HOLSTEIN IMMUNITY+® SIRES
FUNCTIONAL TRAITS
HOLSTEIN GENOMIC YOUNG SIRES
HOLSTEIN GENOMIC YOUNG SIRES CONTINUED
HOLSTEIN PROVEN SIRES
SIRE SEARCH
Check out the SemexGO™ sire search app! This free app is available in English and Spanish and easily delivers fast results by breed, trait or brand. Search your favorite sires, create lists and find the latest proof information all in the palm of your hand. Future releases will include even more functionality designed to work seamlessly with Semex’s growing suite of solutions.
Efficient, Fast-Growing Calves for High-Value Carcasses Demanded by Supply Chains
Citation: Kovacs, M., Renaud, D., Keunen, A., & Steele, M. (2026). Health and performance of Holstein versus dairy × beef calves: A retrospective single-cohort study. Journal of Dairy Science. https://doi.org/10.3168/jds.2025-27748. Martín N, Schreurs N, Morris S, López-Villalobos N, McDade J, Hickson R. Sire Effects on Carcass of Beef-Cross-Dairy Cattle: A Case Study in New Zealand. Animals (Basel). 2021 Feb 27;11(3):636. doi: 10.3390/ani11030636. PMID: 33673584; PMCID: PMC7997217.
High Quality, Balanced Calves for Feeder Profitability
The Economic Choice for Proven Genetics Faster gains and finish sooner INCREASED GAIN & FEED EFFICIENCY
Difficult calvings can reduce milk yield by
500–700 kg/ 1100-1540 lbs per lactation
Day-old calf sales Or feeding to finish
Citation: Roche SM, Ross JA, Schatz C, Beaugrand K, Zuidhof S, Ralston B, Allan N, Olson M. Impact of Dystocia on Milk Production, Somatic Cell Count, Reproduction and Culling in Holstein Dairy Cows. Animals (Basel). 2023 Jan 19;13(3):346. doi: 10.3390/ani13030346. PMID: 36766235; PMCID: PMC9913294.
PowerMixTM is heterospermic semen which contains the semen of three different sires in one straw and this combination is proven to improve conception rates.
ANGUS POWERMIX 144 0200PS00144
ANGUS POWERMIX 146 0200PS00146
ANGUS POWERMIX 147 0200PS00147
LIMFLEX POWERMIX 142 0200PS00142
SIMANGUS POWERMIX 143 0200PS00143 *SUITABLE FOR HEIFERS
Fore
Habit 99%-I DUCKETT
Fore
Pashion
DR. SHANNON BEARD PHD, SEMEX RESEARCH GENETICIST
A Genetic Tool for Managing HPAI H5N1 in Dairy Herds
Proven For Fewer Treatments & Faster Recovery
When highly pathogenic avian influenza (HPAI H5N1) enters a dairy herd, the most immediate and costly consequence is not mortality: it is milk loss. Abrupt drops in production, prolonged recovery periods, and uneven impacts across cows have made this emerging disease especially challenging for producers to manage. As the industry adapts to this emerging challenge, understanding what drives disease severity has become increasingly important.
A recent peer-reviewed study published in the Journal of Dairy Science Communications by researchers at Semex and the University of Guelph now provides the first large-scale evidence that immune response genetics significantly influence how dairy cows experience and recover from HPAI H5N1 infection under commercial farm conditions.
HPAI H5N1: A New and Costly Challenge for Dairy Herds
HPAI H5N1 has recently emerged as a new and unexpected challenge for the dairy industry. In March 2024, the USDA confirmed the first documented spillover of HPAI H5N1 into dairy cattle, marking the first time the virus had been identified as the cause of clinical disease in lactating cows.
Following the initial detection, additional cases were identified across multiple states, indicating that the virus can spread efficiently within and between dairy herds.
As of December 2025, 1,084 dairy herds across 19 U.S. states have reported confirmed infections (USDA-APHIS, 2025). However, the true number of affected herds is likely higher because testing and reporting requirements vary among states.
