style="text-align: left;">pH</td>
</tr>
<tr style="text-align: left;">
<td style="text-align: left;">7.4</td>
<td style="text-align: left;">6.6</td>
<td style="text-align: left;">6.6</td>
<td style="text-align: left;">pH</td>
</tr>
<tr style="text-align: left;">
<td style="text-align: left;">52</td>
<td style="text-align: left;">29</td>
<td style="text-align: left;">54</td>
<td style="text-align: left;">Ammoniac-N, mg/l</td>
</tr>
<tr style="text-align: left;">
<td style="text-align: left;">36</td>
<td style="text-align: left;">492</td>
<td style="text-align: left;">363</td>
<td style="text-align: left;">Bactéries/gramme x 10E+6</td>
</tr>
<tr style="text-align: left;">
<td style="text-align: left;">0.9</td>
<td style="text-align: left;">2.6</td>
<td style="text-align: left;">21.4</td>
<td style="text-align: left;">E. Coli/ gram x 10E+6</td>
</tr>
<tr style="text-align: left;">
<td style="text-align: left;">0</td>
<td style="text-align: left;">5600</td>
<td style="text-align: left;">0</td>
<td style="text-align: left;">Protozoaires/ gramme</td>
</tr>
</tbody>
</table>
<p>&nbsp;</p>
<p style="text-align: justify;"><span id="result_box" lang="fr"><span class="hps">La concentration des</span> <span class="hps">microbes dans</span> <span class="hps atn alt-edited">le </span><span class="alt-edited">gros intestin</span> <span class="hps alt-edited">du </span> <span class="hps">cheval</span> <span class="hps">est approximativement la même</span> <span class="hps">que celle trouvée</span> <span class="hps">dans les estomacs</span> <span class="hps">des ruminants.</span> <span class="hps">L'activité</span> <span class="hps alt-edited">et le nombre de</span> <span class="hps">microorganismes sont</span> <span class="hps">fortement dépendants des</span> <span class="hps">nutriments</span> <span class="hps">qui atteignent</span> <span class="hps atn alt-edited">le </span><span class="alt-edited">gros intestin</span> <span class="hps">avec le contenu</span> <span class="hps">de l'iléon</span><span>,</span> <span class="hps alt-edited">la vitesse</span> <span class="hps">de passage</span>, <span class="hps">et la capacité de</span> <span class="hps alt-edited">tamponnage</span> <span class="hps">des glandes</span> <span class="hps">de la paroi intestinale</span><span>.</span> <span class="hps">Une croissance microbienne</span> <span class="hps">efficace</span> <span class="hps">dépend d'un</span> <span class="hps">approvisionnement adéquat</span> <span class="hps">d'azote</span> <span class="hps">(comme</span> <span class="hps">les protéines, les</span> <span class="hps">acides aminés</span> <span class="hps">ou des ions ammonium</span><span>)</span><span>.</span> <span class="hps">Une certaine quantité</span> <span class="hps">d'hydrates de carbone</span> <span class="hps">facilement</span> <span class="hps">fermentescibles</span> <span class="hps">(amidon</span> <span class="hps">et</span> <span class="hps">monosaccharides)</span> <span class="hps">permettra d'accélérer</span> <span class="hps">la croissance bactérienne et</span> <span class="hps">la synthèse des protéines</span><span>.</span></span></p>
<p style="text-align: justify;"><br /><span id="result_box" lang="fr"><span class="hps alt-edited">Les acides gras</span> <span class="hps atn alt-edited">à courte chaîne (</span><span>acétate</span><span>,</span> <span class="hps">propionate</span><span>,</span> <span class="hps">butyrate</span> <span class="hps">et</span> <span class="hps">lactate</span><span>)</span> <span class="hps alt-edited">qui sont produits</span> <span class="hps alt-edited">par les bactéries</span> <span class="hps">durant</span> <span class="hps">la digestion des fibres</span> <span class="hps">sont absorbés dans</span> <span class="hps">la circulation sanguine</span> <span class="hps">et utilisés</span> <span class="hps">comme source d'énergie</span> <span class="hps">par</span> <span class="hps alt-edited">le </span> <span class="hps">cheval</span><span>.