Significance of atrophic ovaries in livestock production in northern Nigeria.

In a study of 3000 cattle of different breeds and origin (Bos indicus and Bos taurus) in Northern Nigeria, an overall 22.7 per cent incidence of anoestrus associated with organic genital abnormalities was observed. Of this 19.3 per cent was due to ovarian atrophy. This was observed mostly during the pre-dry and dry seasons, periods of poor and inadequate feed. The average incidence of atrophic ovaries in the exotic breeds (Bos taurus) was 17.1 per cent, while an incidence of 20.4 per cent was observed in the indigenous (Bos indicus) cattle; there was no significant difference between the two groups. A relatively higher incidence of functional anoestrus (27.5 per cent) which showed no seasonal pattern and no significant difference between the breeds was observed. Inadequate nutrition was the major cause of the ovarian atrophy and subsequent anoestrus. Other clinical genital abnormalities included hypoplastic ovaries (1.9 per cent), follicular cysts (4.5 per cent), pyometra (4.5 per cent) and freemartinism (0.3 per cent). The influence of anoestrus (50 per cent total incidence) on the economic aspect of livestock production in Northern Nigeria is discussed.