• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1
  • Tagged with
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Effects of dubbing on the production and behavior of chickens maintained in different environments from 20 to 72 weeks of age

Marks, Henry Lewis January 1959 (has links)
Purpose of this study was to (1) compare egg production of dubbed and non-dubbed females, (2) determine the social relationships between and among dubbed and non-dubbed females in large and small flocks maintained under various housing conditions, and (3) determined egg quality, sexual maturity, mortality, body weight and other traits of economic importance in dubbed and non-dubbed chickens. The studio involved two large flocks, each consisting of 170 Leghorn-type hybrid females and eight small flocks each composed of six White Rock females. In all flocks, the combs and wattles were removed from half of the birds. One of the large flocks was housed in a conventional type house while the other was housed in a modified solar house. The results obtained on birds in the large flocks indicate that there were no significant differences between comb treatment for any of the following traits: age of the first egg, age at 50 percent production, fall and spring egg weight, Haugh units, specific gravity, yolk mottling, blood and meat spots, body weight at 72 weeks of age, liveability and fertility. Differences between comb treatments for percentage egg production to 72 weeks of age were also not significant on a yearly basis; however, a significant comb treatment x month interaction was found. The dubbed birds laid at a higher rate during the colder months, while during the warmer months the undubbed females were superior in egg production. A definite effect from dubbing was observed in the social behavior in both the large and small flocks. In both types of flocks, the dubbed birds were subordinate to non-dubbed ones. Chickens maintained in the conventional type house reached sexual maturity significantly later and weighed significantly less than those in the modified solar house. The moisture content of the litter in the former house was significantly higher than that in the latter house during the colder months of the year. Differences between houses for other traits measured were not significant. / M.S.

Page generated in 0.0386 seconds