Hi Waghmare,
Currently we found two type of animation effects that can be applied to the bootstrap panels so please refer below sample.
HTML
<div>
    <div id="dvAccordian" class="panel-group" style="width: 400px;">
        <asp:Repeater ID="rptAccordian" runat="server">
            <ItemTemplate>
                <div class="panel panel-default">
                    <div class="panel-heading">
                        <h4 class="panel-title">
                            <a class="accordion-toggle collapsed" data-toggle="collapse" data-parent="#dvAccordian"
                                href="#collapse<%# Container.ItemIndex %>">
                                <%# Eval("Title") %></h4>
                        </a> </h4>
                    </div>
                    <div id="collapse<%# Container.ItemIndex %>" class="panel-collapse collapse" aria-expanded="false">
                        <div class="panel-body">
                            <p>
                                <%# Eval("Content") %>
                            </p>
                        </div>
                    </div>
                </div>
            </ItemTemplate>
        </asp:Repeater>
    </div>
    <div>
        <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
        <script type="text/javascript" src="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
        <link rel="stylesheet" href="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" />
        <script type="text/javascript">
            $(document).ready(function () {
                $(".panel").hide().fadeIn('slow'); // or $(".panel").hide().slideToggle('slow');
            });
        </script>
    </div>
</div>
C#
protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        this.BindRepeater();
    }
}
private void BindRepeater()
{
    string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    using (SqlConnection con = new SqlConnection(constr))
    {
        using (SqlCommand cmd = new SqlCommand())
        {
            cmd.CommandText = "select Title, Content from AccordianContent";
            cmd.Connection = con;
            con.Open();
            rptAccordian.DataSource = cmd.ExecuteReader();
            rptAccordian.DataBind();
            con.Close();
        }
    }
}
VB.Net
Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load
    If Not Me.IsPostBack Then
        Me.BindRepeater()
    End If
End Sub
 
Private Sub BindRepeater()
    Dim constr As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
    Using con As New SqlConnection(constr)
        Using cmd As New SqlCommand()
            cmd.CommandText = "select Title, Content from AccordianContent"
            cmd.Connection = con
            con.Open()
            rptAccordian.DataSource = cmd.ExecuteReader()
            rptAccordian.DataBind()
            con.Close()
        End Using
    End Using
End Sub
ScreenShot
