INSECT PROTEIN, myths and facts – we look at a study.

Since the European Commission officially approved insects as food, countless pro and con opinions have circulated online.

Attempts are being made to ban the valuable use of insect meal protein from various insect species from the diet, with opposing opinions, but this also applies to animal feed.

It should be noted that the black soldier fly (Hermetia illucens) is only regulated by the Feed Act and is currently not permitted in food. According to Regulation (EU) 2017/893, insects are considered farm animals if they are used for the production of processed animal protein. This means that the feeding bans of Regulation (EC) 999/2001 and Regulation (EC) 1069/2009 also apply to insects, and no food scraps or ruminant proteins may be fed to farmed insects. This is not prohibited outside the EU. This is where the crux of the matter begins. Where does the insect protein come from? What was it fed? How are the insects processed before they are used in food or animal feed.

The breeding and processing of Hermetia larvae?

There are already insects from sustainable circular economy systems. These are washed and inactivated during growth under strict official regulations to ensure no contamination. Inactivation is simultaneously sanitization or sterilization. Furthermore, larvae contain only 2% chitin before the pupal stage. Through countless tests and experiments with technical universities, the best pupal stage of the larvae for further processing into animal feed has been determined. The chitin can also be separated from the larvae, as this valuable chitin is often seen as a sustainable alternative in the cosmetics and packaging industries. Thus, not all insect protein is created equal. However, the majority of insect producers still process insects conventionally, without taking advantage of the new technological possibilities. Herosan is working very intensively on the above-mentioned sustainable circular economy of Hermetia larvae breeding.

We've had insects on our menu for a long time - did you know this fact?

Scarlet scale insects and lacquer scale insects have been used in the food industry for much longer.

For example, a red dye called "red carmine" (E120) is extracted from the scarlet scale insects. Pregnant lice are dried and boiled, and this substance is often incorporated into sweets. In cosmetics, this extracted substance is listed as "carmine," CI 75470, or "conchinille."

Shellac, in turn, is extracted from the excretions of the lac insects. Shellac forms a shiny coating; its uses range from paints and varnishes to nail polish, hairspray, and even as a glazing agent for sweets under the code number "E904."

Do Hermetia larvae feel like humans?

Hermetia larvae do not have a brain or a central nervous system as we know it, so these little creatures do not feel like other animals or humans.

Myth: Hermetia illucens have “antinutrients” to protect against predators?

This isn't the case with the larvae of Hermetia illucens, as they are also eaten by their fellow insects, including chickens and other animals. Their natural metabolism eliminates anything harmful. Not all insects are created equal.

Myth: Insects aren't healthy? Is insect protein really such a loss-maker?

As described in the inaugural dissertation of Dr. Heide in 2017 at the Free University of Berlin under the supervision of Univ.- Prof. Dr. Zentek: Larval meal of Hermetia illucens as a protein carrier in dog food, we are now devoting ourselves to the topic.

entoVITAL® food from HEROSAN is based on the soldier fly larvae and is therefore free from antibiotic contamination like protein from beef, pork or chicken.

Conclusion of the dissertation

The results demonstrated a similarly high apparent digestibility of the raw nutrients compared to a commercial complete feed with lamb as the main protein source.

The present results show no evidence of intolerance, so that the use of the investigated larval meal as a protein component in the diet of dogs is possible.

No immunological or hematological differences were detected between the two feeding groups. Examination of the concentrations of microbial metabolites in the fecal samples revealed higher concentrations of short-chain fatty acids and ammonium in the feces of the dogs after consuming the control diet. As expected, more chitin was detected in the experimental diet than in the control diet. Chitinase activity in the feces was not affected.

In this study, no negative effects of the test feed containing Hermetia illucens larval meal were detected in dogs in the feeding trial, so that good tolerance can be assumed within the dosage range investigated.

What was the topic of this dissertation?

The chitin content and digestibility of chitin were determined, as well as whether the chitin content in the feed has an effect on enzymatic processes, especially on chitinase activity in the dog's digestive tract.

The total amount of feces per day was used to determine the apparent total digestibility of nutrients and the chlorine utilization.

Chitinase content in feces was determined using a color reaction. When chitinase converts colloidal chitin into azure, the azure pigment is released and can be measured photometrically at 560 nm.

Chitin is a polysaccharide composed of N-acetyl-D-glucosamine units.

Both blood parameters and feces were used for analysis to evaluate digestive physiological parameters, bacterial metabolites, determination of chitin content and measurement of chitinase activity.

None of the dogs showed any health problems during the experiment or had to be removed from the test series, which can generally be considered a positive thing.

However, the dry matter content of the feces did not differ between the two feeding groups. Hematological parameters did not differ between the two feeding groups, and the differential blood count also showed no differences; all parameters were within the normal range. There were also no statistically significant differences in the lymphocyte populations between the two feeding groups during the experiment.

