Lactation Curve and Factors Affecting Persistency in Ongole Cattle

Background: The present study was aimed to investigate the lactation curve and factors influencing persistency in Ongole cattle, utilizing the daily milk production records and history sheets available in the Livestock Research Station, Mahanandi. Methods: Key parameters such as peak yield (PY), day of peak yield (DPY), average weekly yield (AWY), lactation length (LL), standard lactation milk yield (SLMY), total lactation milk yield (TLMY) and persistency indices given in three prominent reports (denoted as P1, P2 and P3 in the ascending order of reporting years) were computed using the milk production records. Other parameters such as parity, age at first calving (AFC), season of calving (Rainy, Autumn, Winter, or Summer), sex and birth weight of calf were extracted from the history sheets. Result: The findings revealed that the lactation curve typically displayed a concave downward shape, with the peak of milk production occurring around the eighth week of lactation. The mean values of P1, P2 and P3 were 75.799±0.979, 88.038±0.929 and 57.897±0.775 per cent, respectively. All the three persistency indices (P1, P2 and P3) showed a significant positive correlation with SLMY and TLMY. The P1 and P2 had a significant positive correlation with DPY, LL and AFC. Further, P1 exhibited a significant negative correlation with parity, while P2 was significantly influenced by the season of calving. The coefficients of determination for the regression models of P1, P2 and P3 were 0.622, 0.282 and 0.223, respectively. In conclusion, the study suggests that the lactation curve in Ongole cattle follows a typical concave downward shape with the peak milk yield occurring in the eighth week of milking. Furthermore, lactations characterized by higher LMY tend to have greater persistency.