The effect of exogenous enzyme supplementation on growth performance and digestive enzyme activities inOreochromis mossambicusfed kikuyu-based diets

Abstract

The utilization of plant‐based diets in fish is limited by the presence of anti‐nutrients, which bind to dietary nutrients and reduce their bioavailability. Exogenous enzyme supplementation may alleviate the effects of anti‐nutrients and improve feed utilization. In this study, a commercial multi‐enzyme Natuzyme50® was added to a kikuyu‐based diet at a rate of 0 (control), 0.25, 0.5, 0.75 and 1.00 g kg−1 DM. Each diet was fed to triplicate groups of Oreochromis mossambicus for 60 days. All fish fed diets containing Natuzyme50® had higher (P < 0.05) growth performance compared with those fed the control diet. Fish fed the diet containing 0.50 g kg−1 had the best growth performance, highest protein digestibility and the highest levels of digestive enzyme activities. When Natuzyme50® was supplemented above 0.50 g kg−1 in the diet, growth performance and enzyme activities decreased. The improved growth performance observed with Natuzyme50® supplementation was attributed to the presence of enzymes such as cellulase, xylanase and phytase in the cocktail that are not naturally produced by fish. The presence of these enzymes released bound nutrients that would have not been available to the fish. Natuzyme50® supplementation also increased (P < 0.05) the activities of endogenous enzymes, improving the efficacy of the digestive process. The optimal dietary level of Natuzyme50® for optimal growth performance in O. mossambicus was 0.62 g kg−1 DM feed. Cost benefit analysis indicate that adding up to 0.5 g Natuzyme50® kg−1 in the diet results in higher profits as the increased growth attained offset the additional cost of Natuzyme50®.

Effects of exogenous multienzyme complex supplementation in diets on growth performance, digestive enzyme activity and non‐specific immunity of the Japanese seabass,Lateolabrax japonicus

“…In the present study, the activity of lipase and trypsin in the liver and intestines of the fish in all the experimental groups was significantly increased compared to that in the control group, which was consistent with the results of Lin et al () who supplemented the multienzyme complex in diets, The activity of protease and amylase in the intestine and hepatopancreas of tilapia were observed improving significantly. Furthermore, the addition of 0.5 g/kg EC could significantly improve the digestive enzyme activities of tilapia in the experiment of Hlophe‐Ginindza et al (), and the activity of protease, amylase and lipase in hepatopancreas of Penaeus vannamei were also observed significantly improving by the addition of supplement 175 mg/kg protease in diets (Song et al, ).The improvement of the digestive enzyme activity was also probably due to the substrates and anti‐nutrition factors hydrolysed which makes the diet to digest easily (Ai et al, ). A significant decrease in the activity of amylase in the fish intestine was observed in the EC4 group.…”

“…In the present study, the addition of 1.5 g/kg EC had the best effect on the final weight, the weight gain rate, the specific growth rate and the feed conversion of the Japanese seabass, which was consistent with the results of Lin, Mai, and Tan () who found that the specific growth rate and feed utilization of tilapia ( Oreochromis niloticus × O. aureus ) were significantly improved by the supplementation of 1.5 g/kg EC composed of neutral protease, β‐glucanese and xylanase. Meanwhile, increased growth performance was also observed in the results of Ghomi, Shahriari, Langroudi, Nikoo, and von Elert () and Hlophe‐Ginindza, Moyo, Ngambi, and Ncube () who found the significantly enhanced growth performance of great sturgeon fingerlings ( Huso huso ) and tilapia ( Oreochromis mossambicus ) by the supplementation of multienzyme complex composed of protease and xylanase. The effect of EC on the growth performance of fish may be related to the increase of nutrient absorption and digestive capacity.…”

“…It is generally considered that exogenous enzymes may have been active during the feed‐drying process, thus hydrolysing substrates and anti‐nutrition factors in the feed ingredients (Ai et al, ). Moreover, numerous experiments have proved that the addition of exogenous enzyme will not reduce the activity of endogenous enzymes, but can promote it and improve the utilization rate of feed (Hlophe‐Ginindza et al, ; Lin et al, ; Song et al, ; Zhu et al, ). In this study, the feed conversion and feed intake of experimental groups had improved in different levels, which conjectured that the hydrolysates may have attraction to fish, and it was also speculated that fish which had better digestion had a better appetite, thus the feed intake, feed conversion and the growth performance of fish were improved.…”

Exogenous enzymes as functional additives in finfish aquaculture

“…Ghomi et al () reported that great sturgeon ( Huso huso ) fingerlings fed with 250 mg/kg exogenous multienzyme complex contains phytase, lipase, xylanase, protease, β‐glucanase, ɑ‐amylase, pentosanase, hemicellulase, cellulase and pectinase, exhibited higher weight gain and specific growth rate, and also significantly improved feed conversion ratio. Similarly, it was also reported that fed diets containing multienzyme Natuzyme50 ® (Bioproton) containing protease, phytase, xylanase, β‐glucanase, ɑ‐amylase and cellulase could significantly increase protein digestibility and digestive enzyme activities of tilapia, and promote its growth performance (Hlophe‐Ginindza et al, ). Diógenes et al () demonstrated that turbot ( Scophthalmus maximus ) juveniles fed diets with Natugrain ® TS, BASF (NAT) containing endo‐1,4‐beta‐xylanase (5,600 TXU/g) and endo‐1,4‐beta‐glucanase (2,500 TGU/g) significantly increased the apparent digestibility coefficient and digestive enzyme activity in the posterior intestine of fish.…”

“…While fish lack the enzyme to hydrolyse phytate phosphorus in the digestive system, therefore, the phosphorus combined with phytic acid cannot be absorbed and utilized by fish in the feed, resulting in a pollution of phosphorus discharged into water. The use of exogenous phytase can transform the phytic acid‐bound phosphorus into the available phosphorus of fish, thus improving the utilization rate of phosphorus in feed and reducing pollution To enhance growth performance and optimize whole‐body composition (Deguara, ; Ghomi et al, ; Hlophe‐Ginindza et al, ; Hung et al, ; Kolkovski et al, ; KuzMina & Golovanova, ; Li et al, ; Liu et al, ; Xavier et al, ). It was observed that the growth performance of larvae was lower when feeding formula feed, which may be due to their incomplete development of digestive tract with insufficient enzyme activity for the formulated diets (Kolkovski et al, ).…”