Clinical Expression and Production Consequences
Clinical signs of HPAI H5N1 include reduced feed intake and rumination, lethargy, respiratory symptoms, and abnormal milk appearance and consistency (Caserta et al., 2024). The most economically important consequence, however, is an abrupt decline in milk yield, which occurs soon after clinical signs appear. Average herd-level losses are approximately 5.7%, equivalent to $504 USD per affected cow (Rodriguez et al., 2025), while individual losses can reach 22% or as much as $950 per cow (Peña-Mosca et al., 2025; Rodriguez et al., 2025). In many cases, reduced production persists for several weeks.
Once HPAI H5N1 enters a herd, exposure is widespread because of efficient transmission through shared environments such as bedding, flooring, and milking equipment (Caserta et al., 2024). Management and biosecurity remain critical, but they cannot fully eliminate risk once the virus is present. This reality has increased interest in tools that can help reduce the severity and production impact of disease.
Objective:
Assess if Immunity+ genomic selection improves resilience to HPAI H5N1 in commercial dairy herds.
Immunity+®: A Genetic Tool to Reduce Disease Impact
Semex’s Immunity+ is a scientifically proven strategy that enhances broad-spectrum disease resistance by identifying cows and bulls with superior immune response. With a robust health index supported by data from other industry disease evaluations, Immunity+ directly measures both antibody- and cell-mediated immune responses to pathogens.
Proven benefits include not only reduced disease incidence, but also improved hoof health, reproductive performance, vaccine response, milk and colostrum quality, and heifer growth rates (Wagter et al., 2000; Thompson-Crispi et al., 2013; Cartwright, 2017; Larmer and Mallard, 2017). As the industry navigates emerging disease challenges like HPAI H5N1, Immunity+ provides a sustainable path to healthier herds, improved productivity, and long-term profitability.
Evaluating Immunity+ Genetics During HPAI H5N1 Outbreaks
Newly published research from Semex and the University of Guelph analyzed treatment and production data from six large commercial dairy herds in the United States with confirmed HPAI H5N1 outbreaks. Treatment records from 15,286 cows were evaluated, along with daily milk yield records from cows that required supportive treatment. Treatment in this study was producerdriven and based on observable clinical signs, with vitamin B supplementation given to individually affected animals serving as a proxy for illness severity.
To evaluate the association between Immunity+ breeding values and resilience to HPAI H5N1, the study examined both the likelihood that cows required supportive vitamin B treatment during an outbreak and the amount of milk lost during the recovery period after treatment.
STUDY CONTEXT
STUDY CONTEXT
Emerging threat: HPAI H5N1 has spilled over into dairy cattle, threatening herd health and milk production in North America.
METHODS
Objective:
Assess if Immunity+ genomic selection improves resilience to HPAI H5N1 in commercial dairy herds.
METHODS
KEY RESULTS
METHODS
15,386 cows from 6 U.S. dairy herds with confirmed HPAI outbreaks.
High Immune Response Cows:
ANALYZED:
Likelihood of needing supportive treatment
Milk loss and milk fluctuation duration after treatment
(Odds Ratio = 0.76; 95% CI: 0.64–0.90)
COMPARED HIGH, AVERAGE, AND LOW IMMUNITY GEBV COWS.
Lost ~295 lbs less milk post-treatment (1068 lbs vs. 1363 lbs)
Lower Treatment Risk and Reduced Milk Loss with Immunity+
ANALYZED:
Likelihood of needing supportive treatment
Cows with high Immunity+ breeding values were significantly less likely to receive supportive treatment for HPAI H5N1 than cows with low Immunity+ breeding values. After accounting for parity, days in milk, and herd effects, high immune responder cows were approximately 24% less likely to require treatment.
Immunity+ reduced
15,386 cows from 6 U.S. dairy herds with confirmed HPAI outbreaks. CONCLUSION for
Immunity+® cows have lower reduced milk loss during
15,386 Cows
Milk loss and milk fluctuation duration after treatment treatment production STRENGTHENS resilience Were 24% less likely to require treatment
COMPARED HIGH, AVERAGE, AND LOW IMMUNITY GEBV COWS.
