The phrase “properly fed and kept,” as used in Section 35602 of the Food and Agricultural Code, is construed to mean that milk must be produced from animals fed only such feeds as will not impart strong disagreeable flavors or odors to the milk or the products thereof. (The intentional or willful feeding of mustard, purple-top turnips, rape, onions, etc., is specially prohibited and the use of pastures where such feeds as mustard, turnips, rape, onion, etc., are growing to such an extent that the quality of milk from cows grazing on such pastures is injured thereby (tainted) does not constitute proper feeding, whereas most natural grasses, alfalfa, clover, vetch, peas, ensilage, beets, carrots, coconut meal, grains, etc., which are not moldy or decayed are entirely suitable for feeding animals producing milk.) All feeds must be wholesome and fed in such quantities as will nourish and not impair the health of the animals. Milk-producing animals must not be subject to undue exposure so that their health is injured thereby.