Effects of crude protease produced by Bacillus subtilis (MAFIC Y7) on growth performance, immune indices, and anti-inflammatory responses of broilers fed soybean meal- or cottonseed meal-based diets.

Autor:	Guo X; State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China., Li Q; State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China., Wang L; State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China., Zhang Y; State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China., Johnston LJ; Department of Animal Science, West Central Research and Outreach Center, University of Minnesota, Morris, MN 56267, USA., Levesque CL; Department of Animal Science, College of Agriculture and Biological Sciences, South Dakota State University, Brookings, SD 57007, USA., Cao Y; State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China.; College of Animal Science and Technology, Sanya Institute of China Agricultural University, Sanya 572000, China., Dong B; State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China.; College of Animal Science and Technology, Sanya Institute of China Agricultural University, Sanya 572000, China.
Jazyk:	angličtina
Zdroj:	Journal of animal science [J Anim Sci] 2024 Jan 03; Vol. 102.
DOI:	10.1093/jas/skae047
Abstrakt:	A strain of Bacillus subtilis (MAFIC Y7) was isolated from the intestine of Tibetan pigs and was able to express high protease activity. The aim of this study was to characterize the proteases produced by MAFIC Y7, and to investigate the effects of protease addition on growth performance, ileal amino acid digestibility, and serum immunoglobulin and immune factors of broilers fed SBM-based diets, or on growth performance, carcass characteristics, and intestinal morphology of broilers fed CSM-based diets. B. subtilis (MAFIC Y7) expressed protease showed its optimal enzyme activity at 50 °C and pH 7.0. The coated crude enzyme (CCE) showed greater stability at pH 3.0 than its uncoated counterpart. Experiment 1 was conducted with six diets based on three levels of crude protein (CP)-CPlow, CPmedium, and CPhigh-with or without CCE. In CPlow, CCE increased gain:feed (G:F) (days 1 to 21, days 1 to 42) by 8%, 3%, respectively, and enhanced apparent ileal digestibility (AID) of crude protein and lysine (on day 42) by 8.8%, 4.6%, respectively, compared with diets containing no CCE (P < 0.05). CCE increased G:F from days 1 to 21 from 0.63 to 0.68, improved G:F and average daily gain (ADG) during days 1 to 42, and enhanced AID of crude protein, lysine, cysteine, and isoleucine on day 42 compared with the unsupplemented treatments (in CPmedium, P < 0.05). CCE increased serum IgA (on day 21), serum IgA and IgG and increased serum IL-10 (on day 42), but decreased serum tumor necrosis factor-α (TNF-α; on day 21), and serum IL-8 and TNF-α (on day 42) compared with unsupplemented treatments. At CPhigh, CCE decreased serum levels of IL-6 and TNF-α (on day 21), and IL-8 and TNF-α (on day 42) compared with unsupplemented treatments (in CPhigh, P < 0.05). In experiment 2, CSM-based diets with two lysine-to-protein ratios (5.2% or 5.5%) with or without CCE. In the high Lys diet (5.5% Lys:protein), CCE increased ADG and G:F, increased carcass, but decreased abdominal fat compared with the unsupplemented treatment (P < 0.05). In the 5.2% Lys:protein dietary treatment, CCE improved duodenal villus height compared with the unsupplemented treatment (P < 0.05). Supplementation of protease produced by MAFIC Y7 was associated with lower inflammatory responses in SBM diets (CPmedium or CPhigh) and improved ADG in broilers fed CPmedium or CPhigh. The proteases improved ADG and the efficiency of CSM use when the ratio of Lys to protein was 5.5%. (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Society of Animal Science. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
Databáze:	MEDLINE
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