For cows that required treatment, immune response genetics also influenced production outcomes during recovery. Daily milk yield data showed that cows with low Immunity+ breeding values experienced substantially greater milk losses during the post-treatment recovery period than cows with high Immunity+ breeding values. On average, low immune responder cows lost more than 1300 lbs of milk during this period, while high immune responder cows lost closer to 1060 lbs. Although the duration of recovery was similar across immune response groups, cows with stronger immune response genetics maintained production closer to expected levels throughout the recovery window.
24% HIR cows
$950 est cost/clinical
STUDY
CONTEXT
Building Resilience for What Comes Next
Emerging threat: HPAI H5N1 has spilled over into dairy cattle, threatening herd health and milk production in North America.
These results are particularly relevant because milk loss is the primary driver of economic impact during HPAI H5N1 outbreaks. Reduced production can persist for weeks, creating lasting effects on herd performance and profitability. The study demonstrates that immune response genetics affect not only whether cows exhibit clinical signs, but also the amount of production lost when illness occurs.
Taken together, the results provide peer-reviewed evidence that Immunity+® delivers meaningful benefits during emerging disease challenges such as HPAI H5N1. While genetics cannot prevent exposure to infectious agents, this study demonstrates that Immunity+ is associated with reduced disease severity and significantly lower milk losses during outbreaks.
KEY RESULTS
KEY RESULTS
High Immune Response Cows:
Immunity+® cows have lower treatment risk and reduced milk loss during HPAI H5N1 outbreaks
The genetic solution designed to enhance broad-based disease resistance in dairy cattle by identifying bulls and cows with superior immune response
ROBUST HEALTH INDEX:
Objective:
Assess if Immunity+ genomic selection improves resilience to HPAI H5N1 in commercial dairy herds.
- Individual response to bacteria & viruses
Were 24% less likely to require treatment (Odds Ratio = 0.76; 95% CI: 0.64–0.90)
- Directly evaluates antibody-mediated and cell-mediated immune response
In a disease landscape where new threats can emerge rapidly and unpredictably, Immunity+ offers a proven tool to protect herd productivity, reduce economic risk, and build more resilient dairy systems.
- Genetic health data from CDCB and Lactanet
THE DATA IS IN
Lost ~295 lbs less milk post-treatment (1068 lbs vs. 1363 lbs)
CONCLUSION
STUDY CONTEXT
METHODS
15,386 cows from 6 U.S. dairy herds with confirmed HPAI outbreaks.
KEY RESULTS
CONCLUSION
METHODS
Genetic selection for immune response:
GENETIC SELECTION FOR IMMUNE RESPONSE:
ANALYZED:
REDUCES treatment needs
Emerging threat: HPAI H5N1 has spilled over into dairy cattle, threatening herd health and milk production in North America.
Likelihood of needing supportive treatment
LIMITS production loss
Milk loss and milk fluctuation duration after treatment
15,386 cows from 6 U.S. dairy herds with confirmed HPAI outbreaks.
High Immune Response Cows:
ANALYZED:
STRENGTHENS economic resilience during outbreaks
Objective:
References
Likelihood of needing supportive treatment
COMPARED HIGH, AVERAGE, AND LOW IMMUNITY+® GEBV COWS.
Were 24% less likely to require treatment (Odds Ratio = 0.76; 95% CI: 0.64–0.90)
Immunity+® cows have lower reduced milk loss during
Assess if Immunity+® genomic selection improves resilience to HPAI H5N1 in commercial dairy herds.
Milk loss and milk fluctuation duration after treatment
Beard, S.C., M.E. Carson, B. Mallard, M.Lohuis, and F. Malchiodi. 2025. High immune responder cows have lower treatment risk and reduced milk loss during highly pathogenic avian influenza H5N1 outbreaks. JDS Communications. Article in Press. https://doi.org/10.3168/ jdsc.2025-0869.
COMPARED HIGH, AVERAGE, AND LOW IMMUNITY GEBV COWS.
Cartwright, S. L., L. R. Schaeffer, E. B. Burnside, and B. A. Mallard. 2012. Adaptive immune response, survival, and somatic cell score between postpartum Holstein and Norwegian Red × Holstein first-calf heifers. J. Anim. Sci. 90:2970–2978. https://dx.doi.org/10.2527/jas.20114233.
