Insect-based diets (house crickets and mulberry silkworm pupae): A comparison of their effects on canine gut microbiota

Background and Aim

The gut microbiome plays an important role in the overall health and well-being of dogs, influencing various physiological processes such as metabolism, nutrient absorption, and immune function. Edible insects are a sustainable and nutritious alternative protein source attracting increasing attention as a potential component of animal feeds, including pet food. However, little is known about the effects of insect-based diets on the gut microbiota of dogs. This study aimed to examine the fecal microbiota of dogs fed a diet that substituted common protein sources (poultry meal) with the house cricket (Acheta domesticus [AD]) or mulberry silkworm pupae (Bombyx mori pupae [BMp]) at different levels.

Materials and Methods

Fifteen healthy adult mixed-breed dogs were systemically randomized and assigned into each block under a completed randomized block design into the following five experimental dietary groups: control diet, 10% AD, 20% AD, 7% BMp, or 14% BMp for 29 days. The amounts fed to the dogs were based on the daily energy requirement. Fecal samples were collected on days 14 and 29 and analyzed for bacterial community structure using 16S ribosomal ribonucleic acid gene sequencing.

Results

At the phylum and genus levels, microbiota and their diversity were generally relatively similar among all treatments. The diets containing insects did not significantly alter the major phyla in the gut microbiome of dogs (p > 0.05). A few significant changes were found in the relative abundance of bacterial genera, with the levels of Allobaculum and Turicibacter being reduced in dogs fed a higher level of BMp. In contrast, only a decrease in Turicibacter was found in dogs fed the lower level of AD than the control diet (p < 0.05). Corynebacterium and Lactobacillus levels in the dogs fed 14% BMp were significantly increased compared with those in the control group (p < 0.05).

Conclusion

These findings suggest that insect-based diets may slightly alter the gut microbiota of dogs. Further research is needed to fully understand the mechanisms by which insect-based diets influence the gut microbiota of dogs and the long-term potential health implications.

Influence of dietary supplementation with new Lactobacillus strains on hematology, serum biochemistry, nutritional status, digestibility, enzyme activities, and immunity in dogs

Background and Aim

The use of antibiotics is associated with many side effects, with the development of bacterial resistance being particularly important. It has been found that dogs and their owners host similar resistant bacteria. This contributes to increased concurrent bacterial resistance and a possible trend of increased bacterial resistance in humans. Thus, using probiotics in dogs is an alternative option for preventing and reducing the transmission of bacterial resistance from dogs to humans. Probiotics are characterized by their potential to endure low pH levels and high concentrations of bile acids in the gastrointestinal tract. Lactobacilli are more acid-tolerant and resistant to bile acid, so they are ideal probiotics to be added to the canine diet. According to the previous studies, the benefits of Lactobacillus are a stable nutritional status and greater digestibility, along with improved fecal scores and reduced ammonia in dogs. However, no studies have been conducted with Lactobacillus plantarum CM20-8 (TISTR 2676), Lactobacillus acidophilus Im10 (TISTR 2734), Lactobacillus rhamnosus L12-2 (TISTR 2716), Lactobacillus paracasei KT-5 (TISTR 2688), and Lactobacillus fermentum CM14-8 (TISTR 2720), or their use in combination. Hence, the aim of this study was to examine the possible effects of the aforementioned Lactobacillus on hematological indices, nutritional status, digestibility, enzyme activities, and immunity in dogs. From the results, a new and safe strain of Lactobacillus may emerge for use as a probiotic in the future.

Materials and Methods

In this study, 35 dogs were allocated equally into seven groups: Group 1 received a basal diet (control), while Groups 2-7 received the same diet further supplemented with L. plantarum CM20-8 (TISTR 2676), L. acidophilus Im10 (TISTR 2734), L. rhamnosus L12-2 (TISTR 2716), L. paracasei KT-5 (TISTR 2688), L. fermentum CM14-8 (TISTR 2720), or a mixture of probiotics (L. plantarum, L. acidophilus, L. rhamnosus, L. paracasei, and L. fermentum), respectively. All probiotics were administered at a dose of 10⁹ colony-forming unit/dog for 28 days. Nutritional status, hematology, serum biochemistry, digestibility, enzyme activities, and immunity parameters were assessed.

Results

There were no differences among the groups in body weight, feed intake, body condition score, fecal score, and fecal dry matter on the different sampling days. The hematology and serum biochemical analyses showed a difference only in creatinine activity (p < 0.001), with higher values in group L. fermentum CM14-8 (TISTR 2720) and lower values in group L. paracasei KT-5 (TISTR 2688) than in controls. However, all measurements were within the normal laboratory reference ranges. Fecal characteristics (fecal ammonia and fecal pH), fecal digestive enzyme activities, serum immunoglobulin (IgG), and fecal IgA did not differ significantly among the groups (p > 0.05).

