I think the allegation that you are referring to is one from 2006 by the Andhra Pradesh (AP) Sheep Growers association, which alleged that more than 10,000 sheep/goats died after eating Bt cotton leaves.
It was unfortunate that farmers lost that number of animals. However, there are several interesting points about the allegations:
- There was no actual data presented that showed that Bt cotton was the cause of death. It was an easy correlation for the activists groups to make simply because there was Bt cotton grown in parts of the area where the animals had been grazing.
- The veterinarian who performed the autopsies on four to five sheep came to a scientifically reasonable conclusion that the sheep deaths may be due to insecticide poisoning.
- Large amounts of Bt Cotton were grown in India starting in 2002 with no adverse reports of animal deaths until this large amount in 2006. It also has not been reported since.
What is known is that safety studies on goats, cows, buffaloes, chicken and fish were conducted as part of the regulatory process for the approval of Bt cotton in India. Mahyco, an Indian seed company, conducted multiple field trials and did extensive nutritional and bio safety studies with Bt cotton in co-operation with many national institutions. All the data generated from the trials and studies were submitted to the Indian Regulatory authorities prior to approval in 2002.
In addition, a 90-day goat feeding study was conducted by Industrial Toxicology Research Center, Lucknow in 1998. The treatment groups included goats fed Bt cottonseed and control groups that were fed non-Bt cottonseed. According to Dr Vishwanathan, the scientist involved in this goat feeding study, “The feed analyses showed the similarity in nutrient and toxicant compositions between Bt & non-Bt cotton seeds, feed intake, weight gain, hematology and serum enzymes were measured for each animal during the feeding period of the study. At the end of this study, the animals were assessed for gross pathology and histopathology. It was concluded from the result by the above analyses that Bt cottonseed is as wholesome and safe for animal feed as non-Bt cottonseed. The differences observed across 48 goats in gross pathology and histo-pathology was attributed to any cottonseed feeding treatments, and was typical for goat feeding on cottonseed.”
International independent scientists also weighed in on this allegation and dismissed it. One particular Op-Ed written by Dr. Shanthu Shantharam and Dr. C. S. Prakash can be found at the following link: http://www.biospectrumindia.com/biospecindia/news/155705/bt-culprit
This is a good example of an unfounded allegation that is propagated in social media to disparage GMOs. I appreciate the opportunity to share information that hopefully dispels this myth.