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Reproductive status of cows in Dairy Herd Improvement programs and bred using artificial insemination ()

H.D. Norman, F.L. Guinan, J.H. Megonigal, and J.W. Dürr

Background

Positive fertility is an important trait in all livestock enterprises. It is a key trait for dairy producers as the following calvings are the primary means of raising milk yield each lactation to a profitable level. Fertility traits receive 5% of the relative emphasis in Net Merit dollars and 15% in Grazing Merit dollars. Seven different measures of reproductive performance are summarized from Dairy Herd Improvement (DHI) herds from 2010 to present. Norman et al. (2009, Journal of Dairy Science 92:3517-3528) provided a comprehensive summary from 1996 through 2007 for many of the same traits for U.S. Holsteins and Jerseys. The same report published in May 2020 provides updated statistics for the reproductive traits by breed for 2008 and 2009. Historically most reproductive performance studies were limited primarily to days open or calving intervals, often from research herds.

More selection emphasis has been placed on fertility in recent years following considerable decline in a few of the important reproductive traits. For example, days open, which is used to calculate daughter pregnancy rate for genetic evaluations increased by 37 days for Holsteins from 1960 through 2000; around 75% of that increase was attributed to the change in correlated traits, a consequence of selection for higher milk trait yields. Genetic evaluations are now also available for cow conception rate and heifer conception rate.

The purpose of this annual report is to provide updates for several of the common ferility traits. The phenotypic averages provided are a reflection of both genetic and environmental changes. A few traits deteriorated for a time, but all now show slight or considerable improvement. Holsteins and Jerseys drive industry trends since they account for over 99% of the U.S. purebred dairy cattle population. Considerable fluctuation across time is evident for the other breeds, partly attributed to their smaller population sizes.

Table Summaries

TABLE 1. 20201 REPRODUCTIVE TRAIT AVERAGES AND STANDARD ERRORS BY BREED.
 
SAS Output
Trait Ayrshire Brown_Swiss Guernsey Holstein Jersey M_Shorthorn RedWhite
Breedings per conception 1.8± 0.03 2.4± 0.02 2.3± 0.04 2.0± 0.00 1.9± 0.01 1.7± 0.05 1.9± 0.06
Days from calving to first breeding 98± 1.1 94± 0.5 96± 1.1 83± 0.0 88± 0.1 88± 1.9 85± 1.5
Days from calving to last breeding 128± 1.9 141± 1.2 136± 2.3 114± 0.1 116± 0.3 114± 3.7 115± 3.6
Days from first to last breeding 37± 1.5 59± 1.0 57± 1.9 38± 0.1 34± 0.2 32± 2.6 39± 3.0
Conception rate for first breedings 0.40± .013 0.30± .006 0.30± .011 0.38± .000 0.40± .002 0.40± .025 0.35± .027
Conception rate for all breedings 0.40± .009 0.27± .003 0.28± .007 0.36± .000 0.38± .001 0.38± .017 0.35± .018
Calving interval 414± 2.7 435± 1.6 435± 3.0 397± 0.1 400± 0.4 422± 6.4 410± 5.6

1Cows first bred in 2020 for all traits except calving interval; for calving interval, cows first calving in 2019.
  • The fewest number of inseminations was 1.7 for Milking Shorthorns; the highest was 2.4 for Brown Swiss
  • Days from calving to first breeding averaged 83 for Holsteins; the highest average was 98 for Ayrshires
  • Days from calving to last breeding were fewest for Holsteins and Milking Shorthorns (114) and highest for Brown Swiss (141)
  • Days from first to last breeding, the breeding interval varied considerable across breeds; were fewest for Milking Shorthorns (32) and Jerseys (34), and highest for Brown Swiss and Guernseys (59 and 57)
  • Conception rate for first breedings was high for Ayrshires, Jerseys, and Milking Shorthorns (40%), and lowest for Brown Swiss and Guernseys (30%)
  • Breeds ranked similar for conception rate for all breedings as for first breedings, but were often slightly lower
  • Calving interval (days) was shortest for Holsteins (397) and Jerseys (400), and longest for Brown Swiss and Guernseys (435)


 
TABLE 2. AVERAGE NUMBERS OF INSEMINATIONS PER CONCEPTION BY BREED AND YEAR OF FIRST BREEDING.
 
