Beef 2 Flashcards
Objectives of calving management
-minimize losses at birth
-minimize post-natal losses
-reduce disease in calving females
Two cattle breeds
-bos indicus- hump, tropical climate
-bos toris
Calf crop %
(Number of calves weaned/ number of cows exposed to bull) x100
What results in reduction in calf crop?
-failure to conceive (infertility)
-failure to calve (abortions and stillbirth)
-failure to survive neonatal period
-failure to wean (calf mortality on pasture)
Factors contributing to neonatal losses
-dystocia
-maternal nutrition
-maternal behaviour
-climate (hypothermia)
-infectious agents and environment
Calf mortality linked with dystocia
-69% of preweaning mortality within first 96hrs of birth and most contributed to dystocia
-2.7% die within 24hrs
-calves with higher calving difficulty are 2.4x more likely to be sick in first 45 days of life
-calves that experience dystocia are 13x more likely to die within 12 hrs of birth
Who is most likely to experience dystocia?
-calves born to 1st calf heifers
(5% cows assisted, 18.7% heifers, overall 7%)
-male calves more likely than females
-twins
-calves born to cows in poor body condition
Dystocia prevention
Likely linked with continental breeds and small european breeds being bred together
Must select bulls for low birth weights in calves
**weights account for 30-50% of variability
Ways to select for low birth weights
-use an easy calving breed especially on heifers
(eg. long horned bull)
-select bulls with low birth weights
-use Expected Progeny Difference data on purebred bulls
Expected progeny difference
Pooling all genetic information of an animal into one number
-used to compare bulls within breed
-use lbs
*need to know breed average for EPD
*typically have an accuracy value
Calving ease vs birth weight EPD
-CE: the higher the number predicts more calving ease
-BW: a lower EPD predicts more calving ease
Replacement heifer rearing program
Ensure that heifers are mature and large enough at breeding to prevent dystocia
-need to be 65% of mature weight at breeding
-85% of mature weight at calving
-avoid over conditioning
-do not restrict nutritional intake in late gestation
-pelvic measurements are of limited value because larger pelvis often means larger calves so not necessarily better
Adequate surveillance and early assistance
-Can lead up to 9% increase in number of animals cycling at the onset of the breeding season and a 14% increase in fall preg
-increases likelihood of live calf
Stage 1 of calving
3hrs-72 hrs
-ligaments of pelvis relax, cervix and vagina dilate, cervical mucous plug released
-cows separate from herd
-tail raised, back arched, may strain
Stage 2 of calving
-appearance of water bag
-expulsion of calf through birth canal
-30mins to 3 hrs
Stage 3 of calving
-expulsion of fetal membranes
-usually expelled within a few hours of birth
-involution of uterus may take up to 40days
Calving heifers before cows
-dystocia prevention
-2-3 wks before allowing owner to concentrate workload early in calving season because heifers more likely to have dystocia
-will allow heifers to calve on least contaminated calving area
-lines up timing for next breeding season because they need longer to return to estrus than cows
When should you interfere>
-cow actively strains for 40mins and no progress
-90 mins have passes since the first waterbag appeared
-legs emerge with sole of hooves up= coming backwards
-head or tail only emerged
-cow with more than 5-6hrs of anxiety
-an uncalved cow mothering another calf
When should a producer call for help?
-calf is too big
-can’t get hands alongside feet in pelvis
-can’t get head and feet into pelvis at same time
-heifer been actively straining for 30mins and can’t get head and feet into birth canal
-if you can’t correct the position in 20mins or less
What % of beef heifers require assistance at calving?
~18%
Weak calf syndrome
-in birth canal too long
-head swollen, tongue swollen, acidotic= dumb
Calf from birth to sternal recumbency
-should be 2-3mins (more than 15mins than likely acidotic)
Suckle reflex
-weak suckle= fail to consume colostrum= poor health
-connection between suckle reflex and calving ease
Assessing suckle reflex
-10mins after birth
-two fingers along length of top of calfs tongue
-gently rub roof of calves mouth
Weak= poor jaw tone and poor suckling rhythm
Strong= good jaw tone, good rhythm, quick strong latch
When is Abnormal maternal behaviour likely to occur?
