N-acetyl-L-cysteine improves the performance of chronic cyclic heat-stressed finisher broilers but has no effect on tissue glutathione levels

1. It was hypothesised that dietary N-acetyl-L-cysteine (NAC) in feed, as a source of cysteine, could improve the performance of heat-stressed finisher broilers by fostering glutathione (GSH) synthesis. GSH is the most abundant intracellular antioxidant for which the sulphur amino acid cysteine is rate limiting for its synthesis.2. In the first experiment, four levels of NAC: 0, 500, 1000 and 2000 mg/kg were added to a diet with a suboptimal level of sulphur amino acids in the finisher phase. In the second experiment, NAC was compared to other sulphur amino acid sources at equal molar amounts of digestible sulphur amino acids. Birds were allocated to four groups: control, 2000 mg/kg NAC, 1479 mg/kg L-cystine, and 2168 mg/kg Ca-salt of 2-hydroxy-4-(methylthio)butanoic acid. A chronic cyclic heat stress model (temperature was increased to 34°C for 7 h daily) was initiated at 28 d of age.3. In the first experiment, growth performance and feed efficiency in the finisher phase were significantly improved by graded NAC. ADG was 88.9, 92.2, 93.7 and 97.7 g/d, and the feed-to-gain ratio was 2.18, 1.91, 1.85 and 1.81 for the 0, 500, 1000 and 2000 mg/kg NAC treatments, respectively. However, liver and heart GSH levels were not affected by NAC. On d 29, liver gene transcript of cystathionine-beta-synthase like was reduced by NAC, which suggested reduced trans-sulphuration activity. The second experiment showed that L-cystine and Ca-salt of 2-hydroxy-4-(methylthio) butanoic acid were more effective in improving performance than NAC.4. In conclusion, N-acetyl-L-cysteine improved dose-dependently growth and feed efficiency in heat-stressed finishing broilers. However, this was not associated with changes in tissue GSH levels, but more likely worked by sparing methionine and/or NAC's and cysteine's direct antioxidant properties.

Medienart:

E-Artikel

Erscheinungsjahr:

2023

Erschienen:

2023

Enthalten in:

Zur Gesamtaufnahme - volume:64

Enthalten in:

British poultry science - 64(2023), 6 vom: 02. Dez., Seite 751-762

Sprache:

Englisch

Beteiligte Personen:

Pertiwi, H [VerfasserIn]
Majdeddin, M [VerfasserIn]
Degroote, J [VerfasserIn]
Zhang, H [VerfasserIn]
Michiels, J [VerfasserIn]

Links:

Volltext

Themen:

48TCX9A1VT
Acetylcysteine
Amino Acids, Sulfur
Antioxidants
Broilers
Butyrates
Cystine
GAN16C9B8O
Glutathione
Heat stress
Journal Article
N-acetyl-L-cysteine
Redox status
Sulphur amino acids
WYQ7N0BPYC

Anmerkungen:

Date Completed 19.12.2023

Date Revised 19.12.2023

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1080/00071668.2023.2264234

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM362779600