SAS Output
Breed 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
Ayrshire 2.0 2.0 2.0 2.0 1.9 1.9 1.8 1.9 1.9 1.8 1.8
Brown Swiss 2.5 2.4 2.4 2.4 2.4 2.4 2.4 2.4 2.4 2.4 2.4
Guernsey 2.6 2.4 2.5 2.6 2.5 2.5 2.3 2.4 2.2 2.4 2.3
Holstein 2.5 2.5 2.5 2.5 2.4 2.4 2.3 2.2 2.1 2.0 2.0
Jersey 2.2 2.2 2.2 2.2 2.2 2.2 2.2 2.1 1.9 1.9 1.9
Milking Shorthorn 1.8 1.9 1.7 1.9 1.7 1.8 1.8 1.7 1.7 1.6 1.7
Red & White 2.2 2.1 2.1 2.2 2.2 2.2 2.2 2.2 2.0 2.1 1.9

  • Inseminations per conception (or number of services/conception) declined from 2010, by 0.1 to 0.5 in all breeds
  • The greatest decline was for Holstains (0.5)

 
TABLE 3. AVERAGE DAYS FROM CALVING TO FIRST BREEDING BY BREED AND BREEDING YEAR.
 
SAS Output
Breed 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
Ayrshire 94 95 95 92 91 93 94 90 93 97 98
Brown Swiss 89 89 87 88 89 88 88 87 89 91 94
Guernsey 90 91 92 89 92 92 91 94 93 95 96
Holstein 81 79 78 78 78 78 78 78 80 81 83
Jersey 77 76 75 74 76 79 82 86 87 88 88
Milking Shorthorn 93 99 95 90 91 91 90 92 88 101 88
Red & White 84 85 86 84 85 84 84 81 80 86 85

  • Days from calving to first breeding increased by 1 to 11 since 2010 in all breeds except Milking Shorthorns which decreased by 5
  • Some of the early decreases after 2010 probably resulted from the practices of heat synchronization and timed AI

 
TABLE 4. AVERAGE DAYS FROM CALVING TO LAST BREEDING BY BREED AND YEAR OF FIRST BREEDING.
 
SAS Output
Breed 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
Ayrshire 133 134 133 127 126 125 127 124 126 125 128
Brown Swiss 147 144 140 143 141 141 141 136 139 142 141
Guernsey 145 144 146 143 144 141 140 140 136 144 136
Holstein 132 130 126 126 124 123 120 117 114 114 114
Jersey 115 113 110 110 111 114 116 119 114 115 116
Milking Shorthorn 123 132 121 120 118 120 120 116 116 123 114
Red & White 129 128 127 126 128 125 124 118 113 119 115

  • Days from calving to last breeding decreased by 5 to 18 days for all breeds except Jerseys from 10 years earlier
  • The Holsteins and Red & Whites showed the largest decreases of 18 and 14 days, respectively

 
TABLE 5. AVERAGE DAYS FROM FIRST TO LAST BREEDING BY BREED AND YEAR OF FIRST BREEDING.
 
SAS Output
Breed 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
Ayrshire 50 47 47 44 43 41 40 41 41 34 37
Brown Swiss 72 69 66 67 66 65 63 62 63 63 59
Guernsey 72 65 65 69 68 64 64 63 58 64 57
Holstein 62 61 58 58 56 55 52 48 42 40 38
Jersey 47 45 43 45 45 43 44 42 33 34 34
Milking Shorthorn 37 39 30 37 33 36 36 31 33 30 32
Red & White 53 48 48 50 50 49 49 48 43 48 39

  • Breeding intervals are shorter in 2020 by 5 to 24 days than in 2010 for all breeds.
  • The Holsteins showed the largest decrease with 24 days.

