Evaluation of protein enriched co‐products originating from wheat fermentation in diets of common carp Cyprinus carpio to examine effects on growth response, mineral retention, haematological status and intestinal integrity

Abstract

Six experimental isonitrogenous (380 g kg -1 crude protein) and isolipidic (80 g kg -1 ) diets were formulated for juvenile carp Cyprinus carpio. The fish meal protein component of a basal diet (control treatment) was effectively replaced by yeast protein concentrate unrefined (YPC U ), yeast protein concentrate refined (YPC R ), yeast protein concentrate potable alcohol (YPCPA) at 300 g kg -1 of total dietary protein originating from a novel wheat fermentation process. Distillers dried grains with solubles (DDGS) at two levels (150 and 300 g kg -1 ) of dietary protein were also tested separately. After an 8-week feeding trial, carp fed YPCU30 recorded the highest (p ≤ .05) growth performance and feed efficiency. The apparent net protein utilization of phosphorus, sodium, magnesium and chromium for all diets tested showed significant differences of retention efficiencies. The control fed carp had (p < .05) significantly lower phosphorus and magnesium efficiency than the carp fed other diets. Histological examinations showed the density of microvilli in the region of fish fed YPCU30, YPCPA30, DDGS15 and DDGS30 was decreased compared with the control fed fish with no significant differences were found among the treatments (p ≥ .05). Significant differences in the number of hepatocytes were observed between fish fed YPCR30 or YPCPA30 and DDGS30. Furthermore, no significant (p ≥ .05) differences were obtained in the number of hepatocytes in the fish fed YPCU30 and DDGS15 diets with fish fed the control diet. Hepatic structure showed that the liver of the fish fed the control, YPCU and YPCR diets appeared to be healthy with no signs of pathological change. In conclusion, fermented wheat-derived yeast protein concentrate and distillers dried grains with solubles are promising ingredients in carp diets to reduce feed costs and achieve aquaculture sustainability. K E Y W O R D Scommon carp, distillers dried grains, growth performance, haematology, hepatic enzyme activities, liver and intestine histology, wheat fermentation, yeast enriched co-product | 1337 OMAR et Al. | INTRODUC TI ONFeed formulation receives the most attention in the production of fish for intensive aquaculture, the key aspect being to provide a balanced diet that meets the full nutritional requirements based on reliable and quality ingredients. Fish meal (FM) has typically been the main source of dietary protein in the commercial production of fish as reported over the years (Edwards et al., 2004). This is due to its high protein content, excellent amino acid profile, as well as its high nutrient digestibility (Gatlin et al., 2007). However, being too reliant on any one available ingredient imposes increased risks associated with supply, price and quality fluctuations as reported by Glencross et al. (2007). In fact, aquafeed production costs are very high (over 50%) in some aquaculture practices. In order to decrease dietary costs, increase profitability and obtain good growth, expensive ingredients may be substituted with lower-cost ingredients How to...

Evaluation of Distillers Dried Grains With Solubles in Aquafeeds – A Review

“…The nutrient digestibility (ADC) of a feed ingredient is an important factor in evaluating the nutritive value of the ingredient because it is related to the quantity of the nutrient absorbed by the fish (Fang et al, 2016). As a result, the digestibility coefficients for respective nutrients, particularly protein, EAA, and energy, are one of the most important aspects of any new feed ingredient (Omar et al, 2021;Sándor et al, 2021 a). The nutri-ent digestibility of DDGS is dependent on the digestive ability of the non-protein energy fraction.…”

“…The concentration and functional forms of minerals need to be maintained within narrow ranges for essential metabolic activities in cells, tissues, and organs for fish. Recently, results of studies showed the increased inclusion of DDGS increases the tissue retention levels of some minerals (Omar et al, 2021;Anwar et al, 2020). Øverland et al (2013) reported that a diet including DDGS promoted better phosphorus retention compared with a fish meal-based reference diet for rainbow trout.…”

Addressing Phosphorus Waste in Open Flow Freshwater Fish Farms: Challenges and Solutions

“…Studies have shown that fish with a higher gut surface area or longer intestine tend to exhibit higher FCE, indicating their enhanced ability to digest and absorb nutrients from the feed [60,61] Moreover, the relationship between FCE and phosphorus pollution in aquaculture is crucial. Low FCE is associated with decreased phosphorus retention efficiency in farmed fish, resulting in increased phosphorus excretion into the water [62][63][64][65][66][67][68]. Understanding this relationship enables the creation of effective management strategies to reduce phosphorus pollution in aquaculture systems.…”