Term
| ______________ is inflammation of the mammary gland. |
|
Definition
|
|
Term
Which of the following is considered to be the most costly disease facing the dairy industry?
a. Lameness
b. Infertility
c. Mastitis
d. Respiratory disease
e. All of the above are equally costly |
|
Definition
|
|
Term
Which of the following is the leading cause for culling cows?
a. Lameness
b. Infertility
c. Mastitis
d. Respiratory disease
e. All of the above are equally common in culling cows |
|
Definition
|
|
Term
Match the following terms with their respective definitions: subacute mastitis, acute mastitis, peracute mastitis, chronic mastitis
1. Udder changes with grossly abnormal milk and hot, hard, and swollen infected quarter. Fever can reach 108F and the cow exhibits extreme depression, anorexia, and other signs of toxemia.
2. Persistent infection that can be clinical or subclinical. Infection leads to induration of the affected quarter.
3. Flakes present in the milk but few other signs are present.
4. Milk is grossly abnormal and the affected quarter is hot, hard, swollen, and sensitive. Systemic signs are also present and include slight to moderate fever and depression. |
|
Definition
1. Peracute mastitis
2. Chronic mastitis
3. Subacute mastitis
4. Acute mastitis |
|
|
Term
70% of mastitis cases are ________________ in nature.
a. Clinical
b. Subclinical |
|
Definition
|
|
Term
The most important nonspecific defense mechanism of the cow against mastitis is the:
a. Anatomical barriers
b. Milk leukocytes
c. Nonspecific soluble factors
d. Involution
e. Diet |
|
Definition
|
|
Term
| The teat duct lumen of the mammary gland remains open for up to ____ hours following milking. |
|
Definition
|
|
Term
| T/F: cows should always be placed in a clean environment after milking, as the teat duct lumen can remain open for up to two hours following milking. |
|
Definition
|
|
Term
When does a keratin plug form in the teat duct lumen of the mammary gland?
a. 2 hours post-milking
b. 5 days post-dry off
c. 6 hours post-milking
d. 16 days post dry-off
e. 24 hours post-milking |
|
Definition
|
|
Term
Select the true statement concerning keratin plugs:
a. Fatty acids, present in the keratin, play a role in inhibiting bacterial growth
b. Defensins, present in the keratin, play a role in inhibiting bacterial growth
c. The keratin plug forms approximately 16 days post-dry off
d. All of the above statements are true
e. All of the above statements are false |
|
Definition
| d. All of the above statements are true |
|
|
Term
| T/F: Cows undergoing intramammary therapy during their dry period may be predisposed to mastitis, as bacteria can colonize the keratin plug. |
|
Definition
| True--in Dr. G's notes, one study shows that the use of short infusion cannulas resulted in a 50% reduction in cases of new mastitis |
|
|
Term
| ________________ is the predominant leukocyte in normal milk. |
|
Definition
|
|
Term
| _________________ is the predominant leukocyte in mammary secretions in an infection. |
|
Definition
|
|
Term
The highest numbers of leukocytes are found in the:
a. Foremilk
b. Bulk milk
c. Stripping milk
d. A and B
e. A and C |
|
Definition
|
|
Term
| __________________ and ________________, found in the milk, inhibit the ability of neutrophils to kill bacteria. |
|
Definition
Casein micelles
Fat globules
The neutrophils basically become "drunk" on fat, and then don't function properly. |
|
|
Term
Which of the following is a reason for why milk leukocytes have a decreased ability to function?
a. The lack of glucose in the milk
b. Decreased glycogen
c. A deficiency of opsonins and complement
d. Coating of the neutrophil surface with casein
e. All of the above contribute to inhibited neutrophil function |
|
Definition
e. All of the above
Note that lactose is the main sugar in milk |
|
|
Term
| T/F: Diapedesis of neutrophils into the mammary gland is delayed in recently fresh cows, possibly explaining in part the higher incidence of new infections in this group. |
|
Definition
|
|
Term
| _________________ is synthesized by the mammary epithelium and helps to inhibit the growth of S. aureus, streptococci, and coliforms. |
|
Definition
|
|
Term
| __________________ is derived from green feedstuffs and is present in normal milk. It helps to inhibit the growht of S. aureus, most streptococci, and coliforms. |
|
Definition
|
|
Term
| The _________________________________ system in milk works to inhibit the growth of S. aureus, most streptococci, and coliforms. |
|
Definition
| lactoperoxidase/thiocyanate/H2O2 |
|
|
Term
| _________________ produces H2O2, part of the lactoperoxidase/thiocyanate/H2O2 system. |
|
Definition
|
|
Term
| When lactoperoxidase, thiocyanate, and H2O2 are all present, ________________ is oxidized and bacteriostatic compounds are produced. |
|
Definition
|
|
Term
| Aside from refrigeration, ______________________ is the only FAO/WHO-approved method of preserving raw milk. |
|
Definition
Lactoperoxidase system
Note: thiocyanate and H2O2 are also added to the system to inhibit bacterial growth |
|
|
Term
| T/F: Lysozyme concentrations are relatively high in normal milk but gradually decrease during infection. |
|
Definition
False: low in normal milk, high in infections
Note: lysozyme is enzyme that breaks beta 1,4 linkage in peptidoglycan |
|
|
Term
| T/F: lactoferrin is present in low quantities in normal milk but increases greatly during mammary involution and serves to chealate iron and make it unavailable for bacteria. |
|
Definition
|
|
Term
| ______________ is a major protein of the secretions from a nonlactating mammary gland. |
|
Definition
|
|
Term
Which of the following is NOT a nonsepcific soluble factor that makes up the defense system of the mammary gland?
