NEWBORN CALF VITALITY: RISK FACTORS, … · newborn calf vitality: risk factors, characteristics,...
Transcript of NEWBORN CALF VITALITY: RISK FACTORS, … · newborn calf vitality: risk factors, characteristics,...
NEWBORN CALF VITALITY: RISK FACTORS, CHARACTERISTICS, ASSESSMENT, RESULTING OUTCOMES AND STRATEGIES FOR IMPROVEMENT
Christine Murray, PhD Candidate
Outline
Dystocia: effects on the calf Causes of reduced newborn vitality Consequences of reduced vitality Vitality scoring Methods to improve calf vitality Study results Biomarker for calf vitality
and long-term health Conclusions
Dystocia: Effects on the Calf
Parturition can be the most hazardous and traumatic event in the life of a calf
Dystocia and subsequent health events account for up to 50% of all calf deaths
In severe dystocia cases, calves have:
20.7 greater odds of stillbirth
1.7 & 1.3 greater odds of being treated for respiratory & digestive disease, respectively
6.7 greater odds of mortality
(Lombard et al., 2007; Furman-Fratczak et al., 2011)
Dystocia: Effects on the Calf
Factors causing dystocia may include: Pelvic dimension of the dam
Calf size
Feto-pelvic disproportion
Calf presentation
Inappropriate timing of intervention or excessive force applied during delivery
Maternal factors, such as weak labor, insufficient dilation of the cervix and uterine torsion
(Meijering, 1984; Schuijt, 1990; Mee, 2008)
Dystocia may have implications for calf vitality, as well as long-term health and productivity
Vitality: having the capacity to live and grow with physical and mental energy and strength
Physiological effects of dystocia:
Inflammation, pain, injury, inability to maintain homeostasis, hypoxia and acidosis
Behavioral repercussions:
Reduced motivation to perform natural behaviours for survival, including standing up and suckling colostrum after birth
Dystocia: Effects on the Calf
(Breazile et al., 1988; Besser et al., 1990; Carstens, 1994; Barrier et al., 2012)
Pain, injury & inflammation
Hypoxia/acidosis
Respiratory acidosis
Metabolic acidosis
Impaired thermoregulation
Causes of Reduced Calf Vitality
(Meyer et al., 2000; Lombard et al.,2007; Waldner and Rosengren, 2009)
Improper obstetrical assistance & excessive force: Fetal Blood loss
Improper clamp timing
Premature umbilical cord rupture
Fractures Long bones
40% rib fractures
10% fractured vertebra
Trauma Liver rupture
Tracheal collapse
Meningeal hemorrhages
Pain, Injury and Inflammation
Hypoxia/Acidosis
Hypoxia refers to an inadequate supply of oxygen to the cells & tissues of the body
Premature umbilical cord rupture causing an inability to breath = Respiratory Acidosis
Termination of blood oxygenation from the placenta
Intense and prolonged labor contractions
Trauma during forced extraction
If severe, fetal tissues will derive O2 from anaerobic glycolysis = Metabolic Acidosis
Asphyxia can cause decreased blood flow to the liver and kidneys leading to hepatic necrosis, liver dysfunction and renal tubular necrosis
Other implications include aspiration pneumonia, edema, bleeding, and death
Schuijt and Taverne (1994) found that calves born from a severe dystocia had more serious acidosis, took longer at achieve a normal pH (>7.2) and had a greater risk of mortality
(Mulling, 1977; Ikeda et al., 2000; Poulsen and McGuirk, 2009)
Hypoxia/Acidosis
Hypoxia/Acidosis
7.05
7.1
7.15
7.2
7.25
7.3
7.35
15 30 45 60 75 90 105 120 135
pH
at
SR
Duration of Calving (Min)
0 people
1 person
2 people
3 people
(Murray et al., unpublished results)
Depending on the degree of stress, calving environment and season of birth, maintaining homeostasis can be challenging
Decreased available energy needed for the mobilization and metabolic activity of brown adipose tissue during non-shivering thermogenesis
Reduced muscle tonicity, preventing shivering
Less able to withstand cold stress
Thermoregulation
(Stott and Reinhard, 1978; Okamoto et al., 1986; Vermorel et al., 1989; Bellows and Lammoglia, 2000)
Newborn calves can generate body heat through physical activity
Standing up, walking and consuming colostrum may be challenging for calves with low vigor, especially in temperatures outside of their thermoneutral zone (10-25°C or 50-78°F)
Energy and heat acquired through colostrum ingestion may also be delayed or reduced in calves with low vitality
Thermoregulation
(Vermorel et al., 1989; Grove-White, 2000; Barrier et al., 2012)
Outline
Dystocia: effects on the calf
Causes of reduced newborn vitality
Consequences of reduced vitality
Dystocia causing pain, injury, inflammation, hypoxia, acidosis, and impaired thermoregulation all lead to calf weakness and reduced vitality
Decreased ability to perform tasks for survival Standing
Walking
Suckling colostrum
Consequences of Dystocia
(Schuijt and Tavern ,1994 ; Diesch et al., 2004 ; Barrier et al, 2012)
0.0
00
.25
0.5
00
.75
1.0
0
0 5 10 15analysis time
calving_score = 1 calving_score = 2
calving_score = 3 calving_score = 4
