The Effect of Dietary Replacement of Fish Meal with Whey Protein Concentrate on the Growth Performance, Fish Health, and Immune Status of Nile Tilapia Fingerlings, Oreochromis niloticus

Abstract

The present study was conducted to assess the effect of replacing fish meal with whey protein concentrate (WPC) on the growth performance, histopathological condition of organs, economic efficiency, disease resistance to intraperitoneal inoculation of Aeromonas hydrophila, and the immune response of Oreochromis niloticus. The toxicity of WPC was tested by measuring the activity of caspase 3 as an indicator of cellular apoptosis. Oreochromis niloticus fingerlings with average initial weight 18.65 ± 0.05 gm/fish (n = 225) for a 10-week feeding trial. The fish were randomly allocated to five experimental groups, having five replacement percentages of fish meal with WPC: 0%, 13.8%, 27.7%, 41.6%, and 55.5% (WPC0, WPC13.8, WPC27.7, WPC41.6, and WPC55.5); zero percentage represented the control group. The results show that the fish fed WPC had the same growth performance as the WPC0. The total weight of bacterially challenged surviving fish increased linearly and quadratically (p ≤ 0.05) by increasing the replacement percentage of fish meal with WPC. The growth hormone, nitric oxide, IgM, complement 3, and lysozyme activity were seen to increase significantly in WPC27.7, especially after a bacterial challenge. The phagocytic percentage and phagocytic index increased significantly in WPC27.7, WPC41.6, and WPC55.5 groups. Histopathological examination of liver sections was badly affected by high replacement in WPC41.6–55.5. The activity of caspase 3 in the immunohistochemical stained sections of the intestine was increased significantly by increasing the inclusion level of WPC. Economically, the total return of the total surviving fish after the bacterial challenge was increased significantly by fish meal replacement with WPC. It could be concluded that WPC could replace the fish meal in Nile tilapia diets up to 27.7%, with improving the gut health, the total weight of survival fish, and immune status of fish challenged with A. hydrophila. High inclusion levels of WPC are not recommended in fish diets, since they negatively affected the intestinal and liver tissues and increased the level of cellular apoptosis, as indicated by the increased caspase 3 activity. Further researches are recommended to evaluate the effect of fish meal replacement with WPC on the histopathological examination of the kidney and to test the capacity of serum IgM to clot the bacteria used for the challenge.

Effects of Dietary Doum Palm Fruit Powder on Growth, Antioxidant Capacity, Immune Response, and Disease Resistance of African Catfish, Clarias gariepinus (B.)

“…Increased surface area for the absorption, improved feed digestion, nutrient utilization, and defense against pathogens by mucin layers on the intestinal mucosa were, therefore, substantiated by these findings, which in turn reflected the effect on the fish growth performance as reported by Reference [57]. The digestive and absorptive capacity of the fish is estimated by the effective indicators, including the numbers of goblet cells (mucus-secreting cells) and the intestinal villous heights [16,58,59]. Defense against foreign antigens is attributed to IEL, effective components of gut-associated lymphoid tissue [60].…”

Synbiotic Effects of Saccharomycescerevisiae, Mannan Oligosaccharides, and β-Glucan on Innate Immunity, Antioxidant Status, and Disease Resistance of Nile Tilapia, Oreochromis niloticus

“…Pseudomonas septicemia is considered a critical fish disease, causing high mortality rates and economic losses among freshwater fishes [65]. The challenge test is used as an ultimate assay to assess the fish immune response [66][67][68][69][70][71]. The results displayed an increase in the survivability of fish fed a SYN diet following challenge with P. aeruginosa, indicating improvement of the immunity of fish fed a diet complemented with synbiotic and a competitive efficiency against pathogenic bacteria [40,41] as previously proven by the enhancement of several immunological markers.…”

Growth Performance, Feed Utilization, Gut Integrity, and Economic Revenue of Grey Mullet, Mugil cephalus, Fed an Increasing Level of Dried Zooplankton Biomass Meal as Fishmeal Substitutions

“…One of the greatest impacts of replacement studies is the improvement of economic visibility of the diet, among other goals. Several alternatives have been used in partial replacement of FM and reduce feed costs, including high protein distillers dried grains [66,67], meat and bone meal [68], silkworm (Anaphe infracta) [69], insect meal [70], animal by-products [70], and whey protein [71]. Interestingly, the findings of the present study revealed the success of total replacement of FM with ZBM regarding the zootechnical performance and economic benefit by considering the natural collection of ZBM.…”