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 (<i>Gryllus bimaculatus</i>) 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 (<i>p</i> < 0.05), while the potential extent of gas production (a + b), acetate (C₂), acetate and propionate (C₂:C₃) ratio, and protozoal population were reduced (<i>p</i> < 0.05) by lowering the R:C ratio and the replacement of SBM by CM. In addition, rumen CH₄ production was mitigated (<i>p</i> < 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 (<i>p</i> < 0.05) at low levels of roughage.