Mastitis Prevention and Treatment: Reducing Somatic Cell Counts in Dairy Herds

# Mastitis Prevention and Treatment: Reducing Somatic Cell Counts in Dairy Herds Mastitis represents the costliest disease affecting dairy operations through reduced milk production, discarded milk, treatment costs, and premature culling. Effective prevention and treatment protocols significantly improve profitability and animal welfare. ## Understanding Mastitis Economics Subclinical mastitis costs dairy operations $100-$300 per case annually through reduced production and milk quality penalties. Clinical cases cost $200-$400 each including treatment, discarded milk, and production losses. Severe cases requiring culling cost $1,000-$2,000 in replacement expenses and lost production. Bulk tank somatic cell counts above 200,000 trigger milk quality premiums in many markets. Count increases from 150,000 to 300,000 typically cost $0.30-$1.00 per hundredweight, translating to $6,000-$20,000 annually for 200-cow dairies shipping 4-5 million pounds yearly. ## Prevention Strategies Pre-milking teat preparation significantly impacts new infection rates. Effective protocols include predipping with approved teat disinfectant, 30-second contact time, thorough drying with individual towels, and forestripping to remove contaminated first milk. Post-milking teat dipping provides primary defense against contagious pathogen spread. Complete coverage of entire teat surface immediately after unit removal prevents bacterial invasion through open teat canals. Iodine-based, chlorhexidine, and barrier dips all demonstrate effectiveness when properly applied. Milking equipment maintenance prevents liner-related infections and cross-contamination between cows. Replace inflations every 1,200-2,000 cow milkings or 6-12 months. Test vacuum levels, pulsation rates, and system cleaning effectiveness quarterly. Address any equipment deficiencies immediately as delayed repairs multiply infection rates. Environmental hygiene controls exposure to coliform and environmental streptococci bacteria. Maintain dry, clean bedding in stalls and calving areas. Properly size and maintain ventilation systems preventing excessive moisture. Scrape alleys frequently removing manure buildup. ## Monitoring and Detection Somatic cell count testing identifies problem cows requiring treatment or enhanced monitoring. Individual cow linear scores above 4.0 (equivalent to 200,000 cells/mL) warrant investigation. Elevated counts on consecutive tests indicate chronic infection requiring aggressive intervention. California Mastitis Test (CMT) provides cow-side rapid screening. Scores of 2 or 3 indicate elevated cell counts justifying follow-up culture or treatment. Monthly testing of high-producing cows catches subclinical cases before significant production losses. Milk culture identifies causative bacteria guiding treatment decisions. Culture high-SCC cows, clinical cases before treatment, and non-responders after therapy. Submit samples to qualified laboratories using proper sterile collection technique. Results determine appropriate antibiotics and prognosis. ## Treatment Protocols Intramammary antibiotic tubes provide primary treatment for most bacterial mastitis cases. Select products based on culture results when available or use broad-spectrum antibiotics for empirical therapy. Follow label dosing instructions precisely and complete full treatment courses. Treatment success rates vary significantly by pathogen type. Streptococcus agalactiae responds favorably with 80-90% cure rates. Staphylococcus aureus proves difficult to cure with success rates only 30-50%. Environmental coliforms often self-cure but benefit from supportive therapy. Systemic antibiotics supplement local treatment in severe cases showing systemic signs like fever, depression, or decreased rumen fill. Combine intramammary and systemic therapy for deep-seated chronic infections. Monitor severely affected cows closely for deterioration requiring additional intervention. ## Dry Cow Therapy Blanket dry cow treatment using long-acting intramammary antibiotics cures existing infections and prevents new infections during dry period. Infuse all quarters of all cows at drying off for maximum benefit in chronically high-SCC herds. Selective dry cow therapy treats only infected cows based on SCC history, conserving antibiotics while maintaining mastitis control. Requires accurate identification of infected cows through systematic testing programs. Best suited for well-managed herds with bulk tank SCC below 150,000. Internal teat sealants provide physical barrier against bacterial invasion during dry period. Use alone in uninfected low-SCC cows or combine with antibiotics for infected animals. Substantially reduces new infection rates particularly for environmental pathogens. ## Chronic High-SCC Cow Management Cows failing to respond to treatment after two therapy attempts rarely cure and should be segregated or culled. Chronic shedders continuously expose herdmates to contagious pathogens despite not showing clinical signs themselves. Milking chronically infected cows last reduces spread to healthy animals. Dedicate separate inflation sets or thoroughly sanitize equipment between groups. Consider automatic takeoff delays preventing overmilking that damages teat ends. Evaluate replacement economics for chronic high-SCC cows. Animals with SCC consistently above 500,000 typically cost more in lost production and milk quality penalties than replacement expenses. Cull before negatively impacting bulk tank prices. ## Troubleshooting Persistent SCC Problems Persistent bulk tank SCC elevation despite individual cow management indicates environmental or equipment issues. Review bedding management, stocking density, ventilation, and cow comfort. Often multiple factors combine causing problems. Equipment evaluation should include milking system performance testing by qualified technicians. Vacuum fluctuations, liner slip, or inadequate pulsation cause teat end damage predisposing to infection. Don't overlook parlor design problems like poor cow positioning or rushed milking routines. Culture bulk tank milk to identify predominant pathogen types. Contagious pathogen predominance indicates inadequate milking hygiene or infected cow identification. Environmental pathogen predominance points toward bedding or housing issues. ## New Technologies Automated mastitis detection systems using conductivity, color, or composition analysis alert to clinical cases earlier than visual detection. Reduced treatment delays improve cure rates and minimize production losses. Investment justified in herds experiencing frequent clinical mastitis. Culture-based treatment decision systems guide therapy using rapid on-farm culture results. Treat gram-positive cases with appropriate antibiotics while withholding antibiotics from gram-negative self-limiting infections. Reduces antibiotic use 30-50% while maintaining or improving cure rates. Precision application methods like targeted dry cow therapy based on individual quarter infection status and SCC history optimize antibiotic use. Requires systematic testing and record analysis but substantially reduces treatment costs while maintaining udder health. ## Record Keeping and Analysis Track treatment records, SCC results, and clinical case incidence monthly. Calculate new infection rate, cure rate, and chronic infection prevalence. These metrics guide protocol adjustments and identify emerging problems early. Benchmark performance against industry standards. New infection rates should stay below 5% monthly. Clinical mastitis incidence should remain under 2% monthly in well-managed herds. Bulk tank SCC below 150,000 indicates effective overall mastitis control.