The food antigen-induced lymphocyte proliferation test showed no differences in the stimulability of the lymphocytes (stimulation index) between the two feeding groups.

The difference in the analysis revealed that the apparent dry matter digestibility of potassium, zinc, phosphorus, and sodium was higher in the dogs fed the experimental diet. The apparent digestibility of calcium, magnesium, and iron was higher in the control group.

The concentrations of acetic acid and total fatty acids in the feces were higher in the dogs fed the control diet.

No differences were detected in the distribution of short-chain fatty acids in the faeces between the feeding groups.

Neither D- nor L-lactate concentrations in the faeces differed significantly between the two feeding groups.

A difference in fecal ammonium concentration was demonstrated between the two feeding groups. The control group showed higher fecal ammonium levels.

Some excerpts from the dissertation

Chitinase activity in the stool sample

When comparing the chitinase activity in the feces of both feeding groups, no difference was found.

Blood count and differential blood count

To assess the dogs' health during the study, a complete blood count, including a differential blood count, was performed. The results show no feeding-related differences between the two diets, and all values ​​are within the reference range. Swanson et al. (2004) compared a plant-based and an animal-based diet over a period of 12 months. This study also found no feeding-related differences between erythrocytes, hematocrit, and hemoglobin.

Total digestibility

The higher the crude fiber content of the ration, the lower the apparent digestibility of the organic matter. The type of plant cell wall components is also crucial. Compared with the control diet with lamb as the protein source, the experimental diet had a higher apparent digestibility of the organic matter, dry matter, and crude ash. In contrast, the apparent digestibilities of crude fiber, crude fat, and crude protein were higher when fed the control diet. Both diets also contained other protein sources, so the apparent digestibilities cannot be related solely to the main protein sources. Furthermore, the crude fiber and crude ash values ​​of the two diets are different, so the apparent digestibility of these crude nutrients can only be compared to a very limited extent.

Bacterial metabolites in stool samples

There were some differences in the fecal concentrations of short-chain fatty acids and ammonium levels between the feeding groups. The lactate levels measured in the feces of the experimental animals in the present study showed no feeding-related influence.

Short-chain fatty acids

Despite the higher crude fiber content of the experimental diet with Hermetia illucens in the present study, no higher levels of short-chain fatty acids were observed in the feces of the dogs fed this diet.

In general, the results for short-chain fatty acids show that there was greater fermentation in the large intestine of the dogs after feeding the control diet. However, the percentage distribution of short-chain fatty acids relative to the total fatty acids is comparable to other studies (Middelbos et al., 2007; Sunvold et al., 1995).

Ammonium and feces

If increased amounts of protein enter the large intestine, microbial fermentation processes produce end products such as ammonia or ammonium (Meyer and Zentek, 2013). Beloshapka et al. (2016) also observed decreasing ammonium concentrations in dog feces with increasing soybean meal levels in the diet. The highest fecal ammonium concentrations were achieved in dogs that received poultry by-products as their primary protein source. The ammonium concentration, or ammonia absorption, depends on the pH value in the intestine. Furthermore, the rate of ammonium production and thus the fecal concentration also depends on the microbiota of the large intestine and the available energy (Hesta et al., 2003).

Chitin content in feed and feces samples

There are studies in which the chitin content in insects was measured using gravimetric methods (Lovell et al., 1968). Since the chitin content in feces and food is very low compared to the chitin content in insects, a new method using ion chromatography was evaluated for the present study. Chitin is a polysaccharide composed of N-acetyl-D-glucosamine units. The glucosamine formed by hydrolysis is thus related to the chitin content in the samples.

The more chitin there was in the ration, the lower the digestibility of chitin.

In the present study, it remains questionable why glucosamine was measured in the control diet and in the feces of dogs fed the control diet. It is likely that the control diet contained N-acetyl-D-glucosamine in the form of other polysaccharides and not in the form of chitin. N-acetyl-D-glucosamine is a component of some glycosaminoglycans such as hyaluronic acid, heparan sulfate, and keratan sulfate. These glycosaminoglycans are found, among other things, in synovial fluid, blood vessels, cartilage, the cornea, and the nucleus pulposus (Thonar et al., 1985). The detection of glucosamine after feeding the control diet can presumably be explained by the fact that it was not chitin but other polysaccharides containing N-acetyl-D-glucosamine.

Dipl. Veterinarian Daniel Vozicky

Source: Larval meal of Hermetia illucens as a protein carrier in dog food.

From the Institute of Animal Nutrition at the Department of Veterinary Medicine at the Free University of Berlin; veterinarian Carolin Heide, Professor Dr. Jürgen Zentek, Professor Dr. Susanne Hartmann, and Professor Dr. Corinna Eule;