Search
Search Results
-
Investigation of the production parameters, nutrient and mineral composition of mealworm (Tenebrio molitor) larvae grown on different substrates
129-133Views:187During the rearing of mealworm (Tenebrio molitor) larvae, the optimisation of the growing substrate has a particular importance. The application of the appropriate substrate is a fundamental pillar for intensive and safe production. The requirements for substrate include the lack of toxins, high nutrient and micro-macro element content. The aim of this study was the evaluation of the effects of different substrates on the production parameters, nutrient and mineral composition of the mealworm larvae. The experiment lasted through 14 days. 5 treatments were set up at, where the variable was the substrate. The test system consisted of 25 units (5 treatments and 5 replicates). 10 mealworm larvae per unit, (total of 250 larvae) were used at the beginning of the experiment. Regarding the substrates, our study included sweet potato (SP), may turnip tuber (MT) and may turnip leaf (ML). In addition to the plant by-products, wheat flour (WF) and wheat semolina (WS) were used as control substrates. Trace element uptake and production parameters of the larvae were determined at the end of the experiment. Regarding the production parameters, it can be stated that the wheat semolina (0.081 ± 0.005 g) and wheat flour (0.069 ± 0.007 g) substrate used as control gave the best results for the final body weight. In terms of plant raw materials and by-products, sweet potatoes (0.063 ± 0.007) can only be recommended as substrate, while may turnip tuber and may turnip leaf produced significantly lower final body weight results (MT=0.034 ± 0.002 g ; ML= 0.036 ± 0.002 g). The nutrient composition of the larvae was not affected by the substrate, these results confirmed the high protein and fat content reported in the literature. The results with the production parameters were contradicted by the micronutrient content. Larvae reared on may turnip leaf (ML) and tuber (MT) showed the highest values for most of the macro- and microelements (potassium, calcium, magnesium, iron, zinc, copper) tested.
-
Examination and statistical evaluation of physico-chemical parameters of windrow composting
33-38Views:189The treatment and utilization of plant and animal waste and by-products from agriculture is very diverse. Traditional environmental management practices for waste management have been retained through soil conservation and the applied of recycle degradable organic substances in soil. The management of by-products from agriculture (animal husbandry) is important because a closed loop can be created to utilize by-products (manure, feathers) from the production of the main product (eggs, meat, milk) and to form a raw material for a new product. It is important to treat the resulting by-products, especially deep-litter manure, as it has served as a basis for compost-treated manure to develop an organic-based, soil-conditioning product line. Poultry manure by itself is not suitable as a substrate for aerobic decomposition, so it has to be mixed with other substances (zeolite, bentonite, soil), because of its high nutrient capacity, it is an acidifying substance.
The aim of this study was to compost the mixture of poultry manure and hen manure by the addition of zeolite and to monitor the composting process. It was also our aim to statistically determine the effect of the zeolite on parameters describing the composting process.
The windrow composting experiments were set up in the composting area of the University of Debrecen, Institute of Water and Environmental Management. The composting experiment was 62 days long, during which the main parameters describing the composting process were continuously monitored: temperature (°C), moisture content (w/w%), electrical conductivity (mS/cm), organic matter content (w/w%), examination of nitrogen forms (w/w%). In this study, three factors were investigated: temperature, humidity, and pH. For statistical evaluation, R software and RStudio user interface were used. We developed a repeated measurement model, in which the fixed and random effects were determined for our parameters under study, and the resulting relationships were shown on interaction plots.
Based on our results, the temperature of the prisms has become independent of the ambient temperature and the composting stages can be separated in both the control and the zeolite treated prisms. In the repeated measurement model, we proved that treatment, time and treatment: time interaction were significant at both temperature and pH.
-
Influencing the growth kinetics of yeast strains with vitamin supplementation
113-115Views:143The aim of the current experiment was to optimize the creation process of single cell protein on plant-based substrate solution with the intention to improve end-product turn out by means of adding vitamin solution. Based on the results of the fermentation processes of yeast strains, it was concluded that the vitamin-supplementation produced its greatest effect on the dry matter production, primarily on the K. marxianus DSM 4908 strain, while it was less beneficent when it comes to the figures of wet cell mass. In addition, it can be assumed that vitamin supplementation increased the maximum specific rate of growth (μmax) and decreased the generation time (tg) significantly. In the case of the K. marxianus yeast strain on corn steep liquor treated with vitamin-supplementation, the highest (μmax) and the lowest (tg) data were observed [(0.226 h-1) and (4.4 h), respectively]. Based on the results it was found that K. marxianus DSM 4908 is expedient to be applied on corn steep liquor medium in order to determine its suitability to produce additive for feeding.