import re


def is_heading(this_line):
    """Determine whether a given line is a section header 
    that describes subsequent lines of a report.
    """

    cattle_clue = '(bulls?|steers?|cows?|heiferettes?|heifers?|calves|pairs?)'
    has_cattle = re.search(cattle_clue, this_line, re.IGNORECASE)
    is_succinct = len(re.split(r'\s{3,}',this_line)) < 3
   
    return bool(has_cattle and is_succinct)