Replacement heifers, transition period, parturition in dairy cows Flashcards
Which bedding material is associated w/ growth of Klebsiella?
wood shavings
What is important about replacement heifers?
- genetic future of the farm
- contribute 22-25% cost of milk production (so need 1.5-2 lactations to make a profit)
- `20% of live heifer calves do not contribute to profit
- calves are 55% efficient in converting feed to body mass
Replacement heifer stats in Canada?
- preweaning (first 8 weeks) mortality ~6%
- weaned heifer mortality ~2%
- first lactation culling rate ~15%
What should you do with a dairy calf post birth?
- ensure calf is resuscitated
- navel dipping
- remove calf from cow to prevent disease transmission (like Johne’s)
- need to get > 300g IgG into calf by linear absorption: intranasal vaccination & colostral management for this (allow calf to suckle first; if doesn’t work may need to bottle feed calf; if this doesnt work may need to stomach tube calf)
How do we assess colostral quality in dairy cows?
- hydrometer or colostrometer, refractometer, weight of 1st milking colostrum
- hydrometer & refractometer overestimate IgG concentration but are better than weight
How do we assess transfer of passive immunity in dairy cows?
- serum total protein should be > 5.2 g/dl in healthy calves & 5.5 g/dl in sick calves (due to dehydration)
- sodium sulfite precipitation
- growth factors in colostrum
What is important during preweaning of dairy calves?
- 1st 6-8 wks of age
- calf often housed in a hutch
- feed appropriately
- hutches should be 2 m apart
- maybe pair housing
- dehorning/disbudding/ supernumerary teat removal as early as possible
What must be used for dehorning/disbudding/ supernumerary teat removal?
- analgesia & hemostasis
What is important to keep dairy cows warm in hutch housing?
- wind breaks, deep bedding, exposure to the sun
What are feeding strategies in dairy calves?
- milk + calf starter + forage
- 20% of body weight in milk should be fed per day initially in 2-3 feedings
- whole milk (best but people prefer to sell), milk replacer, waste milk (bad as a lot of these cows have been treated w/ abx or are colonized w/ bact)
What does milk replacer quality depend on?
protein source
What does calf starter for dairy cows look like?
pelleted, </= 22% crude protein, 30-40% starch
Why should you give dairy calves forage?
- calves cannot digest forage, but high fiber forage buffers rumen acid production & increases gut wall health
What is important about weaning in dairy calves?
- > 8 wks of age (10 wks seems ideal)
- solid feed intake is critical (2kg of starter per day)
- immune suppression (avoid vaccination & stressful procedures)
- less stressful in pair housed calves
what are step down protocols during weaning in dairy calves?
- gradual reduction in milk provided
- 2-3 steps down over 2-3 wks
What is important during the growing period for dairy calves?
- group housing
- ration formulated for their stage of growth
- monitor growth
- 70 kg more body weight at calving = 1000 kg more milk in first lactation
how do we monitor growth in dairy calves?
- weight tape
- scale
what is important in regards to breeding heifers?
- synchronization is less common w/ dairy heifers
- beware of freemartins
Grouping dry cows into 2 groups:
2 groups
- early dry period (low energy ration)
- close to calving (increased energy density in ration)
Does a single dry cow ration make more sense?
- would have a consistent ration (rumen microflora takes at least 3 weeks to adapt to a dietary change)
- less pen moves (cause social disruption)
- move in the industry to move towards this
How do we control metabolic disease in dairy cattle pre-calving?
- > 30” or 75 cm feed bunk space / animal
- 1 kg decreased dry matter intake (DMI) = 2x risk of ketosis, 3x risk of metritis
- ideal BCS for calving (3.0-3.5) as higher body weight will make animal not eat enough in late pregnancy
- do not supplement calcium prepartum (shuts off natural calcium mechanisms & prevents cows from accessing them)
- avoid high-carb diets
- anionic salts (can allow cows to better access the calcium in their bones) OR oral calcium at calving
What are the different pen strategies for calving dairy cows?
- individual stall
- pre-fresh pen
What are the pros & cons of individual stalls at calving of dairy cows?
- need hourly checks then move to calving stall
- easier disease control
- easier control of colostral intake
- more employees are needed
What are the pros & cons of calving in pre-fresh pen in dairy cows?
- bedding packs
- less supervision (missed dystocias)
- decreased dystocia risk as cows not moving into new pen
- more difficult disease & colostral intake control
What are the 3 stages of parturition in dairy cows?
- calf engages w/ pelvis
- calf is born
- placenta is passed
what is important during parturition in dairy cattle?
- intervene at appropriate time
- proper use of traction
- careful hygiene
- simple plan of action for calving
- keep records
when is a calving considered abnormal?
if you have to intervene at all
What are dystocias and what should we check for?
- abnormal calving
- rate should be < 5%
- check for PAIRS & TEARS
What is the most common dystocia in heifers?
feto-pelvic disproportion
What is the most common dystocia in cows?
malpresentation
What can we do about dystocia?
- correct malpresentations
- potentially pull calf
- c-section
- fetotomy
What is the fate of the dairy cow post parturition?
- joins milking herd
- w/hold period for dry cow treatment
- separate fresh cow pen
- keep fresh & sick cow pens separate!
- milk fresh cows before sick cows
