get_page_by_title returns an id not content. here is an example of what I use to get content from a certain page id.
call the function
$page_id = get_page_by_title('title');
$excerpt = get_excerpt_by_id($page_id);
in functions.php
function get_excerpt_by_id($post_id) {
global $wpdb;
$query = "SELECT post_content FROM $wpdb->posts WHERE ID = $post_id LIMIT 1";
$result = $wpdb->get_results($query, ARRAY_A);
return $result[0]['post_content'];
}