Caserta, L.C., E.A. Frye, S.L. Butt, M. Laverack, M. Nooruzzaman, L.M. Covaleda, A.C. Thompson, M.P. Koscielny, B. Cronk, A. Johnson, K. Kleinhenz, E.E. Edwards, G. Gomez, G. Hitchener, M. Martins, D.R. Kapczynski, D.L. Suarez, E.R. Alexander Morris, T. Hensley, J.S. Beeby, M. Lejeune, A.K. Swinford, F. Elvinger, K.M. Dimitrov, and D.G. Diel. 2024. Spillover of highly pathogenic avian influenza H5N1 virus to dairy cattle. Nature 634:669–676. https://dx.doi.org/10.1038/ s41586-024-07849-4.
Larmer, S. G., and B. A. Mallard. 2017. High immune response sires reduce disease incidence in North American large commercial dairy populations. Cattle Pract. 25:74–81.
Lost ~134 kg less milk post-treatment (484.46 kg vs. 618.10 kg)
REDUCES treatment needs LIMITS production loss STRENGTHENS economic resilience during outbreaks
15,386 Cows
Peña-Mosca, F., E.A. Frye, M.J. MacLachlan, A.R. Rebelo, P.S.B. de Oliveira, M. Nooruzzaman, M.P. Koscielny, M. Zurakowski, Z.R. Lieberman, W.M. Leone, F. Elvinger, D.V. Nydam, and D.G. Diel. 2025. The impact of highly pathogenic avian influenza H5N1 virus infection on dairy cows. Nat. Commun. 16: 6520. https://doi.org/10.1038/s41467-025-61553-z.
24% HIR cows
Rodriguez, Z., C. Picasso-Risso, A. O’Connor, and P.L. Ruegg. 2024. Hot topic: Epidemiological and clinical aspects of highly pathogenic avian influenza H5N1 in dairy cattle. JDS Communications 5:S8–S12. https://dx.doi.org/10.3168/jdsc.2024-0650. Thompson-Crispi, K. A., F. Miglior, and B. A. Mallard. 2013. Incidence rates of clinical mastitis among Canadian Holsteins classified as high, average, or low immune responders. Clin. Vaccine Immunol. 20:106–112. https://dx.doi.org/10.1128/CVI.00494-12.
USDA-APHIS. 2025. HPAI confirmed cases in livestock herds. https://www.aphis.usda.gov/ livestock-poultry-disease/avian/avian-influenza/hpai-detections/hpai-confirmed-caseslivestock.
THERE’S ONLY ONE HEALTH INDEX THAT MATTERS.
Immunity+® gives you what you’ve been looking for - A genetic solution to herd health.
$950 est
Wagter, L. C., B. A. Mallard, B. n. Wilkie, K. E. Leslie, P. J. Boettcher, and J. C. M. Dekkers. 2000. A quantitative approach to classifying Holstein cows based on antibody responsiveness and its relationship to peripartum mastitis occurrence. J. Dairy Sci. 83:488–498. https://dx.doi. org/10.3168/jds.S0022-0302(00)74908-3.
BIRD FLU
BIRD FLU
HIR cows were 24% less likely to need treatment than low HIR cows
HIR cows were 24% less likely to need treatment than low HIR cows
Using Immunity+® sires can lead to HIGHLY HERITABLE
Using Immunity+® sires can lead to
29 REDUCTION IN DISEASE
Daughter of Immunity+ Bull
LESS DISEASE 29 REDUCTION IN DISEASE
VACCINE RESPONSE
High immune genomic females have 33% LESS DISEASE
High immune cows respond better to commercial vaccines High immune genomic females
VACCINE RESPONSE
Immunity+ Daughters Have
HIGHER QUALITY COLOSTRUM
High immune cows respond better to commercial vaccines
Through first 6 weeks of lactation High immune cows have significantly more total
Through first 6 weeks of lactation High immune cows have significantly more total
Fleming et al 2014.
in colostrum Fleming et al 2014.
