It was observed that there was a linear increase in the incidence of several diseases, including retained placenta, ketosis, displaced abomasum, and mastitis, as plasma NEFA values of cows increased. Plasma NEFA testing is available from the Nutrition Section and can be of diagnostic benefit in some cases. The test is too costly for routine monitoring, but under certain circumstances it can be very useful. No matter how carefully the ration has been balanced, what the cows eat and what has been calculated may not be the same thing. When there are problems on an apparently well balanced diet, NEFA testing can be helpful in sorting out whether or not the problem is with energy balance.
Owner believes ration to be adequate.
Owners may be reluctant to believe that fresh cow problems originate in the dry cow diet. NEFA testing is an objective means of demonstrating to them that something is wrong nutritionally in the dry cow pen. The ration has been changed recently. When changes are made in a dry cow diet, plasma NEFA can be used as a monitor to determine if the cows are responding in the manner anticipated. Monitoring via plasma NEFA can be more economical than waiting to monitor disease incidence.