Case Report: Ration Manipulations During Passover and Milk Fat Depression in an Israeli Dairy Herd

This report describes a case of milk fat depression (MFD) that occurred in a commercial Israeli dairy herd during spring 2012. Fat yield decreased by 15% during two weeks in response to changes in the rumen fermentation profile. Diet changes included a decrease in effective fiber content of the ration as a result of changes in roughage sources and the feeding of finely ground concentrates. Fat yield responded positively to corrections made in the roughage source together with changes in concentrate processing method. During the episode cows did not show any apparent health disorders. In the following months following adjustments to the diet there was an increase in claw lesions related to increased rumen fermentation changes.