Selection for Fertility in Dairy Cattle Paul Van

Selection for Fertility in Dairy Cattle Paul Van. Raden Animal Improvement Programs Laboratory, USDA Agricultural Research Service, Beltsville, MD, USA paul@aipl. arsusda. gov 2007

Factors Affecting Fertility Ø Environment and management • • Ø Season, region, herd, age, milk yield Calving difficulty, twins, mastitis, health Estrus detection and / or synchronization Voluntary waiting period Genes of cow (Daughter Pregnancy Rate) Ø Fertility of bull (ERCR) Ø Interaction of bull’s and cow’s genes Uberlandia, Brazil 2007 (2) P. M. Van. Raden 2007

Genetic Interactions Ø Lethal recessive genes • • • CVM aborts pregnancy 30 -280 days DUMPS aborts embryo at ~45 days New defect causes loss at ~5 days Ø Inbreeding reduces fertility Ø Crossbreeding improves fertility • 1. 8% increase in pregnancy rate Uberlandia, Brazil 2007 (3) P. M. Van. Raden 2007

USA Bull Fertility Evaluation Ø Ø Ø Measure of current semen fertility Based on 1. 6 million inseminations in last 3 years Estimated Relative Conception Rate (ERCR) ranges +5% to – 6% Uberlandia, Brazil 2007 (4) P. M. Van. Raden 2007

Bull Fertility Research Kuhn, 2006 Ø Ø Moved evaluation to USDA from DRMS in Raleigh, NC in 2006 Data from eastern half of United States Planning to use all services and pregnancy exams Bull fertility is not correlated to daughter fertility (heifers or cows) Uberlandia, Brazil 2007 (5) P. M. Van. Raden 2007

Why Does Fertility Differ? Ø Male fertility includes • • Ø Ability of sperm to fertilize egg Bull’s environmental conditions Female fertility includes • • Ability to cycle and show estrus Ability of egg to conceive Maternal support of embryo Milk production stress (cows only) Uberlandia, Brazil 2007 (6) P. M. Van. Raden 2007

Heifer Fertility Research Kuhn et al, 2006 J Dairy Sci 89: 4907 Ø Ø Insemination records for 537, 938 heifers in years 2003 -2005 Average conception rate = 57% Heritability =. 5% (linear model), 1% (logistic model) Genetic correlation =. 39 with cow conception rate, -. 19 with milk yield Uberlandia, Brazil 2007 (7) P. M. Van. Raden 2007

Heifer Fertility is Good Paul Van. Raden, 1995 Uberlandia, Brazil 2007 (8) P. M. Van. Raden 2007

Problem: Cows Conceive Later USA Holsteins 1965 -2000 Lactation 5 th 4 th 3 rd 2 nd 1 st Uberlandia, Brazil 2007 (9) P. M. Van. Raden 2007

Pregnancy Rate Ø Ø The percentage of nonpregnant cows that become pregnant during each 21 day time period Pregnancy rate < conception rate • • Ø Cows that are not cycling Estrus not expressed or detected Typical pregnancy rates • • 20% if calving interval is 14. 3 months 25% if calving interval is 13. 6 months Uberlandia, Brazil 2007 (10) P. M. Van. Raden 2007

Pregnancy Rate and Days Open 100 90 Pregnancy Rate 80 70 60 50 40 30 20 10 1 0 60 2 81 3 102 4 123 5 144 6 165 7 186 8 207 9 228 249 Number of Chances Days Open Uberlandia, Brazil 2007 (11) P. M. Van. Raden 2007

Sources of Fertility Data Percentages from 1998 -1999 records Breeding date: Verified by next calving date BSW HOL 54 57 8 5 15 19 No breeding reported, only next calf Cow sold for infertility 9 6 5 5 No information for fertility 9 8 Disagrees with calving date Breeding date but no next calf Uberlandia, Brazil 2007 (12) P. M. Van. Raden 2007

Distribution of Days to Conceive Holstein Calvings 1990 - 2001 Cows culled for reproductive reasons ≤ 50 Uberlandia, Brazil 2007 (13) ≥ 0 25 P. M. Van. Raden 2007

Seasonal Effects on Fertility Holsteins calving since 1997 in each USA region Uberlandia, Brazil 2007 (14) P. M. Van. Raden 2007

USA Cow Fertility Evaluation Ø Holstein data in evaluation • • • Ø 44 million lactation records since 1960 17 million cows Lactations 1 -5 are included Reliability for recently proven bulls • • 59% REL for Daughter Pregnancy Rate 61% REL for Productive Life 69% REL for Somatic Cell Score 85% REL for Milk Yield Uberlandia, Brazil 2007 (15) P. M. Van. Raden 2007

