Cricket Meal (Gryllus bimaculatus) as a Protein Supplement on In Vitro Fermentation Characteristics and Methane Mitigation

Abstract

The aim of this work was to conduct the effects of cricket (Gryllus bimaculatus) meal (CM) as a protein supplement on in vitro gas production, rumen fermentation, and methane (CH4) mitigation. Dietary treatments were randomly assigned using a completely randomized design (CRD) with a 2 × 5 factorial arrangement. The first factor was two ratios of roughage to concentrate (R:C at 60:40 and 40:60), and the second factor was the level of CM to replace soybean meal (SBM) in a concentrate ratio at 100:0, 75:25, 50:50, 25:75, and 0:100, respectively. It was found that in vitro DM degradability and the concentration of propionic (C3) were significantly increased (p < 0.05), while the potential extent of gas production (a + b), acetate (C2), acetate and propionate (C2:C3) ratio, and protozoal population were reduced (p < 0.05) by lowering the R:C ratio and the replacement of SBM by CM. In addition, rumen CH4 production was mitigated (p < 0.05) with increasing levels of CM for SBM. In this study, CM has the potential to improve rumen fermentation by enhancing C3 concentration and DM degradability, reduced methane production, and C2:C3 ratio. The effects were more pronounced (p < 0.05) at low levels of roughage.

Can insects be used in the nutrition of ruminants?

“…When using four edible insects, namely the house cricket (Acheta domesticus L.), the Taiwan giant cricket (Brachytrupes portentosus Serville), the two-spotted cricket (Gryllus bimaculatus De Geer) and the silkworm (Bombyx mori L.), as substitutes for the 25% of SBM in a 60:40 F:C diet, Ahmed et al (2021) found no adverse effects on rumen fermentation characteristics or nutrient digestibility. This clearly suggests, as expected and recently confirmed by Phesatcha et al (2022), that the insect dietary inclusion level also significantly affects fermentation and digestibility, as already reported to occur for monogastric animals (Elahi et al, 2022;Hong and Kim, 2022;Tran et al, 2022). Furthermore, Phesatcha et al (2022) demonstrated that, when using G. bimaculatus meal as a protein replacement for SBM, regardless of the insect dietary inclusion or substitution level, fermentation and digestibility parameters were also affected by the F:C ratio of the diet, thus highlighting the great complexity of factors and interactions involved.…”

“…This clearly suggests, as expected and recently confirmed by Phesatcha et al (2022), that the insect dietary inclusion level also significantly affects fermentation and digestibility, as already reported to occur for monogastric animals (Elahi et al, 2022;Hong and Kim, 2022;Tran et al, 2022). Furthermore, Phesatcha et al (2022) demonstrated that, when using G. bimaculatus meal as a protein replacement for SBM, regardless of the insect dietary inclusion or substitution level, fermentation and digestibility parameters were also affected by the F:C ratio of the diet, thus highlighting the great complexity of factors and interactions involved.…”

“…Another field of interest for researchers working in the nutrition of ruminants is the mitigation of enteric methane emissions, as the latter contribute to global greenhouse gas emissions and represent a loss of feed energy, consequently determining a reduction of feed efficiency (Haque, 2018). In the study by Ahmed et al (2021), the inclusion of G. bimaculatus and B. mori determined a 16% to 18% reduction of rumen methane production, confirming the results obtained for the same (G. bimaculatus; Phesatcha et al, 2022) and other insect species (Jayanegara et al, 2017a), and highlighting the potential environmental benefits of using insects as feed ingredients for ruminants. The oils chemically extracted from five insect species, namely H. illucens, Z. morio, T. molitor, G. bimaculatus and the weaver ant (Oecophylla smaragdina Fabricius), despite variations in their FA profile, were shown to be able to mitigate enteric methane emissions when added to both high forage (70:30 F:C) and high concentrate (30:70 F:C) diets (Jayanegara et al, 2020).…”

Comparative Analysis of In Vitro Fermentation Parameters in Total Mixed Rations of Dairy Cows with Varied Levels of Defatted Black Soldier Fly Larvae (Hermetia illucens) as a Substitute for Soybean Meal

“…Chitin, present in insects, is considered a hard-to-degrade fiber that can reduce nutrient digestibility and absorption [44]. Therefore, removing chitin content from insect products has been suggested as a way to improve nutrient availability and digestibility [45]. However, a study with Jamaican cricket beetles found no difference in in vitro OM digestibility when the chitin content was manually or chemically removed [2].…”

Which Protein Source is Best for Mass-Rearing of Asian Weaver Ants?

“…However, the highest protein content is in cricket Gryllus bimaculatus, with 61% -69% protein (this species was used in this study) (Jeong et al, 2021;Phesatcha et al, 2022;Udomsil et al, 2019). The carbohydrate-protein ratio from that report is also compared directly from the references (Figure 4).…”