Abstract

The objective of this study was to evaluate the reproductive performance of pure Holstein Friesian dairy cows exploring 28 years records (1987 to 2015) in Alage Agricultural Technical and Vocational Education Training (ATVET) College dairy farm. General linear model procedures of SAS version 9.2 was employed to determine the effects of period of birth, season of birth, period of calving, season of calving and parity on reproductive traits. The overall mean of age at first service (AFS), age at first calving (AFC), calving interval (CI), days open (DO) and number of services per conception (NSC) were 31.8±0.44 months, 42.5±0.46 months, 470.3±9.8 days, 228.2±10.2 days and 1.32±0.03, respectively. Period of birth (P<0.001) and season of birth (P<0.05) exerted significant effect on AFS, while AFC was not significantly influenced by season of birth. Days open and calving interval of Holstein Friesian (HF) cows affected by all fixed factors. Except period of calving (P<0.05), none of the factors influenced NSC. Except NSC, the results obtained for AFS, AFC, CI and DO were disappointing. The most probable factors accounted for the poor reproductive performances (AFS, AFC, CI and DO) in the study area were poor efficiency of estrus detection and expression, poor management practice and health problem and genotype × environmental interactions. Therefore, improving the level of management is required for optimal reproduction performance of HF breed in the area.

Key words: Alage, Holstein Friesian, reproductive performance.