Rearing density effects on a commercially important insect species
Kuupäev
2024-07-15
Autorid
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Abstrakt
Putukate kasutamine toidu ja söödana on viimasel ajal pälvinud järjest rohkem tähelepanu kui jätkusuutlik alternatiiv traditsioonilisele loomakasvatusele. Kuna putukate töönduslik tootmine on alles kujunemisjärgus, vajab kasvatusmetoodikate optimeerimine rohkeid lisauuringuid.
Elukäiguteooria aitab mõista organismide keerukaid elutsükleid ja elukäiguomaduste evolutsiooni muutuvas keskkonnas. Piiratud ressursside tõttu on elukäiguomadused, sageli omavahel lõivsuhetes. Sellistel suhetel on määrav mõju organismide kasvule, paljunemisele ja elumusele erinevates keskkondades.
Liigikaaslaste asustustihedusel kasvukeskkonnas on suur mõju putukate elukäigu kujundamisel. Kõrge vastsete asustustihedus viib reeglina väiksemate kehamõõtmete, kõrgema suremuse ja kas lühema või pikema vastseperioodini.
Doktoritöös läbiviidud katsete tulemused näitavad, et optimaalsed tingimusedogakärblase Hermetia illucens (BSF) vastsetele on madal asustustihedus ja temperatuur umbes 27 °C. Nendes tingimustes kasvavad ogakärblased suuremaks, arenevad kiiremini ja nende keha on kõrgema rasvasisaldusega. Kõrge asustustihedus küll tugevdab immuunvastust, kuid viib ka kehamõõtmete vähenemise ja arenguaja pikenemiseni. Vastsetiheduse mõju BSF elukäigule sõltus temperatuurist, seenpatogeenist ja substraadi tüübist.
Doktoritöö tulemused näitavad, et BSF-i puhul võib fermentatsioon lisaks otsestele positiivsetele mõjudele toidu omastamisel aidata ka leevendada kõrge vastsetiheduse negatiivseid mõjusid. Teisalt sõltub fermentatsiooni tõhusus substraadi tüübist ja teistest keskkonnatingimustest.
Doktoritöö toob esile vajaduse pidada silmas ja hallata putukate kasvatamisel mitmeid keskkonnategureid samaaegselt. Nende interaktsioonide mõistmine võimaldab tootjatel optimeerida keskkonnatingimusi putukavastsete masskasvatamiseks. See omakorda loob eeldused söögiks ja söödaks kasvatatavate putukate toodangu suurendamiseks ning tootmise tõhustamiseks.
The use of insects for food and feed has recently attracted attention as a sustainable alternative to traditional livestock. Edible insects such as the black soldier fly (BSF) provide nutritional benefits similar to those of conventional animal products. However, the industry is still emerging, and much remains to be learned about utilising the species for mass-rearing purposes. Life history theory aids in understanding the complex life cycles of organisms and the evolution of their life history traits in changing environments. Life history traits are closely related to fitness and are frequently traded off against each other, so investing more in one trait typically comes at the expense of others. This profoundly influences how organisms grow, reproduce, and survive in various environments. For insects, a key environmental factor for insects is larval density. High larval density often leads to smaller body size, higher mortality, and faster or slower development. Our results revealed that optimal conditions for BSF larvae are low densities and temperatures around 27 °C. They grow larger, develop faster, and have higher fat content at low larval densities. Contrary to this, high densities, while boosting immune responses, often result in smaller larvae with longer development times. As the influence of larval density on BSF life history traits depends on temperature, fungal pathogen and substrate type, maintaining optimal larval density and controlling other key environmental factors is crucial. Fermentation serves as a way to alleviate some of the negative effects of high larval density. However, the effectiveness of fermentation depends on the substrate type and the environment. Our study highlights the importance of managing multiple environmental factors simultaneously. By understanding this, producers of insects for food and feed can optimise rearing conditions to maximise yields and increase production efficiency.
The use of insects for food and feed has recently attracted attention as a sustainable alternative to traditional livestock. Edible insects such as the black soldier fly (BSF) provide nutritional benefits similar to those of conventional animal products. However, the industry is still emerging, and much remains to be learned about utilising the species for mass-rearing purposes. Life history theory aids in understanding the complex life cycles of organisms and the evolution of their life history traits in changing environments. Life history traits are closely related to fitness and are frequently traded off against each other, so investing more in one trait typically comes at the expense of others. This profoundly influences how organisms grow, reproduce, and survive in various environments. For insects, a key environmental factor for insects is larval density. High larval density often leads to smaller body size, higher mortality, and faster or slower development. Our results revealed that optimal conditions for BSF larvae are low densities and temperatures around 27 °C. They grow larger, develop faster, and have higher fat content at low larval densities. Contrary to this, high densities, while boosting immune responses, often result in smaller larvae with longer development times. As the influence of larval density on BSF life history traits depends on temperature, fungal pathogen and substrate type, maintaining optimal larval density and controlling other key environmental factors is crucial. Fermentation serves as a way to alleviate some of the negative effects of high larval density. However, the effectiveness of fermentation depends on the substrate type and the environment. Our study highlights the importance of managing multiple environmental factors simultaneously. By understanding this, producers of insects for food and feed can optimise rearing conditions to maximise yields and increase production efficiency.
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