Solid-State Hydrolysis (SSH) Improves the Nutritional Value of Plant Ingredients in the Diet of Mugil cephalus

Abstract

The possibility of improving the nutritional quality of plant byproducts (brewers’ spent grain and rice bran) through an enzyme treatment was tested in a formulated feed for grey mullet (Mugil cephalus). The enzyme treatment was carried out by Solid-State Hydrolysis (SSH) using a commercial preparation including carbohydrases and phytase. A feed prepared without the treatment and a commercial feed for carp were used as controls. In a preliminary short-term trial carried out at laboratory facilities, fish receiving the enzyme-treated feed showed significant improvement in both FCR and SGR when compared to those obtained with the untreated diet, although both experimental diets presented worse values than those obtained with the commercial feed. Different metabolic indicators including higher values of muscle glycogen and plasmatic triglycerides supported the positive effect of the enzyme treatment on the nutritional condition of the fish over those fed on the diet containing non-treated ingredients. Results of growth and feed efficiency that were obtained in a second long-term trial developed for 148 days under real production conditions evidenced the equivalence among the experimental and commercial diets and confirmed that enzyme pretreatment of plant ingredients by SSH may be a useful procedure to improve the nutritive value of high fiber plant byproducts when included in practical diets for this species and others with similar nutritional features.

Sustainable Aquafeed with Marine Periphyton to Reduce Production Costs of Grey Mullet, Mugil cephalus

“…The measured FCR in the current study using periphyton agrees with those measured in a previous study of grey mullet fingerlings by Luzzana et al (2005) [48], in which the experimental diets consisted of soybean meal or torula yeast to replace part of the fish and hemoglobin meal content to achieve an FCR of 4.3-4.9. Martínez-Antequera et al (2022) [51] obtained relatively similar SGR and FCR values to those in the present study (10% FM and 3% FO) when feeding M. cephalus with a diet containing either a high level of fish products or one with only 13% fish products and a high (>75%) plant content. The high-plant diets resulted in an SGR between 0.2 and 0.5% d −1 (compared to 0.75% in the control diet) and an FCR between 3.1 and 5.9 (compared to 2.19 in the control diet).…”

Valorization of weed Portulaca oleracea L. as an alternative to fish feed ingredient

“…[25] reported that incorporating hydrolyzed wheat bran at levels of up to 20% into Nile tilapia (Oreochromis niloticus) diets resulted in elevated protein content, reduced fiber content, and improved growth, feed utilization, and blood parameters as well as intestinal and liver development. [40] reported that enzyme pretreatment successfully enhances the nutritive value of high-fiber plant byproducts, leading to increased growth and feed efficiency in Mugil cephalus [41] presented research findings regarding the influences of a carbohydrase-rich extract obtained from hydrolyzed Brewer's spent grain (BSG). This extract was introduced into the European seabass (Dicentrarchus labrax) diet to improve the digestibility of dry matter, starch, cellulose, glucans, and energy.…”

Effects of Phytase and Microalgae Supplementation on the Utilization of Aquafeeds for European Seabass (Dicentrarchus labrax) Formulated with a High Inclusion Level of Plant Protein

“…6 In total, 78% crude protein (Lorca Nutrición Animal SA, Murcia, Spain). Total P: 0.718 g 100 g; total phytate P: 0.01 g 100 g. 7 Soycomil, 60% crude protein, 1.5% crude lipid (ADM, Poland). Total P: 0.66 g 100 g; total phytate P: 0.42 g 100 g. 8 Pea protein concentrate, 85% crude protein, 1.5% crude lipid (Emilio Peña SA, Spain).…”

“…Moreover, phytic acid has a strong complexing activity on several minerals of nutritional importance, such as calcium, magnesium, iron, and zinc, which become insoluble, precipitate, and cannot be absorbed in the intestine, thus reducing their bioavailability. It is also well-known that phytate inhibits proteolytic enzymes [7]. Phytate is widely distributed among plants, and concentrations up to 7% can be found in seeds, in which phytic phosphorous can account up to 80% of total P [7,8].…”

“…It is also well-known that phytate inhibits proteolytic enzymes [7]. Phytate is widely distributed among plants, and concentrations up to 7% can be found in seeds, in which phytic phosphorous can account up to 80% of total P [7,8].…”