Comparative study of first lactation performance of Norwegian Red crossbred cows with traditional breeds in New Zealand dairy systems.

Some New Zealand dairy farmers are using semen from Norwegian Red (NR) bulls to explore the performance of this breed under local grazing conditions. The objective of this study was to compare the first lactation performance of first cross NR cattle with traditional New Zealand breeds. Data were collected from six dairy farms in Southland, New Zealand, during 2022–2023 milk production seasons. Data were collected from 1178 first lactation cows including herd test of daily yields of milk, fat and protein and somatic cell counts, and persistency. Breeds included 386 NR cross (NRX), 231 Holstein Friesian (F), 84 Holstein Friesian cross (FX), 134 Holstein Friesian x Jersey (FJ) and 58 Jersey cross (JX) cows. Findings indicate F cows produced the greatest cumulative milk yield (3,744 kg), 138.6 kg more than NRX cows. There were no significant differences among the breed groups for milk yield and milk solids yield persistency and SCS (SCS = Log2 SCC). The total lactation milk yield of NRX cows was lower than that of the other breeds, excluding JX. These results pertain specifically to first lactation cows; therefore, it is necessary to undertake further analysis to evaluate the long-term productivity and longevity of NR breeds under New Zealand conditions. [ABSTRACT FROM AUTHOR]