a. Lactoperoxidase/thiocyanate/H2O2 system
b. Casein micelles
c. Lysozyme
d. Lactoferrin
e. Defensins |
|
Definition
|
|
Term
| T/F: most streptococci have low iron requirements and are not affected by lactoferrin. |
|
Definition
|
|
Term
| _________________ are antibacterial proteins produced by mucosal epithelial cells and neutrophils. |
|
Definition
|
|
Term
| T/F: during the period of active involution, the non-lactating mammary gland is very resistant to infection. |
|
Definition
| False. At this stage, the mammary gland is very susceptible to new infection. However, after the gland reaches the fully involuted state, it is very resistant to infection. |
|
|
Term
| T/F: defensins may be a major effector of natural immune responses. |
|
Definition
|
|
Term
| The average lactation is _________ days. |
|
Definition
|
|
Term
| What is the reason for a dry period in dairy cows? |
|
Definition
Must allow regeneration of the mammary epithelium.
The dry period is typically 45 days, though 35 is becoming more and more common |
|
|
Term
What factor during the drying off period has been shown to increase the amounts of lactoferrin, antibody, and phagocytes in the mammary gland?
a. Gradually decreasing milking frequency
b. Reduction in feed
c. Increase in feed
d. Shortening the drying off period to less than 35 days
e. All of the above lead to an increase in lactoferrin, antibody, and phagocytes in the mammary gland. |
|
Definition
|
|
Term
Decreasing the dietary cation-anion difference in dairy cows should be done during the cow's:
a. Drying off period
b. Transition period
c. Freshening period
d. Current lactation |
|
Definition
|
|
Term
| DCAD is done by adding cation/anion sources to the cow's feed during the transition period. |
|
Definition
|
|
Term
Transitioning from a dry cow diet to a lactating cow diet decreases the incidence of:
a. Milk fever
b. Mastitis
c. Metritis
d. Retained Placentas
e. All of the above |
|
Definition
|
|
Term
| The cations present in DCAD are: |
|
Definition
|
|
Term
| The anions present in DCAD are: |
|
Definition
|
|
Term
All of the following have been utilized to decrease the DCAD except:
a. Cationic salts
b. Acidified fermentation products
c. Hydrochloric acid
d. Low potassium forages
e. All of the above have been used |
|
Definition
a. Cationic salts
This should be anionic salts |
|
|
Term
| Describe the mechanism behind DCAD: |
|
Definition
| The greater dietary anion intake induces a mild metabolic acidosis and increases the blood ionized Ca concentration because parathyroid hormone and Vitamin D mobilize bone Ca. Urine pH must be monitored closely to maintain an acid pH value (usually 6.0-6.7) and not overdo the decreased DCAD, which depresses feed intake. |
|
|
Term
| __________________ is the consequence of overdoing a decreased DCAD. |
|
Definition
|
|
Term
| _______________ supplementation of the diet of dairy cattle has been shown to enhance the killing ability of mammary PMNs. |
|
Definition
Selenium
Note: Vitamin E is also usually supplemented |
|
|
Term
All of the following are often supplemented in the diet of dairy cows except:
a. Selenium
b. Vitamin E
c. Chromium
d. Copper
e. Zinc |
|
Definition
e. Zinc
I made this answer up, so hopefully it's not supplemented--just went with an option that wasn't in his notes... |
|
|
Term
| ___________________ is the predominant immunoglobulin in milk. |
|
Definition
|
|
Term
IgG1 has been shown to opsonize bacteria for engulfement by:
a. macrophages
b. neutrophils
c. both
d. neither |
|
Definition
|
|
Term
| ________ is opsonic for neutrophils and may be more important when these cells enter the mammary gland during inflammation. |
|
Definition
|
|
Term
IgA functions in all of the following capacities except:
a. Neutralizes toxins
b. Agglutinates bacteria during milking to facilitate their removal
c. Opsonizes bacteria for engulfement by macrophages
d. Prevents the multiplication of bacteria
e. Prevents the adherence of bacteria to mammary epithelial cells |
|
Definition
| c. Opsonizes bacteria for engulfement by macrophages (IgG1) |
|
|
Term
| T/F: vaccination is a highly effective way to control and prevent mastitis in dairy cows. |
|
Definition
| False. Neutrophils are compromised in the mammary gland. Because of this, vaccinations are not as effective because the effector cell (neutrophil) is not working properly. |
|
|
Term
| ______ (immunoglobulin) can sometimes perform some of the roles of IgA. |
|
Definition
|
|
Term
What is the predominant immunoglobulin in both milk and colostrum?
