The nutrient composition of yellow mealworm (YM) Tenebrio molitor varies based on the stages of the life cycle, the rearing conditions, and the feeding substrate. This study monitored the growth of yellow mealworm larvae at 8, 10, and 12 weeks of age, separating samples into large-sized and small-sized insects. During the experiment, we measured the nutrient composition: dry matter (DM), crude protein (CP), crude fat (CF), crude fibre, chitin, crude ash, and nitrogen free extract (NFE) of YM at different age groups and sizes. We measured the nutrient composition of the pre-moult, moult, cuticle, and pupae as well. The results show that there is no significant difference between the compositions of the different age groups, but larger-sized individuals had a higher DM and crude fibre and lower chitin and NFE than the smaller sizes. The pre-moult and moult stages showed no significant difference in nutrient composition. Although the cuticle had a high DM (97.5%), that did not cause any significant difference between the DM of the moult and pre-moult, because it is only a negligible part of the total wet weight. With the increased DM, the crude protein content and the chitin content, fibre, ash content, and NFE increased, while the fat content decreased. The DM, CF, and chitin contents of pupae are significantly lower than those of the pre-moult and moult stages. Our results show that it is the size and not the age that has a positive effect on the nutrient composition of YM.

The consumption of insect protein, as well as its use in animal feeding, has become a trend. This trend is particularly receiving a lot of attention in animal nutrition because the current protein source of the highest quality in animal feeding which is fishmeal is unsustainable, expensive and its demand is higher than supply. Insect protein can be of great potential in combating world hunger as the world population continues to increase. The potential of insect protein is wide-ranging, it could improve the economics of feed production, lead to cleaner production due to its low environmental footprint. This review focuses on the need, (nutritional and environmental) advantages of insect protein in feed production, as well as previous research findings. The unanimous conclusion of the reviewed papers is that insect protein has a great potential in feed production in terms of nutritional value, environmental implication, sustainability as well as economic implication. However, there is a need for the intensification of research on this alternative protein source in Europe, especially in aquaculture due to the approval of 7 insect species in aquafeeds by the European Union. Another reason for the intensification is that there is still much to be done as a result of past research which shows that growth effects vary based on species and inclusion level.

The common carp (Cyprinus carpio L.) is the most important fish species in Hungary, it is more than 70% of the total Hungarian fish production. The common carp production is important not only just in Hungary but in Middle-East Europe, as well as Southeast Asia. Majority of the production comes from fishpond culture. If the production sector wants to meet the increasing customer demands, there is need to intensify research on the intensive fish production opportunities for example all-female common carp technologies. The all-female technology is one of a genom-manipulation technology. Its production showed better growth rate than mixed-sex population in pond culture. Our experiment combined the recirculation aquaculture system (RAS) and the all-female common carp stocks intensification technologies. The reason for the experiment, is that there are no result about the growth of all-female common carp growth in RAS. The experiment used the „Tatai grey scale type” common carp stocks. We propagated two all-female stocks (T2 and T3) and a control group (TK). Due to technological characteristics of RAS, the water quality parameters were the same for all treatments and corresponded to the technological tolerance of common carp. The experimental period was from July 10, 2019 – November 20, 2019. Result of growth performance showed that the growth of mixed-sex stock was significantly higher than all-female stocks; (Control=3692.0±590.5g, T2=3438.8±415.4g, T3=3294.1±659.1g). Feed conversation ratio (Control=1.3±0.1 T2=1.5±0.2 T3=1.6±0.5) and SGR% (Control=0.8±0.0 T2=0.7±0.1 T3=0.7±0.1) were similar. By the results it can be said the all-female common carp technology has neither advantages nor disadvantages compared to the mixed-sex stock. The all-female technology can be beneficial if the consumers need female common carps. It is worth continuing the experiment and examine how the stocks will perform above 3kg body weight.

Effect of different water temperatures on sex ratio, gonad development and production parameters of common carp