Control of Mastitis Flashcards
1
Q
Two Categories of Mastitis
A
- Contagious
- Environmental
*Important to distinguish between these in terms of treatment and control- controlled quite differently
- bit of an oversimplification, but can be extremely useful
2
Q
Contagious:
5 point plan
(know each point)
A
- sometimes considered the 6 pt. plan as it can involve environmental disease
- 5pt. plan WILL bring a high SCC down as long as it is implimented correctly
- Need to treat clinical cases quickly
3
Q
Understanding National Milk Records
A
4
Q
Contagious
A
- often cause subclinical: no clinical signs (no swelling, heat, clots in the udder or infected quarter, but bacteria is just grumbling away there)
- LIVE in udder and under teat skin
- fast spreading, especially in the milking parlor!
- Go from cow to cow, udder to udder, quarter to quarter
5
Q
Main bacteria causing Contagious Mastitis (and like to live in the udder)
A
- S. agalactiae - is probably the most adapted to the udder and doesnt really live anywhere else
- S. dysgalactiae - variable in where it lives, tends to like to invade teat lesions. often invade abcesses or ulcers and keep reifecting the cow
- S. aureus–> particularly NASTY cause of mastitis, tends to be resistant to AB’s. very difficult. resistant, chronic, long lived
- S. uberis - will spread around cows as a contagious organism, however it often originally comes from the environment (crosses over from the contagious group to the env’tal) - associated with straw bedding, is then often spread around by the cows
6
Q
Minor Pathogens
(Contagious)
A
- Tend to cause infections but don’t cause problems - not normally pathogenic, but cannot say that for certain
- sometimes the presence of these bacteria in the udder may have a protective function! - low level infections stop the invasion of other bacteria
7
Q
Environmental
A
- Once they gain entry into the udder, 2 things can happen, either:
- They get eliminated quite quickly
- or they can cause really serious mastitis and the cow sometimes die
*This can happen with both categories, but we find the ones that hit these cows very hard often are envt’al mastitis
- will often have both in the herd often (contagious, env’tal)
- If the cows are infected during the dry period (time between last milking and next calving) - we can get env’tal organisms getting in the udder or the quarter at this time.
- they can persist and not get eliminated before calving and then can become an issue after calving and during lactation (if the effects if the envt’al mastitis is shown in early lactation- first 100 days- they were possibly acquired during the dry period)
- Need to make sure cows are in clean, sanitary housing during dry period especially! (very prone to infections that can cause problems later)
8
Q
Env’tal - Housing
A
- Housing design is very important in preventing, but also MILKING HYGIENE
- although we spread around contagious organisms at milking, we have env’tal bacteria on dirty udders/teats when milking –> can be forced into the quarter during milking time
- Make sure the cows teats aren’t dirty! - parlor preparation–> also impo. for contagious
- cubicle design- mastitis is just one of the important reasons to design the cubicle properly. dry cow housing is also important
- Make sure there is dry straw - check thoroughly for dirty, matted straw
9
Q
Cubicles
A
- check for space for them! - need to be able to lunge forward and not hurt herself to get up (needs space in front of her head)- if that space is not available, she is less likely going to want to lie down due to fear of hurting herself
- are they still standing after not being disturbed for a while? - If so, NOT GOOD
- have a barrier where they aren’t going too far forward
- overcrowding can lead to mastitis issues
10
Q
Main Env’tal Organisms causing mastitis
A
- E.Coli, S. uberis (mainly in straw bedding/straw yards), Klebsiella (seems to be in wood chips) and a variety of Coliform bacteria
- B. cereus tends to be associated with cows that live on brewers grains (seems to live in there)
- can very rarely see fungi and yeasts, they can be really nasty! - if you treat mastitis with AB’s for a long time, you can kill off bacteria for fungi and yeasts to then invade. tough to get rid of
11
Q
Somatic Cell Counts (SCC)
A
- Individual cell counts is referred to as ISCC
- Somatic Cells are NOT bacteria- people tend to get confused between SCC and bacterial count
- SCC: are on account of the number of inflammatory cells and epithelial cells in milk (2 types).
