Calf & Youngstock Rearing Flashcards
what % of cows and heifers should require calving assistance
<2% cows
<5% heifers
how much space should a cow have for calving
10-12m^2
how much g of colostrum is needed
50g of Ig/litre of colostrum
what are factors that affect quality of colostrum
Nutrition
Heifer
Vaccination status of dam
how do you measure the quality of colostrum
- colostrometer
- brix
what is the % indicates good quality colostrum in brix
22% good
<20% bad
why does colostrum need to be given quickly
Calf gut ‘closes’ within a few hours of birth
Closure accelerates after first feed — not volume dependent
Mucosal protection though persists
how much colostrum should be given calf
10-15% body weight in first 4-6 hours
3-4 litres is a good target within a reasonable time period
how should colostrum be given quitely
Low stress
Make the job easy
Method:
- Cow
- Bottle
- Tube
why does colostrum need to be given cleanly
bacteria can lead to
reduced Ig
reduced absorption
increased levels of disease
what TBC and TCC should be in colostrum
TBC <100,000 cfu/ml
TCC <10,000 cfu/ml
what % of calves should have total protein levels >54g/L
85% calves should have total protein levels of >54g/L
how much energy does milk replacer and whole milk provide approx
1L of calf milk replacer at a concentration of 125g/L –> provides 2.5MJ
1L of whole milk is closer to ~2.8MJ
what is the lower CT of calves
<21d 15C
>21d 5C
what is the upper CT of calves
25C
what does high level milk feeding cause
May cause loose feces NOT scouring and no requirement for treatment
Improves growth rate
Improves innate immune function
Double birth weight at point of weaning
what should the weight be by the point of weaning
should be doubled
what helps rumen development
- concentrates (VFAs)
- water
- forage
what needs to occur for rumen deveopment to occur
Muscle development
Blood vessel supply increases
Papillary development
Bacterial ecosystem
what is weaning based on
Weight
Age
Concentrate intake
Monitor success of weaning
BHBs?
- Indicator of rumen epithelium maturation and its ability to use VFA production by fermentation of solid feeds by the rumen microflora
Reduce stress
what is quality of stockmanship
Communication
Number of stock persons
Technical knowledge
Empathy
Motivation
Time
what are considerations for good calf housing
Moisture
Air
Cleanliness
Temperature
what are the factors that influence the stack effect
- # and size of animals
- surface area of building
- gradient of roof
what is the target for age at first calving
22-24 months
what % of adult BW should heifers be at breeding
65% of adult BW
what % of adult BW should heifers be at post-calving
85%
how much should an holstein fresian heifer weight at 24 months
average 480kg (1050 pounds)
how much should an holstein fresian heifer be at mature weight
550kg average (1200 lb)
what should the DLWG be from birth to calving at 24 months for replacement heifers
0.6kg (1.3lb)
what should the target mortality be for heifers from 3-24 months
<1%
how do you define the scouring calf problem on a dairy
Age affected
Numbers/% affected
Severity
Duration of problem
Patterns (season, groups, signalment, stockperson)
what should be the target of calves treated for scours
<5%
what are the calf scour pathogens and their approx age
when you arrive to a farm that is having a calf scour problem what should you do for a clinical exam & history
Severity, age, appearance of stool, pyrexia, management history
Relevant history of farm:
- Previous cases/diagnostics, treatment being used, health and vaccination status of herd
Opportunity to examine the farm risk factors
how can inadequate milk feed lead to scours
Time of day
Method of feeding
Volume
Temperature
Concentration
Mixing
Cleanliness
Poor choice of powder
Ruminal drinking
what are two key factors in hygiene
- build up
reduce the build up of pathogens that is occuring in environment
- spread
prevent spread from one animal to another
how are scours diagnosed
Some patter recognition
Calf side kits:
- E. Coli, Rotavirus, Coronavirus, Cryptosporidium
Microscopy:
- Cryptosporidium, Cocci
Culture of feces especially Salmonella
Blood/tissue for BVD antigen
Post-mortem
- Concurrent disease, rumenal drinking, culture
Remember to monitor for passive transfer
No ‘positive results’?
what are specific preventative treatments
Vaccinations available for:
- Rota, corona, E.coli
- Salmonella
- BVD
Halofuginone:
- Prophylactic medication for cryptosporidium
Coccidiostats:
- Can be given as an individual one-off prophylactic or therapeutic drench (toltrazuril or diclazuril) or given as in-feed medication (deccoquinate)
Improve husbandry is an effective preventative for all causes of scours!
what is the target % of calves treated for pneumonia
<5%
what is the cost of pneumoina to a dairy farmer
4% reduction in first lactation
8% reduction in 2nd lactation
109 less milking days
2 week delay to first calving
>£1,000
how is pneumonia diagnosed
Paired serology
Maternal antibodies can interfere with results
Long time for results
Culture (nasopharyngeal swabs, BLA, trans-tracheal)
PCR
Post-mortem
- Lungs: gross appearance, histology, culture, PCR
Best candidate for diagnostics?
Are all findings significant?
what are pneumonia pathogens
Mycoplasma
Mannheimia hemolytica
Pasteurella multocida
Histophilus somni
Parainfluenza virus 3 (PIV3)
Respiratory syncytial virus (RSV)
Bovine viral diarrhea (BVD)
Infectious bovine rhinotracheitis (IBR)
what are specific preventative treatments
There are vaccines for almost everything although scientific literature is sometimes lacking
So you want to vaccinate for your respiratory problem
what are questions to consider when deciding what pneumonia vaccine to admin
Is there a perceived respiratory disease problem?
Is there evidence of specific pathogen involved?
Is there a vaccine available?
Are vaccinated animals going to be able to mount an effective immune response?
