Neonatal Ruminants Flashcards
Why is it beneficial to remove calf from the dam after birth?
Because maternal shedding of enteric pathogens increases around the time of parturition
What is a critical source of concentrated energy in neonates?
Colostrum
— brown adipose tissue & muscular glycogen are also shortlived,stored energy
In the mammary gland how is IgG1 transported from blood to mammary cell?
In endosomes— via transcytosis
What are needed for the transport of IgG1 from blood-mammary gland?
Intracellular proteins— small GTPases (bind Fc receptors) in the presence of estrogen & progesterone
Whey protein at calving is primarily made up of:
Immunoglobulins: 80% IgG1 10% IgG2 7% IgA 5% IgM
What are components of colostrum?
Hormones: growth hormone, relaxin, prolactin, insulin, glucagon
Essential fatty & amino acids
Mienrals
Trace elements
Vitamins: betacarotene, vitamins A, B, D, E
Cytokines
Growth factors (insulin like growth factors)
Antimicrobial factors: lactoferrin
Copper
What typ eof placenta do cows, sheep and goats have?
Epitheliochorial
Maternal immunoglobulins are absorbed through which process within neonates GI tract?
Pinocytosis
What is the lactocrine hypothesis?
The effect of bioactive factors in colostrum & milk on the development of specific tissues and/or physiologic functions in the neonate
IGF-1, lactoferrin & other bioactive substances are key regulators in the development of the GIT of bovine neonates through what:
Stimulation of mucosal & submucosal growth Brush border enzymes Intestinal DNA syntehsis INC duodenal villus size & apoptosis Protein synthesis & degradation Digestion Absoprtion
Administration of how much colostrum ensure adequate passive transfer of immunity?
7.5-10% of body weight within 2 hours after birth
(Max of 7.5%)
What are risk factors for inadequate colostrum uptake?
- Concentraiton of immunoglobulins in colostrum fed
- The volume of colostrum ingested
- The age of the calf at first colostral feeding
- Bacterial load of colostrum ingested
At the herd level, what are qualities that affect colostrum quality
Breed
Parity
Climate
At the individual level, what are factors that affect colostrum quality in cows
Colostral volume
Time from calving until milking
Breed variability in colostrum quality in cows
Lowest: Holsteine
Best: jersey
How has parity shown to affect colostrum quality?
First and second calving have lower immmunoglobulin concentrations compared to cows of third or fourth parity
Is protein restriction recommended prior to calving?
No
—> because decrease in protein, may inc IgG d/t volume response, but makes the colostrum more viscous & difficult to suckle
Calves should be fed a minimum of what IgG concentration within 4 to 6 hours of birth to reach appropriate passive transfer?
150 g of IgG
What are factors that influence “gut closure” in calves?
Age it receives its first feeding
Amount of immunoglobulins received
When does gut closure occur in calves?
24 to 36 hours
Factors that increase risk of failure of passive transfer of immunity:
Dystocia
Primiparous cows
Dams udder & ventral abdomen conformation
Protein restriction in last 1/3 of gestation
What are best practices for colostrum management for dairy calves?
- milk cows as soon as possible after calving
- remove calves from the calving area at least twice daily
- measure colostrum quality (Brix refractometer)
- feed an additional 5-7.5% bwt by 12 hours of age
- on farms with history of Johne’s disease, salmonella, mycoplasma or leukosis, pasteurize colostrum
- avoid pooling colostrum
- implement monitoring program for failure of passive transfer
How quickly does immunoglobulin g (IgG) concentration decline after calving?
3.7% for each hour after calving
What are best practice colostrum management for beef calves?
- avoid severe restriction of dietary intake prior to calving
- minimize disruption of calving cows
- ensure that calves receive colostrum w/in 6 hours of calving (active suckling), intervene when there is dystocia or dumb calve
In beef calves, when needing to administer colostrum what is the best practice?
To restrain dam & encourage calving (active suckling) or administer colostrum by a nipple bottle
— esophageal feeder should be used only when volumes greater than 1.5 L are available or if the calf will not suck
Colostrum with high bacterial levels not only presents a disease risk, but also affects colostrum intake via:
Blocking uptake nand trasnport of immunoglobulin across intestinal epithelial cells or by biding free immunoglobulin in the gut lumen
How long can colostrum be refrigerated?
2 days prior to administration
— can add 50% potassium sorbate solution per liter of colostrum + refrigeration will inhibit bact growth for 4 days
Freezing or lyophilization has what effect on colostrum IgG?
**it does not change immunoglobulin & nutritional content
—> does decrease cellular content that can have prolonged effects on immunity
Do vaccines improve colostrogenesis?
Yes- however timing of vaccine is important - follow manufacturers directions
At what level of serum IgG that indicates adequate passive transfer
10 mg/ml (1000 mg/dL)
At what age can refractometer be used to assess passive transfer?
Between 24 hours and 7 days of age
What are factors that influence protein refractometer (falsely), in assessment of appropriate passive transfer?
Illness
Dehdyration
What is measurement of adequate passive transfer on serum refractometer?
> 5.5 g/dL
FPT: <5 g/dL
Marginal Passive transfer: 5.0-5.5 g/dL
A Brix refractometer can used to assess appropriate transfer on serum, what values indicate appropriate passive transfer?
8.3%— estimate FPT (serum IgG<1000 mg/Dl)
**sensitivity: 85.5%, specificity: 82.85%
What dose of plasma to manage failure of passive transfer in calves?
20 to 40 ml/kg
Which solution (s) is/are better for navel treatment?
