Performance of a herd of Holstein cows managed without the dry period

Abstract

The performance of a commercial herd of 37 high-yielding Holstein cows managed without the dry period is described. Milk yield was high (9 340 kg for primiparous and 10 900 kg for multiparous cows in 300 days) and rich in proteins (33.2 g/kg). The somatic cell count was relatively high (326 000 and 484 000/ml for primiparous and multiparous cows, respectively) and tended to be positively related to immunoglobulin content and, between cows, to free fatty acid content. In each of the 13 udders studied for bacteriological analysis, at least two quarters were not negative. In late pregnancy, the milk was progressively enriched with fat, proteins, immunoglobulins and somatic cells, with growing individual differences. Between months 3 and 10 of lactation, the cows gained over 100 kg body weight. The career of the 28 multiparous cows in the study was completed with monthly data recorded by the Contrôle Laitier. Milk yield increased by about 11 and 15% between lactations 1 and 2, and 2 and 3, respectively. Monthly persistencies in the declining phase were 97.2, 94.0 and 94.5%, respectively.