Выражение встречается в следующем контексте: Trading income: herd basis rules: meaning of "substantial part of herd": section 111 and section 118
This change gives statutory effect to the practice of treating 20% of the herd as substantial.
It brings the income tax and corporation tax codes back into line.
A number of sections in the herd basis rules refer to "a substantial part of the herd".

Заранее спасибо