HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Zhang, X. Articles by Roland, D. A. Search for Related Content PubMed Articles by Zhang, X. Articles by Roland, D. A.

Responses of Broiler Lines Selected for Tibial Dyschondroplasia Incidence to Supplementary 25-Hydroxycholecalciferol

Department of Poultry Science, Alabama Agricultural Experiment Station, Auburn University, AL 36849-5416; Phone: (334) 844-2634; FAX: (334) 844-2641

Correspondence: X. Zhang

The effect of 25-hydroxycholecalciferol (25-OH-D₃) on tibial dyschondroplasia (TD) incidence was evaluated by a factorial experiment of two broiler lines and three diets. Birds from lines with high (HTD) and a low (LTD) incidence of TD were fed three diets (69 µg/kg basal level of vitamin D₃ plus 25-OH-D₃ at 0, 69, and 345 µg/kg finished feed, respectively). Supplemented 25-OH-D₃ decreased TD incidence in LTD line birds, but not in HTD line birds. The relationship between amount of supplementary 25-OH-D₃ and reduction of TD incidence was largely linear in LTD line males and greatly quadratic in LTD line females. Each increase of 10 µg 25-OH-D₃/kg feed, up to 70 µg/kg, is predicted to decrease TD incidence by about 1 and 2% in LTD line female and male birds, respectively. The magnitude by which 25-OH-D₃ supplementation can decrease TD incidence might be affected by age and genetic background of broiler chicks.

Key Words: Broiler • genetic selection • tibial dyschondroplasia • 25-hydroxycholecalciferol