<p style="text-align: justify;"><span id="result_box" lang="fr"><span class="hps">La</span> <span class="hps">digestion des protéines</span> <span class="hps">commence</span> <span class="hps">dans l'estomac,</span> <span class="hps">et</span> <span class="hps alt-edited">se poursuit</span> <span class="hps">dans l'intestin</span> <span class="hps">par les enzymes</span> <span class="hps">pancréatiques.</span> <span class="hps">Les protéines</span> <span class="hps">doivent être</span> <span class="hps alt-edited">réduites</span> <span class="hps">à leurs</span> <span class="hps alt-edited">éléments de base,</span> <span class="hps">les</span> <span class="hps">acides aminés</span><span>,</span> <span class="hps">avant qu'ils puissent être</span> <span class="hps">absorbés et utilisés</span><span>.</span></span></p>
<p style="text-align: justify;">&nbsp;</p>
<p style="text-align: justify;"><span id="result_box" lang="fr"><span id="result_box" lang="fr"><span class="hps">Lorsque le</span> <span class="hps">digesta</span> <span class="hps">arrive à la fin</span> <span class="hps">de l'intestin grêle</span> <span class="hps">environ</span> <span class="hps">2/3</span> <span class="hps">de la protéine</span> <span class="hps">digestible</span> <span class="hps alt-edited">des</span> <span class="hps">grains</span> <span class="hps">et des</span> <span class="hps">suppléments en protéines</span> <span class="hps alt-edited">auront été</span> <span class="hps alt-edited">absorbés</span> <span class="hps">par rapport à seulement</span> <span class="hps">un tiers</span> <span class="hps">de celle des</span> <span class="hps">fibres.</span> <span class="hps">En plus de</span> <span class="hps">l'azote</span> <span class="hps alt-edited">alimentaire</span> <span class="hps alt-edited">non digéré</span><span>, le contenu de</span> <span class="hps">l'iléon</span> <span class="hps">contient</span> <span class="hps">également de l'azote</span> <span class="hps">d'origine</span> <span class="hps">endogène</span><span>, à savoir</span> <span class="hps">de l'azote</span> <span class="hps">qui est dérivé de</span> <span class="hps">l'urée sanguine</span><span>,</span> <span class="hps">sécrétée</span> <span class="hps">dans</span> <span class="hps">le</span> <span class="hps">tube digestif,</span> <span class="hps">et</span> <span class="hps">à partir de cellules</span> é<span class="hps">pithéliales</span> <span class="hps">desquamées</span>.</span></span><br /><span id="result_box" lang="fr"><span title="The bacteria require nitrogenous compounds for the production of amino acids which are integral components of their enzymes and structural proteins."><span id="result_box" lang="fr"><span class="hps"></span></span></span></span></p>
<p style="text-align: justify;">&nbsp;</p>
<p style="text-align: justify;"><span id="result_box" lang="fr"><span title="The bacteria require nitrogenous compounds for the production of amino acids which are integral components of their enzymes and structural proteins."><span id="result_box" lang="fr"><span class="hps">Les bactéries</span> <span class="hps">qui peuplent</span> <span class="hps alt-edited">le </span><span class="alt-edited">gros intestin</span> <span class="hps">ont</span> <span class="hps alt-edited">une durée de vie courte</span>, <span class="hps">seulement quelques heures</span><span>.</span> <span class="hps">Toutes les bactéries</span> <span class="hps">et les protozoaires</span> <span class="hps">sont continuellement</span> <span class="hps">transportés</span> <span class="hps">avec le</span> <span class="hps">digesta</span> <span class="hps">vers l'anus</span><span>.</span> <span class="hps alt-edited">Seules les </span> <span class="hps">bactéries</span> <span class="hps alt-edited">ayant un taux</span> <span class="hps">élevé de</span> <span class="hps atn">multiplication (</span><span>ou</span> <span class="hps">mécanismes</span> <span class="hps">pour la fixation à</span> <span class="hps">la paroi intestinale</span><span>)</span> <span class="hps">seront donc</span> <span class="hps">en mesure de vivre</span> <span class="hps">dans le gros intestin</span> <span class="hps">pour des périodes de</span> <span class="hps">temps prolongées</span><span>.</span> <span class="hps">Les</span> <span class="hps">bactéries ont besoin</span> <span class="hps">de composés</span> <span class="hps">azotés</span> <span class="hps">pour la production</span> <span class="hps">d'acides aminés qui</span> <span class="hps">font partie intégrante de</span> <span class="hps">leurs</span> <span class="hps alt-edited">enzymes et</span> <span class="hps">protéines structurales</span>.</span> </span><span title="As a consequence of their ability to synthesise amino acids from ammonia, bacteria significantly change the amino acid composition of the digesta (table 8)"><span id="result_box" lang="fr"><span class="hps alt-edited">Les </span> <span class="hps alt-edited">composés contenant de l'azote</span> <span class="hps">qui entrent dans le</span> <span class="hps alt-edited">gros intestin</span> <span class="hps alt-edited">seront découpés</span> <span class="hps">par les enzymes</span> <span class="hps">microbiennes</span> <span class="hps alt-edited">en acides aminés</span> <span class="hps">ou</span> <span class="hps alt-edited">encore dégradés</span> <span class="hps alt-edited">en ammoniac</span><span>.