The Commissioner of Agriculture, by and with the consent and advice of the Board of Agriculture, shall promulgate and enforce such rules and regulations as may be necessary for the proper transporting of livestock by motor vehicle, and may require a permit for such vehicles if it becomes necessary in order to prevent the spread of animal diseases. This section shall not apply to any county  having a local law providing for the vaccination of hogs against cholera. (1937, c. 427, ss. 1, 2.)