Abstract

The present study was undertaken to evaluate the effect of non-genetic factors on reproductive performance of Holstein Friesian × Deoni crossbred cows. Data representing 256 HF × Deoni crossbred cows from cattle crossbreeding project with 1485 total records of lactation over a 30 years period were analyzed to determine the effects of period of calving, season of calving, age at first calving and parity on reproductive performance. The parameters used as indicators of reproductive performance in this study were age at first calving (AFC), days open (DO), dry period (DP) and inter calving period (ICP).  The overall least squares mean of age at first calving (AFC), days open (DO), dry period (DP) and inter calving period (ICP) were 1198.54±8.18, 149.15±3.87, 126.90±1.76 and 422.95±2.53 days, respectively. All sources of variations except season of calving had significant effect on AFC and ICP. The AFC as seen in this study was somewhat longer. Cows calving in summer had reduced reproductive performance, as measured by DO and DP. First lactation cows had longer DO, DP and ICP, which were poorest values as reproductive traits. It is therefore concluded that, the reproductive performance of these crossbred cows is affected by some non-genetic factors and hence, additional reproductive strategies are needed to improve their performance.

Key words: Reproductive traits, period, season, parity, crossbred cows.