Rates and Causes of Calf Losses in Dairy Cattle of Southern Highlands of Tanzania

Abstract

This study was undertaken in five large scale dairy farms located in the southern highlands of Tanzania. The intention was to establish rates of abortions, stillbirths and postnatal calf losses and to examine causes of deaths. All data was transcribed from farm books and reports. Influence of various factors (farm, sex and years) was tested by chi-square   statistic. Overall abortion rates for individual farms ranged from 1.8 to 9.5% and the difference between farms in incidence rate was significant (P < 0.001). Rates of stillbirths were 3.4, 9.8, 9.6, 3.8 and 5.0 % for Ihimbu, Iwambi, Kitulo, Mbarali and Uyole farm, respectively. Farm differences and yearly variations were large. Pre-weaning calf losses ranged between 9. 3 and 25.5%. Effect of sex on death rates was not important (P > 0.05).  From weaning to 18 months of age,  death rates ranged from 13.2 to 29.2% and from 18 months of age to first calving heifer mortality ranged from 7.1 to 29.6%. Overall loss of heifers from birth to calving was estimated to be between 32.1 and 68.8 %. Thirty two to 52% of all calf deaths were caused by pneumonia, scours/diarrhoea and nutritional deficiencies. Other important causes of deaths were tick-borne diseases, bloat, poisoning, accidents and abscesses. It was concluded that the results did not deviate at all from other reported findings from the tropics.