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AIPL RESEARCH REPORT
K2-06 (3-08)		 State and National Standardized Lactation Averages by Breed for Cows Calving in 2006

H.D. Norman, L.L.M. Thornton, and G.R. Wiggans
Animal Improvement Programs Laboratory, ARS-USDA, Beltsville, MD 20705-2350
301-504-8334 (voice) ~ 301-504-8092 (fax) ~ inquiry@aipl.arsusda.gov ~ http://aipl.arsusda.gov

Lactation yields are often standardized to provide a reasonably equitable comparison of dairy cows having different lactation characteristics (i.e., age at calving, days milked, milking frequency, etc.). This report gives the average of standardized yield for calvings in 2006 for each State and the nation by breed. The data available originated in herds enrolled in the Dairy Herd Improvement (DHI) program. The test-day data used by the Animal Improvement Programs Laboratory to determine the lactation records were provided by the dairy records processing centers (DRPC). DHI participation and DRPC activity also have been summarized using the same data source.

Only data used in calculation of national genetic evaluations are included in these State and national averages. Thus, records beyond fifth lactation or by cows that lacked either a first lactation record or lacked valid sire identification were excluded. For other editing requirements, see complete evaluation documentation.

Breed yields are different between this report and the herd-average report because this report summarizes standardized lactation yield (e.g., adjusts yield to 305 days and twice a day milking), whereas the herd-average report is determined from actual herd yields. Input data to the herd-average reports are not restricted to those usable for national genetic evaluations. Herd-average report is impacted also by the length of lactation and dry period. Relative yields among breeds differ between the two reports because of large breed differences in percentage of usable records and differences in age-parity factors. Also, the herd-average reports tend to be more current (about 6 mo) than the standardized yield reports published at the same time.

Lactation records were calculated using the best prediction method starting in 1997 and were standardized for age-parity, calving month, previous days open, and times milked per day. Records shorter than 305 days were extended to 305 days as part of the best prediction process. Prior to 1997 the records were calculated using the test interval method. This change was responsible for a portion of the increases in yields observed between 1996 and 1997 because the current method gives a more favorable prediction for the lower producing cows. Numbers of records and averages for yields and component percentages are in Tables 1 through 7 by State for Ayrshires, Brown Swiss, Guernseys, Holsteins, Jerseys, Milking Shorthorns, and Red and Whites, respectively. Protein testing for records contributing to genetic evaluations is 97 to 100% except in California (89% for Guernseys and Holsteins, and 85% for Red and Whites) and Nevada (75% for Holsteins). Component percentages were computed from averages of standardized yields for milk and components.

Numbers of records and national averages for milk and component yields and component percentages are in Tables 8A-8F by breed for selected years. All breeds except one had increased calvings in 2006. Ayrshire calvings were up 5.7%; Brown Swiss calvings increased by 8.8%. Holstein, Jersey, Milking Shorthorn, and Red and White calvings were up 4.3%, 7.3%, 13.6%, and 1.1%, respectively. Guernsey calvings declined by 5.8%.

Milk yield was virtually unchanged (-0.4 to +0.4%) for all breeds but Guernsey which increased by 1.4%. A failure to increase is unusual, but might have been expected with the large increase in cow numbers, reflecting less culling. Fat percentage showed little change for 5 breeds, but increased by 0.05 and 0.06% for Milking Shorthorn and Red & Whites. Fat yield increasedby 9 and 12 lbs. for Guernsey and Red & Whites; there was little change for Ayrshire and Brown Swiss. Protein percentage remained the same for Brown Swiss and Guernsey, and increased by 0.01 for the other five breeds. Breed average protein yield increased from 4 to 8 lbs. for most breeds but decreased by 1 and 3 lbs for Ayrshire and Milking Shorthorn, respectively. Brown Swiss remained the same.

While milk and beef prices, feed availability and operating expenses, Government programs, and characteristics of herds entering and leaving eligible testing programs can affect production averages, genetic change continues to have a positive effect on yield. The leveling off of average yields most likely reflects changes in management strategies and more genetic emphasis on other traits such as health and longevity. For instance, average somatic cell count during 2007 dropped considerably from 2006 (Herd somatic cell count report) and days open is no longer increasing. Interpretation of trends in lactation averages should be made in view of other changes affecting profitability, and will be impacted by changes in number of records across years as well.

DHI Lactation Averages for Ayrshire  
Table 1. Ayrshire State and National Standardized Lactation Averages for Cows Calving in 2006 With Records
Used in National Genetic Evaluations.