Kaplan-Meier survival estimates
Probability of not achieving sternal recumbency within 15 minutes of birth
Consequences of Dystocia
(Murray et al., unpublished results)
(min)
Pro
bab
ility
0.0
00
.25
0.5
00
.75
1.0
0
0 50 100 150analysis time
calving_score = 1 calving_score = 2
calving_score = 3 calving_score = 4
Kaplan-Meier survival estimates
Probability of not attempting to stand within 15 minutes of birth
Consequences of Dystocia
(Murray et al., unpublished results)
(min)
Pro
bab
ility
0%
10%
20%
30%
40%
50%
60%
Weak Medium Strong
% C
alve
s
Suckling Response
Suckling Response vs Calving Difficulty at 2 Hours
Unassisted
Easy Pull
Hard Pull
Consequences of Dystocia
(Murray et al., unpublished results)
Increased time to achieve sternal recumbency (SR), first attempt to stand and reduced suckling response
Suckling reflex and time to SR have been used as objective indicators of fetal stress and vigor in newborn calves
Calves forcefully extracted took significantly longer to achieve SR and had a lower overall state of vitality
Consequences of Dystocia
(Schulz et al.,1997; Schuijt and Taverne, 1994, Murray et al., unpublished results)
Calves with low vigor have an increased risk of failure of passive transfer due to low volume of ingested colostrum
Failure to get up and drink
Reduced suckling reflex
Up to 74% reduced colostrum intake in calves with fetal distress 12h after birth
Consequences of Low Calf Vitality
(Vermorel, 1989; Furman-Fratczak et al., 2011; Barrier et al., 2012)
In other studies, IgG absorption is reduced in calves with dystocia induced respiratory acidosis
In severely acidotic calves, a 52% decrease in colostrum intake is correlated with a 35% decrease in serum IgG concentration
Significant inverse relationship between venous partial pressure of CO2 at birth and 12h post feeding serum IgG concentration
(Besser et al., 1990; Boyd, 1989; Drewery et al., 1999)
Consequences of Low Calf Vitality
Failure of passive transfer may result in:
31% of pre-weaning mortality
30% decrease in pre-pubertal growth rate
30 day increase to first insemination
Produced 2,263 lbs less milk over first 2 lactations
16% decrease in survival to the end of the second lactation
Long Term Health Effects
(DeNise et al., 1989; Faber et al., 2005; Furman-Fratczak et al., 2011)
Outline
Dystocia: effects on the calf
Causes of reduced newborn vitality
Consequences of reduced vitality
Vitality scoring
APGAR (Virginia Apgar)
5 essential assessments:
Appearance (Color)
Pulse (Heart rate)
Grimace (Stimulation)
Activity (Muscle tone)
Respiration
Human Fetal Monitoring
Modified APGAR Scores
Developed for piglet, foal and puppy
Included variables such as heart and respiratory rate, reflexes, mobility and mucous membrane colour
Pups with low vitality scores were less likely to seek the mammary gland and had weaker suckling reflexes and mortality was increased
Piglets with low vitality scores were slower to stand, had more difficulty breathing, had slower heart rates, decreased arterial blood pH and increased partial pressure of CO2, indicating a state of acidemia and hypercapnia
(Randall, 1971; Veronesi et al., 2009)
A modified Apgar score has been assessed in calves in several German studies
Used signs of asphyxia: muscle tone, movement, reflexes, respiration and mucous membrane colour
The modified Apgar score was only marginally correlated with the results of blood-gas analysis
Did not accurately assess the vitality status of the calf, and calves were more appropriately classified into vitality groups based on acid–base status.
Modified APGAR Scores: Calves
(Mulling, 1977; Schafer and Arbeiter, 1995; Herfen and Bostedt, 1999a; Herfen and Bostedt, 1999b)
Hypoxia and acidosis may be indicative of newborn calf vitality
Require expensive, inconvenient and invasive lab tools
A more practical assessment using visual and physical measures can be easily performed on farm
Presence of meconium staining, peripheral edema, cyanosis of the mucous membranes, heart and respiration rates, muscle tone, stimulation reflexes, rectal temperature, time to SR and attempts to stand and suckle (Mee, 2008).
Modified APGAR Scores: Calves
Outline
Dystocia: effects on the calf
Causes of reduced newborn vitality
Consequences of reduced vitality
Vitality scoring
Methods to improve calf vitality
Assessment of Pain Following Dystocia
Studies have shown that dystocia is one of the most painful conditions in adult cattle
The severity of pain following dystocia in adult dairy cattle was 7, whereas it was only rated 4 in newborn calves
Pain is a subjective experience that is not possible to measure directly
(Huxley and Whay, 2006; Kielland et al., 2009; Laven et al., 2009)
Behaviours and physiological measures that can indicate pain in farm animals: Withdrawal reflex
Movement after birth
Heart and respiration rate
Body temperature
Are calf vitality scores directly correlated with the degree of pain experienced by a newborn calf?
