scholarly journals Effects of Dietary Protein Under High Ambient Temperature on Body Weight, Breast Meat Yield, and Abdominal Fat Deposition of Broiler Stocks Differing in Growth Rate and Fatness

1995 ◽  
Vol 74 (6) ◽  
pp. 968-975 ◽  
Author(s):  
A. CAHANER ◽  
Y. PINCHASOV ◽  
I. NIR ◽  
ZAFRIRA NITSAN
1988 ◽  
Vol 68 (3) ◽  
pp. 881-889 ◽  
Author(s):  
S. LEESON ◽  
L. J. CASTON ◽  
J. D. SUMMERS

Two experiments were conducted to note the broilers' response to graded levels of dietary protein (CP). Female birds were fed one of six diet series ranging from 22–20–18 to 18–18–16% CP from 0–21 days, 21–35 days and 35–42 days, respectively. Males were fed diet series from 28–24–22 to 20–18–16 over the same time periods (Table 1). Each diet program was tested with four replicate groups of 60 birds. Body weight and feed intake were monitored at time of feed change-over and at termination of experiment. Twenty birds per replicate were used for carcass analyses. Females were heavier when diets of higher protein content were offered (P < 0.05). These birds consumed more feed (P < 0.05) but exhibited feed efficiency that was not different to birds fed diets of lower protein content. Carcass weight and breast meat yield were not influenced by diet, although higher-protein diet series resulted in reduced proportional abdominal fat pad size (P < 0.01). Diet protein had no effect on body weight of male birds at 42 d (P > 0.05). Male birds reared on a program involving die lowest CP levels of 20–18–16 exhibited inferior feed utilization relative to birds from most other treatments (P < 0.05). Programs with low-protein diets for males resulted in reduced carcass weight, reduced breast meat yield and increased abdominal fat deposition (P < 0.05). It is concluded that male birds can be reared on very low protein diets without loss of weight, although carcass quality will be inferior. Female broilers are heavier when diet protein intake is increased through use of diets with higher protein content. Key words: Broiler, diet protein, performance, carcass composition


Author(s):  
Jiří Zelenka ◽  
Jaroslav Heger ◽  
Vlastislav Machander ◽  
Markus Wiltafsky ◽  
Martin Lešták

An experiment with broiler chickens was conducted to compare the relative bioavailability of liquid methionine hydroxy analogue free acid (MHA-FA) with that of DL-methionine (DLM) during fattening to 35 days of age. Ross 308 male chicks were allotted to 9 treatments, each consisting of six replicates of 140 birds/pen. Four graded levels (0.04, 0.08, 0.16, and 0.28 %) of MHA-FA or DLM products (weight/weight comparison) were added to a maize-wheat-soyabean meal basal diet deficient in sulphur amino acids. The criteria of response were body weight, feed conversion ratio, carcass yield and breast meat yield. Significant responses to graded levels of both methionine sources were observed in all response criteria. Using a multi-exponential model describing the dose-response relationships, the bioavailability estimates of MHA-FA relative to DLM on a weight-to-weight basis were 68, 70, 54 and 59 % for body weight, feed conversion, carcass yield and breast meat yield, respectively. If MHA-FA was compared with DLM on equimolar basis its bioavailability was 77.7, 79.0, 59.3 and 64.6 for body weight, feed conversion, carcass yield and breast meat yield, respectively. The bioavailability of MHA-FA for carcass yield and breast meat yield was significantly (P < 0.05) lower than that of DLM on a weight-to-weight and on equimolar basis.


BMC Genetics ◽  
2011 ◽  
Vol 12 (1) ◽  
pp. 14 ◽  
Author(s):  
Muhammad L Aslam ◽  
John WM Bastiaansen ◽  
Richard PMA Crooijmans ◽  
Bart J Ducro ◽  
Addie Vereijken ◽  
...  

2014 ◽  
Vol 30 (3) ◽  
pp. 473-479
Author(s):  
Z. Pavlovski ◽  
Z. Skrbic ◽  
M. Lukic ◽  
V. Petricevic ◽  
A. Stanojkovic

The aim of this study was to investigate the effect of conformation of chickens of different genotype on the yield of breast meat. As a typical example of the chickens of very poor conformation pure breed Naked neck chickens were taken, fattened 8 and 10 weeks (groups K8 and K10). As an example of good conformation, an imported hybrid of chickens was taken, known for its broiler qualities and as medium growing hybrid, Red Bro (R). The second experiment included commercial hybrids of fast growth (Ross, Cobb and Hubbard) reared according to all technological standards of intensive fattening until the age of 42 days. The results obtained were contrary to the conclusion obtained a few decades ago, at the beginning of the study the conformation of chicken, by Scots and Darrow (1953), according to which the selection of chickens of heavy type, despite the fact that, to some extent, it had improved meat yield of the breast, did not significantly improve slaughter traits of fattening chickens, confirming that better conformation and higher body weight had a positive impact on improving relative share of breast, i.e. white meat. The results regarding the slaughter traits of chicken genotypes of different conformation suggest that breeding - selection work to improve the conformation of broilers significantly improved slaughter yields and breast meat yield. In this sense, the conformation can be treated as an indicator of the slaughter value of carcasses, rather than an aesthetic category.


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