TITLE:
Assessing Lysine Requirement of Growing Chicken by Direct Comparison between Supplementation Technique and “Goettingen Approach”
AUTHORS:
Samadi, Christian Wecke, Anja Pastor, Frank Liebert
KEYWORDS:
Growing Chicken, Lysine Requirement, Supplementation Technique, Diet Dilution Technique, N Utilization Model, Amino Acid Efficiency
JOURNAL NAME:
Open Journal of Animal Sciences,
Vol.7 No.1,
January
16,
2017
ABSTRACT: Validated procedures play an
important role to obtain accurate information about individual amino acid
requirement data. The aim of the present study was to assess lysine (Lys)
requirement of growing chicken both by classical supplementation technique and principles of diet dilution technique as
applied with “Goettingen approach”. During the starter period (1 - 21 d),
a growth study with male meat type chicken (Ross 308) was conducted making use
of five graded dietary Lys-levels (3 repetition boxes with 3 birds/box). L-Lys×HCl was gradually added to a diet based on wheat,
soybean protein concentrate, wheat gluten and fishmeal to yield 80%, 87.5%, 95%,
102.5% and 110% of the expected requirement level (13 g Lys/kg as fed). Diets
were iso-energetic (12.8 MJME/kg) and iso-nitrogenous (21.65% crude protein).
Birds were fed on free choice level also to assess the feed intake (FI) effects
as important factor on traditional response criteria. Analyzed body composition
at start and end of the growth study yielded N deposition (ND) data for further
data assessment using exponential approximations depending on dietary Lys
content or observed Lys intake. The results indicated significant differences (p (BWG, ND) taking also into account the expected real feed intake to formulate the
needed in-feed concentration.