Lecture 22: Masitits and udder health

What is the most frequent disease in the dairy industry?

Mastitis

Costs of mastitis

• Increased amount of non-salable milk

• Decreased milk production

• Decreased milk quality

• Increased treatments/culling

Parallel

Tandem side opening

Herringbone

Rotary

• Where the milk is collected to be transported to the milk company

• Where the samples for milk cultures are collected

• Only milk from cows more than 3 days fresh and/or not an antibiotic, NSAIDs, etc. are collected

Bulk tank

A- The Claw

B- Milk line/hose

C- Vacuum tubes

D- Teat cup

Benefit of herringbone over parallel?

Herringbone allows more cows to be milked in the same amount of space

What happens with the liner is opened?

Machine milk in creates a pressure difference that causes milk to flow, ad the teat canal is open

Automatic detacher or “take-offs”

Goal mean claw vacuum

10.5 to 12.5 Hg

Max claw vacuum flucation?

< 3 hg

__% of milking use manual mode when automatic takeoffs are used?

<5%

What is the time for D phase of the pulsations cycle

>150-200 ms

How do you have optimal milk letdown?

• Optimize production and prevention mastitis

• Process where the muscle surrounding in to the ducts and cistern for efficient milk harvest

A- Gland cistern/sinus

B- Test cistern/sinus

C- Streak canal/papillary duct

How much milk is stored in the ducts and cisterns?

20%

Pathophysiology of milk letdown

1. Teat stimulation by milker and sound and smell of the milking area

2. Presence of milk in unit elicits constant oxytocin release during milking

3. Nerve impulse to hypothalamus then to posterior pitutary

4. Post pitutary releasing oxytocin

5. Oxytocin reaches myoepithelial cells in the mammary gland

6. Myoepithelial cells constrict causing milk to be screwed into the ducts

7. Milking units removes milk from ducts and cisterns

What is skill time?

The pre-dip time to reduce the bacteria load

What is stripping?

The first 2-3 streams of milk contains the highest number of somatic cell counts therefore milk quality is enhanced and allows the milkier to look for clinician mastitis

What is the benefit of wiping the teat?

Removes pre-dip and removed a large number of bacteria

__-__ seconds optimizes milking unit attachment to match max oxytocin effect

90-120 seconds

How can managers monitor if the milkers are following procedures

Cameras and electronic monitoring systems

What is the only what you can definitively diagnose a mastitis causing agent?

Culture

What can cause false negatives?

• Pathogen load is below limit of detection

• Pathogen has been cleared, abnormal milk has not resloved

• Special media required

• Inhibitors in milk

• Sample was mishandled

What is bulk tank milk cultures used for?

• Determine the presence or absence of a pathogen in the herd

• ID the predominant bacterial groups in the herd

What affects the BTM frequency?

• Size of the herd

• Likelihood of down-grade

• Presence/abscence of contagious pathogens

• Owner’s tolerance for risk

Who are the only two who can take milk samples?

The owner or milk truck driver

SCC for grade A milk

<750,000 cells/mL

What can cause samples to be contaminated?

• Dirty teat ends

• Wet udders

• Milker’s hands

• Non-sterile containers

How do you properly collect a BTM sample?

• Agitate the take for 10-15 minutes prior to sampling

• Use a sterilized dipper or syringe to collect milk from the top of the talk

Where should you not collect BTM sample from?

Tank outlet valve

How do you collect individual cow milk sample?

1. Wear latex/nitrile gloves

2. Prep the cow as usual and dry udder

3. Clean teat ends with alcohol wipe

4. Sample the teats closes to you first then far teas

5. Discard 1-2 squirts of milk

What overrides oxytocin?

Epinephrine

What are the draw backs for freezing a sample?

• Strep and staph no greatest affected

• Nocardia can have reduced likelihood of isolating these organisms

• Can reduce likelihood of E. coli isolation less

How often do you need to replace the liners of claw?

1-2 times a month

Expect __% of individual samples to be contaminated

10% (>20% need to discuss collection techinique)

Physical barriers to teat?

• Teat end (sphincter

• Keratin lining of the teat canal

  • Bacteriostat FA

Immune factors of the mammary gland?

• NS immunity (neutrophils, macrophages)

• Specific immunity

• Lymphocytes

What is the only organism that causes mastitis after hematogenous spread?

Mycoplasma

Cow risk factors for teat end lesions

• Teat shape

• Teat position on udder

• Production level

• Stage of lactation

• Parity

• Main reservoir in the udder of infected cows

• Infections resulted from cow-to-cow transmission

• Via contaminated fomites

• Examples: Staph aureus, Strep agalactiae, Mycoplasma

Contagious mastitis

• Main reservoir is the environment

• Infection is result of environmental exposure

• Example: E. coli, Non-aureus Staph, Strep dysgalactiae/uberis

Environmental mastitis

According to the lecture, what is the primary reason why udder health is important in the dairy industry? a) It ensures cows are comfortable. b) It prevents environmental contamination. c) Mastitis is the most frequent and costly disease of the dairy industry. d) It improves the taste of milk.

c) Mastitis is the most frequent and costly disease of the dairy industry.

Which of the following is a direct economic cost associated with mastitis in dairy cows? a) Increased feed consumption b) Higher veterinary bills for routine check-ups c) Increased amount of non-saleable milk. d) Lower cost of labor

c) Increased amount of non-saleable milk.

