JavaScript does not show menu

My menu code:

        <!-- SIDEBAR -->
    <div id="wrapper" class="toggled">

        <!-- Sidebar -->
        <div id="sidebar-wrapper" class="blue-grey darken-4">
            <ul class="sidebar-nav">
                <li>
                    <div id="info-user-menu">
                        <img src="assets/imagens/boi.png" alt="" class="circle center" id="perfil-sidebar">
                        <h6 class="white-text center" id="user-name-sidebar">Menu</h6>
                    </div>
                </li>

                <li class="indent">
                    <a href="javascript:void(0)" class="master-menu">
                        Animais
                        <i class="material-icons right">add</i>
                    </a>
                    <ul class="child-menu blue-grey darken-3">
                        <li>
                            <a href="javascript:void">
                            <span>Lotes</span>
                            <i class="material-icons right">person</i>
                            </a>
                        </li>
                    </ul>
                </li>

            </ul>
        </div>
    </div>

        <!-- HEADER -->
        <header class="navbar-fixed">
            <nav class="blue darken-2">
                <div class="nav-wrapper">
                    <ul>
                        <li>
                            <a href="javascript:void(0)" id="btn-sidebar">
                                <i class="material-icons">dehaze</i>
                            </a>
                        </li>
                        <li>
                            <a href="javascript:void(0)" id="header-logo">SISTEMA BRAVO</a>
                        </li>
                    </ul>
                    <ul class="right">
                        <li>
                            <a href="javascript:void(0)">
                                <i class="material-icons left">directions_run</i>
                                <!--<span class="new badge amber">Sair</span> -->
                            </a>
                        </li>

                    </ul>
            </nav>
</header>

My JS code:

$(document).ready(function(){
$('#btn-modal-footer').leanModal();
$('#btn-dropdown-animais').dropdown();

});



$('.master-menu').click(function(e){
e.preventDefault();
$(this).next('ul').slideToggle('slow');
$('.child-menu').not($(this).next()).slideUp('slow');
});

$('#btn-sidebar').click(function(e){
e.preventDefault();
$('#wrapper').toggleClass('toggled');
$('#btn-sidebar').toggleClass('toggled');
});

My problem is that the menu does not descend for example when clicking on animals should appear the menu lots, and where should make the menu appear if I take the toggled class it does not appear when clicking, can anyone identify the error? I am a beginner .. I am about 3 hours doing this following a tutorial I have already reviewed it several times I do not understand why it does not work, I would appreciate it if you could help me.