Prevalence of Clinical Mastitis and the Suitability of Gamma Function in Predicting Milk Yield of Mastitic and Non-Mastitic Friesian x Bunaji Dairy Cows in Zaria, Nigeria

Abstract

Bovine mastitis has been known to cause considerable losses in the dairy industry. Knowledge of the occurrence and incidence of clinical mastitis in dairy cows is of great importance for monitoring the health status of the mammary glands, also in institution and implementation of control programs for the disease. The aim of this study was to determine the occurrence of clinical mastitis in Friesian X Bunaji crossbred dairy cows in a Research farm in Zaria, Nigeria. This was a cross-sectional study which involved the use of passive data (lactation records) generated from 2000 to 2015 in the Dairy Research Programme of a National Animal Production Research Institute, Shika-Zaria. The prevalence of clinical mastitis was determined and the lactation curve for the Friesian x Bunaji cows was designed and analyzed using the Gamma Function by Wood(1967). The prevalence of clinical mastitis was found to increase with increasing parity number (0.30, 0.32 and 0.43 for parity 1, 2 and 3 respectively). High prevalence of clinical mastitis occurred in early lactation period of parity 1 cows, but highest prevalence was recorded during the late lactation period in parities 2 and 3 cows.