Effects of dietary <i>Aloe vera</i> crude extracts on digestive enzyme activities and muscle proximate composition of GIFT tilapia juveniles

Abstract

This study investigated the effects of dietary Aloe vera powder extract on the activities of digestive enzymes and muscle composition of Oreochromis niloticus (GIFT strain) juveniles. Five dietary groups were formulated in which A. vera powder was added into a tilapia feed at 0.5%, 1.0%, 2.0%, and 4%/kg feed, and fed for eight weeks. Amylase, trypsin, and lipase activities in the liver and along the alimentary canal (stomach, midgut, and hindgut) varied significantly between dietary groups. Amylase activity was significantly enhanced in the liver of fish fed 0.5, 1, and 2% dietary A. vera, and in the stomach of those fed 1%. Total amylase activity in the gastrointestinal tract (total gut) was significantly enhanced in fish fed 0.5% and 1% compared with control and those fed 4% dietary A. vera. Trypsin activity was significantly enhanced in the stomach of fish supplemented with 0.5% dietary A. vera and in the duodenum of those supplemented with 1%, 2%, and 4% dietary A. vera when compared with the control. Lipase activity was increased in the duodenum of fish fed 1.0% dietary A. vera when compared with the control. Muscle moisture content was significantly lower in all A. vera-supplemented fish, whereas protein was lower in those fed 2% and 4% A. vera diet when compared with the control. Based on second-order polynomial regression analysis, dietary A. vera inclusion level less than or equal to 1.76%, 1.82%, 2.10%/kg feed was determined to be suitable in enhancing carbohydrate, protein and lipid digestion, respectively, in GIFT tilapia in this study. ______________________________________________________________________________________

Tolerance Assessment of Atractylodes macrocephala Polysaccharide in the Diet of Largemouth Bass (Micropterus salmoides)

“…However, in this study, no significant difference in growth was found between fish with dietary AMP levels of 4000 mg/kg and 8000 mg/kg. These results are consistent with those on Aloe vera polysaccharide supplementation in African catfish [38], which might be due to higher feed additive levels affecting intestinal morphology, feed digestibility, and absorption [39,40].…”

Effect of dietary Aloe vera polysaccharides supplementation on growth performance, feed utilization, hemato-biochemical parameters, and survival at low pH in African catfish (Clarias gariepinus) fingerlings

“…This as a result improves feed digestibility and availability of nutrients from feedstuffs, and shortens the feed transit time, which might have beneficial influence on digestive enzymes (Platel and Srinivasan 2004) as well as minimizing the amount of feed substrate available for proliferation of pathogenic bacteria (Citarasu 2010). Feed digestibility enhancement in fish following herbal extract administration was supported by our previous study (Gabriel et al 2017), which reported that 100% A. vera extracts had significantly increased amylase, trypsin, and lipase activities in GIFT. The same herb was also reported to have improved gastrointestinal morphology of O. mykiss by increasing intestinal villi lengths and intestinal surface area for increased feed digestion and absorption capacity of the gut (Heidarieh et al 2013).…”

Effects of Extracts of Feed Additives Including Rosemary (Rosmarinus officinalis) and Aloe Vera (Aloe barbadensis) on the Growth Performance and Feed Utility of Nile Tilapia (Oreochromis niloticus)

“…Similarly, when the rosemary was added to the feed of sea bass with an average weight of 20.43 g, no significant change was observed in the whole-body proximate composition (p>0.05) (Yılmaz et al, 2012). Gabriel et al (2017) found in their study that aloe vera plant did not change the amount of moisture, ash, or lipid in tilapia juveniles, but it reduced the amount of protein. In light of all these studies, it is seen that plant sources, with the components they contain, make positive or negative changes in fish meat nutritional values.…”