ECONOMIC IMPACT
+$147 USD* Daughter benefit for Immunity+ bull or $23 USD* per point of Immunity Index
ECONOMIC IMPACT
+$33 USD* per point of Immunity Index for genomic tested female *compared to herdmates
+$147 USD* Daughter benefit for Immunity+ bull or $23 USD* per point Immunity Index
+$33 USD* per point of Immunity Index for genomic tested female *compared to herdmates
INDEX - STUD CODE ORDER
0196HO59405 CONTIGO 18
0200HO10845 FUEL 26
0200HO10992 SIDEKICK ..................... 58
0200HO11586 EINSTEIN 22
0200HO11822 ALLEYOOP 12
0200HO12049 TONKA 61
0200HO12123 MONTEVERDI ..............44
0200HO12145 EVENT 23
0200HO12156 EARLYBIRD 21
0200HO12158 MIDMARCH 42
0200HO12178 ELEVATOR-P *RC ....... 23
0200HO12220 STEINBECK 59
0200HO12222 HOLYSMOKES 34
0200HO12275 BALLGAME 14
0200HO12276 ROZTAC 57
0200HO12331 ADIDAS 12
0200HO12343 NOVELTY 46
0200HO12355 ZUMBA 65
0200HO12363 MAASTRICHT 41
0200HO12374 CLARO 18
0200HO12376 BULLSEYE 16
0200HO12393 HAMPSHIRE 27
0200HO12399 DROPBOX 20
0200HO12456 MISTER 44
0200HO12458 TOTAL 61
0200HO12489 POWERSTAR 53
0200HO12528 OUT-THERE 47
0200HO12529 HAVENOFEAR 29
0200HO12546 PERKY 50
0200HO12580 AMBROSE *RC 12
0200HO12667 CONNOR 18
0200HO12669 THRILLER 60
0200HO12699 PARBO *RC 48
0200HO12700 HICCUP-RED 32
0200HO12736 PROACTIVE 54
0200HO12737 PROTECTOR 55
0200HO12751 HANSEL 28
0200HO12753 DREW 20
0200HO12759 OVERTIME 47
0200HO12764 POLISHED 52
0200HO12772 LIFESAVER 40
0200HO12782 TIDEWATER 61
0200HO12784 RELOCATE-P 56
0200HO12805 HABIT 26
0200HO12811 HOTS 36
0200HO12813 COOPERSTOWN 18
0200HO12825 PREFER 53
0200HO12828 MAISEN 41
0200HO12872 HI-NOTE 31
0200HO12873 HI-FIVE .........................30
0200HO12904 PARIFIC 49
0200HO12906 MARLEY 42
0200HO12909 PARX 49
0200HO12950 ARAGON ........................ 13
0200HO12953 ROADTRIP 56
0200HO12968 BULLDING 16
0200HO12971 ANEESH 13
0200HO12988 HI-POWER .................... 32
0200HO13005 HANIEL-P 28
0200HO13006 PARMENT 49
0200HO13015 PRECEDENT 53
0200HO13018 MANKIND ...................... 41
0200HO13021 MORNINGSTAR 45
0200HO13023 VIOLIN 63
0200HO13032 LARIZIO 39
0200HO13040 EFFECTIVE .................... 21
0200HO13045 CAMRY 17
0200HO13054 CARTEL 17
0200HO13062 SUGARBOY 59
0200HO13063 FAITHFUL 24
0200HO13086 PROMISSORY 54
0200HO13090 DINABEAST 19
0200HO13091 BORN2BEWILD 16
0200HO13092 VANGELO 63
0200HO13095 HEAVENLY 29
0200HO13097 TORCHLIGHT 61
0200HO13099 POPEYE 52
0200HO13107 PERSIMMON 51
0200HO13114 CREED 19
0200HO13116 PARDEL 48
0200HO13117 HI-HOPES 31
0200HO13118 HI-LIGHT 31
0200HO13119 THADDEUS 60
0200HO13126 PROMOTER 54
0200HO13127 PECANPIE 50
0200HO13131 HOPS 35
0200HO13135 WATCHMAN 64
0200HO13139 SHAKE IT 57
0200HO13163 HOVERBOARD 36
0200HO13166 HIKEHOME 33
0200HO13168 PEVEL-P 51
0200HO13170 JUNCTION 38
0200HO13172 JIPSON 37
0200HO13173 BORDERS 15
0200HO13176 HI-PACE 32
0200HO13182 PRESTON 53
