Document Detail

Estimation of nitrogen maintenance requirements and potential for nitrogen deposition in fast-growing chickens depending on age and sex.
MedLine Citation:
PMID:  16903472     Owner:  NLM     Status:  MEDLINE    
Experiments were conducted to estimate daily N maintenance requirements (NMR) and the genetic potential for daily N deposition (ND(max)T) in fast-growing chickens depending on age and sex. In N-balance studies, 144 male and 144 female chickens (Cobb 500) were utilized in 4 consecutive age periods (I: 10 to 25 d; II: 30 to 45 d; III: 50 to 65 d; and IV: 70 to 85 d). The experimental diets contained high-protein soybean meal and crystalline amino acids as protein sources and 6 graded levels of protein supply (N1 = 6.6%; N2 = 13.0%; N3 = 19.6%; N4 = 25.1%; N5 = 31.8%; and N6 = 37.6% CP in DM). The connection between N intake and total N excretion was fitted for NMR determination by an exponential function. The average NMR value (252 mg of N/BW(kg)0.67 per d) was applied for further calculation of ND(max)T as the threshold value of the function between N intake and daily N balance. For estimating the threshold value, the principle of the Levenberg-Marquardt algorithm within the SPSS program (Version 11.5) was applied. As a theoretical maximum for ND(max)T, 3,592, 2,723, 1,702, and 1,386 mg of N/BW(kg)0.67 per d for male and 3,452, 2,604, 1,501, and 1,286 mg of N/BW(kg)0.67 per d for female fast-growing chickens (corresponding to age periods I to IV) were obtained. The determined model parameters were the precondition for modeling of the amino acid requirement based on an exponential N-utilization model and depended on performance and dietary amino acid efficiency. This procedure will be further developed and applied in the subsequent paper.
F Samadi; F Liebert
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Poultry science     Volume:  85     ISSN:  0032-5791     ISO Abbreviation:  Poult. Sci.     Publication Date:  2006 Aug 
Date Detail:
Created Date:  2006-08-14     Completed Date:  2006-09-07     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  0401150     Medline TA:  Poult Sci     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1421-9     Citation Subset:  IM    
Institute for Animal Physiology and Animal Nutrition, Georg-August-University, 37073 Goettingen, Germany.
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MeSH Terms
Age Factors
Amino Acids / metabolism
Animal Feed
Animal Nutritional Physiological Phenomena
Chickens* / genetics,  growth & development,  metabolism
Dietary Proteins / administration & dosage*,  metabolism
Energy Intake
Models, Biological
Nitrogen / administration & dosage*,  metabolism*
Nutritional Requirements*
Nutritional Status
Predictive Value of Tests
Random Allocation
Sex Factors
Weight Gain / drug effects
Reg. No./Substance:
0/Amino Acids; 0/Dietary Proteins; 7727-37-9/Nitrogen

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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