a. IgA
b. IgD
c. IgE
d. IgG
e. IgM |
|
Definition
|
|
Term
| List the major pathogens that are classified as "contagious." |
|
Definition
Streptococcus agalactiae
Lancefield Group G Streptococci
Staphylococcus aureus
Mycoplasmas |
|
|
Term
| List the major pathogens that are classified as "environmental." |
|
Definition
Coliforms
Streptococci other than S. agalactiae |
|
|
Term
| The primary reservoir for this pathogen is the udder and extramammary reservoirs are the teat skin and milking machine liners. Infections are mainly spread during milking and range from subclinical to peracure. It is not unusual for a cow to become infected in one or more quarters and initially be subclinical. Clinical mastitis milk is white with a candle-wax garget (clots). This organism can cause gangrenous mastitis in a small percentage of infected animals. The organism can also form abscesses which occasionally break open and cause the cow to be re-infected. It is pretty much impossible to get rid of this organism. |
|
Definition
|
|
Term
| This organism is very contagious and is spread during milking. It is an obligate udder parasite but can survive for short periods in the environment and on hands. It is a common cause of chronic subclinical mastitis with subacute and acute flare-ups. |
|
Definition
|
|
Term
| This organism is a highly contagious problem in some herds and is becoming more widespread in the US. It was formerly thought to be confined to the Southwestern US in large herds, especially California. Spread occurs during the milking process through contaminated milking machines, treatments, instruments, and hands. Can also spread via colostrum and respiratory routes. This organism is refractory to antibiotic treatment. |
|
Definition
| Mycoplasma, especially M. bovis |
|
|
Term
| These organisms survive in the environment and on teat skin. Usual spread is from environment to cow but they can be spread from cow to cow during milking. The infection rate is higher during the dry period and early lactation. About 50% of infected animals show a subacute and transient mastitis with flaky milk and little to no swelling quarters. only 20% of infections become chronic and the incidence of infection in a herd is usually <10%. |
|
Definition
Environmental streptococci
S. uberis, S. dysgalactiae |
|
|
Term
| The reservoir for these organisms is the GI tract and the environment. Incidence of infection in a herd is usually <5%, but infection rates increase during the last 2 weeks of the dry period and during the first 2 weeks of lactation. The majority of infections are short (<30 days). Milk is frequently watery with few clots. Toxemia is caused by release of endotoxin from bacteria and from various mediators of the inflammatory response. |
|
Definition
Coliforms
*E. coli*
Klebsiella pneumoniae
Enterobacter
NOTE: heat stress and coliform mastitis is a bad combination |
|
|
Term
| With what type of mastitis (organism) is heat stress a particularly bad thing to have? |
|
Definition
|
|
Term
| These organisms are found on the skin. Infections are generally subclinical and common, especially in herds with low numbers of major pathogens. It is very common to find these organisms in milk. |
|
Definition
| Coagulase-negative staphylococci |
|
|
Term
| This organism can be found in wet bedding, contaminated water supplies, teat dips, and antibiotics. Mastitis can be very severe. |
|
Definition
|
|
Term
| __________________ is a relatively rare cause of mastitis that can be gangrenous. |
|
Definition
|
|
Term
| _________________ comes from the soil and causes subclinical to acute to chronic mastitis and can be spread by contaminated infusion cannulas, medicines, etc. |
|
Definition
|
|
Term
| _____________ may cause a mild mastitis and can be considered a minor pathogen. Some reports indicate that this agent along with the coagulase-negative staphylococci may play a role in prevention of new infections caused by the major pathogens. |
|
Definition
|
|
Term
| _____________________ causes mastitis usually secondary to udder injury or to prior infection. There is a poor prognosis for infected quarters but the animal usually survives. |
|
Definition
|
|
Term
| T/F: yeasts and molds can be spread from contaminated treatments, equipment, and the environment and are refractory to antibiotics. |
|
Definition
|
|
Term
| ________________ are achlorophyllic algae found in wet environments and are spread from environment to cow. These organisms can be shed in high numbers in milk. |
|
Definition
|
|
Term
Just know that Pasteurella can cause mastitis in cattle
There are reports of both P. multocida and Mannheimia haemolytica causing severe mastitis. |
|
Definition
|
|
Term
| ____________________ is the standard method for detection of mastitis. |
|
Definition
Somatic Cell Count
Performed in association with bacterial culturing and clinical signs |
|
|
Term
The Somatic Cell Count refers to a count of all of the following except:
a. Epithelial cells
b. Erythrocytes
c. Neutrophils
d. Bacterial cells
e. All of the above can be found in the SCC |
|
Definition
d. Bacterial cells
Epithelial cells from the mammary gland are normally present in small numbers
Erythrocytes can be normally present after parturition or due to injury
Leukocytes, primarily neutrophils, infiltrate the mammary gland from the blood in response to injury (small number are also normally present) |
|
|
Term
Which of the following is a SCC test that uses an anionic detergent to lyse the somatic cells and release DNA, resulting in a gel-like mixture in the presence of high numbers of somatic cells?