Conclusion

Lactobacillus plantarum CM20-8 (TISTR 2676), L. acidophilus Im10 (TISTR 2734), L. rhamnosus L12-2 (TISTR 2716), L. paracasei KT-5 (TISTR 2688), and L. fermentum CM14-8 (TISTR 2720), along with their mixture are safe and non-pathogenic additives for use as new probiotic strains of Lactobacillus in dogs. Although the new Lactobacillus strains had no effect on hematology, serum biochemistry, nutritional status, digestive enzyme activities, immunity, body weight, feed intake, or body condition scores in dogs, further studies should investigate the intestinal microbiota and the development of clinical treatments.

Effects of environmental condition, size, coat type, and body condition score on rectal temperature prediction in dogs using infrared auricular and surface temperature

Background and Aim:

Generally, rectal body temperature (BTrectum) is used to prefer as core body temperature in dogs. However, this procedure is time- and labor-consuming with stress induction. Therefore, infrared auricular temperature (BTear) and surface temperature (ST) could be applied to estimate BTrectum. This study aimed to estimate BTrectum from BTear or ST in various areas and determined the factors that influenced the accuracy of prediction equations.

Materials and Methods:

Under controlled temperature (n=197) and ambient temperature (n=183), the parameters BTrectum, BTear, and ST at internal pinna, auricular canal, lateral aspect of shoulder, hip, axillary area, inguinal area, footpad, and anal area (STrectum) were measured. In addition, temperature and humidity levels of the surrounding environment were recorded. The correlation between each measurement technique was calculated. The BTrectum prediction equation was created using all measured data and several influencing factors (environmental condition, size, coat type, and body condition score [BCS]).

Results:

The highest correlation with BTrectum was observed for BTear (r=0.61, p<0.01), which was similar to STrectum (r=0.61, p<0.01). Based on multiple linear regression model results using BTrectum as the dependent variable, BTear or STrectum were first selected as independent variables in all estimation equations. Ambient temperatures (R²=0.397), small breed (R²=0.582), long hair (R²=0.418), and/or a BCS of 2 (R²=0.557) provided the highest coefficients of determination of the prediction equation.

Conclusion:

The most appropriate predictors for estimating BTrectum were STrectum and BTear, which were impacted by the dog’s signalments and the environment. To obtain satisfactory outcomes, the equation must be selected depending on the dog’s signalments and the environmental conditions. However, based on the findings of this investigation, the accuracy remains low in several equations, and further studies are needed to improve the accuracy of the equation, mainly by increasing the sample size and developing a specific equation for each dog’s signaling and environmental condition.

Effects of eri silkworm (Samia ricini) pupae inclusion in broiler diets on growth performances, health, carcass characteristics and meat quality

OBJECTIVE

The objective of this study was to determine the appropriate amount of eri silkworm pupae meal (Samia ricini) to add to the broiler diet.

METHODS

Two hundred 1-day-old male chicks with initial weight at 50.03±0.56 g/chick were divided into four groups (five replicates per group and ten chicks per replicate): a control group fed a corn-soybean diet and experimental groups supplemented with 5%, 10%, or 15% eri silkworm pupae meal. All experimental diets were isocaloric and isonitrogenous and formulated respecting nutrient requirements. Growth performances were collected during the experimental period and other parameters were collected at the end of experiment when broilers reached thirty-eight days old.

RESULTS

A higher cold carcass weight and skin yellowness in the broilers fed 10% eri silkworm pupae meal compared with the other groups (p<0.05). Therefore, supplementation with 10% eri silkworm pupae meal is suggested for the broiler diet formulation because it did not cause any serious negative consequences on growth performance, health status, carcass characteristics and meat quality. However, the usage of eri silkworm pupae meal at 15% is not recommend because it led to negative outcomes.

CONCLUSION

The addition of eri silkworm pupae at 10% can be used as an alternative protein sources for broiler chickens which provided benefits on cold carcass weight and skin yellowness without adverse effects.

