Replacement heifers, transition period, parturition in dairy cows

Question 1

Which bedding material is associated w/ growth of Klebsiella?

Answer 1

wood shavings

Question 2

What is important about replacement heifers?

Answer 2

• 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

Question 3

Replacement heifer stats in Canada?

Answer 3

• preweaning (first 8 weeks) mortality ~6%
• weaned heifer mortality ~2%
• first lactation culling rate ~15%

Question 4

What should you do with a dairy calf post birth?

Answer 4

• 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)

Question 5

How do we assess colostral quality in dairy cows?

Answer 5

• hydrometer or colostrometer, refractometer, weight of 1st milking colostrum
• hydrometer & refractometer overestimate IgG concentration but are better than weight

Question 6

How do we assess transfer of passive immunity in dairy cows?

Answer 6

• 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

Question 7

What is important during preweaning of dairy calves?

Answer 7

• 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

Question 8

What must be used for dehorning/disbudding/ supernumerary teat removal?

Answer 8

• analgesia & hemostasis

Question 9

What is important to keep dairy cows warm in hutch housing?

Answer 9

• wind breaks, deep bedding, exposure to the sun

Question 10

What are feeding strategies in dairy calves?

Answer 10

• 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)

Question 11

What does milk replacer quality depend on?

Answer 11

protein source

Question 12

What does calf starter for dairy cows look like?

Answer 12

pelleted, </= 22% crude protein, 30-40% starch

Question 13

Why should you give dairy calves forage?

Answer 13

• calves cannot digest forage, but high fiber forage buffers rumen acid production & increases gut wall health

Question 14

What is important about weaning in dairy calves?

Answer 14

• > 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

Question 15

what are step down protocols during weaning in dairy calves?

Answer 15

• gradual reduction in milk provided
• 2-3 steps down over 2-3 wks

Question 16

What is important during the growing period for dairy calves?

Answer 16

• 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

Question 17

how do we monitor growth in dairy calves?

Answer 17

• weight tape
• scale

Question 18

what is important in regards to breeding heifers?

Answer 18

• synchronization is less common w/ dairy heifers
• beware of freemartins

Question 19

Grouping dry cows into 2 groups:

Answer 19

2 groups
- early dry period (low energy ration)
- close to calving (increased energy density in ration)

Question 20

Does a single dry cow ration make more sense?

Answer 20

• 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

Question 21

How do we control metabolic disease in dairy cattle pre-calving?

Answer 21

• > 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

Question 22

What are the different pen strategies for calving dairy cows?

Answer 22

• individual stall
• pre-fresh pen

Question 23

What are the pros & cons of individual stalls at calving of dairy cows?

Answer 23

• need hourly checks then move to calving stall
• easier disease control
• easier control of colostral intake
• more employees are needed

Question 24

What are the pros & cons of calving in pre-fresh pen in dairy cows?

Answer 24

• bedding packs
• less supervision (missed dystocias)
• decreased dystocia risk as cows not moving into new pen
• more difficult disease & colostral intake control

Question 25

What are the 3 stages of parturition in dairy cows?

Answer 25

1. calf engages w/ pelvis
2. calf is born
3. placenta is passed

Question 26

what is important during parturition in dairy cattle?

Answer 26

• intervene at appropriate time
• proper use of traction
• careful hygiene
• simple plan of action for calving
• keep records

Question 27

when is a calving considered abnormal?

Answer 27

if you have to intervene at all

Question 28

What are dystocias and what should we check for?

Answer 28

• abnormal calving
• rate should be < 5%
• check for PAIRS & TEARS

Question 29

What is the most common dystocia in heifers?

Answer 29

feto-pelvic disproportion

Question 30

What is the most common dystocia in cows?

Answer 30

malpresentation

Question 31

What can we do about dystocia?

Answer 31

• correct malpresentations
• potentially pull calf
• c-section
• fetotomy

Question 32

What is the fate of the dairy cow post parturition?

Answer 32

• 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