a. DNA Coagulation Tests
b. California Mastitis Test
c. Wisconsin Mastitis Test
d. Coulter and Fossomatic Counters
e. Salinity/Conductivity Sensors |
|
Definition
|
|
Term
Which of the following is a cow-side test that is fast, cheap, and relatively free from error but is a semiquantitative (subjective) test?
a. DNA Coagulation Tests
b. California Mastitis Test
c. Wisconsin Mastitis Test
d. Coulter and Fossomatic Counters
e. Salinity/Conductivity Sensors |
|
Definition
| b. California Mastitis Test |
|
|
Term
Which of the following is a laboratory test used by veterinarians and dairy plants to determine the SCC in bulk milk samples for each farm?
a. DNA Coagulation Tests
b. California Mastitis Test
c. Wisconsin Mastitis Test
d. Coulter and Fossomatic Counters
e. Salinity/Conductivity Sensors |
|
Definition
| c. Wisconsin Mastitis Test |
|
|
Term
A cow with a SCC of 230,000 according to the California Mastitis Test would be classified as:
a. Negative
b. Trace
c. Grade 1
d. Grade 2
e. Grade 3 |
|
Definition
b. Trace
Negative = 0-200,000
Trace = 150,000-500,000
Grade 1 = 400,000-1,500,000
Grade 2 = 800,000-5,000,000
Grade 3 = >5,000,000 |
|
|
Term
Which test is usually more reliable and accurate than DNA tests and gives a readout of # of cells/sample?
a. DNA Coagulation Tests
b. California Mastitis Test
c. Wisconsin Mastitis Test
d. Coulter and Fossomatic Counters
e. Salinity/Conductivity Sensors |
|
Definition
| d. Coulter and Fossomatic Counters |
|
|
Term
Which test gives continuous readouts of cows with electronic IDs as they are milked? This test requires that a baseline is established for each cow, as an alarm will sound if there is a deviation from the mean.
a. DNA Coagulation Tests
b. California Mastitis Test
c. Wisconsin Mastitis Test
d. Coulter and Fossomatic Counters
e. Salinity/Conductivity Sensors |
|
Definition
| e. Salinity/Conductivity Sensors |
|
|
Term
| What is the most important factor affecting SCCs? |
|
Definition
| Infection status of the quarter |
|
|
Term
| Younger/Older cows tend to have higher SCCs. |
|
Definition
| Older--more opportunity to be infected |
|
|
Term
The best milk to sample for the SCC is the:
a. Foremilk
b. Middle milk
c. Strip milk |
|
Definition
b. Middle milk
Both the foremilk and the strip milk are high in SCC. |
|
|
Term
| Cell counts tend to be higher in the morning/night because cows produce more milk in the morning/night. |
|
Definition
Night
Morning
More milk = dilutes the cells |
|
|
Term
| The SCC may vary day to day up to ____ percent from the baseline for an individual cow. |
|
Definition
|
|
Term
SCC is highest in the:
a. Spring
b. Summer
c. Fall
d. Winter |
|
Definition
b. Summer--peak in August
This is due to the increased exposure to pathogens in the summer |
|
|
Term
| During what stages of lactation is SCC more likely to be elevated? |
|
Definition
Parturition--in absence of infection, these levels will lower within 2-3 weeks
Late lactation--these cows are producing less milk and thereby concentrate the cells |
|
|
Term
| T/F: during periods of high milk production, SCCs may be lowered by dilution. |
|
Definition
|
|
Term
| T/F: stress can cause an increase in SCCs. |
|
Definition
| True, especially in cattle that are already infected |
|
|
Term
| List the variables that can contribute to SCC in cows: |
|
Definition
Infection status of the quarter
Age of cow
Type of milk sample
Diurnal variation
Daily variation
Season
Stage of lactation
Milk volume
Management practices |
|
|
Term
| Normal animals should have an SCC below ____________ and very good cows may have an SCC around ___________ or less. |
|
Definition
|
|
Term
| Cows with counts greater than __________________ are possibly infected but a positive culture is required to confirm infection in all cows. |
|
Definition
|
|
Term
| T/F: an individual SCC is a good predictive measure of whether a subclinical case is going to become clinical, as well as to determine a causative agent. |
|
Definition
|
|
Term
| T/F: composite cow counts may be used to help identify cows for culling. |
|
Definition
|
|
Term
| T/F: cows with high SCCs should be grouped and milked first to prevent mastitis spread. |
|
Definition
|
|
Term
| T/F: SCCs can be used to identify cows for early dry off, preferably near their 100th day of lactation. |
|
Definition
| False--want to make sure cows are close to the END of lactation (close to the 300 mark??) |
|
|
Term
| T/F: composite cow counts are the diagnostic of choice in determining which cows to treat. |
|
Definition
False--not cost-effective
Exception is herds with S. agalactiae or in herds at risk of losing their market because of excessively high SCC. Instead, composite cow counts may be used to measure treatment success/failure and management programs. |
|
|
Term
| On a herd basis, according to the "suggested goals for mastitis control in a herd" and DHIA, ___% of the herd should be below 4 (of log linear somatic cell count score) |
|
Definition
80%
See table in page 8 of Tichy notes |
|
|
Term
| Herd goals should include no more than ___% of the herd being treated for mastitis per month, ____% of the herd being culled because of mastitis per year, and _____% of the herd being dead because of mastitis. |
|
Definition
|
|
Term
| What are the two approaches to determining a herd basis SCC? |
|
Definition
Bulk Tank Sample
Calculate herd average from individual SCCs |
|
|
Term
| What are some benefits and drawbacks to a bulk tank SCC (BTSCC)? |
|
Definition
Good:
