¹Undergraduate Student, Faculty of Animal Science, Universitas Gadjah Mada, Indonesia

²Postgraduate Student, Faculty of Animal Science, Universitas Gadjah Mada, Indonesia

³Department of Animal Production, Faculty of Animal Science, Universitas Gadjah Mada, Indonesia

*Email: bali_arti@ugm.ac.id

This study was conducted to observe the primipara reproductive performance of Bali cattle between natural mating compared to artificial insemination. Fifty Bali cattle owned by 44 farmers in Central Lombok Regency, West Nusa Tenggara was used as the research sample. 19 cattle with natural first mating (NM) and 31 cattle with artificial insemination (AI). Farmers profile data, maintenance system, and reproductive performance (the first estrus age, the first mating age, gestation length, post partum estrus, post partum mating, calving interval) obtained from farmers interview and AI officers record. Descriptive and an independent sample t-test analyzed the data to show the differences between NM and AI groups. The results showed that there were significant differences (P<0,05) in post partum estrus (48,94 ± 12,75 vs 82,74 ± 26,51 days), post partum mating (59,00 ± 14,00 vs 85,64 ± 25,45 days), and calving interval (348,57 ± 18,20 vs 393,19 ± 31,05 days). It can be concluded that the reproductive performance of Bali cattle with natural first mating system is better than artificial insemination. So recommended for the first mating, it better used natural first mating.