 
TABLE 6. AVERAGE CONCEPTION RATES FOR FIRST BREEDINGS BY BREED AND BREEDING YEAR.
 
SAS Output
Breed 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
Ayrshire 0.36 0.37 0.38 0.41 0.41 0.40 0.42 0.39 0.39 0.42 0.40
Brown Swiss 0.29 0.30 0.30 0.30 0.30 0.29 0.30 0.31 0.29 0.29 0.30
Guernsey 0.27 0.29 0.29 0.28 0.29 0.30 0.29 0.27 0.31 0.28 0.30
Holstein 0.32 0.32 0.33 0.33 0.34 0.34 0.36 0.37 0.38 0.38 0.38
Jersey 0.41 0.42 0.43 0.41 0.41 0.41 0.41 0.41 0.42 0.40 0.40
Milking Shorthorn 0.42 0.38 0.43 0.40 0.44 0.39 0.40 0.40 0.40 0.39 0.40
Red & White 0.33 0.35 0.37 0.36 0.35 0.34 0.34 0.34 0.37 0.32 0.35

  • Conception to first breeding improved for 5 of 7 breeds in the last decade (by 1 to 6%). Lowest conception rates for Holsteins were from 2009 to 2011 (32%) and the highest was in 2019 (38%)

 
TABLE 7. AVERAGE CONCEPTION RATES FOR ALL BREEDINGS BY BREED AND YEAR OF FIRST BREEDING.
 
SAS Output
Breed 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
Ayrshire 0.36 0.37 0.36 0.38 0.40 0.39 0.40 0.38 0.36 0.40 0.40
Brown Swiss 0.27 0.27 0.27 0.28 0.27 0.27 0.27 0.28 0.27 0.26 0.27
Guernsey 0.25 0.26 0.27 0.27 0.27 0.27 0.27 0.26 0.27 0.26 0.28
Holstein 0.30 0.30 0.31 0.31 0.32 0.32 0.33 0.34 0.35 0.36 0.36
Jersey 0.37 0.37 0.38 0.37 0.37 0.37 0.36 0.36 0.39 0.38 0.38
Milking Shorthorn 0.39 0.38 0.41 0.39 0.41 0.37 0.38 0.37 0.40 0.40 0.38
Red & White 0.34 0.33 0.34 0.33 0.33 0.33 0.34 0.33 0.36 0.32 0.35

  • The conception rates for all breedings in 2020 were lower (2 to 3%) than those from first breedings in 5 of the 7 breeds but yet improved in the last decade for 5 of the 7 breeds (by 1 to 6%)

 
TABLE 8. AVERAGE CALVING INTERVALS (DAYS) BY BREED AND YEAR OF FIRST CALVING.
 
SAS Output
Breed 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019
Ayrshire 418 421 417 411 410 409 410 411 412 414
Brown Swiss 432 434 430 430 432 430 431 427 430 435
Guernsey 432 436 433 430 431 431 436 436 434 435
Holstein 409 408 404 403 401 399 398 396 397 397
Jersey 393 392 390 388 391 395 395 398 400 400
Milking Shorthorn 402 420 407 404 407 410 408 409 401 422
Red & White 415 416 409 408 411 409 409 399 396 410

  • The long-term increases in calving interval reported by Nieuwhof et al. (1989) and Hare et al. (2006) have ended and have decreased recently
    • Length of calving interval for Holsteins has decreased from 409 days in 2010 to 397 days in 2019
    • Jersey calving intervals decreased from 393 days in 2010 to 388 days in 2013, but increased by 12 days from 2013 to 2019
  • Improvement of this trait is especially important to herds engaged in seasonal calving

 
TABLE 9. NUMBERS OF RECORDS (2010–2020): A) AYRSHIRE, B) BROWN SWISS, C) GUERNSEY, D) HOLSTEIN, E) JERSEY), F) MILKING SHORTHORN, AND G) RED & WHITE USED TO CALCULATE REPRODUCTIVE STATISTICS BY BREED, TRAIT, AND YEAR.
  • Information in Tables 1 through 8 was based on the numbers of records in Tables 9A through 9G.