  Records Milk Fat Protein
State (no.) (lb) (%) (lb) (%) (lb) Reporting
Alabama 5 14,779 3.81 563 3.12 460 100
Arizona 1 21,069 3.81 802 3.27 689 100
Arkansas 43 18,501 3.81 705 3.17 586 100
California 24 22,722 3.89 884 3.18 722 100
Colorado 7 19,427 3.74 726 3.12 607 100
Connecticut 119 19,026 4.00 762 3.18 605 100
Delaware 1 20,092 4.33 870 3.30 663 100
Florida 4 20,828 3.27 681 2.96 617 100
Idaho 3 18,327 3.90 715 3.09 566 100
Illinois 276 19,007 3.71 705 3.12 593 100
Indiana 65 16,415 3.77 619 3.12 513 100
Iowa 561 20,262 3.82 774 3.14 637 100
Kansas 67 17,008 3.60 613 3.19 542 100
Kentucky 38 14,694 3.56 523 3.17 467 100
Louisiana 10 16,942 3.53 597 3.02 512 100
Maine 128 16,721 3.77 630 3.05 510 100
Maryland 308 20,098 3.99 802 3.14 630 100
Massachusetts 21 17,850 3.85 688 3.18 567 100
Michigan 56 19,877 3.89 773 3.08 612 100
Minnesota 186 17,977 3.81 684 3.10 557 100
Missouri 98 15,834 3.90 617 3.14 497 100
Nebraska 70 16,809 3.90 655 3.21 539 100
New Hampshire 147 18,404 3.86 710 3.12 574 100
New Jersey 18 16,584 3.96 657 3.12 517 100
New Mexico 181 15,407 3.82 588 3.18 490 100
New York 1,123 17,886 3.83 686 3.10 554 100
North Carolina 52 14,764 4.10 606 3.09 457 100
North Dakota 1 15,908 3.88 617 2.93 466 100
Ohio 462 18,535 3.84 712 3.14 583 100
Oklahoma 103 20,685 3.45 713 3.12 646 100
Oregon 39 18,378 3.60 662 3.07 565 100
Pennsylvania 916 18,370 3.83 703 3.12 574 100
Rhode Island 34 15,937 3.90 621 3.17 506 100
South Carolina 8 19,856 3.70 735 3.10 615 100
Tennessee 21 17,809 4.13 736 3.17 565 100
Texas 88 17,795 3.71 661 3.21 570 100
Utah 16 14,085 3.98 561 3.33 470 100
Vermont 397 17,126 3.89 666 3.12 534 100
Virginia 28 18,446 3.84 708 3.20 590 100
Washington 17 17,617 3.86 681 3.26 575 100
West Virginia 24 16,784 3.78 634 3.14 527 100
Wisconsin 566 18,069 3.81 688 3.11 561 100
US 6,332 18,232 3.83 698 3.13 570 100 

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DHI Lactation Averages for Brown Swiss  
Table 2. Brown Swiss State and National Standardized Lactation Averages for Cows Calving in 2006 With Records
Used in National Genetic Evaluations.

