Lecture 6: Dairy 2- Weaning to Calving 1 Flashcards
What is perinatal mortality?
-A calf carried to term or at least longer then 260d and born dead or dying within 24-48h of birth
-Dystocia plays a big role in the cause and (big cause of dystocia; fetal pelvic disproportion)
What are 3 diseases occurring after weaning?
-Pneumonia - MOST COMMON DISEASE!
-Emerging disease- Salmonella Dublin
-Coccidosis
What are a calfs respiratory disease defences?
-Nares: to filter pathogens and dust
-Cilia: move in one direction in trachea (stress and cld slows them down so increase infection in those conditions)
-Neutrophils, macrophages and cytokines
TRUE OR FASLE: Over reactive cells can cause bigger issues/damage from a mild infection?
TRUE.
Increased risk of bovine respiratory disease occurs with that factors?
-Mixing of animals (big stressors)
-Transportation
-Lightweight or younger animals within a group (Can’t get enough food)
-Persistent infection with BVDV
What is BRSV?
Bovine respiratory syncytial virus
-one of the 2 most important reparatory pathogens in dairy
-High morbidity (lots of calves get sick)
-Low mortality (most will recover)
-Predisposes cattle to severe bacterial pneumonia
-Mostly affects calves that are 2-6 months old
What are clinical signs for BRSV?
-High morbidity within 1 week (every calf sick)
-High fever
-Depression
-Anorexia
-Serous (clear) Nasal discharge
-increased respiratory rate (bc having diffucty breathing)
What is the secondary infection to BRSV?
Mannheim Haemolytica
-One of the 2 most important respiratory pathogens in dairy calves
-Normal bacterial inhabitant of upper airway (waits for BRSV or stressor and then goes down into lungs cases problems)
-Leading cause of death as a result of respiratory disease in calves
-Causes pneumonia on own but if co-infection with viral pathogen, mortality greatly increased (more likely to die infection foes into blood stream)
What are the clinical signs of Mannheim haemolytica?
-Fever
-Depression
-Anorexia
-Mucoid (lot of mucus/pus white) Nasal discharge
-Rapid respiration (area of lung will become very hard no air moving through)
-Moist, painful cough
What are the 2 most important respiratory pathogens in dairy calves?
-BRSV
-Mannhemia Haemolytica
What are prevention strategies for pneumonia?
-Minimize failure of transfer of immunity (colostrum)
-Improve housing and ventilation
-Adequate nutrition
-Vaccination
-Minimize weaning stress
What are key areas for housing to minimize infections/disease?
1.Reduce stocking density 35sqf for preened calf
2. Improve air quality (no dust, delivering fresh air continuously)
3. Prevent contact with older animals (old ones w/ pathogen can infect young ones)
-use bedding calves can nest in (stay warm)
Why is ventilation important?
-Link between respiratory disease and poorly ventilated calf housing
-Many different types
1. Postive pressure
2. Natural ventilation
3. Negative pressure
What are the 2 vaccination programs for calves?
-vax program is difficult due to the complex nature of the immature immune system of calves
1. Intranasal vax <60 (YOUNG CALVES)
-Prevent infection
-Provides defence where pathogens will be invading
-Develop immune proteins (IgA) on the musical surface
-Shorter duration of immunity (only last 150d) relatively short
2.Systemic modified live vax: >60d (OLD CALVES) till after weaning
-Prevent disease
-Produces systemic humoral and cell-mediated immunity
-Produce long lasting immunity
What are the effects of pneumonia on performance?
If treated for pneumonia as calf:
-Increase risk of mortality prior to calving
-Decreased growth rate
-Increased age at first calving
-Increased risk of dystocia at first calving (bc decreased growth rate and increase of pelvic disproportion)
Costs:$25-81 per case due to the long term impact on growth and survival
What is salmonella Dublin?
-Emerging disease in ON
-Zoonotic
-Multiple routes of transmission
-Fecal-oral spread (calf ingest fecal matter)
-Hardy bacteria (can survive for log periods of time through cold and heat)
-Transmitted herd to herd through carriers
-carriers can be older animals that look healthy but shading in milk and manure (no clinical signs)
What are the clinical signs of Salmonella Dublin?
-Calves that show clinical sings are typically infected at calving (in calving area and stressed out so shading virus into bedding)
-Importance of clean maternity area
-2m usually (2w-7m)
-Wide variety of presentations
-Pneumonia (main one)
-Septicemia (main one)
-No diarrhea
-High mortality and viable morbidity (die suddenly)
What are prevention and control strategies for salmonella Dublin?
- Reduce exposure (best way): through biosecurity (can prevent carrier into herd by doing blood test to see)
- Improve immunity: Vax of calves and cows which is not available in CA
What is coccidiosis?
-caused by Eimeria Boris and zuernii (parasitic protozoa)
-Calves infected by oocysts passed from feces of cattle with parent infections
-Moisture and cool conditions are conducive to sporulation (rainy and cold perfect environment for them)
What are clinical signs (rarely occurs)?
Prevention?
-diarrhea containing mucus and blood in manure
-straining
-depression and reduced appetite
Most infections are subclinical
-Lack of growth
-Loose manure
-Poor hair coat
Immunity develops over months; ADULTS NOT AFFECTED
Prevention
-Inclusion of coccidiostat (ex monensin, lasalocid) in heifer diets
-must consume enough feed to get adequate dose but most diets are formulated for “average” calf in group
-Sanitation of environment
What are the goals of the replacement program?
-Produce at least enough replacements to maintain milking herd as efficiently as possible
-Calve successfully- on average better then cows they replace
-Age of first breeding 12-14month
-Age at first calving 23-24month
What are the pre-weaning nutrition goals?
-Double birth weight by weaning (avg calf born 42-52kg want to double by 6w)
-800-900g/day average daily gain
What are some feeding strategies for pre-weaning nutrition to maximize health?
-Offer clean, ab-lib water from day 1-2
-Offer starter/grain from 1-2 weeks of age (papilla in stomach more developed)
-Provide chopped (2cm) straw or hay (grain may build up place on rumen wall and straw will help scrape away better digestion)
What is weaning and why is it important?
-It is the change from milk diet to forages and grains
-Time of greatest stress for dairy calves
Recommended weaning criterion:
-Minimum of 3 weeks on starter
-2 lbs (0.9kg) of starter per day for 3 consecutive days
-Leave in hutch or pen for 5-7 days after weaning (1 stressor at a time)
-Dehorn at 1-4w (ideally dehorn before weaning)
What are the 2 types of weaning strategies?
2 Main strategies employed;
-Abrupt (calves on milk cold turkey to grain)
-Gradual (slowly decrease level of milk and slowly increase level of solid diet)
TRUE OR FALSE: No matter what weaning strategy employed there will always be reduced gain surrounding weaning the period.
TRUE:
But gradual with not be as much of a decrease in growth so its better