1. Easily acquired
2. Offers relative index of herd mastitis status at single point in time
3. Estimate losses in production due to mastitis.
Bad:
1. Bias--high producing cow has greater effect than low producing cow
2. Ignores any cow whose milk is not in tank (treated, fresh cows)
3. Considerable daily variation/sampling errors (not agitating milk adequately before sampling) |
|
|
Term
| A BTSCC < ____________ represents normal, with a BTSCC < ______________ representing very good udder health and a BTSCC < _________________ representing excellent udder health. A BTSCC of ______________/ml is thought to represent at least a 5% reduction in milk yield, which contributes to significant economic loss. |
|
Definition
300,000
<200,000
<100,000
500,000 |
|
|
Term
| When comparing individual cow SCCs on a herd basis, in general, > ____% of the heifers, _____% of the second lactation cows, and _____% of the older cows should have SCCs <300,000. |
|
Definition
|
|
Term
| T/F: Heifers should freshen with the lowest mastitis prevalence so they should be the most sensitive indicator of mastitis pathogen problems. |
|
Definition
|
|
Term
| T/F: individual mastitis samples for culture should be collected 6 hours before or immediately after milking. |
|
Definition
| False: milk should be collected immediately before or 6 hours after milking. |
|
|
Term
| Describe the appropriate steps for preparing and performing an individual mastitis sample for culture. |
|
Definition
1. Collect milk immediately before or at least 6 hours after milking.
2. Clean the teat.
3. Remove the first 3-4 squirts of milk.
4. Swab teat with alcohol and be sure teat is dry.
5. Collect samples into sterile container, directing the stream of milk HORIZONTALLY into the container.
6. Culture promptly or refrigerate sample--DO NOT FREEZE. |
|
|
Term
| T/F: when culturing individual cows for mastitis detection, it is best not to mix all 4 quarters on one plate. |
|
Definition
|
|
Term
| One or more colonies of what bacterial agents are considered significant? |
|
Definition
S. agalactiae
S. aureus
Mycoplasma |
|
|
Term
| T/F: a single coliform colony is considered significant. |
|
Definition
|
|
Term
| T/F: for organisms other than S. aureus, S. agalactiae, and Mycoplasma, a pure culture plus an elevated CMT (>500,000) is needed to be considered significant. |
|
Definition
True
Sometimes it is difficult to get a pure culture, but want to see dominant organism |
|
|
Term
| How often should bulk tank screening be performed? Why is it important? |
|
Definition
| Bulk tank screening is a good way of detecting early infections, especially for S. agalactiae, S. aureus, and Mycoplasma spp. It should be sampled and cultured 2-3 consecutive days or 3x per month and should be REGULARLY performed. The milk should be thoroughly agitated before sampling. Note that a dirty or malfunctioning milking machine may be the source of many of these organisms. |
|
|
Term
| ____________________ is a sampling technique that can be used to decrease the number of cows needing to be cultured. In large herds, the cows are divided into smaller groups based on a variety of factors such as production level, SCC, or stage of lactation. These groups can be cultured as a bulk sample and then positive cows in a group are identified with individual cultures. |
|
Definition
|
|
Term
| Total bacterial counts of a herd can be determined through bulk tank screening using the ______________ method. Good quality milk should have values between _________ and ___________ bacteria per mL. |
|
Definition
Standard Plate Count
3000 to 6000 bacteria per mL |
|
|
Term
| See table 2 on page 10 of Tichy notes |
|
Definition
|
|
Term
| T/F: treating a mastitis case based on a guess of what the pathogen is is equivalent to not treating. |
|
Definition
| True--culture and sensitivity is recommended, though there is a cost:benefit ratio to this |
|
|
Term
| Describe the major steps involved in a cow physical exam regarding mastitis cases: |
|
Definition
1. Strip cup--can be useful as preliminary step to examine foremilk, but strip cup is MAJOR FOMITE, so care should be taken when using it.
2. Udder palpation: may be able to detect induration and chronic mastitis in an udder; also might be easy to detect a hot, swollen, painful udder.
3. Control and treatment: no dairy herd can expect total eradication; control program should be practical, effective, cost-efficient, and give results apparent to farmer. Record keeping is an essential part of mastitis control in a herd. |
|
|
Term
| How can pathogens spread in a herd? |
|
Definition
Infected quarter to uninfected quarter in the same cow due to milk impaction on the teat end.
