Stronger Cows. Healthier Herds. More Profit.
Backed by over 25 years of research at the University of Guelph, Immunity Technology is a world-leading genetic solution that helps you breed cows with naturally stronger immune systems.

  • Healthier cows with fewer cases of mastitis, metritis, and respiratory disease
  • Lower vet and treatment costs
  • Improved fertility and longevity, keeping cows in your herd longer
  • More profit, with gains that build every generation
    By monitoring immunity in your herd, you’re not just treating disease — you’re preventing it.

  • MASTITIS

    Immunity+® & Mastitis
    Mastitis is the most economically costly disease in dairy production worldwide. It affects milk yield, quality, cow longevity, and farm labor — with both clinical (visible symptoms) and subclinical (no visible signs, but high somatic cell count) forms.

    Estimated Cost of Mastitis/Case:
    Clinical Mastitis: $150–$400+
    Subclinical Mastitis: $60–$200+

    Subclinical mastitis is more common, persistent, and harder to detect — making it a major hidden cost.

    How Immunity+ Helps Fight Mastitis
    • Stronger Initial Immune Defense
      • HIR cows are better at recognizing and responding to invading bacteria in the udder. This means:
        • Faster recruitment of immune cells to the site of infection
        • Quicker containment of bacterial spread
        • Lower severity of symptoms
      • In studies, HIR cows showed fewer infections and lower SCCs than low responders when challenged with mastitis pathogens.
    • Better Regulation of Inflammation
      • Mastitis can cause excessive inflammation that damages milk-producing tissue.
      • HIR cows have more controlled inflammatory responses, which:
        • Limits tissue damage
        • Promotes faster recovery
        • Helps maintain milk yield
    • Lower Somatic Cell Count (SCC)
      • High SCC is a key indicator of mastitis.
      • Cows sired by Immunity+ bulls consistently show:
        • Lower average SCC
        • Fewer SCC spikes during lactation
        • Longer productive life due to reduced udder issues
    • Herds using Immunity+ sires have reported fewer clinical mastitis cases and less bulk tank SCC penalties.
    • Long-Term Genetic Resistance
      • Immunity+ is a heritable trait — it builds resistance from generation to generation.
      • Over time, herds improve their natural resistance to mastitis, reducing:
        • Treatment costs
        • Milk loss
        • Culling due to chronic infections
    • Reduced Antibiotic Use
      • With fewer infections and better recovery, Immunity+ cows require:
        • Fewer antibiotic treatments
        • Shorter withdrawal periods
        • Better fit for antimicrobial stewardship programs

    Summary: Semex’s Immunity+ helps fight mastitis by selecting cows with genetically superior immune systems that are better able to prevent, control, and recover from udder infections — especially during high-risk periods like early lactation.

    While Immunity+ is not a treatment or vaccine, it offers a genetic solution to reducing mastitis risk over the long term. Cows with a high immune response (HIR) are less likely to develop mastitis, and if they do, they typically experience milder cases, faster recovery, and lower somatic cell counts (SCC).

    FIND OUT MORE
  • High Immune Responder Cows Have Lower Treatment Risk And Reduced Milk Loss During Highly Pathogenic Avian Influenza H5N1 Outbreaks

  • Genetic Selection Of Cattle For Improved Immunity And Health

  • Immune Competence In Livestock

  • Genetic Selection Of Cattle For Improved Immunity And Health

  • Variation Of Lactoferrin And Total Immunoglobulin G Concentrations In Colostrum From Canadian Holstein Dairy Cattle Classified As High, Average Or Low Immune Responders

  • Genetic And Epigenetic Regulation Of The Bovine Immune System: Practical Implications Of The High Immune Response Technology

  • Genetic Regulation Of The Bovine Immune System And The Practical Application Of The High Immune Response Technology In Dairy Health Management

  • The Use Of High Immune Response Bulls In A Herd

  • A Genome-wide Association Study Of Immune Response In Holstein Bulls

  • Genetic And Epigenetic Effects On Bovine Immune Responses And Their Implications To Dairy Health

  • Genetic Selection Of Cattle For Improved Immunity And Health

  • The Association Between Sire Estimated Breeding Value For Antibody-Mediated Immune Response (AMIR) And Offspring AMIR Phenotype

  • Identifying Healthier Herds

  • Immunity+ Frequently Asked Questions - Version 1

  • Immunity+ Frequently Asked Questions - Version 2

  • Immunity+ Evidence Growing

  • The 3000 Cow High Immune Response (HIR) Genomics Project

  • Immunity+ And SCS

  • Prevalence Of Digital Dermatitis In Canadian Dairy Cattle Classified As High, Average Of Low Antibody And Cell-Mediated Immune Responders

  • Breeding Cows With Superior Immune Response

  • Profiting From Genetic Disease Resistance

  • History Of Innovation

  • Immunity+ - What's Known So Far

  • Genetic Selection For Immunity

  • Breeding Your Cows For High Immune Response Can Result In A Herd Less Prone To Mastitis

  • Dairy Farmers Have A New Tool To Help Them Build A Healthier Herd

  • We Can Now Find The Best Immune Systems

  • Genetic And Epigenetic Regulation Of Immune Response And Resistance To Infectious Diseases In Domestic Ruminants

  • A Genome-Wide Association Study For Natural Antibodies Measured In Blood Of Canadian Holstein Cows

  • Variation Of Total Immunoglobulin G And β-Lactoglobulin Concentrations In Colostrum And Milk From Canadian Holsteins Classified As High, Average, Or Low Immune Responders

  • High Immune Response Sires Reduce Disease Incidence In North American Large Commercial Dairy Populations

  • Genetic Selection Of Cattle For Improved Immunity And Health

  • Association Of Disease Incidence And Adaptive Immune Response In Holstein Dairy Cows

  • Genetic Parameters Of Adaptive Immune Response Traits In Canadian Holsteins

  • Variation In Production Parameters Among Canadian Holstein Cows Classified As High, Average, And Low Immune Responders

  • A Genome-wide Association Study Of Immune Response Traits In Canadian Holstein Cattle

  • Bovine Mastitis: Frontiers In Immunogenetics

  • Incidence Rates Of Clinical Mastitis Among Canadian Holsteins Classified As High, Average, Or Low Immune Responders

  • Genetic Parameters For Natural Antibodies And Associations With Specific Antibody And Mastitis In Canadian Holsteins

  • A Quantitative Approach To Classifying Holstein Cows Based On Antibody Responsiveness And Its Relationship To Peripartum Mastitis Occurrence

  • The Relationship Between Milk Production And Antibody Response To Ovalbumin During The Peripartum Period


  • DISEASES
    BIRD FLU – H5N1
    BOVINE LEUKOSIS
    BOVINE TUBERCULOSIS
    CALF DIARRHEA/SCOURS
    DIGITAL DERMATITIS
    DISPLACED ABOMASUM
    ENDOMETRITIS/METRITIS
    INTERDIGITAL HYPERPLASIA
    JOHNE'S DISEASE
    KETOSIS
    MASTITIS
    PNEUMONIA
    RETAINED PLACENTA

    IMMUNITY TECHNOLOGY
    Only from Semex Elevate® and Neogen®