0200HO13189 PALATIAL 48
0200HO13192 MEEKO 42
0200HO13201 FRIDAY 25
0200HO13203 PRONZE-RED 55
0200HO13228 PERKY MAN 51
0200HO13231 HARQUE 28
0200HO13233 MR DEEDS 45
0200HO13237 REBELLION 55
0200HO13238 PETERSON .................... 51
0200HO13246 ELDON-P 22
0200HO13252 PROSECCO 55
0200HO13258 UNLEASH-PP 62
0200HO13269 MINESWEEPER............44
0200HO13274 SHELTON 58
0200HO13279 EXPLORER 24
0200HO13280 SUGARHILL 59
0200HO13281 HI-HORSE ..................... 31
0200HO13284 LYRICS 41
0200HO13287 HEARTMAKER 29
0200HO13299 HANDCRAFT-RED 27
0200HO13303 HOBNOB ...................... 34
0200HO13304 PENNE 50
0200HO13305 HOLZER-PP *RC 34
0200HO13306 PASHION 49
0200HO13311 ZARNET- RED ..............64
0200HO13313 FICTION 24
0200HO13321 AUBURN-RED 14
0200HO13326 MONKEY 44
0200HO13330 BURPEE *RC 17
0200HO13338 VERACRUZ 63
0200HO13344 KOMET 39
0200HO13346 DODGEBALL 19
0200HO13347 ZYDECO 65
0200HO13356 MINDFUL-P 43
0200HO13362 KOLE 39
0200HO13365 EMOJI-RED 23
0200HO13369 OBERON 47
0200HO13380 KENZO 38
0200HO13383 DUNE 20
0200HO13395 ARTORIUS 14
0200HO13405 KYLIAN 39
0200HO13408 APPLAUSE-PP 13
0200HO13427 LINUS 40
0200HO13439 HOOTY-PP 35
0200HO13442 RINGOSTAR 56
0200HO13463 HUMPY-PP 36
0200HO13464 MEGAMILK 42
0200HO13467 WINDSOR-PP 64
0200HO13474 DREAMER 20
0200HO13484 NATURALIST 46
0200HO13485 MINESTRONE 43
0200HO13486 PIERRE *RC 52
0200HO13497 NOAH 46
0200HO13499 HONDO 35
0200HO13505 FOOTBALL 25
0200HO13509 RIGHT 56
0200HO13510 UPL 62
0200HO13519 SHEAMUS-P 58
0200HO13531 HEART2HEART 29
0200HO13533 BOOGIEDANCE 15
0200HO13544 SWERVE 60
0200HO13550 HI-END 30
0200HO13554 SWANSON-RED 59
0200HO13558 NADAL .......................... 45
0200HO13569 DUPLEX 21
0200HO13573 HALVIN 27
0200HO13574 HALBRAN 27
0200HO13580 HOSPITALITY .............. 36
0200HO13586 HINTE 33
0200HO13590 ORKIN 47
0200HO13594 JETT 37
0200HO13597 FITZGERALD ................ 25
0200HO13606 ZION 64
0200HO13608 SERENGETI-P-RED 57
0200HO13640 HEYMAN 30
0200HO13641 HOORAY ....................... 35
0744HO00203 JUDGE 38
0744HO00207 VICTORY 63
0744HO00208 HIJACK-P *RC 33
0777HO03913 UNIX ............................. 62
0777HO11000 ALCOVE 12
0777HO12321 PATTERN 50
0777HO12457 MILLBAY 43
0777HO12688 MIKLOS 43
0777HO12726 ANAHITA 13
UR GUS{0}-P
15,386 Cows studied from six US herds
24% HIR cows less likely to require treatment
$950 est cost/clinical care
Using Immunity+ is your best choice to naturally strengthen your herd against bird flu and everyday diseases.
Ϙ A robust health index with CDCB, Lactanet, Zoetis1, Semex data, and the bull’s response to bacteria and viruses
Ϙ IM+ cows have 30% less mastitis than herd mates
Ϙ High-reliability, permanent genetic solution
1 Zoetis information is male only
Ϙ Cumulates like milk, fat & other traits with each generation
Ϙ Female genomic results & herd rankings with Elevate®
Ϙ A decade of proven on-farm results
