Protease supplementation reduced the heat increment of feed and improved energy and nitrogen partitioning in broilers fed maize-based diets with supplemental phytase and xylanase

Title
Protease supplementation reduced the heat increment of feed and improved energy and nitrogen partitioning in broilers fed maize-based diets with supplemental phytase and xylanase
Publication Date
2022-09
Author(s)
McCafferty, Klint W
Choct, Mingan
( author )
OrcID: https://orcid.org/0000-0002-2242-8222
Email: mchoct@une.edu.au
UNE Id une-id:mchoct
Musigwa, Sosthene
( author )
OrcID: https://orcid.org/0000-0002-1089-0786
Email: smusigw2@une.edu.au
UNE Id une-id:smusigw2
Morgan, Natalie K
( author )
OrcID: https://orcid.org/0000-0002-9663-2365
Email: nmorga20@une.edu.au
UNE Id une-id:nmorga20
Cowieson, Aaron J
Moss, Amy F
( author )
OrcID: https://orcid.org/0000-0002-8647-8448
Email: amoss22@une.edu.au
UNE Id une-id:amoss22
Type of document
Journal Article
Language
en
Entity Type
Publication
Publisher
Zhongguo Xumu Shouyi Xuehui,Chinese Association of Animal Science and Veterinary Medicine
Place of publication
China
DOI
10.1016/j.aninu.2021.10.011
UNE publication id
une:1959.11/60860
Abstract

An experiment was conducted to explore the effects of digestible amino acid (dAA) concentrations and supplemental protease on live performance and energy partitioning in broilers. Ross 308 male broilers (n ¼ 288) were distributed into 24 floor pens and offered 1 of 4 dietary treatments with 6 replicates from 1 to 35 d of age. Dietary treatments consisted of a 2 2 factorial arrangement with dAA concentrations (standard and reduced [34 g/kg below standard]) and supplemental protease (without or with) as the main factors. At 1, 15, 28, and 35 d of age, feed and broilers were weighed to determine live performance. From 20 to 23 d of age, a total of 32 birds (2 birds/chamber, 4 replicates) were placed in closed-calorimeter chambers to determine respiratory exchange (heat production, HP), apparent metabolisable energy (AME), retained energy (RE), and net energy (NE). From 29 to 35 d of age, supplemental protease in the reduced-dAA diet decreased broiler feed conversion ratio (FCR) by 5.6 points, whereas protease supplementation in the standard-dAA diet increased FCR by 5.8 points. The indirect calorimetry assay revealed that supplemental protease decreased (P < 0.05) the heat increment of feed (HIF) by 0.22 MJ/kg. Also, from 20 to 23 d of age, broilers offered the reduced-dAA diet with supplemental protease had a higher daily body weight gain (BWG) (þ10.4%), N intake (þ7.1%), and N retention (þ8.2%) than those offered the standard-dAA with supplemental protease. Broilers offered the reduced-dAA without supplemental protease exhibited a 3.6% higher AME-to-crude protein (CP) ratio than those offered other treatments. Protease supplementation in the standard- and reduced-dAA diets resulted in 2.7% and 5.6% lower AME intake-to-N retention ratios, respectively, compared with the unsupplemented controls. Reduced-dAA increased (P < 0.05) AME intake (þ4.8%), RE (þ9.8%), NE intake (þ5.8%), NE intake-to-CP ratio (þ3.0%), and RE fat-to-RE ratio (þ8.6%). Protease supplementation increased (P < 0.05) respiratory quotient (þ1.2%) and N retention-to-N intake ratio (þ2.2%), NE-to-AME ratio (þ1.9%), and reduced HP (3.6%), heat increment (7.4%), and NE intake-toN retention (2.5%). In conclusion, protease positively affected FCR and energy partitioning in broilers" responses were most apparent in diets with reduced-dAA concentrations.

Link
Citation
Animal nutrition (Zhongguo xu mu shou yi xue hui), v.10, p. 19-25
ISSN
2405-6383
2405-6545
Start page
19
End page
25
Rights
Attribution-NonCommercial-NoDerivatives 4.0 International

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