Intro to diseases of calves Flashcards
There is a 7 days old calf with diarrhea. She is 10% dehydrated and weighs 50 kg. She has lost a suckle reflex and can not stand up. In order to correct dehydration, the veterinarian should administer i.v. fluids.
A. 5 litres for replacement + 2,5 litres for maintenance
B. 3 litres for replacement + 2 litres for maintenance
C. 2 litres for replacement + 2 litres for maintenance
A. 5 litres for replacement + 2,5 litres for maintenance
Which of the following statements are correct
A. Cryptosporidiosis causes diarrhoea in calves and the primary infection agent is protozoa. This parasite is zoonotic and systemic antibacterial treatment is not effective.
B. Cryptosporidiosis causes diarrhoea in calves and the primary infectious agent is protozoa. This parasite is zoonotic, but we can effectively treat with systemic antibiotic and prevent the spread of infection by using disinfection.
C. Cryptosporidiosis causes diarrhoea in calves and the primary infection agent is bacteria. This bacteria is zoonotic, but we can effectively treat with an oral antibiotic and prevent the spread of infection by using disinfection.
A. Cryptosporidiosis causes diarrhoea in calves and the primary infection agent is protozoa. This parasite is zoonotic and systemic antibacterial treatment is not effective.
The main cause of neonatal septicemia is the failure of passive immunity in calves.
We can improve the level of passive immunity by using vaccination against the most prevalent diseases and by using preventive antibacterial treatment.
Select one:
True
False
False
Calf life can be divided into periods. (4)
0-4 days: colostrum period
4 days- 2,5/3 months: pre-weaning period
weaning until 13-15 months: pre-breeding period
insemination- calving: pregnancy and prep for calving period
heifer minimum body mass required for insemination and conception?
ca 370 kg for holstein
ayshire may be slightly lighter
age 13-15 months, inseminations may begin around 12 months already because on average more than one insemination is needed to produce pregnancy.
95% of calf diseases are one of two
diarrhea or respiratory disease
Diff. between calf and adult bovine stomachs.
In calves, abomasum makes up 80% of stomachs’ volume. Calves also have a functional esophageal groove.
In adult cows, the abomasum makes up 7% of the forestomaches.
How to stimulate development of forestomaches?
begin to feed roughage (hay) AND starter feed.
starter feed (concentrates like muesli) especially, help the ruminal papillae to develop.
don’t forget to provide water even when there is milk! its needed for promoting roughage intake.
Why does calf milk need to be given warm?
due to the physiological stimulus the brain requires to close the esophageal groove (temp., smell, flavor) when suckling or drinking milk otherwise.
if the groove doesn’t close due to cold milk, the milk will go to the rumen and can cause dietary indiscretion and diarrhea.
VFAs produced by ruminal bacteria:
propionate
acetate
butyrate
What VFAs do starter feeds produce in the rumen?
propionic &
butyric acids
pH drops
What VFA does hay digestion produce in the rumen?
acetic acid
pH increases slightly compared to propionic and butyric acids which both definitely decrease pH
What feeds promotes ruminal papillae development?
starter feed or muesli, basically concentrates in order to produce butyric and propionic acids because lower pH stimulates papillae development.
NOT hay although it should be provided as well.
Fibre (hay, silage) is necessary in calves for: (5)
- Development of ruminal volume
- For muscular activity
- Rumination
- Increase pH
- growing Fibre digesting bacteria
What makes the left so dark in color?
dense capillarity
(is a good thing)
Describe Colostrum quality.
- Measure the colostrum quality with colostrometer (or refractometer).
– NB! Temperature of colostrum for this measuring technique must be cooled down to 20-25°C.
+ Fat influences the results.
– Antibodies are farm-specific
– Correlation between specific gravity and IgG content 60-90%.
Ideally, minimum 50 g IgG per liter of colostrum.
Rule of thumb: the older the animal, the better the colostrum quality. + better protein quality in feed in the dry period.
Brix refractometer for
Checking colostrum quality.
- > 22% result = at least 50 g per liter of IgG
- No requirements for the temperature of the milk with this technique of measurement.
Testing herd level passive immunity.
- Absorption of macromolecules up to 24 h after birth.
– Maturation of intestinal cells, secretion of digestive enzymes at 12th hour after birth. - In order to make profound conclusions a sufficient sample size, sensitive test and correct target population are needed.
- Cut-off limit: TP 5.5 g/dl (correlation with Ig level 75%), alarm level 20%.
- Min 12 calves
- Minimum 6 hours between first feeding and blood sampling.
- Pref. All calves between 2 and 7 days suitable for testing.
plasma protein value that indicates good immunity?
and average immunity?
what about poor immunity?
> 6.0 g/dl indicates good immunity
5.5- 6.0 g/dl indicates average immunity
< 5.5 g/dl indicates poor immunity
How to interpret plasma/serum protein content in dehydrated calves?
Always measure HCT as well.
Or else you may have a falsely elevated total protein count but its in fact due to dehydration.
Severely dehydrated calves’ immunity should not be evaluated until after they are rehydrated.
High risk period or immunity gap in calves is when?
at 3-4 weeks of age is when passive immunity is at its lowest and active immunity is only developing.
