milk quality Flashcards
What is the role of the farm vet in milk quality
Promote and ensure cow cleanliness (environment)
Review and monitor
milking routines
Monitor and investigate Bactoscan/Total Bacterial Count (TBC)
Investigate antibiotic failures/review testing systems
What are the sources of bacteria in raw milk
It is important to minimise excessive bacterial contamination of the cows and their udders and teats from the living environment before cows are presented to the milking parlour for milk harvesting
Describe factors in the cows environment as a source of bacteria and how to minimise them
Contamination from pastured environment:
- Minimise poaching of ground & soiling of cow’s feet/legs at gateways & around water troughs by using bark or wood chip
- Rotate access points to fields when cows are grazing
Contamination from house environment:
- Availability of “living space” for cows that are housed is important to reduce soiling & contamination from faeces
- e.g., access to outside yards that are regularly scraped
- Vets should calculate available “living space” for housed cows & advise on importance of space (at least 3sq m)
Contamination from cubicle bedding:
- Comparing bedding materials for cows is difficult due to different management practices between farms
Water quality:
- Only potable water must be used in parlour,
- If non-mains water is used, producers are advised to use UV treatment at source,
- Storage of water can be an issue if header tanks become contaminated
How can environmental bacterial contamination be reduced before we harvest the cow’s milk?
We may improve hygiene at pasture and/or hygiene at housing…
…and optimise teat preparation immediately before we milk the cow
Describe mastitis infections as a source of bacteria in raw milk
Avoid mastitic milk being included in the tank
Describe teat preparation routine
Start with a clean, dry teat that has been disinfected
options:
- Dry wipe only
- Washing & drying with cloths
- Pre-spray/pre-dip and dry
- Medicated wipes (e.g., chlorhexidine)
- Motorised teat scrubbing brushes
Pre-milking teat disinfection and wipe dry is associated with a significant reduction in Streptococcus spp. and Enterococcus spp. counts in bulk milk
what is total bacteria count vs Bactoscan
A Total Bacterial Count (TBC) of 5000 cfu/ml would equate to a Bactoscan of around 30,000 impulses/ml
What is the approach to an increased Bactoscan?
Consider the obvious - teat preparation, milking machine wash up (strip down plant, bulk tank)
Clinical mastitis detection?
Bulk tank bacteriology:
- collect a sample
- Can give indication of likely source of problem
- Must be done by specialist laboratory, easy to misinterpret
- “Qualitative” (which organisms are present)
- “Quantitative” (how many organisms are present)
Analyse this bulk tank report
Write a checklist for increased Bactoscan
Sporadic increases in Bactoscan or always increased?
Collect a bulk milk sample, send chilled to an independent specialist laboratory for analysis of differential counts and a direct plating
Review clinical mastitis detection (differential counts are low but heavy growth of bacteria such as Streptococcus spp.)
Review environment management and pre-milking teat preparation (increased coliform count)
Review water quality in parlour (psychrotrophic count)
Review machine wash up (thermoduric count)
Review bulk tank cleaning (psychrotrophic count)
Fill in the table with liquid milk hazards
