Implications of dam and offspring body mass index on reproductive efficiency in Kebumen Ongole Grade cattle

Abstract Kebumen Ongole Grade (KOG) cattle possess several advantages over other local beef cattle, including larger body size and superior reproductive traits. This study aimed to determine the relationship between calving interval (CI) and dam frame score (DFS), dam body mass index (DBMI), and offspring body mass index (OBMI). A total of 142 pairs of Kebumen Ongole Grade dams and their offspring were observed. The measured variables comprised frame score and biometric traits such as body weight (BW), withers height (WH), body length (BL), hip height (HH), along with reproductive parameter calving interval. Data were analyzed using descriptive statistics, correlation, and regression analyses. The results showed a significant positive correlation between CI and DFS (r = 0.166), and non-significant negative correlations between DFS and DBMI (r = –0.131), and between DFS and OBMI (r = –0.090). The regression equation describing the relationship between CI and the three independent variables was: CI (years) = 0.891 + 0.026(DFS) + 0.003(DBMI) + 0.023(OBMI). The results indicate that skeletal frame score exerts a modest but notable impact on reproductive traits, whereas body mass index of dams and calves shows little association with calving interval. Nevertheless, body mass index remains a critical indicator of health, as both under- and over-conditioned cows are at higher risk of metabolic disorders, reproductive challenges, and reduced fertility. In Kebumen Ongole Grade cattle, calving interval showed a weak but significant positive relationship with frame score, while dam and offspring body mass indexes had weak, non-significant effects.