Milk fat: too much of a good thing?

For decades, Midwest dairy producers, as well as genetics and nutrition consultants, have focused on maximizing milk component yields. These efforts have been driven predominantly by the value that milk fat and protein contribute to the milk check in a Class III market heavily influenced by cheese manufacturing. For those of us who have been in the industry a long time, it’s hard to believe that now we are having conversations about too much butterfat.

The Federal Milk Marketing Order 30 applies to most Dairy Star readers. One year ago, the butterfat pay price within the FMMO 30 was valued close to $3 per pound. Since July, we have seen a steady decline to the most recent announced price of $1.71, the lowest point in five years. On the flip side, milk protein pay price within the FMMO 30 recently climbed to $3.01 per pound.

Butterfat increasing faster than protein

Throughout the past decade, dairy farmers have done a great job of responding to milk price signals by producing a product higher in both milk fat and protein. During this time, butterfat levels increased 13%, and protein output climbed 5%. Today, the Holstein breed is averaging greater than 4.2% butterfat and just shy of 3.3% protein.

Milk protein has biological constraints that limit how quickly it can increase. Extension specialists like Dr. Kent Weigel at the University of Wisconsin-Madison have noted that protein percentage is more physiologically constrained than butterfat and tends to improve more gradually, even under strong selection pressure. While we have nutritional strategies (such as amino acid balancing) to improve milk protein, most nutritionists would agree it is easier to feed for increases in milk fat.

Butterfat’s rapid ascent was enhanced by both genetic selection and feeding strategies. Nutritionally, forage quality continues to improve. Certain levels of effective fiber are necessary to promote cud chewing and rumination. A healthy rumen environment minimizes wide fluctuations in rumen pH through balanced carbohydrate nutrition. This leads to the formation of more acetate and butyrate, which are volatile fatty acids that serve as precursors to milk fat.

Research conducted by Dr. Kevin Harvatine, Pennsylvania State University, has demonstrated the value of rumen-available methionine sources to milk fat synthesis. Rumeninert fats high in palmitic acid have been shown to have a positive impact on milk fat. Feeding elevated levels of sodium and potassium or rumen modifiers, such as yeast and direct-fed microbials, can be beneficial to improving milk fat.

Management decisions on farm have also resulted in improved milk fat yields. Inconsistent feeding time or variation in feed distribution can impact meal patterns and promote slug-feeding. Cow comfort and stocking density can negatively impact resting time. Heat abatement strategies are critical to success in the summer and can promote more consistent intakes and cow comfort. Enhanced management of these factors helps support milk fat production.

Ideal protein-to-fat ratio

High levels of butterfat can enhance production of dairy products such as butter, ice cream and sour cream. The bigger challenge is in cheese manufacturing. Cheese processors look at a ratio of milk protein to milk fat to make cheese. According to Corey Geiger with CoBank, this ratio ranged from 0.82 to 0.84 from 2000 to 2017. Since 2017, the ratio has slipped to 0.77. This means cheese manufacturers have excess cream to deal with, resulting in reduced production efficiencies and added costs to rebalance or standardize their milk supply.

Our two biggest dairy export competitors, New Zealand and the European Union, have also seen milk components increase over the past several years. However, they have not experienced this lopsided growth in butterfat in relation to protein, giving them a more consistent protein-to-fat ratio compared to the U.S.

Geiger makes the point that, if these current component trends continue, U.S. dairy processors will have additional costs to either remove more butterfat or add more protein to make cheese. That ultimately reduces competitiveness on the export front.

Evaluate strategies to increase butterfat

Genetic selection for increased butterfat throughout the past decade was a logical strategy, given market demands. Management tools such as genomics have allowed the dairy industry to shorten the period for genetic progress. However, genetics selected today will not fully express themselves for 3-4 years with the lag time in gestation and heifer rearing.

Milk protein is mostly improved via genetics. Because butterfat and protein are highly correlated traits, even if dairy producers select for protein over butterfat today, we likely will continue to see some gains in butterfat.

The economic return for feed strategies to enhance milk fat yields changes with the market. Work with your nutritionist to evaluate feed decisions designed specifically for improving butterfat, given the rapid decline in butterfat value. That said, remember that cows don’t care what the milk check looks like. Ensure short-term decisions do not lead to negative long-term consequences in the overall health and performance of your herd.

Barry Visser is a nutritionist for Vita Plus.