TITLE:
Age and Gender Dependent Amino Acid Concentrations in the Feather, Feather-Free and Whole Empty Body Protein of Fast Growing Meat-Type Chickens
AUTHORS:
Christian Wecke, Daulat Rehman Khan, Angela Sünder, Frank Liebert
KEYWORDS:
Growing Chickens, Feather Amino Acids, Body Amino Acids, Age, Gender
JOURNAL NAME:
Open Journal of Animal Sciences,
Vol.8 No.3,
July
4,
2018
ABSTRACT: Two consecutive growth
experiments with meat-type chickens (Ross 308) were conducted in order to
quantify the age-dependent amino acid (AA) content in the whole body protein of
male and female birds based on experimental data of the feather and
feather-free body protein fractions. Birds were reared under uniform housing
and feeding conditions (floor pens, 15 pens per gender, 5 birds per pen) during
the starter (day 1 to 22) and grower period (day 22 to 36). Both the starter
and grower diet based on corn, wheat, soybean meal, soybean protein concentrate
and feed amino acids was formulated to ensure an equal feed protein quality close
to the ideal amino acid ratio by adjusting a constant mixture of the feed
proteins. At start of the experiment and further on weekly up to the end of the
5th week, 15 birds per gender (each 3 pens of 5 birds) were selected
and fasted for 24 h, to emptying of gastro-intestinal tract, respectively.
Subsequently, birds were euthanized and the feathers were manually removed.
Nitrogen (N) and AA content were determined both in the feather and
feather-free body fraction. The concentration of individual AAs in both of body
protein fraction is varying considerably. Explicitly higher Cys, Ser and Pro but
importantly lower Met, Lys and His concentrations were found in the feather
protein. Furthermore, significant differences (p for nearly all AAs of the studied body protein fractions and the whole empty body protein dependent on age of birds were
observed. Especially high deviations were obtained during the first week of age
and at the end of the experiment. According to this observed variation of AA
concentrations must be concluded that the body AA composition of meat-type
chickens during growth is not constant. The detected gender-specific
differences for several AAs in the feather and body protein of male and female
birds were rather low and with very low variation.