USA Evaluation Methods Ø Animal model, introduced in 2003 • • • Ø Use same programs as other USDA traits Compare cows within herd, season, and age Convert to pregnancy rate (4 more days to conceive = 1% lower pregnancy rate) Fertility parameter estimates used: • • • Heritability = 4% Repeatability = 11% Sire-by-herd interaction = 4% Uberlandia, Brazil 2007 (16) P. M. Van. Raden 2007

Recent USA Changes November 2003 and November 2004 Ø Earlier evaluation of cow fertility • • • Ø Records in progress used at 130 instead of 250 days in milk Pregnancy exams used in prediction 6% gain in reliability of DPR for new bulls Fertility used to predict longevity • 4% gain in REL of PL for recent bulls Uberlandia, Brazil 2007 (17) P. M. Van. Raden 2007

All-Breed Animal Model Ø Combined analysis of all breeds Ø Data from crossbreds included Ø Ø Genetic differences among breeds are estimated Planning to implement in May 2007 Uberlandia, Brazil 2007 (18) P. M. Van. Raden 2007

Genetic Trends for Each Breed Daughter Pregnancy Rate, 1960 -2000 +1. 8% Heterosis Uberlandia, Brazil 2007 (19) P. M. Van. Raden 2007

Correlation of Yield and Fertility r = -. 35 Uberlandia, Brazil 2007 (20) P. M. Van. Raden 2007

Coefficients of Variation (CV) Standard deviation divided by mean Trait Stature Protein yield Longevity Fertility Uberlandia, Brazil 2007 (21) Heritability. 42. 30. 08. 04 CV (%) Phenotypic Genetic 3 2 13 7 54 16 65 13 P. M. Van. Raden 2007

Value of Cow Fertility Ø Fertility expenses per day open • • Ø Heat detection ($20 / lact . 005) Semen ($15 / unit + $5 labor) *. 025 Pregnancy exam ($10 / exam)*. 012 Lactations too long or short = $. 10 = $. 50 = $. 12 = $. 75 Value of DPR as % of total economic value • • • 9% in Lifetime Net Merit 5% in TPI, also -2% for dairy form in TPI Uberlandia, Brazil 2007 (22) P. M. Van. Raden 2007

Cow Fertility Trait Heritabilities and Genetic Correlations Trait Days Conc. 1 st Cow CR Days to Conceive . 04 . 85 -. 21 . 07 . 24 Days to 1 st Service Cow Conc. Rate . 01 Heifer CR . 39 Heifer Conc. Rate . 005 Heritabilities on diagonal Uberlandia, Brazil 2007 (23) P. M. Van. Raden 2007

Interbull Ø Provides international evaluations using data from 26 countries • • Europe, North America, Australia, New Zealand, S. Africa, Israel, Japan No South American countries yet Ø Office located in Sweden Ø Many traits are evaluated Uberlandia, Brazil 2007 (24) P. M. Van. Raden 2007

Countries with Most Holsteins and Interbull abbreviations Country USA DEU FRA NZL NLD CAN GBR Name United States Germany France New Zealand Netherlands Canada Great Britain (U. Kingdom) Uberlandia, Brazil 2007 (25) P. M. Van. Raden 2007

Fertility Traits and Emphasis In Largest Holstein Populations Trait Country USA DEU FRA NZL NLD CAN GBR Emphasis (%) 9 Days to Yes Conceive Days to first AI Conception rate Heifer conception Uberlandia, Brazil 2007 (26) 1 13 7 10 5 Yes 7 Yes Yes Yes P. M. Van. Raden 2007

Fertility Trait Indexes % of fertility emphasis Trait NLD ITA ESP CAN DNK 1 USA 2 Days to 1 st service 54 56 52 25 15 69 Conception Rate 46 44 48 65 70 31 10 15 Heifer fertility 1 Time from first to last insemination replaces non−return rate 2 Countries that evaluate days to conception or calving interval Uberlandia, Brazil 2007 (27) P. M. Van. Raden 2007

Countries with Days to Conception and Interbull abbreviations Country BEL DFS ESP GBR IRL ITA NLD USA Name Belgium Denmark-Finland-Sweden Spain Great Britain (U. Kingdom) Ireland Italy Netherlands United States Uberlandia, Brazil 2007 (28) P. M. Van. Raden 2007

Fertility Genetic Correlations Interbull test run, Sept. 2006 BEL DFS ESP GBR. 85. 94. 89. 85. 84. 89. 94. 88 IRL. 86. 73. 81 GBR IRL ITA NLD USA . 89. 86. 78. 86. 88 . 82. 85. 76. 75. 84. 72. 86 . 89. 73. 86. 91. 85 Uberlandia, Brazil 2007 (29) . 88. 81. 87. 86. 93 . 82. 85. 86. 82 ITA NLD USA. 78. 86. 88. 86. 91. 85. 87. 86. 93. 86. 75. 84 . 82. 72. 86. 83 P. M. Van. Raden 2007

Correlation of NLD and USA Fertility r =. 91 Uberlandia, Brazil 2007 (30) P. M. Van. Raden 2007