</span> <span class="hps alt-edited">Acides aminés et</span> <span class="hps alt-edited">ammoniac</span> <span class="hps">sont utilisés par</span> <span class="hps">les mêmes types de</span> <span class="hps">bactéries dans</span> <span class="hps">la production de protéines</span> <span class="hps">bactériennes.</span> <span class="hps">Contrairement aux</span> <span class="hps">ruminants</span><span class="alt-edited">, les chevaux ne sont</span> <span class="hps">pas</span> <span class="hps">en mesure d'utiliser</span> <span class="hps">des protéines bactériennes</span><span>, étant donné que</span> <span class="hps">l'absorption</span> <span class="hps">d'acides aminés dans</span> <span class="hps atn alt-edited">le </span><span class="alt-edited">gros intestin</span>, <span class="hps">où se trouvent ces</span> <span class="hps">acides aminés</span> <span class="hps alt-edited">microbiens</span>, <span class="hps">est négligeable.</span> <span class="hps">L'ammoniac</span> <span class="hps">formé à partir de</span> <span class="hps">protéines microbiennes</span> <span class="hps">est</span> <span class="hps">toutefois</span> <span class="hps alt-edited">recyclé dans</span> <span class="hps">l'intestin</span> <span class="hps">sous forme d'urée</span>, <span class="hps">et</span> <span class="hps">peut</span> <span class="hps">fournir</span> <span class="hps">une source d'azote</span> <span class="hps alt-edited">importante</span> <span class="hps alt-edited">aux </span> <span class="hps">chevaux</span> <span class="hps">qui sont</span> <span class="hps">nourris avec des aliments</span> <span class="hps">à faible teneur en</span> <span class="hps">azote</span><span>.</span> <span class="hps">Du fait de</span> <span class="hps">leur capacité à</span> <span class="hps">synthétiser des</span> <span class="hps">acides aminés</span> <span class="hps">à partir de</span> <span class="hps">l'ammoniac</span><span>, les bactéries</span> <span class="hps">changent de manière significative</span> <span class="hps">la</span> <span class="hps">composition</span> <span class="hps alt-edited">en acides aminés</span> <span class="hps alt-edited">du</span> <span class="hps">digesta</span> <span class="hps atn">(</span><span>tableau</span> <span class="hps">8</span>)</span></span></span></p>
<p style="text-align: justify;">&nbsp;<br /><strong><span id="result_box" lang="fr"><span class="hps">Teneur en acides aminés</span> <span class="hps">dans l'alimentation</span>, le contenu <span class="hps">du caecum</span> <span class="hps">et</span> <span class="hps">dans</span> les <span class="hps alt-edited">microorganismes</span> <span id="result_box" lang="fr"><span class="hps alt-edited">du </span><span class="hps">caecum</span> </span><span class="hps"></span><span class="hps">des</span> <span class="hps">chevaux</span>.</span></strong><br />Concentrations chaque acide aminé données en % du total des acides aminés (concentrations molaires) :</p>
<table style="width: 602px; height: 186px;" border="1" cellpadding="4" cellspacing="1">
<tbody>
<tr>
<td class="style1" valign="top" width="37%">
<p class="style3">Acide aminé</p>
</td>
<td class="style1" valign="top" width="17%">
<p class="style3">aliment</p>
</td>
<td class="style1" valign="top" width="26%">Contenu Caecal</td>
<td class="style1" valign="top" width="20%">
<p class="style3">Bacterie</p>
</td>
</tr>
<tr>
<td class="style1" valign="top" width="37%">
<p class="style3">Lysine</p>
</td>
<td class="style1" valign="top" width="17%">
<p class="style3">3.13</p>
</td>
<td class="style1" valign="top" width="26%">
<p class="style3">5.82</p>
</td>
<td class="style1" valign="top" width="20%">
<p class="style3">7.06</p>
</td>
</tr>
<tr>
<td class="style1" valign="top" width="37%">
<p class="style3">Thréonine</p>
</td>
<td class="style1" valign="top" width="17%">
<p class="style3">4.28</p>
</td>
<td class="style1" valign="top" width="26%">
<p class="style3">5.37</p>
</td>
<td class="style1" valign="top" width="20%">
<p class="style3">6.70</p>
</td>
</tr>
<tr>
<td class="style1" valign="top" width="37%">
<p class="style3">Isoleucine</p>
</td>
<td class="style1" valign="top" width="17%">
<p class="style3">3.84</p>
</td>
<td class="style1" valign="top" width="26%">
<p class="style3">4.61</p>
</td>
<td class="style1" valign="top" width="20%">
<p class="style3">5.49</p>
</td>
</tr>
<tr>
<td class="style1" valign="top" width="37%">
<p class="style3">Méthionine</p>
</td>
<td class="style1" valign="top" width="17%">
<p class="style3">1.37</p>
</td>
<td class="style1" valign="top" width="26%">
<p class="style3">1.43</p>
</td>
<td class="style1" valign="top" width="20%">
<p class="style3">1.72</p>
</td>
</tr>
<tr>
<td class="style1" valign="top" width="37%">
<p class="style3">Alanine</p>
</td>
<td class="style1" valign="top" width="17%">
<p class="style3">8.47</p>
</td>
<td class="style1" valign="top" width="26%">
<p class="style3">13.60</p>
</td>
<td class="style1" valign="top" width="20%">
<p class="style3">10.70</p>
</td>
</tr>
</tbody>
</table>
<p class="Fetstilsvart">&nbsp;</p>
<p class="Fetstilsvart">&nbsp;</p>