Possibility of Using House Cricket (Acheta domesticus) or Mulberry Silkworm (Bombyx mori) Pupae Meal to Replace Poultry Meal in Canine Diets Based on Health and Nutrient Digestibility

Simple Summary

Pet foods are one of the fastest-growing products owing to demands by pet owners. In general, soybean meal, meat, meat by-products, meat, and bone meal and fishmeal have usually served as protein sources in canine diets, but they are not sustainable and fluctuate in chemical composition. Recently, several companies around the world have invested in producing edible insects as an alternative protein source for humans, livestock, aquatic animals, and dogs; however, regulation is unique for each country, which has limited the growth of insect industries. Based on several study reports, dogs have been shown to consume diets containing insects without adverse effects on health or nutrient digestibility. House cricket (Acheta domesticus: AD) and mulberry silkworm (Bombyx mori: BM) pupae are other potential insects able to be good protein sources that could replace poultry meal and fishmeal. Healthy adult mixed-breed dogs were divided into five groups fed diets with 10% AD, 20% AD, 7% BM, or 14% BM for 29 days. During the experiments, dogs were evaluated in terms of blood parameters and nutrient digestibility. The study shown AD and BM, at levels of up to 20% and 14%, respectively, can be a substitute for poultry meal in canine diets without any adverse effects on health and nutrient digestibility.

Abstract

There has been increasing interest in using insects as sustainable protein sources for humans and animals. Therefore, this study aimed to explore the possibility of substituting poultry meal with house cricket (Acheta domesticus: AD) or mulberry silkworm (Bombyx mori: BM) pupae. Fifty healthy adult mixed-breed dogs were selected and divided into five experimental groups, which were fed, in amounts based on daily energy requirement, with a control diet, a diet with 10% AD, with 20% AD, with 7% BM, or with 14% BM. Days 0–22 and 23–28 of the experiment served as the adaptation and collection phases, respectively. Haematology and blood chemistry were collected at days 0, 14, and 28, and body weight, body condition score, feed intake, faecal output, faecal score, faecal moisture, and apparent total tract digestibility of dry matter and nutrients were measured during the collection phase. The results from this study suggested that AD and BM can replace poultry meal without any adverse consequences on all measured parameters (p > 0.05). Therefore, AD at 20% or BM at 14% can be used in canine diet formulations. However, long-term feeding trials should be conducted and should focus on clinical signs relating to hypersensitivity disorders.

Screening of in vitro nutrient digestibility coefficients of selected insect meals in broiler chickens, black-meat chickens and quails

The objective of this study is to identify potential insect species comparing with commonly used protein sources based on efficiency of the in vitro digestibility on dry matter (DMd), organic matter (OMd) and crude protein (CPd) in broiler chickens, black-meat chickens (Native breed) and quails. Each of gastric mucosa, pancreas and duodenal mucosa were obtained from proventriculus, pancreas and duodenum, respectively. Crude digestive enzyme extracts (CTE) were extracted from these organs to perform in vitro digestibility. Eighteen insect samples and six commonly used protein sources were served as substrates which were evaluated on DMd, OMd and CPd in triplicate for each substrate. The CTE from gastric mucosa was used to simulate proventriculus, whereas small intestine was simulation by adding the CTE from pancreas and duodenum. The large variation of chemical composition between insect meals was presented. For commonly used protein sources, animal proteins were higher on digestibility than plant proteins (p < .001). Quails represented a great potential to digest insect meals comparing other animals. Based on CPd results, there were potential insect species for broiler chickens (Achroia grisella: AG, Tenebrio molitor: TM and Musca domestica), black-meat chickens (Patanga succincta, TM and AG) and quails (Hermetia illucens, Acheta domesticus and Locusta migratoria; p < .001). The evidences from this study suggest that these insect species contain a great potential to use as alternative protein sources promoting an animal production with sustainability. However, the in vivo experimentation must be performed to confirm in further study.

Comparison of Rabbit, Kitten and Mammal Milk Replacer Efficiencies in Early Weaning Rabbits

Simple Summary

A milk replacer must be given as the main diet to young rabbits that are separated from their mothers before they reach weaning age (31–35 days). This procedure, which is a rescue protocol, allows them to survive. Moreover, the early separation of young rabbits before weaning prevents negative consequences in lactating rabbits, which is beneficial to pet rabbit producers. Kitten (KMR^®, Pet-Ag Inc., Hampshire, IL, USA: KMR) or mammal (Zoologic^® Milk matrix 30/52, Pet-Ag Inc., Hampshire, IL, USA: MMR) milk replacers have generally been suggested for use in rabbits; however, rabbit milk has a unique composition. Therefore, a rabbit milk replacer (RMR) was formulated in this study for comparison with these commercial products. Early weaned rabbits at 18 days of age were fed daily with RMR, KMR or MMR until 36 days after birth, while a commercial pelleted diet and water were provided at an amount exceeding the normal intake. The results indicated that it is possible to use RMR as a milk replacer for rabbits without serious adverse consequences. However, the RMR group presented a lower trend in nutrient digestibility than the other groups, although there was no statistical significant difference. Therefore, prebiotics and/or probiotics should be added to RMR formulations to improve this parameter.

