Investigation of dried distillers grains with solubles (DDGS) susceptibility to red flour beetle (Tribolium castaneum (Herbst)) infestation

Mahsa Fardisi, Purdue University


Protecting livestock feed from insect infestation is a common challenge that feed facility managers and farmers have to deal with. It becomes an issue of importance because insect infestation degrades feed quality and quantity. Dried Distillers Grains with Solubles (DDGS) is added to livestock feed because of its high protein content. As DDGS usage in animal feed increases, understanding the susceptibility of DDGS, when mixed with livestock feed, to insect infestation is necessary for safe feed storage. This research addressed four questions. The first looked at the susceptibility of DDGS, when stored as a raw ingredient, to Tribolium castaneum (Herbst) infestation. DDGS susceptibility to T. castaneum was lower when stored as a raw ingredient compared with normal T. castaneum laboratory diet at 30% r.h.. However, increasing r.h. to 50% and grinding DDGS samples, increased DDGS susceptibility to T. castaneum infestation. The second question concerned the susceptibility of livestock feed that contains DDGS to T. castaneum infestation. Results showed that adding any amount of DDGS to animal feed will not change diet susceptibility to T. castaneum infestation and feed pelletization negatively affected insect development. For the third question, experiments were conducted to determine the chemical and physical characteristics of DDGS which may influence its susceptibility to T. castaneum infestation. Particle size was the main factor affecting DDGS vulnerability to T. castaneum infestation. The fourth question focused on the alternative uses of DDGS as bait for monitoring T. castaneum. Efficacy of traps significantly increased when a combination of DDGS and food oil kairomone lures were used compared with food oil or empty traps. Therefore, DDGS may be a good additive to food oil lures to increase trap efficacy. In conclusion, T. castaneum development significantly increased when fed DDGS. Diet particle size and environmental humidity had significant effects on T. castaneum development. As a result, it is recommended that facility managers store DDGS as a raw ingredient, pelletize DDGS if it is cost-effective, and keep the storage humidity at 30% or lower.




Ileleji, Purdue University.

Subject Area

Entomology|Animal sciences|Animal Diseases

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