Effect of parity, season and year on reproductive performance and herd life of Friesian cows at Stella private dairy farm, Ethiopia
Livestock Research for Rural Development
Addis Ababa University, Faculty of Veterinary Medicine, P.O. Box 34, Debre Ziet, Ethiopia
A retrospective study was carried out at Stella Dairy Farm, Ethiopia, using 13 years data (1993 to 2006) to estimate number of services per conception (NSC), days open (DO), calving interval (CI), herd life (HL), number of lactations (NL) and productive age (PA). Fixed factors considered were parity (8+), season (3) and year (13). Data were analysed using the General Linear Model of SAS. Cumulative frequency (%) was used to study the distributions of DO and CI. The overall mean for NSC, DO and CI were 1.720±0.056 (n=619), 177±5.4 (n=448) days and 456±5.4 (n= 423) days, respectively. Parity had significant effect on NSC (P<0.05) DO and CI (P<0.001). Seasons of conception had no effect on the parameters studied. The overall means (n=105) for HL, NL, and PA were 3048±107days, 3.88±0.23 and 1753±106 days, respectively. Birth year significantly affected the variables. About a third of the heats inseminated required two or more services. About 47% of the DO and 58% of the CI had a length of 130 and 450 days or more, respectively. To improve the efficiency of reproductive performances and herd life, it is recommended to give attention in heat detection, timely insemination, adequate feeding, proper management of postpartum reproductive problems and early growth management of heifers.