Traits to Select For in Fluid Milk Markets.
Dairy Pipeline: November 1995
Genetics and Management
Virginia dairy producers market a lot of milk for fluid consumption. Producers in other parts of the country sell much of their milk for manufactured products. Should sire selection be the same for both markets? Research is beginning to show that there are some differences in the relative value of traits like milk volume, protein, and type under the two types of market conditions. We reported preliminary results of a study of total lifetime merit of dairy cows under fluid and manufactured milk markets at this summer's meeting of the American Dairy Science Association. In the "fluid" market, no premium was paid for protein and SCS brought a small premium. In the "manufactured" market, protein content was an important basis for value of milk and low SCS was paid a higher premium. Our conclusions: "Indexes to select for lifetime merit in a fluid market weighted milk yield much more than fat or SCC and selected against protein yield. Indexes for manufacturing markets gave more weight to the components of milk, SCC, and (type) traits related to productive life." Protein yield is NOT the primary selection criteria for sire selection for herds producing for a fluid milk market. Protein is expensive to produce. In Virginia, the only producers currently paid directly for protein are those receiving solids not fat premiums. On the other hand, the long term survival of the dairy cow as a producer of human foodstuffs depends on her ability to convert roughage unfit for human consumption into protein - not fat or carrier. Current market conditions in this state, however, should be considered before placing all selection emphasis for improved production on protein yield. Our results showed that type traits are even less important in fluid milk markets than in areas producing for a manufactured market. This and many other research projects have shown that type traits have limited utility in extending the productive life of dairy cows. They have been overemphasized in sire selection across the country and are even less important under our market conditions than they are in other regions. Virginia dairy producers are justified in placing major emphasis on milk yield in sire selection.