YOU SAID:

the cow is eating grass because we dont know what else it can eat

INTO JAPANESE

他に何が食べられるかわからないので、牛は草を食べています

BACK INTO ENGLISH

Cows are eating grass because they don't know what else they can eat

INTO JAPANESE

牛は他に何が食べられるかわからないので草を食べています

BACK INTO ENGLISH

Cows eat grass because they don't know what else they can eat

INTO JAPANESE

牛は他に何が食べられるかわからないので草を食べます

BACK INTO ENGLISH

Cows eat grass because they don't know what else they can eat