Cow to cow due to contaminated cluster (fomite). |
|
|
Term
| Describe the milking machine structure: |
|
Definition
| The milking machine is powered by a vaccum that is a dynamic system with a stable vacuum level being maintained by a high rate of air flow. The air flow is affected by air inlets into the system and is controlled by a vacuum regulator. The pulsator controls air pressure in the pulsation chamber (expansion and deflation of the liner), which allows the teat to fill and empty. |
|
|
Term
| A pulsation ratio of __:___ or ___:___ are most common, and a pulsation rate should be between ____ and ____ per minute. |
|
Definition
60:40 or 50:50
Pulsation rate of 45-70/min |
|
|
Term
| T/F: excessive vacuum levels can cause teat end damage that can contribute to mastitis development. |
|
Definition
|
|
Term
| T/F: all milking systems have vacuum fluctuations. |
|
Definition
True
Severe vacuum fluctuation can cause milk impaction on teat ends and bacteria in the milk or on the teat ends can be forced into the quarter. The use of liner shields or anti-impact claw designs may decrease new infections due to impaction. |
|
|
Term
| List some causes of vacuum fluctuations: |
|
Definition
1. Milk flooding the line.
2. Bends in the pipeline that cause air turbulence.
3. Plugged air admission holes.
4. Small diameter milk and vacuum lines.
5. Normal cyclic fluctuations due to pulsation.
6. Inadequate vacuum reserve.
7. Failure to shut off the vacuum before removing the cluster.
8. Liner slip. |
|
|
Term
| In order to help prevent vacuum fluctuations, the vacuum reserve needs to be at least ____% above the calculated air requirements of a system. |
|
Definition
|
|
Term
| T/F: liner slips are always recognized by an audible "squawk." |
|
Definition
| False: can sometimes be identified by an audible squawk, but are frequently inaudible. |
|
|
Term
| What, with respect to the teats, can happen if there is an abrupt, massive loss of vacuum? |
|
Definition
| Teat end impaction and increased new infection rates. |
|
|
Term
The most common causes of acute vacuum drops are:
1. ______________________________
2. ______________________________ |
|
Definition
1. Liner Slip
2. Careless application/removal of the milking machine |
|
|
Term
| Liners should be replaced every ______ to _________ individual milkings. |
|
Definition
|
|
Term
| Why is backflushing a cluster helpful? Is there any type of infection it won't help? |
|
Definition
| Backflushing helps to sanitize the cluster and helps to prevent cow to cow spread of contagious pathogens. This will NOT help control environmental mastitis. |
|
|
Term
| T/F: incidence of mastitis is highly correlated with the number of mastitis pathogens on the teat end at milking. |
|
Definition
|
|
Term
| T/F: premilking hygiene is primarily effective against environmental pathogens. |
|
Definition
|
|
Term
Which of the following is a valid reason why washing the teats has fallen out of favor?
a. excess water contributes to liner slip and contaminates the inside of the slip
b. high concentration of sanitizers in the wash water may cause irritation to the skin of cows
c. high concentration of sanitizers in the wash water may cause irritation to milkers
d. A and B
e. A, B, and C |
|
Definition
|
|
Term
| Describe the process of premilking teat dipping and the benefits of such a program. |
|
Definition
The cows' teats are dipped or sprayed with premilking germicidal (0.1% iodophor) without being washed. The germicidal is allowed to contact the teat skin for 15-30 seconds and then removed with individual towels.
Benefits:
1. may reduce environmental mastitis by as much as 50%
2. Saves labor/time that is critical when high numbers of cows must be handled.
3. Can eliminate problems associated with washing teats (excess water, chapping, irritation, introduction of mastitis pathogens via water supply, dirty water collecting at top of liner) |
|
|
Term
| T/F: individual towels should be used to dry the cow's teats. |
|
Definition
|
|
Term
| Why is drying following predipping so imperative? |
|
Definition
1. Removes excess water (if washing) or excess germicidal on teat ends.
2. Helps prevent liner slip by increasing friction between liner and teat skin.
3. Minimizes disinfectant contamination of milk. |
|
|
Term
| T/F: with any premilking regimen, the milking machine should be applied within 1 minute of beginning udder preparation, as preparation stimulates milk letdown. |
|
Definition
|
|
Term
| While many herds do not perform manual forestripping, why would this be of benefit? |
|
Definition
1. May decrease overall milking time for the cow.
2. Can provide early clinical mastitis detection and removal of the poor milk fraction. |
|
|
Term
| T/F: Incomplete milkout leads to increased chances of infection. |
|
Definition
|
|
Term
| Postmilking teat dipping can reduce new infection rates by as much as ____%. |
|
Definition
|
|
Term
| What are the benefits and drawbacks to latex postmilking dips? |
|
Definition
Good:
1. Provide protective coating around teat end to help prevent environmental bacterial contamination between milking.
Bad:
1. Not as effective in preventing Gram + infection
2. More expensive and require more labor prior to milking |
|
|
Term
Damage to teats can be caused by all of the following except:
a. Blow/collision
b. Harsh chemicals
c. Poorly maintained milking equipment
d. Freezing of the teats in harsh weather
e. All of the above can cause teat damage |
|
Definition
| e. All of the above can cause teat damage |
|
|
Term
| T/F: Latex gloves greatly reduce the spread of contagious pathogens when worn by workers in the dairy. |
|
Definition
False: they are not changed frequently, so basically protect the workers from continuous exposure to teat dip solutions.
