Skip to main content
Research article - Peer-reviewed, 2005

How does extended lactation in combination with different milking frequencies affect somatic cell counts in dairy cows?

Osterman S, Ostensson K, Svennersten-Sjaunja K, Bertilsson J


The objective of this study was to compare the effects of an extended, 18 months, calving interval (Cl) to a traditional 12 months Cl, on the milk somatic cell count (SCC) of high producing dairy cows. In addition, the cows were milked either two or three times per day, resulting in four treatments; referred to as 12-2, 12-3, 18-2 and 18-3. Cows of the Swedish Red and White breed were used in the experiment, and the analyses were based on 90 complete lactations. The analyses were performed on both the whole lactation (WL) and late lactation, defined as the last 10 weeks of the lactation (L10). With 18 months CI, there were no significant differences between the two milking frequencies, neither when analysing the WL nor the L 10 separately. Multiparous cows, irrespective of milking frequency, had higher LSCC (the logarithm of the SCC) values than primiparous cows, and during L10 the difference was significant. This study shows that the LSCC throughout the lactation does not differ as a result of an extended CI, compared to the traditional 12 months CI (P=0.84). Furthermore, the results on extended CI in combination with different milking frequencies show that the LSCC values were not influenced by the milking frequency. Compared to the cows in the traditional system with 12 months CI and milking 2 x daily, cows in 18-2 and 18-3 had no increased LSCC values, P=0.21 and 0.45, respectively. Therefore, these results indicate that a production system with extended calving interval can be used, with milking 2 or 3 times per day, without increased risk of increased milk somatic cell counts. (c) 2005 Elsevier B.V. All rights reserved

Published in

Livestock Production Science
2005, Volume: 96, number: 2-3, pages: 225-232