  Records Milk Fat Protein
State (no.) (lb) (%) (lb) (%) (lb) Reporting
Alabama 7 23,622 3.31 782 3.14 743 100
Arizona 131 22,255 3.96 882 3.14 699 100
Arkansas 112 17,682 3.92 692 3.30 584 100
California 441 22,445 3.90 875 3.34 749 98
Colorado 141 22,299 4.15 926 3.44 767 100
Connecticut 57 18,878 3.98 752 3.27 617 100
Delaware 2 20,290 3.63 736 3.38 686 100
Florida 24 19,569 3.89 760 3.22 630 100
Georgia 91 19,786 3.87 766 3.30 654 100
Idaho 245 21,947 3.97 872 3.41 749 100
Illinois 641 20,714 3.99 827 3.30 684 100
Indiana 503 23,134 4.00 926 3.30 764 100
Iowa 1,509 21,915 4.05 887 3.33 730 100
Kansas 203 22,111 3.83 848 3.35 741 100
Kentucky 128 18,884 3.72 703 3.31 625 100
Louisiana 94 16,081 3.46 556 3.16 508 100
Maine 35 16,358 3.73 610 3.22 527 100
Maryland 305 21,685 3.99 865 3.30 716 100
Massachusetts 149 21,237 4.12 875 3.36 713 100
Michigan 386 23,034 3.93 905 3.28 756 100
Minnesota 1,444 22,402 4.05 907 3.27 733 100
Mississippi 10 17,599 3.81 670 3.23 568 100
Missouri 442 20,065 4.06 815 3.35 672 100
Montana 3 19,720 4.30 848 3.43 676 100
Nebraska 185 20,664 4.08 843 3.30 682 100
Nevada 1 30,938 3.96 1225 0
New Hampshire 108 18,712 4.04 757 3.29 616 100
New Jersey 6 27,193 4.14 1125 3.24 880 100
New Mexico 14 21,983 3.70 813 3.26 716 100
New York 1,137 20,691 4.01 829 3.28 679 100
North Carolina 57 21,638 3.85 834 3.24 702 100
North Dakota 84 17,836 4.01 716 3.45 615 100
Ohio 1,520 21,294 3.97 846 3.30 703 100
Oklahoma 48 17,118 3.76 644 3.34 572 100
Oregon 287 22,114 3.94 870 3.34 739 100
Pennsylvania 1,350 21,100 4.01 847 3.28 693 100
Puerto Rico 23 15,567 3.05 475 3.08 479 100
Rhode Island 1 17,920 4.15 744 3.47 622 100
South Carolina 14 20,536 3.79 778 3.20 657 100
South Dakota 175 19,068 4.42 843 3.39 646 100
Tennessee 272 17,024 4.18 711 3.37 574 100
Texas 472 19,770 3.96 783 3.33 659 100
Utah 74 19,504 4.02 784 3.36 655 100
Vermont 389 19,154 4.17 799 3.36 643 100
Virginia 178 22,543 3.85 867 3.22 727 100
Washington 262 21,207 3.91 830 3.42 725 100
West Virginia 7 23,663 3.69 874 3.32 786 100
Wisconsin 3,672 22,400 4.00 895 3.27 733 100
US 17,439 21,413 4.00 857 3.30 707 >99 

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DHI Lactation Averages for Guernsey  
Table 3. Guernsey State and National Standardized Lactation Averages for Cows Calving in 2006 With Records
Used in National Genetic Evaluations.

  Records Milk Fat Protein
State (no.) (lb) (%) (lb) (%) (lb) Reporting
Arizona 11 19,681 3.89 765 2.98 586 100
Arkansas 4 14,514 4.52 656 3.36 488 100
California 404 18,635 4.24 790 3.34 630 89
Colorado 1 12,503 4.13 516 2.77 346 100
Connecticut 52 17,284 4.35 753 3.27 565 100
Delaware 3 18,980 4.37 830 3.14 596 100
Florida 2 17,902 4.29 769 3.41 611 100
Georgia 5 17,678 3.11 549 3.14 555 100
Idaho 22 16,320 4.24 692 3.23 528 100
Illinois 122 17,166 4.38 752 3.17 544 100
Indiana 266 17,034 4.31 734 3.27 558 100
Iowa 592 18,604 4.43 825 3.28 611 100
Kansas 55 17,847 4.51 805 3.34 596 100
Kentucky 25 16,896 3.92 663 3.12 527 100
Louisiana 3 16,927 4.24 717 3.28 555 100
Maine 31 14,306 4.69 670 3.31 473 100
Maryland 318 16,335 4.57 747 3.36 549 100
Massachusetts 21 15,352 4.41 677 3.27 502 100
Michigan 18 13,644 4.24 579 3.22 439 100
Minnesota 362 16,529 4.33 715 3.23 535 100
Mississippi 1 15,616 3.69 576 3.18 497 100
Missouri 334 15,756 4.44 699 3.32 524 100
Nebraska 81 20,267 4.53 918 3.25 660 100
New Hampshire 13 16,298 4.61 751 3.40 554 100
New Jersey 6 16,873 4.85 818 3.41 576 100
New York 556 16,875 4.52 762 3.24 547 100
North Carolina 44 16,668 4.30 717 3.26 543 100
Ohio 269 17,418 4.44 773 3.30 575 100
Oklahoma 37 16,731 4.06 679 3.27 548 100
Oregon 308 18,690 4.35 814 3.25 607 100
Pennsylvania 695 16,824 4.36 733 3.24 545 100
South Carolina 54 15,172 4.48 679 3.34 506 100
South Dakota 52 12,484 4.51 563 3.26 408 100
Tennessee 79 17,121 4.19 718 3.23 553 100
Texas 122 16,513 4.12 681 3.19 527 100
Vermont 138 15,368 4.45 684 3.28 503 100
Virginia 105 15,816 4.51 713 3.28 519 100
Washington 96 18,193 4.42 805 3.32 603 100
West Virginia 11 15,600 4.71 735 3.52 548 100
Wisconsin 1,534 18,260 4.46 815 3.25 594 100
US 6,852 17,394 4.41 767 3.27 569 99