TY - JOUR
T1 - Feeding broiler chicks diets containing keto- and hydroxy-acids
T2 - performance and carcass weight
AU - Adrizal, A.
AU - Patterson, P. H.
AU - Angel, C. R.
AU - Markant, A.
N1 - Funding Information:
We gratefully acknowledge the supply of MHA, keto-acids, and some L-AA from Degussa Corporation (Charlotte, NC, United States) and Fresenius Kabi Deutschland GmbH (Oberursel, Germany) for this study, and Degussa Corporation for the protein and amino acid analysis of the experimental diets. Our sincere gratitude is also extended to the farm staff, students, and technicians from the Department of Animal Science, The Pennsylvania State University, for their assistance during data collection.
Publisher Copyright:
© 2019 Poultry Science Association Inc.
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2019/9/1
Y1 - 2019/9/1
N2 - This study evaluated reduced dietary CP and supplementing amino acid analogs to sustain growth and carcass weight in 0- to 21-day-old Cobb × Avian-48 male broiler chicks. A total of 6 diets with 3 levels of CP (22.5, 19.5, and 16.5%) and 2 sources of AA analogs, either synthetic amino acids (SA) or keto-/hydroxy-acids (KA), were assigned randomly to 36 cages (8 chicks/cage) in a 3 × 2 factorial design. For SA diets, DL-Met, DL-Met + L-Ile, and D-Met + L-Ile + L-Val were used to supplement 22.5, 19.5, and 16.5% CP diets, respectively, and for corresponding KA diets, DL-Met was replaced with methionine hydroxy analog (MHA), L-Ile was replaced with keto-Ile, and L-Val was replaced with keto-Val. Water and all isocaloric diets (3,050 kcal ME/kg) were given ad libitum. Lowering dietary CP to 16.5% reduced BW at 7, 14, and 21 D (P ≤ 0.0001) and feed intake at 8 to 14, 15 to 21, and 0 to 21 D (P ≤ 0.001). Body weight gain (BWG) was reduced and feed-to-gain ratio (FGR) was increased (P ≤ 0.003 to 0.0001) at all times for chicks fed 16.5% CP; however, chicks fed 22.5 and 19.5% CP had comparable performance. Differences in 0 to 7 D BWG (SA, 122.9 vs. KA, 113.9 g/bird; P ≤ 0.04), a 0 to 21 D FGR cumulative effect (1.45 vs. 1.51; P ≤ 0.02), and a 15 to 21 D (P ≤ 0.04) and 0 to 21 D (P ≤ 0.05) CP × AA interaction were also observed. Greater liver weight among 16.5 vs. 19.5 or 22.5% CP fed chicks was found at 14 and 21 D (P ≤ 0.0001 and P = 0.06, respectively). Lower dietary CP reduced spleen weight on day 21 birds (P ≤ 0.0005) with lighter spleens among 16.5 and 19.5% vs. the 22.5% CP fed group (0.090, 0.095, 0.119 g/100 g BW, respectively). Breast weight at 21 D was significantly less for 16.5 vs. 22.5% CP fed chicks. Fat pad weight on day 21 was heaviest among 16.5% chicks (P ≤ 0.0004). Overall, lowering dietary CP to 16.5% had a negative effect, but keto-acid supplementation supported 0 to 21 D broiler growth compared to SA; however, transamination efficiency of KA may be lower for 0 to 7D old chicks compared to older birds.
AB - This study evaluated reduced dietary CP and supplementing amino acid analogs to sustain growth and carcass weight in 0- to 21-day-old Cobb × Avian-48 male broiler chicks. A total of 6 diets with 3 levels of CP (22.5, 19.5, and 16.5%) and 2 sources of AA analogs, either synthetic amino acids (SA) or keto-/hydroxy-acids (KA), were assigned randomly to 36 cages (8 chicks/cage) in a 3 × 2 factorial design. For SA diets, DL-Met, DL-Met + L-Ile, and D-Met + L-Ile + L-Val were used to supplement 22.5, 19.5, and 16.5% CP diets, respectively, and for corresponding KA diets, DL-Met was replaced with methionine hydroxy analog (MHA), L-Ile was replaced with keto-Ile, and L-Val was replaced with keto-Val. Water and all isocaloric diets (3,050 kcal ME/kg) were given ad libitum. Lowering dietary CP to 16.5% reduced BW at 7, 14, and 21 D (P ≤ 0.0001) and feed intake at 8 to 14, 15 to 21, and 0 to 21 D (P ≤ 0.001). Body weight gain (BWG) was reduced and feed-to-gain ratio (FGR) was increased (P ≤ 0.003 to 0.0001) at all times for chicks fed 16.5% CP; however, chicks fed 22.5 and 19.5% CP had comparable performance. Differences in 0 to 7 D BWG (SA, 122.9 vs. KA, 113.9 g/bird; P ≤ 0.04), a 0 to 21 D FGR cumulative effect (1.45 vs. 1.51; P ≤ 0.02), and a 15 to 21 D (P ≤ 0.04) and 0 to 21 D (P ≤ 0.05) CP × AA interaction were also observed. Greater liver weight among 16.5 vs. 19.5 or 22.5% CP fed chicks was found at 14 and 21 D (P ≤ 0.0001 and P = 0.06, respectively). Lower dietary CP reduced spleen weight on day 21 birds (P ≤ 0.0005) with lighter spleens among 16.5 and 19.5% vs. the 22.5% CP fed group (0.090, 0.095, 0.119 g/100 g BW, respectively). Breast weight at 21 D was significantly less for 16.5 vs. 22.5% CP fed chicks. Fat pad weight on day 21 was heaviest among 16.5% chicks (P ≤ 0.0004). Overall, lowering dietary CP to 16.5% had a negative effect, but keto-acid supplementation supported 0 to 21 D broiler growth compared to SA; however, transamination efficiency of KA may be lower for 0 to 7D old chicks compared to older birds.
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U2 - 10.3382/ps/pez091
DO - 10.3382/ps/pez091
M3 - Article
C2 - 30839093
AN - SCOPUS:85071580316
SN - 0032-5791
VL - 98
SP - 3818
EP - 3827
JO - Poultry Science
JF - Poultry Science
IS - 9
ER -