Transgenerational effects of feeding genetically modified maize to nulliparous sows and offspring on offspring growth and health.

This study assessed the effect of feeding genetically modified maize expressing a truncated form of the Cry1Ab protein from Bacillus thuringiensis (Bt MON810 maize) to sows during gestation and lactation and their offspring from weaning to 115 d postweaning on offspring growth and health. After weaning at approximately 28 d of age (d 0), individually penned, mixed sex pigs (approximately 8 kg BW) from sows fed isogenic or Bt maize diets were blocked by sow treatment, sex, and BW and randomly assigned to Bt or isogenic maize diets as follows: i) isogenic maize-fed sow/isogenic maize-fed offspring (iso/iso); ii) isogenic maize-fed sow/Bt maize-fed offspring (iso/Bt); iii) Bt maize-fed sow/isogenic maize-fed offspring (Bt/iso); and iv) Bt maize-fed sow/Bt maize-fed offspring (Bt/Bt). Growth performance was recorded at intervals to harvest at approximately 105 kg BW (n=15/treatment) and blood samples were taken for biochemical analysis on d 0, 30, 70, 100, and 115 postweaning (n=10/treatment). Pigs were harvested on d 115 postweaning (n=10/treatment), and carcass weight, backfat depth, and organ weights (heart, kidney, spleen, and liver) were recorded. Kidney, liver, lymph nodes, and small intestine were collected for histological analysis. Offspring from Bt maize-fed sows were heavier than offspring from isogenic maize-fed sows on d 30 (P<0.05), 100 (P<0.05), and 115 postweaning (P<0.05) and had greater overall ADG (P<0.05). Overall ADFI was greater for offspring from sows fed Bt maize (P<0.05) and for Bt maize-fed pigs (P<0.05). Offspring from Bt maize-fed sows had greater carcass (P<0.05) and lighter spleen (P<0.05) weights. Dressing percentage was greater for Bt maize-fed pigs than isogenic maize-fed pigs (P<0.05), and livers were lighter for pigs in the Bt/Bt group than pigs in the iso/Bt or Bt/iso group (P<0.05). Offspring from Bt maize-fed sows also had greater duodenal crypt depths (P<0.05) and lower villus height/crypt depth ratios (P<0.05). No pathology was observed in the organs, and serum biochemistry values generally remained within normal limits and no overall differences were observed, with the exception of overall γ glutamyltransferase, which was less for pigs on the Bt/Bt treatment than pigs on the iso/Bt and Bt/iso treatments. These results indicate that transgenerational consumption of Bt maize diets is not detrimental to pig growth and health.