University of SaskatchewanHARVEST
  • Login
  • Submit Your Work
  • About
    • About HARVEST
    • Guidelines
    • Browse
      • All of HARVEST
      • Communities & Collections
      • By Issue Date
      • Authors
      • Titles
      • Subjects
      • This Collection
      • By Issue Date
      • Authors
      • Titles
      • Subjects
    • My Account
      • Login
      JavaScript is disabled for your browser. Some features of this site may not work without it.
      View Item 
      • HARVEST
      • Electronic Theses and Dissertations
      • Graduate Theses and Dissertations
      • View Item
      • HARVEST
      • Electronic Theses and Dissertations
      • Graduate Theses and Dissertations
      • View Item

      Physiological and nutritional factors affecting protein digestion in broiler chickens

      Thumbnail
      View/Open
      JMRMScThesis.pdf (483.1Kb)
      Date
      2009-07
      Author
      Rynsburger, Joni Maria
      Type
      Thesis
      Degree Level
      Masters
      Metadata
      Show full item record
      Abstract
      A series of experiments were conducted to examine protein digestion in the young bird and the physiological changes that affect protein digestion as the bird matures. Trial one determined the effect of age on pH of the gastrointestinal tract. The results showed that the pH of the proventriculus and gizzard decreases with age suggesting that gastric acid secretion increases proportionally with age and this may impact protein digestion. Experiment two examined the effect of age on ileal amino acid (AA) digestibility of feed ingredients. AA digestibility increased from 5 to 21 d and the degree of improvement differed among ingredients and specific AA. This finding coupled with the low AA content of some ingredients demonstrates the importance of using appropriate nutrient digestibility values for young birds when formulating pre-starter and starter diets. Experiment three determined the acid binding capacity (ABC) of feed ingredients and the effect of formulating diets based on ABC on diet ABC, gastrointestinal pH and performance. The research confirmed dramatic differences in ABC among ingredients and that diets could be formulated on the basis of ingredient ABC. However, the range in diet ABC was less than predicted suggesting interactive effects among ingredients. Intestinal pH was reduced however broiler performance was not improved when diets low in ABC were fed. Experiment four examined the effect of diet acidification with HCl on diet ABC, gastrointestinal pH, ileal amino acid digestibility and broiler performance. Improvements in performance and reductions in mortality were observed when broilers were fed acidified diets. Adding acid to diets did not improve AA digestibility and therefore was not the reason for improved performance indicating an alternative mechanism of action. It is concluded that acid production by the proventriculus of young birds is low and increases with age however this does not impact protein digestion. Methods of improving performance of broiler chickens may include diet acidification however this is not the effect of remedying the low acid production by young birds. Therefore, alternative mechanisms are positively affecting broiler performance.
      Degree
      Master of Science (M.Sc.)
      Department
      Poultry Science
      Program
      Poultry Science
      Supervisor
      Classen, H.L.
      Committee
      Korver, D.; Hamilton, D.; Laarveld, B.; Drew, M.
      Copyright Date
      July 2009
      URI
      http://hdl.handle.net/10388/etd-09182009-184057
      Subject
      Broiler chickens
      Intestinal pH
      Diet acidification
      Acid binding capacity
      Ileal amino acid digestiblity
      Collections
      • Graduate Theses and Dissertations
      University of Saskatchewan

      University Library

      © University of Saskatchewan
      Contact Us | Disclaimer | Privacy