However, sanitation of the cluster and milker's hands between animals does help prevent the spread of highly contagious organisms. |
|
|
Term
| T/F: Cows make more milk when they are resting. |
|
Definition
True
Cows rest when their environment is clean and comfy. |
|
|
Term
| What environmental management factor(s) is(are) a common cause of coliform mastitis. |
|
Definition
1. Inadequate manure removal
2. High temperature stress (summer heat waves) |
|
|
Term
Which of the following cow scenarios is least likely to acquire environmental mastitis?
a. Cows out on pasture in July
b. Housed cows in July
c. Housed cows in a manure-filled pen (stall?)
d. Cows housed on wood shavings
e. Cows housed in group housing with little room to move. |
|
Definition
| a. Cows on pasture in July |
|
|
Term
| After milking, the teat sphincter is relaxed for up to ____ hours. |
|
Definition
|
|
Term
| T/F: cows are very susceptible to shock. |
|
Definition
| True. Stray voltage can cause poor milk letdown, refusal to eat or drink from metal feeders/bowls, and mastitis. To evaluate whether stray voltage is a problem in a unit requires special equipment which is set up to monitor and graph the voltages over 2-3 days. |
|
|
Term
| Review Dr. Gordon's Powerpoint! |
|
Definition
|
|
Term
| Why are vaccines against Staph aureus not usually effective? |
|
Definition
| The idea behind mastitis vaccines is to increase antibody in the mammary gland which opsonizes the bacteria and allows phagocytosis by the leukocytes. However, high levels of antibodies don't get into the gland until the vascular endothelium and glandular epithelium become more permeable during inflammation. In addition, the poor function of phagocytic cells in milk also makes it difficult to kill S. aureus even when specific antibody is present. |
|
|
Term
| T/F: The J5 vaccine is a highly effective vaccine that only requires one dose for complete protection. |
|
Definition
False: the J5 vaccine does have proven efficacy in preventing or lessening the severity of coliform mastitis, but it must be given at frequent intervals. It is commonly given about a month before the beginning of lactation and once or twice during lactation. The antibody production is aimed at the common core antigens of gram-negative bacteria. However, the antibody has a relatively short half-life, so the vaccine must be administered more frequently.
Basically, this vaccine helps to prevent endotoxemia/bacteremia associated with coliform mastitis. |
|
|
Term
| T/F: Mycoplasma bovis and the streps (agalactiae, dysgalactiae, uberis) can be effectively controlled through vaccination programs. |
|
Definition
| False--lots of research has been done but results have been unrewarding. |
|
|
Term
| List one advantage and one disadvantage to using pasteurized waste milk in calves: |
|
Definition
1. If heated to 70C for 3 min, it effectively kills mycoplasma and helps lower maintenance costs by utilizing the extra milk.
2. Pasteurization does not always effectively kill Staph and strep, so the potential exists to unintentionally infect replacement heifers through the use of pasteurized waste milk. |
|
|
Term
| T/F: formic acid has been used to help restrict bacterial growth (spoilage) in colostrum, waste milk, and milk replacer. |
|
Definition
| True--has been helpful in preventing transmission of S. aureus and M. bovis |
|
|
Term
For a case of acute clinical coliform mastitis, all of the following treatments would be acceptable except:
a. Administration of systemic antibiotics
b. Administration of intramammary antibiotics
c. Repeated stripping-out of the infected quarter with the help of oxytocin
d. Administering corticosteroids and banamine to help combat endotoxic shock
e. Administration of hypertonic saline |
|
Definition
b. Administration of intramammary antibiotics
For cows with acute clinical coliform mastitis in cows with a fever of 105-108 and signs of toxemia, treatment goals should be aimed systemically.
In cases where gangrenous mastitis results and subcutaneous edema is apparent, treatment should be the same as for regular coliform mastitis, but the producer may want to amputate the teat(s) to allow for adequate drainage. |
|
|
Term
| T/F: acute flare-ups of staphylococcal and streptococcal mastitis infections during lactation can be treated with intramammary products on the market. |
|
Definition
| True--just be aware that it is hard to clear many infections during lactation and results are often frustrating. In addition, treating without a culture is just as bad as no treatment at all. ALWAYS CULTURE (don't have to do susceptibility though). |
|
|
Term
| _____________________ is an obligate intramammary pathogen. |
|
Definition
|
|
Term
| The drug of choice for S. agalactiae mastitis is __________________, and more recently has been combined with ____________________ (another drug). |
|
Definition
|
|
Term
| Give a protocol for herd eradication of S. agalactiae. |
|
Definition
1. Culture the entire herd.
2. Treat positive cows and place at end of milking line.
3. Reculture the entire herd in one month.
4. Retreat positive cows.
5. Reculture the entire herd in one month.
6. Cull any positive cows.
Note: all freshening cows and heifers and any purchased animals should be culture-negative before being placed in the milking line. |
|
|
Term
| Intramammary/systemic treatment of lactating cows with penicillin should give a 90% cure rate for S. agalactiae mastitis. |
|
Definition
Intramammary
Systemic penicillin treatment is done by some individuals in addition to intramammary treatment, but it is basically just a way to generate veterinarian income without resulting in a significantly higher cure rate. |
|
|
Term
| T/F: the blitz procedure is the method of choice for S. agalactiae eradication in a herd. |
|
Definition
False. This procedure frequently failed because of breakdowns in sanitation, changes in personnel, etc.
