Objective: This study aimed to determine whether the addition of concentrate to heifers could be the same as the success of AI in calving cows in terms of Return Rate (NRR), Conception Rate (CR), and Pregnancy Rate (PR).

Methods: The material used in this study was 28 Limousine Crossbred cows with 13 cows and 15 heifers. There were two treatments, namely T0: Cows that had given birth with control feed (control without added concentrate) + BIO ATP after AI, while T1: Heifers with control feed and the addition of 1kg/day concentrate for seven days after AI + BIO ATP. Samples were selected by purposive sampling with the criteria of BCS 3-5 (1-9) and aged ≥ 2 years. The artificial insemination method uses rectovaginal with 4+ deposition at the 2nd and 8th hour after estrus, then injection of Bio ATP brand "Rheinbio" intramuscularly as much as 10 ml.

Results: The results showed that the reproductive performance of Limousine Crossbred Cow that had given birth (T0) was NRR1 84.62%, NRR2 84.62%, CR 53.33%, and PR 66.67%, while in heifers (T1), it was NRR1 86 .67%, NRR2 60%, CR 20%, and PR 20%.

Conclusions: The addition of concentrate feed of 1 kg/head/day for seven days before AI in heifers (T1) showed lower reproductive success than in cows that had given birth (T0) even without the addition of concentrate.