[Protein efficiency ratio of genetically modified corn with Cry1Ab-ma gene]

To evaluate the protein efficiency ratio(PER) of genetically modified corn with Cry1Ab-Ma gene and parental corn.

Sixty SD rats(60-80 g) were randomly divided into genetically modified corn group, parental corn group and casein control group, with 20 rats in each group and half male and half female. Casein was added to 10% of the diet in casein control group. When the protein content of the diets in the genetically modified corn group and parental corn group was still less than 10% according to the principle of maximum incorporation, the defective part was supplemented with casein. Rats were free to drink and eat for 28 days. Food intake and body weight of each group were recorded every week. Blood was collected at the end of the experiment to determine hematology and blood biochemical indexes. The main organs were weighed and organ/body weigh indexes were calculated. PER and corrected PER were calculated.

The body weight of all the animals in each group showed an increasing trend, and the weight growth was normal. Although there were statistical differences in the individual indexes of end-stage hematology and blood biochemical indexes, there was no biological significance. There were no significant change in the organ/body weigh indexes. PER of genetically modified corn, parental corn and casein were 2.01±0.22, 1.77±0.30 and 3.64±0.48, respectively. The corrected PER of genetically modified corn and parent corn were 1.38 and 1.22, respectively.

The PER of this batch of genetically modified corn with Cry1Ab-ma gene was better than that of parental corn, but worse than that of casein.