- epithelial cells -will always be there and there is a natural increase towards the end of lactation
- inflammatory cells- increase with inflammation
- When there is an infection, the number of SC’s is viable to go up as the inflammatory cells invade the udders
- A nice clean udder with no subclinical infection in it and no bacteria in it should have a count below 200,000 somatic cells/ml. Clinical infection can go sky high (millions of cells)
- SCC can be used in comparison with the Bacterioscans
12
Q
Subclinical Infection Levels
(in comparison to clinical)
A
- tends to go undetected for long periods
- causes a prolonged and mildly elevated SCC (about 200,000 cells/ml)
- TENDS to be contagious bacteria and spread at milking time
- many quarters are infected with high cell counts, but because it is only one quarter out of four, that is diluted down
- overall SCC count of that cow may not be as high as it could be because the bad quarter is diluted down by the others (for the average amount)
- COntagious organisms like to sit in the udder, live there, and grumble on
- env’tal tend to be in and get eliminated or do something terrible to the cow
13
Q
BMSCC
A
- We really want to keep the Bulk Milk Somatic Cell Count below 100k cell/ml
- If it goes about 150k, we should be seeing what can be done, start investigating
- Most farms will want to keep below 200k bc there is a financial penalty involved implimented by the dairy that buys the milk (where the penalty starts to kick in varies depending on the company)
- If above 400k consistently, the EU will deem it unsuitable for human consumption and you will lose your milking contract
14
Q
Control of the 2 types of mastitis
A
- Different in the ways they cause disease (epidemiology within the herd) so the way we control them is fundamentally different
15
Q
Contagious Control
A
- With contagious mastitis, we need to control spread
- Also need to eliminate resevoirs for infection: the infected quarters or the infected cows which are causing the problems
- Dry Cow therapy
- Culling
- Identify ones with high SC with subclinical infection
- Sometimes cows that are riddled from infection need to be culled to remove them from the herd
- can find by identifying cows with high cell counts
16
Q
Prompt Detection of Clinical Cases
(step 1 of 5 pt plan)
A
- By stripping out, we will be able to detect and cause some oxytocin release which will help the cow let her milk down and make her more comfortable - a bit more work, but if you foremilk, the milk will flow more rapidly and actually make the process quicker!
- fore milk: first bit of milk to come out, will have higher SCC -look for watery milk, clots and even check for pain in the quarter
- that first bit of milk stripped out has the highest amount of bacteria in it - get rid of it to help bacteria levels!
- during milking abcteria grows on the teat and goes up and invades the teat canals
- If we strip out all over the floor there could be splash contamination or other routes
17
Q
Cleaning and Hygiene
(5 pt plan)
A
- Should be cleaning each individually - dispose after each
- don’t want to contaminate udders this way
- easy fix for the problem could even be to rid of udder cloth
- regularly wash hands and change the gloves
- try not to use a lot of water to clean udder as it will just wash the surface bacteria onto the teat- very high bacterial water –> “magic water”
- Therefore, just clean the 4 teats - only part that comes in contact with the milking parlor - use dry paper towels to wipe muck off them
- Pre milking teat dip is very effective! -very rapidly acting to kill off bacteria
- Note: automated systems can be good in that they measure conductivity of the milk and make up for some bad technique that may occur by hand, but you do lose human ingervention and the conductivity of each cow’s milk when normal is different! (use baselines for each cow and then see if there are changes)
18
Q
- PMTD
(5 pt plan)
A
- put teat dip on the cow AFTER she has been milked
- good idea to keep cows feeding after to keep them standing after milking, rather than laying down in muck to allow teats to close (30-40 min)
- They will need a good source of water after milking due to fluid loss in parlor!
- Disinfectant which coats teat skin and kills bacteria (dip)
- Also can aid in maintaining teat skin in good condition (dip) - Often cows can get very chaffed as teat skin is very sensitive and is milked 2 or 3 times a day! doing this dip can keep them soft
- You can get sealants that act as a physical barrier as well, break off once you start milking- some work well and some don’t (can be very $$$, so look at the data for each)
19
Q
Ways to apply PMTD
A
- automatic exit system: they all get done as they leave the parlor
- be careful: make sure the coverage is getting around the whole teat!
- spray can be bad as it is going directly in the air (can affect staff)
- sealants and teat dips can be very useful, but also sometimes overrated
20
Q
3) Dry Cow Therapy
A
- way of controlling contagious mastitis mainly
- therapy to be applied to the quarter during the LAST milking before the cow is dried off (i.e. dry period before calving)
- 2 therapies we tend to use:
- Long Acting Antibiotics
- Teat Sealant
21
Q
Sealants for teats
(diff. to teat sealant)
A
echo
22
Q
DCT: Long Acting AB’s
A
- one of two DCT methods
- If cow has a grumbling subclinical infection that has been going on for some time, this is the time you are able to clear it up
- Give appropriate AB that will be there for several weeks and has a good chance of clearing it up
- much higher efficacy for bacterial cure than if given during lactation
- The long lasting AB is given at the last milking into all the quarters
- 2 problems with this:
- antimicrobial resistance (field of med getting criticized for this type of therapy)
- Long Acting AB’s are very persistent! If we put in a long acting AB into a milking (lactating) cow by mistake, it will persist for an extremely long period (will still have AB traces after 4 weeks). get an AB failure ($$$) or a cow that isnt producing good milk for weeks
23
Q
Teat Sealant
(part of DCT)
A
- gently infuse into teat canal and create a physical blockage
- don’t want that to go into the udder - wont be useful and could cause some damage - gently put into the teat and block the teat canal (stop bacterial entry during dry period)
- need to make sure when we calf that cow, we are stripping out bismuth sulphate- if not done properly, get black spots on cheese (not harmful but a lot of companies wont accept this contamination)
- If we use AB’s and teat sealant together - we need to put AB in first, massage it so that it gets into the udder and then put the sealant in..don’t massage the sealant in!
