Twenty-two cows died in a shelter in Kachhla area of Budaun district on Sunday.
A caretaker of the cow shelter said: "The cows ate fresh bajra leaves in the afternoon. We don't know what happened to them later."
"We noticed the deaths of cows at around 7 pm and immediately informed the senior authorities," he said.
One of the locals said: "Immediately after receiving information, police officials reached the spot along with a medical team to save the rest of the cows."
District Magistrate Dinesh Kumar Singh said: "Yesterday at around 7 pm, 22 cattle died. After receiving information we reached there with a medical team and saved the other 51 cows that were not well."
A team from the Indian Biological Sciences and Research Institute (IBRI) reached Kachhla in the night to find out the reason behind the deaths.
"After the postmortem, and testing of all the samples of food and water, the IBRI team said in its report that the amount of nitrogen in the bajra leaves was high and the cows died due to nitrate poisoning," Singh added.
IBRI team is further testing samples for more details.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)