Recycling of organic residues by black soldier fly larvae - influence of substrate on larval composition

<p>The concept of closed ecological cycles has a high priority in organic farming. As the larvae of the black soldier fly are able to utilize organic residues and convert them into high-quality protein and fat, the larvae could play a role in recycling local organic residues into feed for fish, poultry and pigs and partially replace imported protein feeds. In this work, a wide range of residues was tested as feed components for black soldier fly larvae.</p><p>Total C and S of feed substrates and larvae were determined by CNS analyzer. Crude protein/N<sub>tot</sub> was analyzed by the Kjeldahl method; crude fat after acid digestion. For the analysis of P<sub>tot</sub> and other elements the samples were digested by dry ashing, dissolved in dilute HCl and measured by ICP-OES.</p><p>The yield of larval dry matter ranged from 0.10 to 0.23 kg per kg feed dry matter (DM). The highest larval DM was obtained with substrates of bread residues and wheat bran and of distiller's grain solubles (DDGS) and pasta residues. The lowest larval DM and the lowest yield of larval protein were obtained when feeding with substrates containing beet pulp or potatoes.</p><p>Crude protein contents of the larvae ranged from 33% to 52% DM, the maximum values almost equalling soybean extraction meal, but still below fish meal. High crude protein contents in the feed did not always correlate with high larval contents. The yield of larval protein was 0.105 kg per kg feed DM at maximum, with a substrate containing rapeseed extraction meal and pasta residues. Substrates of brewer's grains and pasta residues and of DDGS and pasta residues yielded 0.101 kg kg<sup>-1</sup> and 0.98 kg kg<sup>-1</sup>, respectively.</p><p>Larval crude fat contents ranged between 18% and 38% DM. Of the feed substrates with high DM and protein yields, only that of rapeseed extraction meal and pasta residues achieved a crude protein/crude fat ratio >2.</p><p>Phosphorus contents of the larvae were 6.9 - 11.5 g kg<sup>-1</sup> DM, sulfur contents 3.3 - 6.1 g kg<sup>-1</sup>. Highest P and S contents were found in larvae fattened on substrates with particularly high P and S contents, such as of corn steep liquor and wheat bran, or of rapeseed extraction meal with maize or pasta residues.</p><p>Calcium was enriched in the larvae. With the exception of larvae from Ca-rich feed substrates such as rapeseed extraction meal or beet pulp, which had Ca contents of 20 and 30 g kg<sup>-1</sup> DM, respectively, the Ca contents of the larvae were in the range of soybean extraction meal, 3.4 to 10.5 g kg<sup>-1</sup> DM.</p><p>Cu contents ranged from 5.7 to 13.9 mg kg<sup>-1</sup> DM, with the exception of larvae fed with brewer's grains, which had 24.7 mg kg<sup>-1</sup> Cu.</p><p>The results show that crude protein and crude fat content of the larvae vary greatly with different feed substrates. In addition to these quality characteristics, the substrate also influences the contents of other nutrients such as P, Ca, Cu, etc. This knowledge can be used specifically in different applications of the larvae in feed production.</p>

Tofu Processing at Tofu Industry Using Fermented Whey as Coagulants

Background: Tofu industry in Indonesia commonly used fermented whey as coagulant. There is a lack of study about tofu producing process which used fermented whey. Generally, the society determine the tofu quality from the texture, however, the industry itself tend to produced tofu rendement. In the tofu industry, the yield and texture of tofu is a very important process parameter. The yield and texture are influenced by various factors, such as the soybean extraction process, cooking temperature, coagulation pH, length of coagulant addition, intensity of coagulant addition, or duration of shaping and pressing. However, every tofu factory applies different levels for each factor. This condition causes the variation in the characteristics of tofu, especially with regard to its texture and yield. Objective: This study aimed to determine the factors that affect the quality and quantity of tofu. Methods: The survey study was conducted among the 21 tofu factories using fermented whey as the coagulant. Results: Based on the survey results, there were seven variables that determine the yield of tofu; the soybean type, soybean and water ratio, pH of fermented whey (coagulant), coagulation temperature (°C), coagulation pH, intensity of coagulant addition (time), and duration of molding (minutes). Conclusion: The six factors that influenced the tofu texture were soybean type, soybean and water ratio, coagulation temperature (°C), coagulation pH, coagulation time (minutes), and duration of molding (minutes).

Biochemical and mineral blood indices in fattening pigs fed mixtures containing yellow lupine (Lupinus luteus)

Thirty crossbred pigs [♀ (Landrace x Yorkshire) x ♂ Duroc] were fattened in a three-stage fattening period. Soybean extraction meal (Group K) or soybean extraction meal with seeds of yellow lupine in the amount of 7.5% (Group D1) or 15% (Group D2) were used as a source of protein in their diet. The animals were slaughtered after reaching a body weight of about 117.5 kg. Blood samples were collected from all pigs at this time. Activity of ALP, AST and ALT and the level of TP, GLU, CHOL, HDL, TG, CREA, UREA, Ca, P, Mg, and Fe were determined in order to assess the impact of the dietary factor on the homeostasis and health of the animals. The values of all biochemical and mineral blood indicators were lower in the experimental groups (D1 and D2) than in the control. Most of these differences were statistically significant (P≤0.05 and P≤0.01). The values of the characteristics were within the reference limits for the species. The dietary factor had no negative effect on homeostasis in the animals.

The efficiency of fattening pigs with mixtures containing yellow lupine (Lupinus luteus)

During a three-stage fattening period, 30 weaners, gilts and young boars of a three-breed cross – ♀ (Landrace x Yorkshire ) x ♂ Duroc – were fattened from body weight 27.2 to 117.5 kg. The animals were divided into three groups of 10, a control (K) and two experimental groups (D1 and D2). The pigs were fed total mixed rations and their daily weight gain and feed conversion were monitored. Soybean extraction meal was the only source of protein in the mixtures for the control pigs. In the mixtures for the experimental animals, the soybean extraction meal was partially replaced with seeds of yellow lupine. The proportion of the seeds was constant, irrespective of the stage of fattening, at 7.5% (D1) or to 15% (D2). After fattening and slaughter, basic carcass parameters were determined: hot carcass weight (kg), backfat thickness between the 3rd and 4th rib (mm), thickness of m. longissimus dorsi (MLD) and meatiness (%). Economic calculations, i.e. the differences between revenue (sale of the fatteners) and costs, were performed as well. The introduction of 7.5% and 15% yellow lupine in the mixtures for the experimental fatteners did not negatively affect the results of fattening. Daily weight gains in groups K, D1 and D2 were very good, amounting to 1,056 g, 1,075 g and 1,081 g, respectively (P>0.05). Feed consumption per kg of BW gain was also good: K – 2.72, D1 – 2.72, and D2 – 2.69 kg/kg. The carcass parameters in the groups were similar (statistically insignificant differences). A simplified analysis of production efficiency showed a positive rate of change, i.e. D1 vs. K – 18.53% and D2 vs. K – 8.56%, which confirms the benefits of using yellow lupine seeds in pig fattening.