Biological evaluation of protein quality of sorghum as affected by insect infestation.

Protein quality of sorghum grains having 25, 50 and 75% infestation caused by mixed population of Trogoderma granarium Everts and Rhizopertha dominica Fabricius was biologically evaluated by rat growth and nitrogen balance studies. Feeding of diet containing insect infested sorghum grains (50 and 75%) resulted in marked decrease in food intake, protein intake, gain in body weight, food efficiency ratio, protein efficiency ratio, nitrogen consumption, nitrogen absorption, biological value, net protein utilization, dry matter digestibility, net protein retention and protein retention efficiency. These parameters showed negative association with insect infestation levels. However, 25% level of grain infestation did not affect these parameters significantly.