The aim of this study was to determine the relationship between the heifers' peripartal metabolism, milk yield data and the productive life achieved. Furthermore, the influence of fertility, back fat thickness and morbidity on the productive life was evaluated.
Metabolic data and back fat thickness measurements, determined between 2004 and 2005 in a herd of Holstein-Friesian dairy cows, were analysed retrospectively. Additionally, the age reached by the 207 (at that time) heifers as well as data on culling, fertility, milk yield and morbidity were determined with the help of the herd management system and related to the laboratory findings.
Heifers with the shortest productive life of < 12 months had the significantly lowest (p < 0.0001) milk yield. The shortest productive life of < 12 months was associated with the significantly lowest (p < 0.0001) oestradiol concentrations 3 days post partum (p. p.) and the significantly smallest (p < 0.0001) albumin concentrations p. p. Furthermore, heifers with the shortest productive life of < 12 months had the significantly lowest (p < 0.0001) cholesterol concentrations 28 days ante partum (a. p.) and p. p. The data showed that heifers with a short productive life had a tendency for lower back fat thickness, tendencially lower oestradiol concentrations 10 days a. p., a trend to lower fertility (regarding inseminations per animal) and an increased incidence of mastitis, stillbirths and endometritis.
The lowest albumin and cholesterol concentrations of the heifers with a short productive life arose from an inadequate food intake. Oestradiol concentration also decreased during the state of energy deficiency. The low oestradiol concentrations 10 days a. p. can lead to repeated stillbirths in such heifers, and this increased the number of clinical endometritis. Furthermore, the low milk yield corresponded with an energy deficiency in these heifers. These results were supported by the low back fat thickness of these animals, which consequently led to poor fertility. As a consequence, for a longer productive life, special attention should be paid to heifers during the periparturient period, in particular focusing on their food intake and body condition.