We have determined the impact of improving milk quality on the quality and yield of dairy products and related that to the economic incentive that can be given to dairy farmers to improve milk quality.

Who cares? Dairy farmers and processors. Why? Better flavor quality of milk will promote more milk consumption by children. Problem: The shelf-life of pasteurized refrigerated milk is too short. What prompted you to begin this work? Dairy farmers and processors provided input that this research was needed. Why is your project needed? Currently refrigerated milk has a shelf-life of 14-24 days. With the increasing number of meals eaten away from home, there is a need for pasteurized refrigerated milk and flavored milks that have a longer shelf-life. How important is the issue? The issue is important for the nutrition and health of teenage (12-17) girls. The consumption of milk by teenage girls decreases dramatically and may have a negative effect on long-term bone health.

Heat stable proteolytic and lipolytic enzymes in raw milk increases with increasing somatic cell count (SCC). We have demonstrated that bonus payments to farmers for low SCC milk, reduces milk SCC. Bonus payments by cheese makers are given because low SCC gives higher cheese yield. In NYS, cheese makers pay an extra $1.5 million to dairy farmers each year for better quality milk. These payments were initiated because our data enabled cheese makers to place an economic value on lower milk SCC. Fluid milk processors are reluctant to pay farmers for low SCC milk until the economic value of lower milk SCC is established. Our work did this. Pasteurized milk containing 2% fat develops an off-flavor due to proteolysis at about 100 and at 54 d for the low SCC, and at about 54 and 19 d for high SCC milk, after storage at 0.5 and 6oC respectively. An off-flavor due to lipolysis in 2% fat pasteurized milk with low SCC will be detected at > 100 days and at 61 d at 0.5 and 6oC, respectively, while for milk with high SCC an off-flavor will be detected at 60 and 35 d at 0.5 and 6oC, respectively. The combination of low SCC and low storage temperature, when coupled with very low bacteria count, will produce better flavor for much more than 61 d at <6oC. New filtration technologies that can remove somatic cells are being coupled with improve mastitis control on the farm to provide better milk flavor quality and improved shelf-life.

The first phase of our work on reducing milk SCC for cheese making has benefited dairy farmers (increased payment for milk) and cheese makers (higher cheese yield). This change has happened as a result of our research and cheese makers pay an extra $1.5 million to NYS dairy farmers each year for better quality milk. An estimate of the impact to dairy farmers in the total US is about $68 million each year. Only a portion of the milk produced in NYS is used for cheese making, so fluid milk processors cannot justify bonus payments to dairy farmers for low milk SCC. Cheese makers all over the US and in other areas of the world pay a bonus for low SCC milk. A bonus payment for low SCC milk was incorporated (2001/2002)into some of the USDA Federal Milk Market Orders as part of the regulated pricing system. In these areas it means that bonus payments go to all dairy farmers not just those selling to cheese factories. Currently, we are communicating and helping fluid milk processors determine the extra economic value of extra shelf-life and improve flavor quality for pasteurized milk products. The longer the shelf-life the more the economic value because it opens up new marketing channels for milk that could result in increased sales against competing beverages of lower nutritional quality. If successful, we hope to increase low fat milk consumption by children and improve long term bone health, particularly in females.

relating milk quality measures like somtic cell count to value of milk

• Yinging Ma (PhD student)
• Marcos Santos (Visitng Fellow, U. of Brazil)
• David Galton (Professor of Animal Science, Cornell)
• Kathryn Boor (Assoc. Professor, Food Science, Cornell)
• Cornell Staff (Cornell Dairy Plant)
• Cornell Staff (Cornell Teaching and Research Center)