The performance records of 207 lactations of 59 Rathi cows were studied and it was found that Lifetime milk yield (LTMY), lactating life, productive life, milk yield per day of lactating life (MYPDLL), Milk yield per day of productive life upto start of next lactation (MYPDCI), milk yield per day of productive life upto termination of last lactation (MYPDLI), breeding efficiency (B.E) and age at first calving (AFC) averaged 6490.59±3107.50 lts, 1160.06±483.37 days, 1720.76±720 days, 5.48±0.68 lts, 3.71±0.65 lts, 4.07±0.65 lts, 75.13±9.26% and 1482.00±314.07 days, respectively. period of calving (POC) had significant effect (P<0.05) for productive life only whereas season of calving (SOC) had significant (P<0.05) effect for LTMY only. The linear regression coefficient of LTMY on AFC was significant (P<0.05). The phenotypic correlations among production efficiency traits were positive, moderate to high in magnitude and significant (P<0.05) except for MYPDCI and MYPDLI. The correlation estimates for B.E. with LTMY, lactating life and productive life were negative, low to moderate in magnitude and significant (P<0.05).
