Insects as Novel Ruminant Feed and a Potential Mitigation Strategy for Methane Emissions

Area of Science:

• Animal Science
• Nutritional Biochemistry
• Environmental Science

Background:

• Soybean meal (SBM) is a common protein supplement in ruminant diets.
• Ruminant production contributes to greenhouse gas emissions, particularly methane.
• Edible insects offer a sustainable alternative protein source.

Purpose of the Study:

• To evaluate the chemical composition of four edible insects.
• To assess the impact of insect inclusion on ruminant in vitro digestibility, rumen fermentation, and methane production.
• To determine the potential of edible insects as a partial substitute for SBM in ruminant diets.

Main Methods:

• In vitro batch culture incubation for 24 hours at 39°C.
• Four edible insect species (Acheta domesticus, Brachytrupes portentosus, Gryllus bimaculatus, Bombyx mori) were analyzed for chemical composition.
• Insects replaced 25% of SBM in a grass hay-based diet, with treatments compared to a control diet.

Main Results:

• Insects were rich in protein (48-61%) and unsaturated fatty acids (60-70%).
• Insect inclusion did not negatively affect nutrient digestibility or volatile fatty acid production.
• Gryllus bimaculatus and Bombyx mori inclusion reduced methane production by up to 18% and 16%, respectively.

Conclusions:

• Edible insects are a viable alternative to SBM in ruminant diets.
• Insects can be incorporated at 25% substitution without adverse effects on digestibility or fermentation.
• Specific insect species demonstrate potential for mitigating methane emissions in ruminant agriculture.