Translation of "Servings" in Spanish

"Why I cannot have four servings of dairies?

"¿Por qué no puedo tomar cuatro lácteos?

That a pint of ice-cream has four servings in it?

que medio litro de helado rinde cuatro porciones?

Harward does not recommend eating more than two servings of dairy a day,"

Harward no recomienda consumir más de dos raciones de lácteos al día",