Culling of bulls in Mozambique

Abstract

The literature on the culling of bulls is reviewed. It shows that the process of culling bulls has become important in many countries both from the viewpoint of economic productivity of cattle as a disease control measure.

Inspection and palpation of the bull external genitalia has been the most common method of examining bulls and of predicting reduced fertility. The reliability and the effectiveness of clinical examination in supporting decisions on culling bulls is investigated in this work.

Material came from a beef unit located in the southern part of Mozambique and comprised 333 sections of testes and epididymes from 21 cull Afrikander bulls.

The results showed that the clinical examination only detected approximately half of the microscopically abnormal testes. A similar result was found in the examination of the epididymes. The most common lesions observed were testicular fibrosis and chronic epididymitis. In a high percentage of bulls, lesions were present in associated testes and epididymes.

The significance of the lesions is discussed and the main conclusion is that histopathology, without parallel semen and microbiological examination, is of limited value in understanding aetiology. A fuller investigation making more use of cull bulls should be carried out in Mozambique.