The Sertoli cell index as a measure of testicular degeneration in the bull.

Testicular degeneration of 1200 Sokoto Gudali bulls was studied and related to the Sertoli cell index (SCI). The total incidence of testicular degeneration (18.3 per cent) was in agreement with previous findings among similar bulls. The degree of degeneration was slight in 10 per cent of bulls, moderate in 5.8 per cent and severe in 2.6 per cent. The averages of the SCI for the normal testes and for the slight, moderate and severe degenerations were 11.5, 11.0, 8.8 and 5.4 respectively. The significance of the SCI as an index of testicular degeneration could not be assessed because of the many factors involved, such as tubular diameter, age of bulls and causes of degeneration.