Even Israeli cows have to give up chametz for Passover. This year, an estimated 130,000 heads of dairy cattle munched on beans and other Passover-approved foods during the holiday.

Eviator Dotan, head of the Israel Cattle Breeders Association, explained that the change in diet is due to Jewish law.

“The prohibition of chametz on Passover applies to the property of Jews, and not just his food,” he said.

To avoid chametz contamination, like Jewish homes all over Israel, kosher cow barns must be thoroughly scrubbed pre-Pesach to make certain no chametz remains.

Then, in the days leading up to Passover and during the holiday the cows are fed chickpea, corn and even hummus mixtures to make sure they stay chametz-free.

Peretz Shorek, coordinator of the Beef and Dairy Growers Association, explained that the need for the barnyard stringency actually had to do with the cow’s spit.

“A Jew’s animal is forbidden to consume products that become chametz,” he said, citing halacha. “When an animal eats, it secretes saliva. When the saliva drips onto one of the five grains, it turns them into chametz, therefore it is forbidden to feed the animal the five species of grain.”

A spokesperson for the Chief Rabbinate, though, said that while it is is true that dairy cattle must eat chametz-free for Passover, the prohibition is less about spit and ownership, than the cow’s skin.

Pointing out that beef cow and other owned animals can eat their usual diet for Passover, Ziv Maor stated the real reason Israeli dairy cows munch on hummus during Passover is cross-contamination.

“It’s not that chametz is processed through the body into the milk,” he stressed, noting why cows eaten for meat do not have to be chametz-free. “The main reason for changing the food is that it might touch the body.”

Once on the body, he continued, the chametz might end up in the milk, lacing the dairy product with chametz at at time it is forbidden for Jews to eat the grain.