dc.description.abstract | A research was carried out to observed effect of lactation period and season on reprodu~tivep erformance of Holstein cows in PT Taurus Dairy Farm (PT TDF). Data of fist service afier calving (FS), service per conception (SIC), days open (DO), conception rate (CR) and calving interval (CI) were collected from 438 animals recorded fiom 1998 to 2004. Rain fall data were collected from Office for research of spices and medicine. The data then clasified according to Schmidth- Ferguson classification. Mitab ver. 14 software was used to analyzed the data. Reproductive performance of PT TDF, except for CR, are going to be better year by year. The reproductive performance, except for SIC, are also going to be better by lactation period. Tb: effect of season (dry vs rain seasons) on the reproductive performance were not observed. Keywords : reproductive performance, lactation period, rainfall | en |