Age and Gender Dependent Amino Acid Concentrations in the Feather, Feather-Free and Whole Empty Body Protein of Fast Growing Meat-Type Chickens

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 5 th 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 < 0.001) 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 differ

Effect of supplemental serine-protease from Bacillus licheniformis on growth performance and physiological change of broiler chickens

“…Therefore, protease supplementation could increase the concentration of free amino acids in breast muscle. It has been reported that the levels of total amino acids in serum, liver, feather, and carcass can reflect the amino acids utilization (Kaczmarek et al 2014;Azzam et al 2015Azzam et al , 2017Dong et al 2016;Morales et al 2017;Wecke et al 2018;Middendorf et al 2019). In addition, amino acids concentrations in carcass could be used to determine amino acid requirements accurately in broiler diets (Stilborn et al 2010;Abd El-Moneim et al 2019;Saleh et al 2019b).…”

Age and Gender Dependent Deposition of Crude Nutrients and Energy in Fast Growing Meat-Type Chickens

“…However, Gous et al [42] and Bonato et al [67] have postulated that the rate of feather protein gain during growth is higher than that for body protein. As already discussed [4] [5], the partitioning of protein in muscle tissues, organs and feathers is differentiates as age advances.…”

“…4 Final body weight of male birds was determined 1 d earlier (see Table 3). 5 Starter period (d 1 -d 22). 6 Grower period (d 22 -d 36).…”

Standardized ileal digestible lysine requirements based on growth performance and histochemical characteristics of male broilers from 10 to 21 d of age

“…(2017) estimated digestible Lys requirements of broilers from 28 to 42 d as 0.879% for BWG, and 0.891% for breast meat yield using a linear broken-line model, which is comparable to the results in the present study. The greater requirement for breast muscle weight compared with BWG may be attributed to the body composition change to more body fat contents as birds aged ( Baker, 1986 ; Wecke et al., 2018 ).…”