The practice of emptying and holding milk cans in barns, corrals, etc., where milking is done is construed to be a violation of Section 33518 of the Food and Agricultural Code, wherein it is required that milk must not be canned or kept in a place occupied by cows or other animals. The practice of pouring milk from a milking machine pail into a stripping pail or other properly protected container from which the milk is removed to the milk house immediately shall not be deemed a violation of this provision. No milk buckets or pails shall be placed on the barn floor, except when in actual use; and any such buckets or pails shall at all times be covered or protected from contamination. Unless protected by other means, teat cups shall be kept off the floor high enough to prevent contamination.