Improvement of hybrid grouper (Epinephelus fuscoguttatus ♀ × E. lanceolatus ♂) by enzyme-digested poultry by-product: Growth performance, amino acid and peptide transport capacity, and intestinal morphology

Xuanyi Yang; Xumin Zhao; Guanghui Wang; Xiaohui Dong; Qihui Yang; Hongyu Liu; Shuang Zhang; Beiping Tan; Shuyan Chi

doi:10.3389/fnut.2022.955734

Improvement of hybrid grouper (Epinephelus fuscoguttatus ♀ × E. lanceolatus ♂) by enzyme-digested poultry by-product: Growth performance, amino acid and peptide transport capacity, and intestinal morphology

Front Nutr. 2022 Jul 19:9:955734. doi: 10.3389/fnut.2022.955734. eCollection 2022.

Authors

Xuanyi Yang¹, Xumin Zhao², Guanghui Wang², Xiaohui Dong^{1

3}, Qihui Yang^{1

3}, Hongyu Liu^{1

3}, Shuang Zhang^{1

3}, Beiping Tan^{1

3

4}, Shuyan Chi^{1

3

4}

Affiliations

¹ Laboratory of Aquatic Nutrition and Feed, College of Fisheries, Guangdong Ocean University, Zhanjiang, China.
² Yichang Huatai Biological Technology Co., Ltd., Yichang, China.
³ Aquatic Animals Precision Nutrition and High Efficiency Feed Engineering Research Center of Guangdong Province, Zhanjiang, China.
⁴ Southern Marine Science and Engineering Guangdong Laboratory, Zhanjiang, China.

Abstract

Background: At present, fish meal (FM) resources are in short supply, and competition for food between humans and animals is becoming increasingly critical. Finding non-grain protein sources that can replace FM is the key to solving the rapid development of aquaculture.

Methods: Seven trial diets were prepared with 0 g/kg (EP0), 30 g/kg (EP3), 60 g/kg (EP6), 90 g/kg (EP9), 120 g/kg (EP12), 150 g/kg (EP15), and 180 g/kg (EP18) of enzyme-digested poultry by-product meal (EPBM) by replacing of FM. A total of 630 hybrid groupers (Epinephelus fuscoguttatus ♀ × E. lanceolatus ♂) were equally portioned into 21 tanks. At 8:00 and 16:00 each day, groupers were fed until they were full for a cumulative period of 8 weeks.

Results: The results showed that 30 g/kg of EPBM significantly increased the rates of weight gain and special growth (P < 0.05). Significantly higher activities of serum glutamic pyruvic transaminase, glutamic oxaloacetic transaminase, catalase, and superoxide dismutase were observed in the EP3 group (P < 0.05). The categories and numbers of the top 10 dominant bacteria in the phylum and genus levels were not significantly influenced by feed (P > 0.05). In the proximal intestine and distal intestine, there were significantly higher expressions of SNAT3, LAAT1, CAT2, and CAT1 in the EP3 group compared with the EP0 group (P < 0.05). In the EP3 group, the expressions of PepT1, LAAT1, B^{0, +}AT, and CAT2 were significantly increased in MI than those in all other groups (except the EP0 group, P < 0.05).

Conclusion: When FM was replaced by 30 g/kg of EPBM, growth performance, antioxidant capacity, and the ability to transport amino acids and peptides of hybrid grouper were significantly improved.

Keywords: amino acid and peptide transporters; enzyme-digested poultry by-product meal; growth performance; hybrid grouper; intestinal microbiota; non-specific immunity.