Trans-generational effect of feeding genetically modified mCry1Ac corn to laying hens and offspring on offspring growth and health

Abstract Text:

The experiment was to assess the chronic effect of the transgenic corn lines containing the mCry1Ac gene from Bacillus thuringiensis strain (BT) to White Leghorn laying hens for 12 wk and their offspring from 1 d to 36 wk on offspring growth and health. Healthy hens (n = 72 placed in cages; 3 hens/cage) were randomly assigned to 1 of 3 corn-soybean meal dietary treatments (8 cages/treatment) formulated with the following corn: 61.7% nontransgenic near-isoline control corn (CT), BT corn, and commercially available nontransgenic reference corn (RF) for 12 weeks. After 12 weeks, fertile eggs were collected daily and hatched for 21 days. A total of 240 offspring pullets were assigned to 3 dietary treatment for 36 weeks, i.e. 1) CT corn-fed parental hens/CT corn-fed offspring pullets (CT/CT); 2) BT corn-fed parental hens/BT corn-fed offspring pullets (BT/BT); and 3) RF corn-fed parental hens/RF corn-fed offspring pullets (RF/RF). Each dietary treatment was assigned to 10 replicates with 8 offspring pullets per replicate for a total of 80 pullets per treatments. Body weight and egg quality of pullets were determined weekly. Offspring hens were harvested at the end of 36 weeks (n = 8/treatment), and carcass yield and organ weights (heart, liver, spleen, lung, kidneys and ovary) were recorded; organs and intestines were sampled for histological analysis. Analysis of serum biochemistry parameters, haematology, and hormone were performed. Immune cell phenotypes of spleen and peripheral blood mononuclear cells were determined. No differences in body weight, egg quality and function of reproductive organs were observed between hens consuming the CT/CT diet and hens consuming the BT/BT diet. Intestinal histology and health were similar between the control and test groups. The relative weight of lung and kidneys of hens fed the BT/BT treatment was less than hens fed the CT/CT treatment (P < 0.05). Liver and kidney histology and health were not affected by the diet treatment. Offspring hens from the BT/BT treatment had greater duodenal goblet cells/villus (P < 0.05) and jejunal villus height/crypt depth ratios (P = 0.06). Similar organosomatic indices, serum biochemistry parameters, haematology, and hormone parameters did not indicate the characteristics of organ dysfunction. Immune response was not affected by the trans-generation feeding BT/BT diet. These results indicate that trans-generational consumption of the BT corn diets is not detrimental to hen growth and health.

Keywords:

Bacillus thuringiensis, genetically modified, hen, mCry1Ac gene corn, trans-generational effect