Dairy-heifer management in the Netherlands

The objective of this study was to describe the Dutch rearing performance o f dairy heifers by the evaluation of performance indices at weaning, breedi ng and calving. The second objective was to determine the extent to which d airy farmers use pre-set rearing targets and data monitoring for the evalua tion of their rearing results. A questionnaire was sent to 3000 randomly ch osen dairy cattle farmers to survey their heifer-rearing practices. Almost a third of the farmers (n=959) completed and returned the questionnaire. Of the farms responding, 29% realised an age at first calving of less than or equal to 24 months, 51% from 25 to 27 months, and 20% of greater than or e qual to 27 months. The farmers indicated that the average body weight after calving was within the range 525-550 kg. Average wither height class was 1 41-145 cm. Most farmers estimated the body-condition score of their heifers at calving to be 3-3.5. In 29% of the cases, weaning occurred at an age of less than or equal to 8 weeks, 35% at 9-10 weeks of age and 36% at greater than or equal to 11 weeks of age. Most farmers (81%) commenced breeding at an age of greater than or equal to 15 months. Intermediate evaluation of the rearing policy by means of performance goals and measurements was limited, and many of the reported performance indices on age and body weight were outside the range of the recommended target va lues. These results indicated that the common Dutch heifer-rearing manageme nt system could be improved considerably. (C) 2000 Elsevier Science B.V. Al l rights reserved.