Manure Pit Temperatures and Relative Humidity of Pennsylvania High-Rise Poultry Houses and Their Relationship to Arthropod Population Development

Abstract

Air temperature and relative humidity (RH) in the manure pits of five central Pennsylvania high-rise poultry houses were measured for at least one year to evaluate the role of the pit environment in the development of manure breeding flies and litter beetles. Pit air temperatures had weekly means ranging between 18.1 and 22.2 C. Seasonal temperature trends were similar at all farms, decreasing in winter and rising in summer. Maximum pit temperatures ranged from 31.7 to 33.3 C and minimum temperatures from .6 to 5.6 C, but these extremes were rare. Three houses had weekly mean RH ca 65%, one ca 61%, and one ca 72%. No seasonal RH trends were evident. Daily temperature fluctuations were lowest at ca 0600 to 0700 h, peaked ca 1700 h, and varied inversely with RH. Pit air temperatures dropped below house fly reproductive thresholds for several weeks during the winter, but were adequate for their survival all year around.Manure temperatures were affected by the shape of the manure pile, depth of the manure, and seasonal air temperature patterns. Manure temperatures differed significantly between houses with either shallow (without scraper boards, χ̄ ca 16 to 19 C) or deep (with scraper boards, χ̄ ca 30 to 40 C) manure profiles. Shallow manure profile temperatures severely limit fly larvae and litter beetle development.