Effects of Apple (Malus pomila) Pomace-Derived Pectin on the Innate Immune Responses, Expressions of Key Immune-Related Genes, Growth Performance, and Digestive Enzyme Activity of Rainbow Trout (Oncorhynchus mykiss)
by
, , , , and
Seyed Hossein Hoseinifar
1,*
,
Ghasem Rashidian
2
,
Hamed Ghafarifarsani
3,
Mohammad Amin Jahazi
1,
Mehdi Soltani
4,5,
Hien Van Doan
6
,
Ehab El-Haroun
7 and
Marina Paolucci
8
1
Department of Fisheries, Faculty of Fisheries and Environmental Sciences, Gorgan University of Agricultural Sciences and Natural Resources, 49189-43464 Gorgan, Iran
2
Department of Aquaculture, Faculty of Natural Resources and Marine Sciences, Tarbiat Modares University, Noor 4641776489, Iran
3
Department of Fisheries, Faculty of Agriculture and Natural Resources, Urmia University, 5756151818 Urmia, Iran
4
Department of Aquatic Animal Health Faculty of Veterinary Medicine, University of Tehran, 1419963111 Tehran, Iran
5
Centre for Sustainable Aquatic Ecosystems, University of Murdoch, Murdoch, WA 6150, Australia
6
Department of Animal and Aquatic Sciences, Faculty of Agriculture, Chiang Mai University, Chiang Mai 50200, Thailand
7
Fish Nutrition Research Laboratory, Department of Animal Production, Faculty of Agriculture, Cairo University, Cairo 12411, Egypt
8
Department of Sciences and Technologies, University of Sannio, 82100 Benevento, Italy
*
Author to whom correspondence should be addressed.
Animals 2021, 11(7), 2117; https://doi.org/10.3390/ani11072117
Submission received: 20 May 2021
/
Revised: 6 July 2021
/
Accepted: 7 July 2021
/
Published: 16 July 2021
(This article belongs to the Special Issue Feed Additives in Health and Immunity of Fish)
Simple Summary
The present study investigated possible administration of pectin derived from apple pomace as a beneficial and cost-effective feed additive to be used in trout culture. To achieve the aim, a range of parameters were measured including immune parameters (both at physiological and molecular levels), growth performance and digestive enzyme activity. The results showed promising effects on the measured parameters and hence we can suggest administration of this feed additive in trout culture.
Abstract
Pectins are a group of carbohydrates found in structural parts of terrestrial plants with wide industrial and biomedical applications. This study was designed to investigate the dietary effects of apple pomace-derived pectin (APDP) in rainbow trout (Oncorhynchus mykiss). Four formulated diets were provided with different inclusion levels of APDP for 30 days: 0, 5, 10, and 20 g kg−1; referred to as control, P1, P2, and P3, respectively. In this study, 300 fish (3.56 ± 0.007 g) were randomly distributed into twelve fiberglass tanks and fed 3% of their respective body weight four times a day. At the end of the experiment, growth parameters, including weight gain, specific growth rate, and food conversion ratio (FCR) were significantly improved in P1 and P2 treatments compared to those of the other treatments. Results from proximate composition analysis showed that protein content increased, and lipid decreased in the P2 and P3 groups. Serum lysozyme, complement activity, total immunoglobulin levels, and total protein were significantly enhanced in all treatments compared to those of the control group. Gene expression results showed no significant difference in regulation of interleukin-1β (IL-1β); however, up-regulation of lysozyme, interleukin-8 (IL-8), and tumor necrosis factor-α (TNF-α) was observed in both P1 and P2. Unlike lipase, the activity of protease and amylase significantly increased in fish receiving different levels of APDP compared to the control (p < 0.05). In conclusion, the present findings suggest APDA as a promising feed additive for rainbow trout.
Keywords:
apple pomace; pectin; prebiotic; rainbow trout; immune genes; innate immunity; growth performance
