Parcours spécifiques : allier réussite et contraintes individuelles

Comprend des références bibliographiquesDepuis plus de douze ans, une structure spéciale et efficace a été mise en place au sein de l’Institut Universitaire de Technologie 1 de Grenoble afin d’accueillir et d’accompagner les nombreux étudiants ayant des contraintes fortes dans le déroulement de leurs études. Celle-ci propose des adaptations pour tous types de contraintes individuelles et repose sur une équipe de correspondants et de tuteurs dans chaque département d’enseignement. Les taux de réussite obtenus sont les mêmes que ceux des étudiants n’ayant pas de contraintes particulières ce qui prouve que la compensation des contraintes est bien effectuée. Cependant, les restrictions budgétaires actuelles risquent de remettre en cause ces adaptations bien qu’elles soient peu onéreuses

Batch-to batch variation in nutrient digestbility of black soldier fly larvae meals in rainbow trout

The aim of this study was to evaluate the apparent digestibility coefficients (ADCs) of four batches of black soldier fly (BSF) meal, named BSF1, BSF2, BSF3 and BSF3, produced by the same company over one year, in rainbow trout (Oncorhynchus mykiss). To assess nutrients and amino acids ADCs, each insect meal was mixed with a high-quality reference diet in a 30:70 ratio on as is basis, including celite as inert marker, and pelleted. The reference diet was also used as control. The ADCs were calculated based on the data collected and determined during an in vivo experiment. A total of 240 fish were randomly divided into 250-L cylindroconical tanks supplied in flow-through open and Choubert systems (3 replicates/treatment). Data were analysed by One-Way ANOVA (SPSS V20.0.0.; P≤0.05). Globally, the four BSF meals showed a high ADC value, between 82.6 and 100%. No statistically significant differences were observed in the ADCs of dry matter, crude protein, ether extract and gross energy, while some differences were observed in the amino acid profile (P0.05). Despite the good digestibility of nutrients for all the insect mealsthe implementation of standardized production is important to have a standardize BSF meal capable of meeting market demands.publishedVersio

Isoenergetic-practical and semi-purified diets for protein requirement determination in Hermetia illucens larvae: consequences on life history traits

BACKGROUND: Black soldier fly (BSF) is one of the most promising species for the intensive breeding of insects given its adaptability and its efficiency in the conversion of waste. To maximize the production and use waste as substrates, it is essential to determine the larvae nutritional requirements. The study aims to evaluate the effects of 5 practical, semi-purified and isoenergetic diets (PSPID) with increasing protein levels (10%, CP10; 14%, CP14; 16%, CP16; 19%, CP19) on BSF life history traits. A total of 2000 six-day-old larvae were weighed and divided into groups of 100 (4 replicates/treatment [PSPID and Gainesville diet (GA) used as environmental control]). In larva-prepupa stage, sampling was carried out on 30 individuals/replicate, while in prepupa-adult stage on 35. RESULTS: In the whole larval stage, the CP16 treatment performed better when compared to the other groups. At 18 days old, the CP14 treatment showed a higher weight than the CP19 (P < 0.01), while the CP10 and CP16 weights were intermediate. On the contrary, the CP10 prepupae weight was higher than the CP19 (P < 0.01). The CP10 and CP14 pupae performed better in terms of weight when compared to the others (P < 0.01). The dietary treatments did not affect the adult parameters. The sex significantly influenced both the exuvia weight, which was the greatest in females (P < 0.001), and the fly lifespan, longest in males (P < 0.05). Fly lifespan was also influenced by the interaction between treatment and sex, with the CP19 females showing a longer life than the others (P < 0.05). CONCLUSIONS: In conclusion, the optimal protein level considering the whole larval stage is 16% on dry matter (DM). At 18 days old, looking at the size intended for the meal production, it can be considered 14% on DM. The result obtained on adult emergence in PSPID may not be attributable to the protein content. Further researches on macronutrients requirements determination have to be conducted to evaluate the substrates composition effects on BSF life history traits

Determination of lipid requirements in black soldier fly through semi-purified diets

The insect market is still far from an effective upscale and, to achieve this goal, it is necessary to know the BSF dietary requirements for the production maximization. Worldwide, given the waste variability, is not always easy to identify the optimal waste-based mixture that can allow to reach the best production, in terms of quantity and quality. Due this reason, nutritional need ranges are the basic knowledge, affordable for everyone, to increase the profitability of the insect farming. The study aims to evaluate the effects of 6 semi-purified, isonitrogenous and isoenergetic diets (SPII) with increasing lipid levels (1%, L1; 1.5%, L1.5; 2.5%, L2.5; 3.5% L3.5; 4.5%, L4.5) on BSF life history traits (6 replicates/treatment and 100 larvae/replicate). The Gainesville diet was used as environmental control. Considering the whole larval stage, 4.5% lipid level guarantees better performance when compared to content lower than 2.5%. The L4.5 10-day-old larvae yielded greater when compared to the other dietary treatments. At 14 and 18 days of age, the larvae of the groups above 2.5% performed better than L1, while the L1.5 showed intermediate results. Lipid levels below 1.5% on DM, when compared to 4.5%, resulted in a smaller prepupa and pupa size. The results obtained on the adult stage do not allow the identification of a lipid levels ideal range, as in the larval stage. In conclusion, in the whole larval stage and in prepupae/pupae phases, lipid percentage lower than (or equal to) 1% have a negative effect on growth. Other research will be needed in order to evaluate lipid levels above 4.5% on DM