Total replacement of fishmeal with poultry by-product meal affected the growth, muscle quality, histological structure, antioxidant capacity and immune response of juvenile barramundi, Lates calcarifer

Abstract

The present study investigates if the total replacement of dietary fishmeal (FM) with poultry by-product meal (PBM), supplemented with methionine influences the muscle fatty acids composition, normal gut morphology, histological traits of the liver, muscle, and gill, liver enzymes, immune and antioxidant response, and stress-related gene in juvenile barramundi, Lates calcarifer in relation to growth and feed utilization. Barramundi (3.58±0.01g) were randomly distributed into six 300 L seawater recirculating tanks (25 fish/tank) and fed two formulated isonitrogenous and isolipidic diets for 6 weeks. The control diet had FM as the sole animal protein source, whereas other test diet had only PBM as an animal protein source. Dietary PBM affected the fish performance and feed utilization. Regarding muscle fatty acid profile, total saturated fatty acids and monounsaturated fatty acids elevated while total PUFA particularly n-3 LC-PUFA and EPA decreased in PBM fed fish than control diet fed fish. Liver, muscle, gill, and intestinal histology showed no obvious alteration in control diet fed fish, however, more lipid droplets and hepatic vacuolization in the liver, necrotic myotome in muscle, hyperplasia in secondary lamellae in gill and short and broken folds in the intestine were observed in PBM fed fish. Similar to light microscopy observation of intestinal morphology, the transmission electron microscopy (TEM) analysis revealed shorter and smaller microvilli in fish fed PBM. Histopathological alterations in the liver of PBM fed fish were further associated with the elevated levels of aspartate aminotransferase (AST) and glutamate dehydrogenase (GLDH) and the significant upregulation of stress-related genes, HSP70 and HSP90. Also, a negative influence on lysozyme activity, and antioxidant enzymatic activities were recorded in fish fed PBM. Overall, it can be concluded that a total substitution of FM protein by methionine supplemented PBM negatively influenced the growth performance, liver health, histological traits of different organs, immune and antioxidant response, and expression of stress-related genes in juvenile barramundi.

Supplementation of tuna hydrolysate and insect larvae improves fishmeal replacement efficacy of poultry by-product in Lates calcarifer (Bloch, 1790) juveniles

“…The total substitution of FM with PBM concomitantly supplemented with TH and HI larvae improved the growth and condition factor in barramundi. Our earlier 20 and other study by Siddik, et al 21 evaluating the total FM substitution with PBM resulted in poor growth performance in barramundi . Also, many other studies reported negative outcomes in the growth of a number of fish when dietary inclusion of PBM exceeded > 50% [15][16][17] .…”

“…Histological damages of immune-sensitive organs including liver, kidney, and spleen could be easily assessed when host species are fed non-FM diets. For example, total substitution of FM with PBM resulted in lipid droplets and multifocal necrosis in the liver of barramundi 13 , 20 . Similarly, higher replacement of FM with PBM (50–70%) and animal protein blend containing PBM, shrimp meal and spray-dried blood meal (20–80%) induced hepatocytes steatosis in juvenile hybrid grouper, Epinephelus fuscoguttatus ♀ × Epinephelus lanceolatus ♂ 8 , 93 .…”

“…However, feeding PBM at replacement levels more than 50% impacted the growth performance in barramundi, L. calcarifer 13 , Florida pompano, Trachinotus carolinus L tench 14 , juvenile tench, Tinca tinca 15 , black sea turbot , Psetta maeoticus 16 and cobia , Rachycentron canadum 17 . In addition, impairment of immunity and serum biochemistry were reported in largemouth bass, Micropterus salmoides 18 , 19 and barramundi fed PBM 13 , 20 and hybrid grouper, Epinephelus fuscoguttatus ♀ × Epinephelus lanceolatus ♂ fed an animal protein blend 8 . In our previous studies 13 , 20 , 21 , we have also shown that the exclusive inclusion of PBM protein at the expense of FM protein caused histopathological changes in the liver and impaired the integrity of intestinal micromorphology of barramundi.…”

“…In addition, impairment of immunity and serum biochemistry were reported in largemouth bass, Micropterus salmoides 18 , 19 and barramundi fed PBM 13 , 20 and hybrid grouper, Epinephelus fuscoguttatus ♀ × Epinephelus lanceolatus ♂ fed an animal protein blend 8 . In our previous studies 13 , 20 , 21 , we have also shown that the exclusive inclusion of PBM protein at the expense of FM protein caused histopathological changes in the liver and impaired the integrity of intestinal micromorphology of barramundi. Though a number of studies have been conducted on re-formulating aquadiets supplementing fish protein hydrolysates (FPH) 22 – 25 and other supplements 26 – 28 that complimented animal proteins and helped to satisfy the needs of barramundi, developing functional sustainable feeds that remain cost-efficient, while promoting fish welfare and maximising growth potential, is a foremost challenge for the aquaculture industry.…”

Effects of Dietary Fishmeal Replacement by Poultry By-Product Meal and Hydrolyzed Feather Meal on Liver and Intestinal Histomorphology and on Intestinal Microbiota of Gilthead Seabream (Sparus aurata)

“…On the other hand, very little is known about the effects of land animal proteins as fishmeal replacements on the liver and intestinal histology. Findings from the limited studies that have been reported up to date have revealed that high inclusion levels of land animal proteins may induce hepatic steatosis and increase hepatic lipid vacuolization in Lateolabrax japonicus [19], in hybrid grouper [20,21] and in Lates calcarifer [22]. In addition, negative effects on the intestinal histology have also been reported with the fishmeal replacement by land animal proteins [22,23].…”