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Mastitis. Simon Kenyon. Udder anatomy. Udder anatomy. Allometric Growth. Economic Impact. 40% of morbidity on dairy farms Most costly cattle disease in the US Estimated cost to the industry greater than 2 billion dollars/yr Estimated to cost $200-300/cow For herd-based worksheet:
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Mastitis Simon Kenyon
Economic Impact • 40% of morbidity on dairy farms • Most costly cattle disease in the US • Estimated cost to the industry greater than 2 billion dollars/yr • Estimated to cost $200-300/cow • For herd-based worksheet: • http://www.uwex.edu/milkquality/Economics/finimpmq.html
Mastitis Classification • Mastitis caused by a wide variety of microbial agents • Classified as: • Clinical • Subclinical • Also classified as: • Contagious • Environmental
Subclinical mastitis • No visible changes in the milk • Elevated somatic cell counts • Normal milk has less than 200,000 SCC/ml • Most common form of mastitis • National Mastitis Council estimate: • 15-40 cases of subclinical mastitis for every 1 case of clinical mastitis
Economic Impact • 70% of loss due to decreased production • Remaining losses due to: • Lost premiums • Treatment costs • Discarded milk • Death/Culling • Veterinary expenses • Cost of violative antibiotic residues
Contagious Strep. agalactiae Staph. aureus Corynebacterium bovis Mycoplasma Environmental Environmental Streps Strep uberis Strep. dysgalactiae Coliforms E.coli Klebsiella Contagious vs Environmental
Contagious Transmitted during milking Control Parlor hygiene Machine function Post-dip Dry cow Rx Environmental Transmitted in the environment or during milking Control Cow environment Udder prep. Health of teat end Dry cow Rx Contagious vs Environmental
Pulsation System Graph 0.6 sec 0.4 sec
Contagious Mastitis • Spread from cow to cow. • Bacteria must live in udder tissue or on skin • Organisms are transferred during the milking process • Major impact is as cause of subclinical mastitis
Environmental Mastitis • Organisms spread from environment to cow • Spread may occur between milkings or during milking • Include some of the common causes of clinical mastitis as well as subclinical infections
Teat ends • Vacuum level • Liner tension • Liner condition • Overmilking Response to mechanical stress or irritation of the teat end is hyperkeratosis
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Risk factors for hyperkeratosis • Long pointed teats • Slow milking • High producing cows • Stage of lactation • Parity • Weather conditions • Chemical irritation • Cluster removal time Mein et al. 2001
Recommendations • Particular attention to cleaning teat ends • D (massage) phase at least 250 ms • Cluster removal when milk flow reaches 1 lb/min • Teat skin in good condition • Follow recommendations: • Vacuum levels • Liner bore • Liner length and tension • Liner replacement schedules
Hyperkeratosis and Disinfection Hyperkeratosis Score Ave. SCC Significance Treatment Gleeson et al. 2004
Risk of New Infections Environmental Streps Contagious mastitis Coliforms Str. uberis Str. dysgalactiae Dry Milking Calving
Mastitis Diagnosis • Physical examination • DHIA reports/SCC reports • Strip Cup • CMT • Milk conductivity • Bacterial culture • On farm observation
Clinical Mastitis • M1 - Changes in the milk (Clots, flakes, clumps, or discoloration) • M2 – Changes in the milk + udder swelling, heat or pain • M3 – Changes in the milk + udder changes + systemic illness
Mastitis Treatment • Treat clinicals during lactation • Treat subclinicals at dry off • Dry treat every quarter of every cow • Coliform infections – supportive therapy +/- antibiotics • ALWAYS CORRECT THE MANAGEMENT FLAW