Genetic Correlations of Traits Mark, 2003 EAAP meeting Trait Countries Average corr. Protein 27 . 87 Stature 21 . 89 Fore Udder 21 . 75 Somatic Cell Score Longevity 20 . 85 14 . 59 Direct Calving Ease Maternal Calving Uberlandia, Ease Brazil 2007 (31) 10 . 83 10 . 58 P. M. Van. Raden 2007

Reporting of Daughter Fertility National evaluation scales Scale BEL CAN CZE DEU DFS ESP FRA Mean 0 66 0 100 100 0 Uberlandia, Brazil 2007 (32) SD 4 3 3 12 10 10 1 Scale Mean GBR 0 ISR 0 IRL 0 ITA 100 NLD 100 NZL -8 USA 0 SD 3 2. 5 5 4 4 1. 4 P. M. Van. Raden 2007

Days to Conception Correlations with other traits DNK ESP GBR IRL NLD USA Milk. 31. 38. 36. 40. 52. 21 Uberlandia, Brazil 2007 (33) Dairy Form. 36. 40 SCS. 18. 16. 13 . 43. 31 . 13. 12 Longevity -. 34 -. 38 -. 30 -. 49 -. 06 -. 48 P. M. Van. Raden 2007

Skewness Uberlandia, Brazil 2007 (34) P. M. Van. Raden 2007

Skewness of Fertility Evaluations within each country Ø Heifer conception rate • Ø Days to first insemination • Ø Range. 09 to. 33 Cow conception rate • Ø Range -. 23 to. 11 Range -. 20 to. 10 Calving interval, days open, or DPR • Range. 04 to. 35, skewness in USA =. 04 Uberlandia, Brazil 2007 (35) P. M. Van. Raden 2007

Skewness of Fertility Ø Ø Ø Fertility trait data often have unusual distributions Genetic evaluations are close to normally distributed Standard linear models work well for large data sets Uberlandia, Brazil 2007 (36) P. M. Van. Raden 2007

Effects of Synchronization Ø Ø Ø Days to first insemination has less variation if herds synchronize heat Sire rank for days to conception is similar in herds with heat detection or synchronization (Goodling et al, 2005 JDS) DPR is adjusted for differences in herd variation Uberlandia, Brazil 2007 (37) P. M. Van. Raden 2007

Are Fertility Proofs Stable? Ø Ø Bulls have about 100 daughters in first crop Bulls later have thousands of daughters in second crop Ø How accurate are predictions? Ø Examined Select Sires bulls Uberlandia, Brazil 2007 (38) P. M. Van. Raden 2007

Top DPR Proof Stability Select Sires bulls born 1995 -96, high reliability in 2006 Bull Mozer Geno Beach Brass Alloy 2003 +. 5 +. 3 +. 2 +. 0 2004 2006 +. 8 +. 6 +. 5 +1. 6 +1. 4 -. 3 -. 9 -. 1 +1. 2 Reliability 67% 82% 96% DPR adjusted to 2005 base Uberlandia, Brazil 2007 (39) P. M. Van. Raden 2007

Bottom DPR Proof Stability Select Sires bulls born 1995 -96, high reliability in 2006 Bull Hi Metro Hillcrest Louie Calvin Sovereign-Red 2003 -3. 4 -2. 6 -2. 4 -2. 2 -2. 0 2004 -3. 0 -2. 1 -1. 9 -1. 6 2006 -2. 8 -3. 1 -1. 6 -1. 8 -1. 6 Reliability 67% 82% 96% DPR adjusted to 2005 base Uberlandia, Brazil 2007 (40) P. M. Van. Raden 2007

Daughter Fertility of Active Bulls Ø +1. 8% DPR average for top 10% Ø – 2. 1% DPR average, bottom 10% Ø Difference = 16 days to conception Ø Reliability for bulls averages 63% Uberlandia, Brazil 2007 (41) P. M. Van. Raden 2007

Daughter Fertility of Famous Bulls November 2006 USA scale Countries Daughters USA REL PTA 11 25, 256 15, 160 99% 2. 7 8 32, 399 27, 602 99% 2. 2 Manfred 15 19, 292 8, 011 99% 2. 0 Morty 13 20, 481 4, 177 97% -2. 5 Demand 14 38, 388 17, 972 99% -2. 2 Emerson 18 50, 811 31, 245 99% -2. 2 Die-Hard Duster Uberlandia, Brazil 2007 (42) Total DPR P. M. Van. Raden 2007

Conclusions Ø Ø Ø Bulls with good fertility and daughter fertility are available Cow fertility traits receive 1% to 13% of total selection in many countries Select for fertility using an index Fertility traits have lower heritability but more variation than yield and type Management and genetics affect fertility Uberlandia, Brazil 2007 (43) P. M. Van. Raden 2007

Questions? Uberlandia, Brazil 2007 (44) P. M. Van. Raden 2007