javascript / jquery selector for getting control's attribute

I am running Visual Studio 2010.  The problem is I don't know how to get the value of a control's' custom attribute.

Here is my HTML:

<div class="row">
                    <asp:RadioButton runat="server" class="petsRadioButton" ID="rbLiveStock" Text=" Livestock  -  Please Describe: " breedCd="LIVESTOCK" />
                    <asp:TextBox runat="server" ID="txtLivestockDesc" onchange="txtLivestockDesc_Updated(this.value)" style="width:100px; margin-top: 2px;"  />
</div>

I am trying to get the value of breedCd attribute of the radio button above.  
Here is the relevant cut from the page generated by VS:

<div class="row">
                    <span class="petsRadioButton" breedCd="LIVESTOCK"><input id="ctl00_Main_rbLiveStock" type="radio" name="ctl00$Main$rbLiveStock" value="rbLiveStock" /><label for="ctl00_Main_rbLiveStock"> Livestock  -  Please Describe: </label></span>
                    <input name="ctl00$Main$txtLivestockDesc" type="text" id="ctl00_Main_txtLivestockDesc" onchange="txtLivestockDesc_Updated(this.value)" style="width:100px; margin-top: 2px;" />
                       
</div>

Here is my function:

function txtLivestockDesc_Updated(text) {
        debugger
        var radioButtonChecked = false;
        var rbLiveStock = 'ctl00_Main_rbLiveStock';
 
        if (text != null && text.trim() != "") {
            $(rbLiveStock).attr('checked', 'checked');
            radioButtonChecked = true;
        }
        else {
            $(rbLiveStock).attr('checked') ? radioButtonChecked = true : radioButtonChecked = false;
        }
 
        var breedCd1 = $(rbLiveStock).parent().attr('breedCd'); //undefined
        //var breedCd2 = rbLiveStock.parent.getAttribute('breedCd'); // parent is null or not an object
        var breedCd3 = $(rbLiveStock.parent).attr('breedCd'); // undefined
 
        updateAnimalExposureInfo($(rbLiveStock.parent).attr('breedCd'), radioButtonChecked, text);
    }

Please help me get the value of the breedCd attribute.
Thank you.




in the txtLivestockDesc_Updated function:

    function txtLivestockDesc_Updated(text) {
        debugger
        var radioButtonChecked = false;
        var rbLiveStock = '<%=rbLiveStock.ClientID%>';

        if (text != null && text.trim() != "") {
            $(rbLiveStock).attr('checked', 'checked');
            radioButtonChecked = true;
        }
        else {
            $(rbLiveStock).attr('checked') ? radioButtonChecked = true : radioButtonChecked = false;
        }

        var breedCd = $(rbLiveStock.parent).attr('breedCd');
}