Abstract

Early weaned rabbits should be fed using a milk replacer in order to survive. Therefore, a rabbit milk replacer (RMR) was developed and compared with a kitten milk replacer (KMR^®: KMR) and a mammal milk replacer (Zoologic^® Milk matrix 30/52: MMR). Thirty-six native crossbred rabbits aged 18 days were divided into three experimental groups (six replicates/group, two rabbits/replicate), fed RMR, KMR or MMR daily until they were 36 days old and euthanized at 38 days, while a complete pelleted diet and water were provided ad libitum. No statistically significant differences were observed in growth performance parameters, water intake, faecal weight, nutrient digestibility, internal organ weight, caecal pH, caecal cellulose activity, number of faecal pellets and amount of crude protein intake (p > 0.05). Caecal amylase activity in the KMR group and caecal protease activity in the RMR group were higher than in the MMR group (p < 0.05). The villus height and crypt depth of the MMR group were greater than in the RMR and KMR group (p < 0.05). In conclusion, it is possible to feed RMR to early weaning rabbits without serious adverse effects. However, probiotics and/or prebiotics should be supplemented in milk replacers and their benefits studied.

Effects of dietary supplementation with different levels and molecular weights of fungal β-glucan on performances, health and meat quality in broilers

Objective

To investigate the effects of dietary supplementation with different levels and molecular weights of fungal β-glucan on productive performances, health, carcass traits and meat quality in broilers.

Methods

Two hundred and ten of one-day-old chicks with equal sex were assigned to seven experimental groups in 2×4 factorial arrangement. These groups were supplemented with (0, 10, 30 and 60 ppm) of molecular weight 1-3, 1-6 β-glucan (low or high). High molecular weight β-glucan (H: 943 kDa) was obtained from Ophiocordyceps dipterigena BCC 2073, whereas H with -Irradiation treatment was performed to achieve low molecular weight β-glucan (L: 8 kDa).

Results

There was no statistical significance in productive performances, apparent digestibility and interaction between fixed factors along 42 days of experiment (P>0.05). A higher caecal amylase activity was present in the group that received L, while there was a dramatic decrease in H and the control groups, respectively (P<0.05). The increase of supplemental dose increased caecal amylase activity (P<0.05). Immunomodulatory effects from L was revealed by the marked increase of phagocytic activity, relative weight of thymus and bursa of fabricius (P<0.05). Similarly, the additive dose at 30 ppm provided the same results, whereas the only significant difference with supplementation at 60 ppm was an increase in phagocytic activity (P<0.05). Interestingly, villi height of broilers fed L was higher than other groups (P<0.05). The treatments did not influence haematology, blood chemistry, antibody production level against vaccination, carcass traits and meat quality (P>0.05).

Conclusion

The supplementation of L at 30 ppm was suggested to achieve benefits of immune modulation without adverse effects on other parameters.

Potential of Insect Meals as Protein Sources for Meat-Type Ducks Based on In Vitro Digestibility

There has been a dramatic increase in duck meat consumption. As a result, ducks are an interesting alternative type of livestock. Animal-based proteins such as fishmeal and animal by-products are valuable nutrients with high digestibility, but they are associated with cost fluctuations, pathogen contamination, and environmental impacts. Therefore, plant-based proteins are used, but they have the disadvantages of inappropriate amino acid profiles, anti-nutritional factors, and mycotoxin contamination. Insect meal contains favorable nutrients and low production costs and is environmentally friendly; however, there is a large number of insect species. Therefore, the purpose of this investigation is to screen insects for their potential use as a protein source in the duck diet. Insect meal with a high proportion of low-digestible components was shown to have low digestibility. Yellow mealworm larvae, giant mealworm larvae, lesser wax moth larvae, house fly larvae, mulberry silkworm pupae, and American cockroach nymph have the potential to be alternative protein sources for ducks. Insect meal has been widely studied and is used in animal nutrition to replace common protein sources that have several disadvantages and to promote sustainability in animal production. Two-step in vitro digestibility using crude enzyme extracts from digestive tracts of meat-type ducks (Cherry Valley) was performed on general protein sources and insect meals to compare the in vitro digestibility of organic matter (OMd) and crude protein (CPd). Variation in chemical components between different types of insect meal was found. A positive correlation was found between OMd and the ether extract composition in insect meal, whereas a negative correlation was shown between crude fiber and acid detergent fiber. Contrasting relationships were found between CPd and crude fiber and acid detergent fiber in insect meal. In conclusion, the yellow mealworm larvae (Tenebrio molitor), giant mealworm larvae (Zophobas morio), lesser wax moth larvae (Achroia grisella), house fly larvae (Musca domestica), mulberry silkworm pupae (Bombyx mori), and American cockroach nymph (Periplaneta americana) are potential protein sources for ducks based on OMd and CPd digestibility after screening with an in vitro digestibility technique.