Chlorhexidine
— wide antimicrobial activity, long duration of activity, high efficacy in presence of organic matter
The esophageal groove is stimulated to close by:
Via reflex that is stimulate by intake of liquids
**milk is best, water becomes ineffective in closing the groove fairly early in life
What is the first enzyme to start break down of milk within the abomasum?
Salivary lipase
At what age does ruminal digestion start?
@ 3-4 weeks of age
—> earlier dry feed is provided, earlier ruminal development starts
The basal maintenance energy requirement for neonatal calves is between:
45-52 kcal/kg/day
Energy requirements for growth in a calf are:
268 to 307 kcal/100 g of body weight gain
Trypsin is a digestive enzyme that helps protect against what bacterial organism and through what mechanism?
Trypsin proivdes protection against clostridial disease by cleaving the clostridial beta toxin
Differentials for abnormal mentation in neonatal ruminants
Meningoencephalitis Hypoglycemia Hypoxic ischemic encephalopathy Calving injury Severe metabolic acidosis
Differentials for abnormal posture of the head and neck in neonates:
Respiratory difficult Meningoencephalitis Otitis media Hypernatremia Polioencephalomalacia Congenital defects of CNS Lasalocid toxicity
On farm risk factors that contribute to the risk of disease in neonates
Inappropriate stocking density Mixed age-groups Inadequate ventilation or shade Wet, muddy conditions Moldy bedding Inadequate protection from adverse weather Evidence of poor hygiene Inappropriate feed on offer Excessive fly challenge
Normal eye ball position is controlled by what cranial nerves?
CN III, IV, VI and VIII
Normal sucking behavior is controlled by which cranial nerves?
V, VII, IX, XII
What cranial nerves are assessed by PLR?
II and III
Gray or cyanotic mucous membranes are a signs of:
Severe hypoxia Circulatory collapse Hypovolemic shock Cardiovascular anomalies (right to left shunt) Severe pulmonary disease
Examples of congenital cardiac anomalies that cause cyanosis
Tetralogy or pentology of Fallot
Eisenmenger’s complex assoc with reversion of L to R shunt secondary to pulmonary hypertension
Hyperkalemia causes what heart arrhythmia and through what mechanism?
Bradycardia
—>decreases the membrane potential and slows down impulse conduction by inactivating sodium (Na) channels
What is the progression of cardiac arrythmias associated with hyperkalemia?
Progressive atrial standstill—> ventricular fibrillation—> asystole
Periods of excitement precipitated by feeding or moving calves out of hutches into group pens can present as a syndrome of sudden death, caused by what cardiomyopathys
Selenium deficiency
Gosspol
Monensin
Lasalocid toxicity
Chymosin (renin) is normal present where? And can help be an indicator of what?
Normal present in abomasal juice
** renin activity in rumen suggests abomasal reflux
How to measure renin activity in rumen fluid?
Add 2 ml rumen juice to 2 ml whol milk on a california mastitis test plate
—> presence of renin— coagulation of casein in the milk
Is chloride a useful measurement in rumen fluid, when trying to determine abomasal reflux in calves?
Rumen fluid chloride is higher in calves than in adults
Causes of arthrogryposis in calves:
Hereditary (Hereford cattle)
Teratogenic viruses
Teratogenic plants (lupines 40-70 days gestation)
Calcium deficiency in calves can cause
Reduced mineralization of bone
—> transverse processes of lumbar vertebrae become soft and bend when palpated
Differentials for posterior paresis in neonates:
Border disease
Enzootic ataxia
Vertebral body abscesses
Caprine arhtritis encephalomyelitis virus
Vertebral body fractures (assoc with dietary copper def or secondary to molybdenosis)—
What factors impact gut closure??
Growth factors including: IGF-1, TGF-beta2, GH
**intestinal epithelial hyperplasia
When does the neonatal immune system start to devleop?
3 to 6 weeks
**consumption of maternal leukocytes in colostrum critical for development of neonatal immune system (ag presentation)
What are specific factors in colostrum that influence long-term outcomes?
IGF-1 IGF-2 insulin growth hormone epidermal growth factor leptin prolactin
What are normal temperature/heart rate/respiratory rate of calves
temperature: 101.5-103
heart rate: 100-140
respiratory rate: 30-60
What are normal temperature/heart rate and respiratory rate of lambs?
temperature: 102.5-104
heart rate: 120-160
respiratory rate: 30-70
What are normal temperature/heart rate/respiratory rate of kids?
temperature: 102-104
heart rate: 120-160
respiratory rate: 40-65
define bacteremia
laboratory finding where bacteria has been found in blood (blood culture) does not imply a systemic effect
define septicemia
systemic disease associated with the presence of pathogenic microorganisms (viruses, protozoa, bacteria) or their toxins in blood
**implies patietn is ill
Define sepsis
combination of infection and a systemic inflammatory response
Define systemic inflammatory response syndrome (SIRS)
host inflammatory cascade initialed with host defense system fails to recognize or clear the infection
define septic shock
aggravation of septic state to the point where hypotension or hypoperfusion develops
List and define forms of shock (other than septic shock)
hypovolemic: fluid loss via capillary leakage
cardiogenic: myocardial depression
distributive: decreased systemic vascular resistance
Factors associated with impaired neutrophil function in calves
- decreased neutrophil receptors
- increased cortisol during 1st 10 days of life
- dampened neutrophil chemotaxis during cold weather
- depressed neutrophil function from protein energy malnutrition and micronutrient deficiencies
what are general treatment guidelines for neonatal septicemia?
- control infection
- modulate inflammatory response
- support animal during critical phase
