Section 14C. All hogs which are affected with, or have been exposed to, hog cholera, shall be quarantined and appraised by an appraiser of the division of animal health in the department of food and agriculture, hereinafter called the division, or an appraiser appointed by the United States Department of Agriculture, animal health division. Any such hogs as the director of the division may determine shall be slaughtered and their carcasses shall be disposed of in such manner as said director may determine. The commonwealth shall pay to the owner of such hogs so slaughtered one half of their value as determined by said appraisal, but not to exceed fifty dollars for a purebred and forty dollars for a grade, said payment to be made from the amounts appropriated therefor; provided, however, that if the federal government undertakes to pay part of the cost of any hogs destroyed, as provided in this section, the payment by the commonwealth shall be limited to the difference between the payment authorized by the federal government and the payment hereinbefore provided. No payment shall be made as herein provided unless the director has determined that the owner or his representative has not, in the opinion of the director, by wilful act or neglect, contributed to the spread of hog cholera. All determinations of value made under this act shall be at fair market value.