Ronald L. Boman
USU Extension Dairy Nutritionist

My new colleague in Dairy Extension, Dr. Allen J. Young, has been pointing out to me, county agents and others, that there are many herds on DHI that have higher average % milk protein than % milk fat (fat:protein inversions). These inversions are indicative of some potentially serious problems like rumen acidosis, reduced feed intake, lower milk production, increased incidence of displaced abomasum, and laminitis or founder. If the average % protein in the herd is equal to or higher than the average % fat, then in all likelihood there are individual cows with serious inversions that would thus be more prone to the problems mentioned above. In fact, some of the cows in the herd with fat:protein inversions may already have rumen acidosis, may not be milking to their potential, or may be walking tenderly or may be lame because of subclinical or acute laminitis.

CHECK YOUR DHI or OTHER MILK PRODUCTION RECORDS to see if you have a number of these inversions on individuals or groups of cows. The causes of rumen acidosis are:

1. Insufficient fiber in the ration or roughages that are too finely processed;

2. Too much concentrate (especially wheat or barley) in the ration in comparison with the roughage;

3. Sorting out and eating the grain, rather than forage, from a total mixed ration, or not eating the forage in a system where grain and forage are fed separately.

NOW, if you've found that you have a problem with fat:protein inversions or rumen acidosis in your herd or if you want to prevent potential future problems, here are a few suggestions and recommendations to follow:

1. Make sure that the cows are getting enough effective fiber into them throughout the day:

     a. don't over process the hay in the TMR wagon;
     b. feed frequently so that cows clean up the feed to minimize the chance of them being able to sort out the grain;
     c. have 2 or 3 lbs. of long hay available for the cows to eat each time they exit the milking parlor, or have fresh feed (TMR) available at this time.

2. Make certain that the proportion of grain in the ration is not excessively high:

     a. have your ration analyzed by your nutritionist, your feed company, or the extension service;
     b. if the concentrates that you are feeding are rapidly fermented in the rumen (wheat, barley or even steam flaked corn), then consider adding things like beet pulp and minimally processed corn or other less rapidly fermented by-product feeds.

3. Consider rumen buffers such as sodium bicarbonate (.25 to .4 lb/cow/day) to help maintain the rumen pH at more nearly normal levels. Also, yeast culture (.25 lb/cow/day) helps to metabolize lactic acid that may be present in the rumen, plus it stimulates fiber digesting bacteria that produce acetic acid (a fat precursor).

IT IS NORMAL AND NATURAL FOR THE MILK FAT % TO BE .3 to .8 PERCENTAGE UNITS HIGHER THAN THE PROTEIN % OF THE MILK. This relationship is indicative of a healthy and normally functioning rumen. It might just pay big dividends to double check your records to see where your herd and individual cows stand in this regard. Then take the corrective steps that have been suggested. ©