Influence of the suppression of dry period on several blood and milk markers in dairy cows

The increase in milk yield at the end of lactation suggested that dry period could be reduced or omitted to increase economical return, but the consequences on cow immune defences are not known. In this study 11 Italian Holstein cows were selected from an experimental herd. Six of them were assigned to experimental group (suppression of dry period) and the other 5 to the control group (with a dry period of about 55 days). Udder health status, cellular and humoral blood and milk markers were considered. The results of this study showed that the blood markers values were within the physiological range for both groups. The absence of a dry period was not associated to an increase of subclinical or clinical mastitis. However, NAGase and lactoferrin were significantly higher in continuous lactation group suggesting the presence of an inflammatory status. Therefore, the omission of dry period could induce potential long-term risks for an impairment of udder immune defences and should be carefully considered, before its implementation.