Dairy herd health

Question 1

What is the ideal environment for a newborn dairy calf?

Answer 1

Born in clean, dry pen
- remove from cow ASAP
- dip navel with 7% iodine ASAP
- colostrum ASAP

Question 2

What are the two most important factors for keeping disease out of newborn calves?

Answer 2

Colostrum and cleanliness

Question 3

What different methods are there to measure colostrum quality?

Answer 3

Colostometer- idiot proofed, but easy to break (rarely used)
Brix refractometer

Question 4

What are the ideal measures of colostrum?

Answer 4

Serum immunoglobulin: >1000 mg/dL OK, >1500 mg/dl even better

Total serum protein: ideally >5.5 mg/dL (slight difference between plasma (6) and serum (5.5))

Question 5

What calves should you test the serum protein levels of?

Answer 5

Calves 1-7 days of age
- exclude sick calves (scours, dehydration can increase the protein falsely)

Question 6

What are some colostrum alternatives? When should you use them?

Answer 6

Replacement colostrum is the only thing you should be used (>125 g IgG) rather than supplements
- these are always a second choice to high quality colostrum

Can use when there is a lack of quality colostrum, as a part of the infectious disease control program (against Johnes, BLV, mycoplasma) or if it is the most convenient way to get colostrum into calves in a timely manner

Question 7

What is the ideal time to get colostrum into calves?

Answer 7

Within the first 4-6 hours of life

Question 8

What should be the goals of a dairy heifer herd health program?

Answer 8

-Ensure good growth
-prevent scours and respiratory disease
-prepare heifers for breeding (prevent repro disease)

Question 9

What are the most important factors affecting disease burden in a dairy heifer operation?

Answer 9

Biosecurity, weather, housing, nutrition, vaccination

Question 10

Why is parasite control so important in dairy heifers?

Answer 10

They are often raised in small lots with a large number of calves per acre
- heifers raised in a barn can never get GI worms (have not been exposed)

Question 11

When is coccidia the biggest problem in heifers? Ostertagia?

Answer 11

Coccidia: a problem from 30 days of age to 1-2 years of age. Often a secondary problem from stress of weaning or other factors

Ostertagia (brown stomach worm): a problem from when the calf starts grazing to 2-3 years old. Primary worm of economic importance

Question 12

What are the main control strategies for coccidia?

Answer 12

Frequent deworming
- dairy heifers should be on coccidiostat all the time (monensin, lasalocid, decoquinate)
- having coccidiostat in feed does not guarantee the animal is getting the correct dose
- changing feed or coccidiostat at a critical stress time may leave animals at risk

Question 13

T/F: a large enough disease challenge can overcome any vaccination program

Answer 13

True

Question 14

T/F: a single dose of a killed vaccine can be effective in some cases

Answer 14

False
-modified live vaccines are so much better

Question 15

What are some of the main considerations when using modified live vaccines?

Answer 15

-must be viable when administered
-must infect macrophages and replicate in order to stimulate the immune system
-the antigen mass is very small compared to killed vaccines

Question 16

What are some ways to reduce the burden of respiratory disease due to the stress of weaning?

Answer 16

Pre- weaning vaccines, feeding the same feed pre and post weaning, group housing of smaller groups immediately post weaning, movement of 1 barn section of calves at the same time

Question 17

What vaccinations should be given pre-weaning? What should be done from 4-8 months? What should be given prebreeding?

Answer 17

Pre weaning: MLV IBR-BVD-PI3-BRSV, +/- Pasteurella, blackleg

4-8 months: MLV IBR-BVD-PI3-BRSV, blackleg, parasite control, brucella? (not really necessary anymore)

Pre-breeding: MLV IBR-BVD-PI3-BRSV, Blackleg, lepto, deworming

Question 18

What are the goals of cow herd vaccination programs?

Answer 18

To promote reproductive efficiency, promote health of the cow and promote colostral immunity

Can use event based (more common) or calendar based program (6 month intervals)

Question 19

Why are all the reasons for palpating cows on routine visits?

Answer 19

-postpartum checks
-cows not cycling and past VWP
-cows bred 35 days or more
-cows confirmed pregnant and show signs of estrus
-cows with 3 or more breedings
-rechecks for cysts, retained placenta or other problems

Question 20

Which group of cows is the most important group to check on palpations?

Answer 20

No heat cows- these cows need semen

Question 21

What cow is the most important to identify?

Answer 21

The open cow
- need to make important decision- try again or cull