A) AYRSHIRE
 
SAS Output
Trait 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
Breedings per conception 3,707 3,625 3,796 3,497 3,230 3,218 3,049 2,477 2,286 1,845 1,533
Days from calving to first breeding 3,853 3,785 3,939 3,603 3,349 3,340 3,168 2,580 2,376 1,926 1,570
Days from calving to last breeding 2,663 2,669 2,771 2,640 2,470 2,369 2,278 1,792 1,608 1,331 1,089
Days from first to last breeding 3,707 3,625 3,796 3,497 3,230 3,218 3,049 2,477 2,286 1,845 1,533
Conception rate for first breedings 3,383 3,362 3,489 3,224 2,998 2,913 2,793 2,271 2,097 1,658 1,325
Conception rate for all breedings 7,542 7,331 7,658 7,006 6,215 6,135 5,726 4,771 4,577 3,469 2,743
Calving interval 1,863 1,946 1,920 1,731 1,697 1,584 1,348 1,128 999 745  




B) BROWN SWISS
 
SAS Output
Trait 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
Breedings per conception 10,163 10,324 10,113 9,759 9,755 10,267 9,479 8,983 8,061 7,095 7,150
Days from calving to first breeding 10,515 10,714 10,506 10,101 10,076 10,649 9,858 9,321 8,353 7,314 7,366
Days from calving to last breeding 6,772 6,821 6,691 6,572 6,458 6,730 6,259 5,952 5,148 4,438 4,562
Days from first to last breeding 10,163 10,324 10,113 9,759 9,755 10,267 9,479 8,983 8,061 7,095 7,150
Conception rate for first breedings 9,482 9,689 9,483 9,173 9,015 9,555 8,843 8,347 7,462 6,434 6,199
Conception rate for all breedings 24,739 25,253 24,684 23,751 23,873 24,733 23,270 21,555 19,983 16,919 17,378
Calving interval 5,363 5,197 5,138 5,007 5,142 4,965 4,585 4,249 3,860 3,473  




C) GUERNSEY
 
SAS Output
Trait 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
Breedings per conception 3,603 3,394 3,237 3,011 2,932 3,054 2,898 2,707 2,285 2,191 1,992
Days from calving to first breeding 3,758 3,538 3,358 3,109 3,041 3,148 3,004 2,817 2,375 2,272 2,066
Days from calving to last breeding 2,361 2,216 2,158 2,037 1,963 2,039 1,838 1,635 1,406 1,388 1,255
Days from first to last breeding 3,603 3,394 3,237 3,011 2,932 3,054 2,898 2,707 2,285 2,191 1,992
Conception rate for first breedings 3,298 3,082 2,972 2,726 2,671 2,749 2,629 2,365 1,922 1,788 1,633
Conception rate for all breedings 9,291 8,569 8,025 7,725 7,404 7,599 7,047 6,455 5,315 5,149 4,738
Calving interval 1,648 1,540 1,451 1,450 1,473 1,481 1,382 1,084 1,012 911  