-most likely in 1st calf heifers
and with heifers and cows with dystocia
-prolonged birth
-less vigorous calf (heifers)
-high incidence in poor condition cows
Treating abnormal mothering behaviour
-match cow and calf correctly
-confine them in box stall with no disturbances
-tube the calf with colostrum
-restrain cow regularly so calf can suck
-make sure calf is not sick
-potential for fostering
Hypothermia issues
-Calf within first 2-3hrs is unable to regulate body temp well
-even a normal calf can easily become hypothermic
Chilled calves will not get up, suckle and not get colostrum
Climate/seasonal effects
Calves born from Dec-Mar were more likely to die
*Calves that were hypothermic were 4.3x more likely to die
Hypothermia protocol
An electronic thermometer is essential to note the severity of hypothermia
*calves under 35 C will have cold mouth, cold limbs, no suck reflex, unable to move limbs
*check whether it has suckled- look at teat of cow
Normal calf temp
More than 37.8 C
*consider duct tape to protect ears from freezing
What to do when a calf is considered hypothermic?
-tube with 1-2 L of warm colostrum
-place in warm room or hot box
-hot water baths essential for calves less than 26C
-warm fluids IV, warm water enemas
Ways to decrease infection pressure
-minimize confinement of the cow herd
-utilize separate wintering and calving areas
-move cows onto calving area 2 weeks before calving
-rotate calving area from year to year
Lacombe-type calving management
1.Wintering area
2. Calving area 2 weeks before calving
3. Move pairs within 24 hrs of calving into two nursing areas
4. Summer pasture at 3-4weeks of age
Sandhills calving system
- Overwintering
- Calving area 1
- Calving area 2
- Calving area 3
5.Calving area 4
6 Calving area 5
** cow calf pairs are left behind, pregnant cows moved to next clean calving area
Ways to decrease infection pressure
-snow removal and adequate bedding
-separate nursery areas for cow-calf pairs
-avoid restricted feeding/bedding areas
-creep areas or calf condos
-quarantine of diarrheic calves
How to increase immunity
-colostrum management
-vaccines
Passive transfer of immunity
-syndesmochorial placentation so no transfer of immunoglobulins from maternal to fetal circulation
**newborn calf has no maternal antibodies and needs colostrum
Timing fo colostrum congestion
-Newborn enterocytes can absorb macromolecules for first ~24hrs of life
**but optimal absorption for first 4 hours and absorptive capacity will decrease rapidly after 12 hours of life
FAilure of passive transfer
-Take blood sample 1-7days old
-less than 10g/dl using Radial Immunodiffusion or total serum protein or Brix refractometer
-Turbidity test using sodium sulfite or zinc sulfate used for qualitative assessment
-other studies suggest adequate colostrum should be more than 24 g/dl
How much colostrum does calf need?
1-2L for first 4 hours
-gut closure at 6hrs and continues until 24-36hrs
-calves need 80-150g of immunoglobulin (1-2L of colostrum)
-normal calves will drink between 1-2 L/feeding
Difference in beef vs dairy cow colostrum
Beef has 150g of IgG/L on avg compared to 64g in dairy cows
Ways to get colostrum
- milk dam and force feed calves
- Use colostrum from other calvings
- colostrum replacer
**ensure 100g of IgG, prefer 150g
**avoid buying colostrum from dairies
Colostrum storage
Any cows that is handled should be milked out
-store for 7-10 days in fridge
-frozen colostrum should be stored in ziploc laid flat and thaw in warm water
When should intervention happen for calves?
if they havent suckled within 2-3hrs
**give them more time in warm weather and might need to interfere sooner in cold weather
*assume all abandoned calves have not suckled
Vaccinations of calves
- Vaccinate dam pre-calving
*e coli and rota/corona virus vaccines
*6 weeks and 2 weeks pre calving - Colostrum still important
