201. Where the basic herd of a class at the end of the year preceding the taxation year minus the deduction required at the end of the year under paragraph a of section 200 exceeds the number of animals of that class owned by the taxpayer at the end of the year, he shall deduct:(a) in computing his basic herd of that class at the end of the year, the number of animals comprising the excess, and
(b) in computing his income from the farming business for the taxation year, the product obtained by multiplying the number of animals determined under paragraph a by the quotient obtained when the fair market value of the animals of that class on 31 December 1971 is divided by the number of the animals of that class on the same day.