Subscribe Now Subscribe Today
Science Alert
 
Blue
   
Curve Top
Asian Journal of Animal and Veterinary Advances
  Year: 2014 | Volume: 9 | Issue: 9 | Page No.: 568-577
DOI: 10.3923/ajava.2014.568.577
 
Facebook Twitter Digg Reddit Linkedin StumbleUpon E-mail

Effects of Dietary Tryptophan Levels and Stocking Density During the Growing-Finishing Phase on Broiler Performance and Immunity

M.R. El- Gogary and M.M. Azzam

Abstract:
A total of 240 Cobb 500 broiler chicks, 18 day old were allocated to 10 treatments groups, each of which included 4 replicates. Experimental treatments consisted of a 5x2 factorial arrangement with 5 levels of L-tryptophan supplementation and 2 levels of stocking density (11.90 birds m-2 as the normal stocking density or 16.66 birds m-2 as the high stocking density). Crystalline L-Trp was added to the basal diet at 0.0 (100%, NRC), 0.25 (114%, NRC), 0.50 (128%, NRC), 0.75 (141%, NRC) and 1.00 (156%, NRC) g kg-1 diet to obtain the dietary Trp level at 1.8, 2.05, 2.3, 2.55 and 2.8 g kg-1. Increasing L-Trp level in the diet did not affect LBW, BWG and FCR (p>0.05). However, feed intake decreased significantly with L-Trp and it was minimized at 0.75 and 1.0 g kg-1 diet. Also, increasing L-Trp level had no effects on immunity, plasma total protein and glucose (GLU). However, adding L-Trp at 0.75 or 1.00 g kg-1 diet increased liver weight. Also, plasma cholesterol (CHO) levels decreased significantly (p<0.05) with L-Trp supplementation and the lowest levels occurred at 0.25 L-Trp (114%, NRC). In addition, plasma triiodothyronine (T3) and thyroxine (T4) levels were higher at 0.75 (141%, NRC) L-Trp supplementation (p<0.05). The normal stocking density resulted in better performance (p<0.05) compared with the high stocking density. However, stocking density did not affect plasma total protein, total Ig, IgG, IgM, GLU, CHO, T3 and T4 levels. Significant interactions between Trp level and stocking density were observed for plasma levels of CHO. Findings suggest that addition of L-Trp up to 0.25 g kg-1 achieve 114% of NRC recommendations of dietary Trp that has a positive effect on decreasing plasma total CHO levels.
PDF Fulltext XML References Citation Report Citation
 RELATED ARTICLES:
  •    Effects of Dietary Threonine Levels and Stocking Density on the Performance, Metabolic Status and Immunity of Broiler Chickens
  •    Influence of Vitamin E Supplementation and Stocking Density on Performance, Thyroid Status, Some Blood Parameters, Immunity and Antioxidant Status in Broiler Chickens
  •    Responses of Modern Broiler Chicks to Stocking Density, Green Tea, Commercial Multi Enzymes and Their Interactions on Productive Performance, Carcass Characteristics, Liver Composition and Plasma Constituents
  •    Influence of Stocking Density and Feed Pellet Quality on Heat Stressed Broilers from 6 to 8 Weeks of Age
How to cite this article:

M.R. El- Gogary and M.M. Azzam, 2014. Effects of Dietary Tryptophan Levels and Stocking Density During the Growing-Finishing Phase on Broiler Performance and Immunity. Asian Journal of Animal and Veterinary Advances, 9: 568-577.

DOI: 10.3923/ajava.2014.568.577

URL: https://scialert.net/abstract/?doi=ajava.2014.568.577

COMMENT ON THIS PAPER
 
 
 

 

 
 
 
 
 
 
 
 
 

 
 
 
 
 
 
 

Curve Bottom