The effects of Cannabidiol oil derived from hemp on the growth performance and wellbeing of oreochromis niloticus

Date
2021-12
Journal Title
Journal ISSN
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Publisher
Stellenbosch : Stellenbosch University
Abstract
ENGLISH ABSTRACT: Cannabis sativa is an herbaceous plant that contains a cannabinoid known as Cannabidiol (CBD) which has similar properties as delta-9-tetrahydrocannabinol (THC), without the psychoactive effect. Industrialised intensive production systems are becoming more prevalent in the aquaculture industry, which indirectly increase the pressure on fish resources due to the inclusion of fish meal in fish diets. Alternative protein feeds for the replacement of fishmeal are available, but diet palatability is compromised when alternative protein sources are used. The complex endocannabinoid system is widely distributed throughout the body and play an essential role in modulatory functions like immune status, inflammation, and emotional responses. Cannabis sativa contains more than 150 phytocannabinoids which can be found in resin within flowers, leaves, and seeds. Cannabidiol (CBD) is the second most studied cannabinoid to THC. Cannabidiol is an antagonist at the CB1 receptor and an agonist at the CB2 receptor which has an immunomodulatory effect that stimulates the immune system to fight disease as well as an anxiolytic effect in humans. In this study, the potential effect of CBD oil, as a feed additive, was studied in Nile tilapia (Oreochromis niloticus, 1758) through monitoring of growth (final body weight and body length) and haematological parameters (i.e. white blood cells, red blood cells, and platelets). Four treatments were prepared with increasing CBD concentrations (i.e. 0 mg/kg, 20 mg/kg, 40 mg/kg, and 60 mg/kg). The treatment diets were fed to Nile Tilapia for a duration of 10 weeks at 4% body weight, four times a day. Data recorded fortnightly included live weight, length, overall survival, and feed conversion ratio (FCR). Blood samples were collected fortnightly, and flow cytometry was used to perform a blood cell count. The respective CBD diets did not influence growth parameters, specific growth rate (SGR), and FCR. Water quality parameters (i.e. water temperature, pH and dissolved oxygen (DO)) recorded were all in the optimum range for O. niloticus. A significant difference for Fulton’s condition index was reported among the treatments, indicating that increasing CBD inclusion resulted in leaner fish. The different CBD diets did not affect blood cell counts, indicating that CBD inclusion did not affect fish wellbeing in this study. The results obtained in this study did not conclusively indicate a treatment effect that recommend the use of CBD as an additive in fish diets for improved growth and overall fish wellbeing.
AFRIKAANSE OPSOMMING: Cannabis sativa is 'n kruidagtige plant wat 'n cannabinoïde bevat bekend as Cannabidiol (CBD) wat soortgelyke eienskappe het as delta-9-tetrahydrocannabinol (THC), sonder die psigo-aktiewe effek. Geïndustrialiseerde intensiewe produksiestelsels word meer algemeen in die akwakultuur bedryf, wat indirek die druk op visbronne verhoog as gevolg van die insluiting van vismeel in visdiëte. Alternatiewe proteïenvoere vir die vervanging van vismeel is beskikbaar, maar dieet smaaklikheid word benadeel wanneer alternatiewe proteïenbronne gebruik word. Die komplekse endokannabinoïde stelsel is wyd versprei deur die liggaam en speel 'n noodsaaklike rol in modulerende funksies soos immuunstatus, inflammasie en emosionele reaksies. Cannabis sativa bevat meer as 150 fitokannabinoïede wat in hars in blomme, blare en sade gevind kan word. Cannabidiol (CBD) is die tweede mees bestudeerde cannabinoïde teenoor THC. Cannabidiol is 'n antagonis by die CB1-reseptor en 'n agonis by die CB2-reseptor wat 'n immunomodulerende effek het wat die immuunstelsel stimuleer om siektes te beveg asook 'n anxiolitiese effek by mense. In hierdie studie is die potensiële effek van CBD-olie, as 'n voeradditief, in Nyl-tilapia (Oreochromis niloticus, 1758) bestudeer deur monitering van groei (finale liggaamsgewig en liggaamslengte) en hematologiese parameters (dws witbloedselle, rooibloedselle en bloedplaatjies). Vier behandelings is voorberei met toenemende CBD-konsentrasies (d.i. 0 mg/kg, 20 mg/kg, 40 mg/kg en 60 mg/kg). Die behandelingsdiëte is vier keer per dag aan Nile Tilapia gevoer vir 'n duur van 10 weke teen 4% liggaamsgewig. Data wat tweeweekliks aangeteken is, het lewende gewig, lengte, algehele oorlewing en voeromsettingsverhouding (FCR) ingesluit. Bloedmonsters is tweeweekliks versamel, en vloeisitometrie is gebruik om 'n bloedseltelling uit te voer. Die onderskeie CBD-diëte het nie groeiparameters, spesifieke groeitempo (SGR) en FCR beïnvloed nie. Waterkwaliteit parameters (d.i. watertemperatuur, pH en opgeloste suurstof (DO)) wat aangeteken is, was almal in die optimum reeks vir O. niloticus. 'n Beduidende verskil vir Fulton se toestand-indeks is onder die behandelings gerapporteer, wat aandui dat toenemende CBD- insluiting tot maerder visse gelei het. Die verskillende SSK-diëte het nie bloedseltellings beïnvloed nie, wat aandui dat SSK-insluiting nie viswelstand in hierdie studie beïnvloed het nie. Die resultate wat in hierdie studie verkry is, het nie beslis 'n behandelingseffek aangedui wat die gebruik van CBD as 'n bymiddel in visdiëte aanbeveel vir verbeterde groei en algehele viswelstand nie.
Description
Thesis (MScAgric)--Stellenbosch University, 2021.
Keywords
Cannabidiol, Cannabis sativa -- Classification, Oreochromis niloticus, Hemp, Cannabinoids -- Analysis, Tetrahydrocannabinol -- Physiological effect, UCTD
Citation