- Also make sure you are making the insertion of sealant sterile as this an lead to really bad mastitis - especially if you are using teat sealant alone without an AB
- If we leave this in for a long time (ex: 6 weeks) can cause a source of infection and really bad mastitis
- Use teats sealants on all cows, not just active cows or you are just sealing it all in?
24
Q
DCT Requirements
A
- Need to have a system where a cow is clearly marked - avoid bulk tank failure
- AB in the tank is $$$
- Must wait the full withholding time for the antibiotic to leave the tank
25
Q
- Cull Persistent Offenders
(5pt plan)
A
- or cows that have 3 or more cell counts above 200k that either haven’t been treated or havent responded to treatment
- Individual SCC that hasn’t respnded to AB may be a resevoir for infection for herd (also may be harboring really nasty bacteria)
- Do not take it lightly - farmers love their cows, you need to understand that this is a careful decision and have good reasoning for it
- try and train farmers to take good sterile samples as they may be taking contaminated samples
26
Q
Common Problem Cow and Action
A
- Problems cows often caused by S. aureus, very persistent, signs keep returning
- what can we do with these animals?
- cull
- or less severe, put in a problem Group: say these cows are housed separately for having persisitent infections and they are away from the herd. we work really hard to treat them, cure some of them or decide they need to be culled - can be very useful!
- can also do treatments at dry off: we know the efficacy of treating at dry of is better as they aren’t being milked out and we have several weeks for it to be able to work
28
Q
Milking
A
- we need to have the pulsation there, if we shut that off, it would be a constant vacuum at the end of the teat
- the machines make it very congested! - so now we have a massaging technique (rubberliner opens and closes to massage the teat to prevent the agony of milking)- this is why we need pulsation!
29
Q
Liners
A
- Liners need to be changed frequently!! - they get cracked and worn (can then harbor infection)
- only part that comes in contact with the cow
- Should be about twice a year!
- Need a good vacuum to make sure the milk from the other quarters doesnt splash up on another and contaminate
30
Q
liner slip
A
- can hear a squeaking noise as air is leaking in
- This could completely foul up the vacuum - great way of causing mastitis
- need to put liner up properly
31
Q
Milking Machine
A
- Need to clean it!
- If there has been modifications, the vacuum reserve may be affected or there may not be enough hot water to wash everything!
32
Q
Subclinical Infections and Contagious cause
A
33
Q
Subclinical Infections and Bulk Tank SCC
A
- If we have got a lot of subclinical infections in the herd, lots of quarters are infected, we will see an increase in the Bulk Tank SCC
- bulk tank SCC could be a very approximate indication of the proportion of quarters infected on the farm
- helps indicate prevelance on the farm on the day the reading was found
34
Q
Types of PMTD
A
35
Q
Dry Cow Therapy and Prevention of Further Infections
A
36
Q
Selective Dry Cow Therapy
A
37
Q
Liner Life
A
- (2,500 milkings (typical liner life) multipied by number of milking units) divided by Number of cows x 2 milkings a day
- this will give you the number of days between liner changes
38
Q
Constant Vacuum
A
- vacuum on the teat end must be constant
- a fluctuation of vacuum (a machine at full power and only just managing to maintain that vacuum) means that milk will get forced up into the teat from other quarters on the same cluster and spread infection
- Need a powerful pump (vacuum reserve) - even more than we need to just make sure
39
Q
Vacuum
A
40
Q
Control of Environmental Mastitis
(2)
A
- Quite often find that both contagious and environmental mastitis are present
- environmental mastitis really comes down to keeping their enviroment clean
- and need to lean teats in the parlor! - do not want environmental pathogens being pushed up into the quarter and causing mastitis
- parlour procedure is also important in terms of contagious mastitis!
41
Q
Environmental Mastitis
A
- need clean and dry straw, very important!
- Also need decent cubicles
- also need a barrier to stop the cows from going to far forward
42
Q
Housing
(what you need to be looking for)
A
- look to see if they are standing up (fed up and uncomfortable) or lying down and comfortable
- see if things are clean and dry! (not a bunch of nasty layers)
- Also need to be able to lie down to ruminate properly (stress–> lower immune system possible –> mastitis prone)
45
Q
Antibiotic Use and Teat Sealant
(Selective Dry Cow Therapy)
A
- To try and be a little more selective with our AB use - can try and identify those cows with evidence of infection and just infuse those cows - Selective Dry Cow Therapy
- there are several criteria you could use: those with a history of mastitis, high cell count (over 200,000) or 3 readings that high during lactation (high risk cow you would want to treat)
- Don’t use a teat sealant if there is an active clinical mastitis going on, you will just seal the infection in
- Need to make you discard milk from ALL quarters and throw away, even if you are just treating one quarter with AB
