Effect of non-genetic factors on first lactation production and reproduction traits in Tharparkar cattle

The present investigation was carried out with the objective of performance appraisal of Tharparkar cattle with respect to production and reproduction traits. Data were collected on 230 cows over a period of 50 years (1959–2011), maintained at NDRI, Karnal. The overall least-squares means for first lactation 305 day milk yield (F305Y), First lactation total milk yield (FTMY), first lactation length(FLL), First lactation total milk yield per day of first lactation length (TMY/FLL), First lactation dry period (FDP), First lactation service period (FSP), First lactation calving interval (FCI) and First lactation total milk yield per day of first lactation calving interval (TMY/FCI) were found to be 1618.47 ± 49.39 (kg), 1822.65 ± 70.2 (kg), 321.47 ± 8.87 (days), 5.65 ± 0.16 (kg/day), 99.80 ± 10.62 (days), 151.13 ± 16.27 (days), 436.75 ± 16.18 (days), 4.59 ± 0.20 (kg/day). Further, the last squares analysis revealed no significant effect of season of calving whereas, the effect of period of calving was found to be significant on first lactation production and reproduction traits.