200. In the case of a disposition referred to in the first paragraph of section 199 of an animal of a class, the taxpayer shall deduct(a) in counting the taxpayer’s basic herd of that class at the end of the year, the least of the number the taxpayer designates in relation to the basic herd, under paragraph a of subsection 1 of section 29 of the Income Tax Act (R.S.C. 1985, c. 1 (5th Suppl.)), in the election referred to in the first paragraph of section 199, the taxpayer’s basic herd of that class of animals at the end of the preceding taxation year, the number of animals of that class disposed of by the taxpayer in the year, and one-tenth of the taxpayer’s basic herd of that class on 31 December 1971; and
(b) in computing his income from the farming business for the taxation year, the product obtained by multiplying the number determined under paragraph a by the quotient obtained when the fair market value on 31 December 1971 of such animals of that class is divided by the number of such animals of that class on that day.