Which of the following is NOT listed as a type of dairy milking parlor in the lecture? a) Parallel b) Tandem c) Herringbone d) Circular

d) Circular

The bulk tank in a dairy operation serves which of the following primary functions related to milk? a) Cooling milk before processing b) Separating cream from milk c) Collecting milk to be transported and providing a source for milk culture samples. d) Pasteurizing milk on the farm

c) Collecting milk to be transported and providing a source for milk culture samples.

What is the purpose of pulsation in a machine milking unit at the cow level? a) To increase the vacuum pressure for faster milking b) To filter impurities from the milk c) To provide a massaging action to keep the teat healthy. d) To measure the milk flow rate

c) To provide a massaging action to keep the teat healthy.

According to the lecture, what is the goal range for Mean Claw Vacuum during milking? a) 8.0 to 10.0” Hg b) 10.5 to 12.5” Hg c) 13.0 to 15.0” Hg d) Less than 3” Hg

b) 10.5 to 12.5” Hg

For optimal milk letdown and prevention of mastitis, what process involves the contraction of muscles surrounding the alveoli? a) Teat stimulation b) Milking unit attachment c) Milk ejection reflex d) Pulsation

c) Milk ejection reflex

What is the primary purpose of stripping 2-3 streams of milk from each teat during the milking procedure? a) To remove residual milk after machine milking b) To clean the teat before attaching the milking unit c) To enhance milk quality by removing milk with high somatic cell counts and to check for clinical mastitis, as well as stimulate oxytocin release. d) To pre-cool the milk before it enters the milking system

c) To enhance milk quality by removing milk with high somatic cell counts and to check for clinical mastitis, as well as stimulate oxytocin release.

According to the lecture, what is the optimal time interval between teat preparation (including pre-dip, stripping, and wiping) and milking unit attachment to match maximum oxytocin effect? a) 30-60 seconds b) 90-120 seconds c) Immediately after wiping d) More than 180 seconds

b) 90-120 seconds

A dairy farm has recently experienced an increase in clinical mastitis cases. The veterinarian recommends culturing individual cows to identify the specific pathogens involved. What type of milk culture is MOST appropriate in this situation? a) Individual Animal Culture b) Bulk Tank Milk Culture c) Composite sample d) Environmental culture

a) Individual Animal Culture

A bulk tank milk culture from a large dairy herd reveals a predominant growth of Streptococcus agalactiae. Based on this finding, which of the following management steps would be MOST relevant according to the lecture's implication (even though specific steps aren't detailed for each pathogen in the excerpt)? a) Improving barn ventilation to reduce environmental bacteria b) Reviewing milking procedures to prevent cow-to-cow transmission c) Focusing on teat end disinfection during the dry period d) Increasing the frequency of bulk tank

b) Reviewing milking procedures to prevent cow-to-cow transmission

What does "NG" indicate as a result of an individual animal milk culture? a) Growth of multiple colony types b) Growth of a pure culture c) No growth, suggesting the animal is free of mastitis (though false negatives can occur). d) The sample was contaminated

c) No growth, suggesting the animal is free of mastitis (though false negatives can occur).

According to the lecture, what is a key factor to ensure quality results when collecting milk samples for culture? a) Collecting a large volume of milk b) Sampling all cows in the herd at the same time c) Aseptic collection d) Freezing the samples immediately

c) Aseptic collection

Who is typically permitted to handle and collect Bulk Tank Milk (BTM) samples, according to the provided material? a) Any farm employee trained in sample collection b) The herd veterinarian c) The milk processor and the milk hauler d) Only the dairy owner

c) The milk processor and the milk hauler

When collecting an individual cow milk sample, which teats should generally be sampled first? a) Teats that appear most inflamed b) Teats farthest from you c) Teats closest to the milking machine d) It does not matter which teats are sampled first

b) Teats farthest from you

What is the general recommendation for storing milk samples for culture if there is a delay in delivery to the laboratory? a) Leave them at room temperature b) Store them in direct sunlight c) Freeze the samples d) Add a preservative

c) Freeze the samples

Which of the following is considered a physical barrier that helps protect the mammary gland from infection? a) Neutrophils b) Lactoferrin c) Teat end sphincter d) Immunoglobulins

c) Teat end sphincter

A dairy cow has recurrent mastitis infections that do not respond well to treatment. The farmer is considering removing her from the herd. According to the lecture's note on mastitis culling, which of the following factors should be considered in this decision? a) The current market price for cull cows b) The availability of replacement heifers c) The animal's age, chronicity of mastitis, and production level. d) The veterinarian's personal preference

c) The animal's age, chronicity of mastitis, and production level.

Which of the following is classified as a contagious mastitis pathogen in the lecture? a) E. coli b) Klebsiella pneumoniae c) Staph aureus d) Strep uberis

c) Staph aureus

According to the lecture, what is the main reservoir for environmental mastitis pathogens? a) The environment b) The udder of infected cows c) Contaminated milking equipment d) Milker's hands

a) The environment

How often should you perform BTM?

As often as possible

How much dose the dairy industry cause?

>2.8 million

Why does the US dairy industry cost so much?

• Increased amount of non-saleable milk

• Decreases milk production

• Decreases the amount of saleable milk

• Decreased milk quality

• Increased treatments and culling

Why must we have optimal milk letdown time?

To prevent mastitis and optimize production

The length of time of the pre-dip has been in contact w/ the tear before drying off. 30 seconds is the minimum recommended time.

Contact time

The interval between manual stimulations and cluster attachment

Prep-lag time

How long should the prep lag time be?

90-120 seconds

What is the most powerful stimulation for Oxytocin release?

Stripping