Productive lifespan and lifetime production of dual-purpose and dairy breeds in mixed herds under grassland-based systems

Dairy cow longevity is a key trait combining multiple functional traits and is decisive for sustainability of dairy production. This study addresses the hypothesis that under low-input production conditions, dual-purpose breeds outperform dairy breeds in terms of longevity. Herdbook data of 1796 culled Swiss cows in 72 mixed dairy farms were used to compare two dual-purpose breeds (Original Braunvieh (OB) and Simmental (SI)) with three dairy breeds (Swiss Fleckvieh (SF), Brown Swiss (BS) and Holstein (HO)). Each selected mixed herd included at least one dualpurpose and one dairy breed managed under the same conditions. Breeds were compared for length of productive lifespan (LPL; days from first calving to culling), lifetime milk production (LTP; kg energy corrected milk) and average daily milk yield during LPL (DMY_LPL; kg energy corrected milk). OB cows lived significantly longer than HO (1946 ± 71 d vs. 1695 ± 55 d, p ¼ 0.046), whereas SI cows did not (1683 ± 62 d, p ¼ 0.999). Both dual-purpose breeds produced significantly less milk per day (OB: 17.8 ± 0.3 kg, SI: 18.0 ± 0.3 kg) than SF (19.1 ± 0.2 kg) and HO (19.7 ± 0.3 kg). However, OB cows compensated with greater longevity, resulting in the numerically highest LTP (35,584 ± 1315 kg), which did not statistically differ from the specialised dairy breeds. In conclusion, choosing a dual-purpose breed does not necessarily ensure longer productive lifespans: while OB showed a clear advantage, SI cows exhibited shorter productive lifespan, likely due to breed-specific production conditions.