The mastitis situation in Canada where do you stand? Richard Olde Riekerink and Herman Barkema 1 Québec City December 11, 2007
Mastitis Most expensive disease on a dairy farm discarded milk, treatment, Antibiotic residues Quality shelf life cheese making qualities Animal welfare 2
Mastitis pathogens Contagious Strep. agalactiae Staph. aureus Mycoplasma spp. Strep. dysgalactiae Environmental E. coli Klebsiella spp. Strep. uberis Not clear cut Environmental E. coli Strep. uberis Strep. dysgalactiae Contagious Strep. agalactiae 3
Clinical mastitis Abnormal milk / udder Incidence rate > numerous studies worldwide Distribution different among countries / regions 4
Subclinical mastitis No clinical signs Somatic Cell Count (SCC) indicator Fast and cheap indicator for IMI 5
Monitoring tool Milk quality Bacteria Subclinical mastitis Cheap Convenient Bulk tank milk 6
Mastitis control 5-point plan (Neave et al., 1969) focused on contagious pathogens proper milking technique and well functioning milking machine treatment clinical cases whole herd dry cow treatment post-milking teat disinfection culling chronically infected cows 10-point recommended control program (NMC) also environmental pathogens 7
Current situation in Canada Incidence of clinical mastitis British Columbia (van Dorp et al., 1999) Ontario (Sargeant et al., 1998; McLaren et al., 2006) Herd prevalence contagious pathogens Mycoplasma (Ruhnke et al., 1976) Staph. aureus (Kelton et al.,1999) Strep. agalactiae (Keefe et al., 1997) 8
Canadian Bovine Mastitis Research Network Founded 2001 Mobilize national and international scientific and financial resources to decrease the incidence of mastitis, reduce financial losses, and maintain milk quality through concerted research, and effective and rapid transfer to end-users 9 www.mastitisnetwork.org
Objectives To determine in Canada: Overall and pathogen-specific IRCM Risk factors associated with IRCM Adoption of mastitis prevention management practices Herd-level prevalence of contagious pathogens and associated risk factors 10
Specific objectives (#1) To determine: Incidence of clinical mastitis (IRCM) on Canadian dairy farms Regional and pathogen-specific IRCM Association of pathogen-specific IRCM with bulk milk SCC and barn type 11 R.G.M. Olde Riekerink, H.W. Barkema, D.F. Kelton, D.T. Scholl. 2007. Incidence Rate of Clinical Mastitis on Canadian Dairy Farms. J. Dairy Sci. submitted.
Sample collection & laboratory 116 Herds in 10 provinces All clinical mastitis abnormal milk and / or abnormal udder Min. 1 year collection Vets and CQMP coordinators Courier to Atlantic Vet College 12
Results 101 herds completed questionnaire free-stalls tie-stalls herd-size 106 (23 649) 3,033 cultures Mean herd IRCM = 23 cases / 100 cow-years Median IRCM = 16.7, range 0.3 97 Different among provinces 13
Distribution of pathogens n = 3,033 Staph. aureus 11% E. coli 8% Strep. uberis 6% CNS 5% Culture-negative 43% Klebsiella spp. 4% Strep. dysgalactiae 4% Enterococcus spp. 2% 14 Contamination 8% Other 4% Streptococcus spp. 2% Yeast 2% A. pyogenes 1%
IRCM by BMSCC class Pathogen < 150 BMSCC 151 to 250 > 250 Staph. aureus 2.78 2.26 3.97 E. coli 1.97 1.92 0.71 Strep. uberis 1.83 1.06 2.02 Coag.-neg. staphylococci 1.11 1.18 0.99 Strep. dysgalactiae 0.63 0.97 1.08 Klebsiella spp. 0.47 0.83 0.40 Streptococcus spp. 1.03 0.81 0.36 Culture-negative 6.09 6.43 2.23 15 Overall IRCM 22.6 24.9 16.2
IRCM by region Pathogen Region Western provinces (n =31 ) Ontario (n =16 ) Québec (n =26 ) Atlantic provinces (n = 33) Staph. aureus 1.80 3.11 3.98 2.70 E. coli 1.37 3.02 1.53 1.36 Strep. uberis 0.76 2.06 1.60 2.00 CNS 0.90 1.59 1.69 0.70 Strep. dysgalactiae 0.27 1.43 1.69 0.66 Klebsiella spp. 1.01 0.85 0.27 0.53 Streptococcus spp. 0.39 0.66 1.20 0.92 Culture-negative 4.25 8.26 6.62 4.44 16 Overall IRCM 15.6 32.5 30.4 18.7