This procedure was to treat all cows w/ clinical mastitis, use dry cow therapy, use good milking techniques, and cull any nonresponsive animals. Response was monitored by routine culture and eradication was expected within 2-4 years. |
|
|
Term
| T/F: S. aureus mastitis organisms are often penicillin-sensitive. |
|
Definition
| False--usually penicillin resistant |
|
|
Term
| S. aureus treatment has classically been better effected during the lactation/dry period. |
|
Definition
|
|
Term
| T/F: treatment is not attempted when cows are infected with mycoplasma species. |
|
Definition
| True--these cows should be removed from the herd as rapidly as possible to prevent spread to other cows. |
|
|
Term
The highest rate of new udder infections occurs:
a. During the first three weeks of the dry period
b. During the first three weeks of lactation
c. During the last three weeks of lactation
d. During the last three weeks of the dry period
e. None of the above |
|
Definition
A. during the first three weeks of the dry period
Also have higher infection rates during the periparturient period, so could argue that the last three weeks of the dry period are also true. |
|
|
Term
| When is antimicrobial therapy of cows the most helpful in preventing new infections at dry off? |
|
Definition
| Abx at the time of dry off--do routine treatment of all quarters of cows. |
|
|
Term
| List a few advantages and a few disadvantages of dry cow therapy. |
|
Definition
Advantages:
1. Higher persistency products can be used
2. Drugs not eliminated from udder by milking
3. Damaged tissue may be regenerated
4. Saleable milk is not contaminated with drug residues.
5. Tx at dry off can cure up to 50% of S. aureus and 90% of strep infections
Disadvantages:
1. Not effective in reducing new infections from environmental organisms during the periparturient period because the abx is gone from the udder at that stage.
2. Many abx formulations are not effective against coliforms even during early dry period. |
|
|
Term
| When performing dry cow therapy, describe the technique: |
|
Definition
1. Clean and dry teats
2. Scrub teat ends with alcohol pads (separate pad for each teat)
3. Insert cannulae PARTIALLY into teat canal--use separate syringe for each infusion
4. Before and after each infusion, the teat should be dipped with post-milking teat dip preparation.
5. Sanitize hands between each treatment. |
|
|
Term
| T/F: palpation of the udder is a routine part of health management and soundness exams in ewes. |
|
Definition
|
|
Term
| T/F: ewes with evidence of fibrosis and scarring or a history of clinical mastitis should be culled. |
|
Definition
|
|
Term
| ________________________, ____________________, and _________________ are agents responsible for causing acute gangrenous mastitis in sheep. |
|
Definition
Staphylococcus aureus
Pasteurella multocida
Mannheimia haemolytica |
|
|
Term
| __________________ doesn't strictly cause mastitis, but is capable of causing "hardbag" in sheep. |
|
Definition
| Ovine Progressive Pneumonia |
|
|
Term
| T/F: sheep rations should be decreased at dry-off to help prevent mastitis development. |
|
Definition
|
|
Term
| T/F: cows will have an increased SCC compared to goats. |
|
Definition
| False--goats have high SCC compared to cows. |
|
|
Term
| Goats secrete milk via ____________ glands, while cows secrete milk via ____________ glands. |
|
Definition
|
|
Term
| __________________ produces very large abscesses within the mammary gland of goats and is refractory to treatment. |
|
Definition
|
|
Term
| _____________________ are the most common cause of mastitis in goats and are probably more often involved in subclinical or mild mastitis. |
|
Definition
| Coagulase-negative staphylococci |
|
|
Term
| ____________________ is highly contagious and is a cause of sudden agalactia in dairy goats. |
|
Definition
|
|
Term
| _________________ causes mastitis and decreased milk production in goats. |
|
Definition
| Mycoplasma mycoides subsp. mycoides LC |
|
|
Term
| ______________________ causes problems in goats similar to OPP of sheep. |
|
Definition
| Caprine arthritis encephalitis virus |
|
|
Term
| T/F: mastitis is relatively common in mares and is most often treated by frequent milking, hot packs, and oral/IM/IV antimicrobials. |
|
Definition
| False: it is treated by frequent milking, hot packs, and oral/IV/IM abx, but it is relatively rare. |
|
|
Term
|
Definition
| Metritis, mastitis, agalactia |
|
|
Term
| The two most common culprits of MMA in sows are _________________ and ___________________. |
|
Definition
Klebsiella pneumoniae
E. coli |
|
|
Term
| Why is culture of the teat more difficult in sows? |
|
Definition
| Anatomy of the teat--multiple openings (1-3 teat canals each coming from a different subcomplex) |
|
|
Term
| T/F: most cases of MMA in sows clear up spontaneously. |
|
Definition
| True--usually clear up in 1-6 days |
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