Evaluation of black soldier fly (Hermetia illucens) larvae as an alternative protein source in pig creep diets in relation to production, blood and manure microbiology parameters

Thesis (MScAgric)--Stellenbosch University, 2016.

ENGLISH ABSTRACT: In the animal nutrition industry it has become a necessity to seek sustainable and alternative protein sources for animal production. As an alternative protein source, insect meals have been reported to have various beneficial effects in both production and health of animals. Thus, the aim of this study was to investigate the potential of black soldier fly (Hermetia illucens) larvae, grown on kitchen waste, as an alternative protein source in pig creep diets. The current trial included two treatment diets, i.e. a control diet containing no black soldier fly larvae meal (BSFLM) and an inclusion diet containing 3.5% BSFLM of the total diet. These diets were fed to 315 pure bred Large White and Landrace piglets from 10 to 28 days of age in a four week phase-over feeding scheme. The BSFLM contained, on a dry matter basis, a crude protein content of 35.9%, 48.1% crude fat, 6.5% crude fibre and 7.8% ash. Both the treatment diets were formulated to contain similar chemical compositions with a crude protein content of 22%, 6% crude fat, 2-4% crude fibre and 4-6% ash, as this provides for the piglet’s requirements (PIC, 2008). The first part of this study was to investigate the effect of larvae meal inclusion on the production parameters of the piglets. There were no significant (P>0.05) differences achieved for cumulative feed intake, 0.276 kg and 0.282 kg, and average daily gain (ADG), 0.203 kg and 0.199 kg, for the control and inclusion diets per piglet, resepectively. It was concluded that the BSFLM sustained normal growth and development of the young pigs and could be effectively utilized to partially replace other protein sources. In the second phase of this study the effect of the BSFLM on the piglet blood parameters, specifically on immunology and mineral bioavailability characteristics, was investigated. There were no significant (P>0.05) differences observed in the haematological and biochemical concentrations (refer to Chapter 4 results), however, the inclusion diet showed increasing levels for both Haemoglobin (HGB) and Haematocrit (HCT) over the trial. Although not statistically different, this phenomena may have biological value as higher values may be correlated with better oxygen binding capacity and transport of the oxygen to the tissues of the body. These results may also be considered as an indication of immunological stress, however, the animals showed no physical signs of distress when compared to the control diet. Due to the issues of both a dilution effect and sample collection mediated stress experienced during the data collection, the exact correlation between the inclusion of BSFLM and obtained HGB and HCT values (immunological influence) could not be pin pointed. Therefore, further research is needed to validate the results achieved in this part of the study. The third and final part of this study investigated the effect of BSFLM on the piglet manure microbiology (bacterial shedding load) and texture. However, due to the unintended administration of antibiotics which had a significant (P<0.05) influence on both treatments’ second collection, the results could not provide for valid conclusions. Therefore, further research is required to discover any possible effects associated with the inclusion of BSFLM on piglet manure matter. Although there were no beneficial effects on the blood and manure parameters, the fact that similar results were achieved between the control and inclusion diets leads to the conclusion that BSFLM could be regarded as a safe protein source that can be utilized to partially replace other traditional sources in the ability to sustain piglet performance, with no adverse effects. However, due to the fact that antibiotics were administered, the negative effects may have been neutralised.

AFRIKAANS OPSOMMING: Die soeke na alternatiewe en volhoubare proteïenbronne vir diereproduksie raak ‘n al groter dryfveer in diereproduksie. As ʼn alternatiewe proteïenbron het insekprotein baie aandag gekry en is bewese in beide die produksie en gesondheid van diere. Die studie is gevolglik gedoen ten einde die waarde van die venstervlieg (Hermetia illucens), gegroei om kombuisafval, as alternatiewe proteïenbron in varkkruipvoer te evalueer. The huidige studie het twee behandelings ingesluit naamlik ʼn kontrole dieet met geen venstervlieg meel in nie en ʼn behandelingsdieet met 3.5% venstervliegmeel in. Hierdie voere is gevoer aan 315 Grootwit en Landras sogende varkies vanaf 10 tot 28 dae ouderdom in ʼn vier weke oorgangs stelsel. Proksimale analises is uitgevoer op die larwemeel en op droë materiaal basis bevat die larwe meel ʼn ruproteïen inhoud van 35.92%, 48.09% ruvet, 6.53% ruvesel en 7.79% as. Die insluiting van larwe meel in die voere van sogende varkies en die gevolglike uitwerking op produksieparameters is vervolgens getoets. Daar was geen betekenisvolle verskille in gemiddelde daaglike inname of gemiddelde daaglike toename nie. Dus kan daar aanvaar word dat larwemeel suksesvol in voere van sogende varkies ingesluit kan word sonder enige nadelige effek. Die tweede gedeelte van die studie het gekyk na die invloed van die teenwoordigheid van die larwemeel op die bloedparameters, spesifiek immunologie en minerale biobeskikbaarheidseienskappe. Geen betekenisvolle verskille is waargeneem vir die haematologiese of biochemiese konsentrasies van die bloed nie behalwe vir Haemoglobien en Haematokritvlakke wat hoër was vir die groep wat larwemeel ontvang het. Hierdie verhoogte vlakke is gekorreleer met verbeterde suurstofbindingsvermoë en suurstofdravermoë. Verdere navorsing op die gebied word aanbeveel aangesien bloedkolleksie stres en verdunnings effekte vermoedelik tot swakker resultate gelei het. Die derde deel van die studie het die effek van larwemeel op fekale mikrobiologie bepaal. Die tegnieke is uitgevoer maar as gevolg van onbeplande toediening van antibiotika is die resultate nie konkreet nie en word daar aanbeveel dat verdere navorsing op die gebied gedoen word. Uit die resultate word daar dus aanvaar dat die gebruik van larwemeel in kruipvoere ʼn veilige en aanvaarbare alternatiewe proteïenbron is wat in die plek van onvolhoubare proteïenbronne gebruik kan word en dat dit nie enige nadelige effek op klein varkie produksie sal hê nie.

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