A comparison of different dairy cow breeds on a seasonal grass-based system of milk production 1. Milk production, live weight, body condition score and DM intake

The objective of this study was to compare the performance of Dutch Holstein-Friesian (HF), upgraded Irish Holstein-Friesian (CL), French Montbeliarde (MB) and French Normande (NR) dairy cow breeds on a spring calving grass-based system of milk production. The HF cows produced the highest (P < 0.05) yield of milk, fat, protein and lactose; the NR produced the lowest, while the CL and MB were intermediate. The NR produced the highest (P < 0.05) milk fat, protein and lactose content. The milk protein content of the MB was higher (P < 0.05) than the HF and CL, while the fat content of the HF was higher (P < 0.05) than the MB and CL. The HF had significantly lower live-weight gain from weeks 12 to 40 of lactation. Both the HF and CL had lower (P < 0.05) body condition score (BCS) at all stages of lactation than the MB and NR. Compared to the HF the CL had similar BCS pre-calving and at week 4 of lactation, while at all other measurements CL were higher. The HF had significantly greater BCS loss over the first 8 weeks of lactation compared to the other three breeds. Similarly from weeks 12 to 40 of lactation the MB had greater BCS gain than the HF. The DM and OM intake estimates of the HF were higher (P < 0.05) than the CL, while the CL estimates were higher than both the MB and NR. The results of this study suggest that although the HF produced the highest milk production, much of this was achieved through greater mobilisation of body reserves in early lactation and lower live weight gain from mid- to end of lactation. (C) 2003 Elsevier B.V. All rights reserved.