</span> <span class="hps">Les bactéries</span> <span class="hps">synthétisent</span> <span class="hps">aussi</span> <span class="hps">de grandes quantités de</span> <span class="hps">vitamines</span> <span class="hps alt-edited">hydrosolubles</span> <span class="hps alt-edited">du </span> <span class="hps">complexe B</span> <span class="hps">(tableau 6)</span><span>,</span> <span class="hps">mais</span> <span class="hps alt-edited">la mesure où</span> <span class="hps alt-edited">celles-ci</span> <span class="hps alt-edited">sont absorbées</span> <span class="hps alt-edited">n'est pas connue</span><span>.</span> <span class="hps">Cependant, les chevaux</span> <span class="hps alt-edited">ayant</span> <span class="hps">une charge de travail</span> <span class="hps">normale</span> <span class="hps">ne connaissent</span> <span class="hps">pas</span> <span class="hps alt-edited">de carences en vitamine</span> <span class="hps">B ou C</span><span>.</span> <span class="hps alt-edited">Les chevaux</span> <span class="hps alt-edited">utilisés</span> <span class="hps alt-edited">pour des exercices intenses</span> <span class="hps alt-edited">ou des compétitions en</span> <span class="hps">endurance</span> <span class="hps alt-edited">sont souvent supplémentés avec</span> <span class="hps alt-edited">des compléments vitaminiques</span><span class="alt-edited">, bien qu'</span><span class="hps alt-edited">aucune exigence</span> <span class="hps alt-edited">précise pour celles-ci</span><span class="hps"></span> <span class="hps alt-edited">n'ait été donnée</span> <span class="hps">dans la littérature internationale</span><span>.</span></span><br /><br /></p>
<p><strong><span id="result_box" lang="fr"><span class="hps alt-edited">Concentrations en</span> <span class="hps">vitamines B</span> <span class="hps">dans les aliments</span> <span class="hps">et</span> <span class="hps">le contenu intestinal</span> <span class="hps">en mg /</span> <span class="hps">kg de matière sèche</span></span></strong></p>
<table style="width: 492px; height: 212px;" border="1">
<tbody style="text-align: left;">
<tr style="text-align: left;">
<td style="text-align: center;">Vitamine</td>
<td style="text-align: center;">Aliment</td>
<td style="text-align: center;">Caecum</td>
<td style="text-align: center;">Début du Côlon </td>
<td style="text-align: center;">Fin du Côlon</td>
</tr>
<tr style="text-align: left;">
<td style="text-align: center;">B1</td>
<td style="text-align: center;">1.1</td>
<td style="text-align: center;">7.1</td>
<td style="text-align: center;">7.8</td>
<td style="text-align: center;">7.8</td>
</tr>
<tr style="text-align: left;">
<td style="text-align: center;">B2</td>
<td style="text-align: center;">0.4</td>
<td style="text-align: center;">7.0</td>
<td style="text-align: center;">9.2</td>
<td style="text-align: center;">12.2</td>
</tr>
<tr style="text-align: left;">
<td style="text-align: center;">B6</td>
<td style="text-align: center;">0.2</td>
<td style="text-align: center;">2.4</td>
<td style="text-align: center;">6.1</td>
<td style="text-align: center;">6.2</td>
</tr>
<tr style="text-align: left;">
<td style="text-align: center;">Acide Nicotinique</td>
<td style="text-align: center;">3.0</td>
<td style="text-align: center;">121.0</td>
<td style="text-align: center;">96.0</td>
<td style="text-align: center;">119.0</td>
</tr>
<tr style="text-align: left;">
<td style="text-align: center;">Acide Pantothénique</td>
<td style="text-align: center;">0.8</td>
<td style="text-align: center;">39.2</td>
<td style="text-align: center;">34.4</td>
<td style="text-align: center;">20.5</td>
</tr>
<tr style="text-align: left;">
<td style="text-align: center;">Biotine</td>
<td style="text-align: center;">0.01</td>
<td style="text-align: center;">0.2</td>
<td style="text-align: center;">3.8</td>
<td style="text-align: center;">2.3</td>
</tr>
<tr style="text-align: left;">
<td style="text-align: center;">Acide folique</td>
<td style="text-align: center;">0.1</td>
<td style="text-align: center;">3.0</td>
<td style="text-align: center;">4.7</td>
<td style="text-align: center;">
<p>2.7</p>
<p>&nbsp;</p>
</td>
</tr>
</tbody>
</table>
<p style="text-align: justify;"><br /><span id="result_box" lang="fr"><span class="hps">Dans la seconde moitié</span> <span class="hps">du tube digestif</span> <span class="hps">les fèces</span> <span class="hps alt-edited">s'assèchent</span> <span class="hps">progressivement en raison de</span> <span class="hps atn">l'absorption de l'</span><span>eau et des ions</span><span>.</span></span></p>