IRCM by barn type 17 Pathogen Staph. aureus E. coli Strep. uberis CNS Strep. dysgalactiae Klebsiella spp. Streptococcus spp. Culture-negative Overall IRCM Tie-stall (n = 43) 4.04 1.36 2.19 1.58 0.89 0.40 1.21 5.45 26.6 Barn type for lactating cows Free-stall (n= 39) 1.62 2.08 0.67 0.68 0.87 1.00 0.37 5.73 19.1 Other (n= 6) 1.62 1.27 2.65 0.74 1.34 0.28 0.56 4.32 19.5
Discussion Selected herds Veterinarians, vet. students, CQMP coordinators Compliance of producers Compliance of collectors 18
Specific objectives (#2) To determine: Risk factors associated with overall IRCM pathogen-specific IRCM 19
Same herds Questionnaire Study design Mail, phone, on-farm Tested, translated 10 categories 20
Associations with IRCM Dry cow therapy All, E. coli Strip All, S. aureus, S. dys., Culture-negative Soft stall base S. aureus Straw bedding S. uberis Long dry period E. coli 21
Conclusions Certain management practices associated with IRCM, e.g.: blanket dry cow treatment strip Producers attitude 22
Specific objectives (#3) To estimate: Adoption mastitis preventive management practices Herd-level prevalence of contagious pathogens Associations of certain management practices with being positive in the bulk tank for contagious mastitis pathogens 23
Random sample Study design stratified per province member of DHI 66% positive response = 291 farms 4 seasonal samples DHI data 2 questionnaires 24
Alberta Saskatchewan Manitoba Ontario Québec New Brunswick Prince Edward Island 25 100 80 60 40 20 British Columbia 0 Barn type per province Nova Scotia T ie-stalls Free-stalls Other Percentage (%)
Prevalence (n=282) Sample Stratified by province Staph. aureus 73% 74% Strep. agalactiae 1.8 % 4.7% (5 farms) Mycoplasma spp. 0 % 0 % 26
27 Staph. aureus per province 100 90 80 70 60 50 40 30 20 10 0 27 Prevalence (%) British Columbia Alberta Saskatchewan Manitoba Ontario Québec New Brunswick Prince Edward Island Nova Scotia
28 Bulk milk SCC per province Strep. ag 500 300 200 150 100 50 positive! Bulk milk SCC (x 1,000 cells/ml) British Columbia Alberta Saskatchewan Manitoba Ontario Québec New Brunswick Prince Edward Island Nova Scotia
Adoption management practices Management practice Tie stalls Free stalls All (%) Pre-milking teat disinfection 48 61 55 Post-milking teat disinfection 95 98 96 Blanket dry cow treatment 68 76 72 Computerised cow records 16 50 32 Milks mastitis cows last and/or with separate cluster 87 32 59 Wear latex gloves during milking 50 74 62 29
Staph. aureus - management Practice P Ration balanced 2x / yr 0.02 Feed company representative balances ration 0.03 Blanket dry cow treatment 0.03 Soft stall base (rubber or mattress) < 0.01 Milking equipment checked 1x / yr 0.02 30
Discussion & Conclusion Prevalence Staph. aureus as expected Strep. agalactiae low, seems trend Mycoplasma spp. no,...method? Management practices Certain practices associated with Staph. aureus 31
Summarizing IRCM 23 cases / 100 cow-years Differences among regions and barn types Staph. aureus and E. coli most frequently Staph. aureus on nearly all farms Strep. agalactiae nearly extinct 32
There is no excuse for a high bulk milk somatic cell count Analyse the situation and make a plan involving your vet and, if necessary, other specialists 33
How to approach this? Culture high SCC and clinical mastitis samples Know who the millionaires are If mostly contagious pathogens: prevent infection of the low SCC cows Reduce the number of high SCC cows 34
Prevention of new infections Milking order One cow per towel Post-milking teat dipping Blanket dry cow treatment Good nutrition 35
Reduction of old infections Culling of problem cows Don t breed chronic S. aureus cows Blanket dry cow treatment Treatment during lactation Check if heifers calve with a high SCC 36
Funding Dairy Farmers of Canada National Sciences and Engineering Research Council Canadian Bovine Mastitis Research Network Atlantic Veterinary College 37
38 Questions