D) HOLSTEIN
 
SAS Output
Trait 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
Breedings per conception 1,676,120 1,735,490 1,814,334 1,847,913 1,933,732 1,998,994 2,002,847 1,963,245 1,808,282 1,448,499 1,247,752
Days from calving to first breeding 1,726,661 1,786,494 1,870,394 1,902,720 1,987,614 2,057,515 2,060,527 2,022,300 1,862,829 1,490,854 1,285,057
Days from calving to last breeding 1,281,749 1,323,217 1,388,400 1,417,672 1,488,353 1,542,050 1,554,332 1,508,155 1,337,436 1,048,326 892,048
Days from first to last breeding 1,676,120 1,735,490 1,814,334 1,847,913 1,933,732 1,998,994 2,002,847 1,963,245 1,808,282 1,448,499 1,247,752
Conception rate for first breedings 1,618,403 1,689,860 1,765,894 1,805,547 1,881,735 1,942,831 1,940,545 1,879,978 1,707,658 1,340,461 1,132,745
Conception rate for all breedings 4,160,473 4,364,501 4,499,403 4,564,763 4,681,454 4,835,597 4,737,234 4,490,397 3,904,074 2,981,443 2,508,144
Calving interval 893,132 928,583 966,098 996,079 1,038,763 1,078,118 1,067,907 967,517 791,563 653,728  




E) JERSEY
 
SAS Output
Trait 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
Breedings per conception 128,134 147,244 157,190 169,106 178,445 175,459 171,962 172,030 142,541 95,918 72,094
Days from calving to first breeding 132,113 151,900 163,029 174,282 183,849 181,294 177,459 177,728 147,337 99,378 74,971
Days from calving to last breeding 106,755 121,854 129,462 138,833 145,054 138,650 135,262 132,431 105,825 68,788 51,620
Days from first to last breeding 128,134 147,244 157,190 169,106 178,445 175,459 171,962 172,030 142,541 95,918 72,094
Conception rate for first breedings 119,895 137,792 145,392 154,501 160,357 146,578 136,804 126,293 105,214 72,641 56,506
Conception rate for all breedings 281,869 322,735 338,750 367,885 392,912 380,724 370,246 376,078 285,421 186,239 138,548
Calving interval 75,627 80,994 87,652 92,962 93,481 85,997 81,289 67,220 45,296 33,812  




F) MILKING SHORTHORN
 
SAS Output
Trait 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
Breedings per conception 928 1,007 1,277 1,235 1,128 1,066 1,050 853 665 529 476
Days from calving to first breeding 956 1,057 1,330 1,300 1,205 1,107 1,085 892 690 546 482
Days from calving to last breeding 650 718 898 870 800 724 706 555 455 348 299
Days from first to last breeding 928 1,007 1,277 1,235 1,128 1,066 1,050 853 665 529 476
Conception rate for first breedings 805 867 1,126 1,099 1,024 925 960 747 579 428 400
Conception rate for all breedings 1,675 1,849 2,163 2,229 1,999 1,948 1,898 1,510 1,190 840 825
Calving interval 382 497 566 497 470 478 373 269 230 185  




G) RED & WHITE
 
SAS Output
Trait 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
Breedings per conception 1,203 1,195 1,136 1,208 1,106 1,146 990 906 809 517 357
Days from calving to first breeding 1,254 1,250 1,180 1,244 1,137 1,186 1,014 929 829 536 368
Days from calving to last breeding 911 820 830 862 807 829 727 649 593 346 249
Days from first to last breeding 1,203 1,195 1,136 1,208 1,106 1,146 990 906 809 517 357
Conception rate for first breedings 1,144 1,128 1,047 1,139 1,046 1,070 924 845 754 469 323
Conception rate for all breedings 2,734 2,609 2,379 2,548 2,566 2,492 2,207 2,025 1,724 1,105 716
Calving interval 579 578 580 565 587 568 479 403 271 190  


Contact: Duane Norman, 301-525-2006, duane.norman@uscdcb.com

We wish to acknowledge the contribution of the dairy producers who supplied data for this report through their participation in the Dairy Herd Improvement (DHI) program and the dairy records processing centers (DRPC) that processed and relayed the information on to the Council on Dairy Cattle Breeding (CDCB).