Comparative performance in Holstein-Friesian, Jersey and crossbred cows milked once daily under a pasture-based system in New Zealand

ABSTRACTProduction and efficiency of Holstein-Friesian (F), Jersey (J) and crossbred F × J milked once-a-day (OAD) were studied at Massey University dairy farm No. 1. Herd test records of milk yields, somatic cell score (SCS), live weight (LW) and body condition score (BCS) were used to model the lactation curves using a third-order orthogonal polynomial. Total lactation yields of milk (MY), fat (FY), protein (PY) and milk solids (MS = FY + PY) were calculated based on predicted daily yields. Predicted efficiencies were feed conversion efficiency (FCE; total lactation MS per kg of predicted total lactation dry matter intake [DMI]); biological efficiency (BE; total lactation MS per 100 kg of LW) and DMI capacity (DMIC; total lactation DMI per 100 kg of LW). Holstein-Friesian cows yielded 376 kg milk more than F × J cows and 1101 kg milk more than J cows per lactation. Holstein-Friesian and F × J produced similar total lactation MSY (366 and 369 kg, respectively). Jersey cows were more efficient than cows o...