(Molony and Kent, 1997)
Assessment of Pain Following Dystocia
Methods to Improve Vitality
Vitality scores should be used as a decision making tool to assess if further intervention is needed
Conventional intervention methods: Artificial respiration
Respiratory stimulants
Oxygen
Buffer therapy for acidosis
Thermal support
Umbilical treatment
Colostrum from esophageal feeder
(Mee, 2004; Mee, 2008)
Administration of non-steroidal anti-inflammatory drugs (NSAIDs) for alleviation of pain and inflammation
Methods to Improve Vitality
(Hudson et al., 2008)
Currently no published literature on NSAID use in calves
39% of dairy cattle veterinarians in the UK indicated occasional use of NSAIDs in calves following dystocia
66% reported using NSAIDs in some cows following dystocia
Decisions to use analgesia to the cow and/or calf are often influenced by cost
The reported use of analgesics in either cows or calves is probably greater than the actual rate of use
(Huxley and Whay, 2006 ; Hudson et al., 2008; Laven et al., 2012)
Methods to Improve Vitality
Limited usage of NSAIDs may be due to the lack of scientific evidence of the benefits following dystocia
It is clear that the physiological effects of dystocia reduce newborn calf vitality
It is uncertain whether there is pain, since this cannot be directly measured
NSAIDs may improve the time to standing, increase colostrum uptake, improve health, overall calf survival and welfare
Methods to Improve Vitality
(Molony and Kent, 1997; Mee, 2008; Laven et al., 2012)
Outline
Dystocia: effects on the calf
Causes of reduced newborn vitality
Consequences of reduced vitality
Vitality scoring
Methods to improve calf vitality
Study results
Meloxicam for Calf Vitality: Field Trial
A field study to evaluate of the efficacy of meloxicam NSAID therapy for improving newborn calf vigor, success of passive transfer, general health and performance
Objectives:
To evaluate the usefulness of pain management therapy for excessive trauma and enhancement of newborn calf vigor using meloxicam injectable solution.
To determine if newborn calf vigor is associated with calving difficulty, as well as subsequent health and performance.
Non-steroidal anti-inflammatory drug (NSAID)
Anti-inflammatory, anti-exudative, analgesic and fever reducing properties
Approved for use in calves in Canada (20mg/mL)
As an aid in improving appetite and weight gains when administered at the onset of diarrhea (Todd et al., 2010)
For relief of pain following de-budding of horn buds in calves less than 3 months of age (Heinrich et al., 2010)
For the symptomatic treatment of inflammation and pain associated with acute clinical mastitis (Fitzpatrick et al., 2013)
Metacam®
Study Methods
Each calf was scored at birth using calf VIGOR score sheet & a birth record was completed by the farm staff
Calves were randomly assigned to receive either 1.0 cc meloxicam or placebo solution s/c by farm staff
Weekly visits to herds
Study Methods
Blood was collected from all calves 1-7 days of age to measure success of passive transfer
Assess for temperature, weight, height and health scores up to 3 weeks old and again at weaning
In a subset of calves: Blood-gas analysis <2h of age 2nd VIGOR score 1-6h post Tx Suckling response
Calf VIGOR Score - Results
0
1
2
3
4
5
6
7
8
9
Unobserved Observed, butunassisted
Easy pull Hard pull
Vig
or
Sco
re
Calving Difficulty
Calf VIGOR Score - Results
Assistance at Calving Coefficient 95% Confidence Interval P-Value lower limit upper limit Visual Appearance Meconium staining 0.042 -0.047 0.13 0.35 Tongue/head 0.21 0.11 0.30 <0.001
Initiation of Movement Calf movement 0.17 0.025 0.32 0.02
General Responsiveness Straw in nasal cavity 0.21 0.10 0.31 <0.001 Tongue pinch 0.16 0.062 0.27 0.002 Eye reflex 0.043 0.0068 0.093 0.09
Oxygenation Mucous membrane colour 0.16 0.055 0.25 0.002 Tongue length 0.12 -0.023 0.25 0.10
Rates Heart rate 0.18 0.061 0.31 0.003 Respiration rate 0.19 0.084 0.29 <0.001
7.16
7.18
7.2
7.22
7.24
7.26
7.28
7.3
7.32
7.34
7.36
7.38
57.1 68.55 78.3
Pre
dic
ted
pH
at
<2h
pC02 at <2h
Excellent Vigor
Moderate Vigor
Low Vigor
Study Results
Study Results
n
Meloxicam
(Mean±SD)
Placebo
(Mean±SD) P-value
Pre-Tx VIGOR Score 61 6.39±2.71 5.06±2.47 0.41
*Post-Tx VIGOR Score 61 4.71±2.34 5.12±2.37 0.091
Difference 61 -1.68±1.94 0.06±2.66 0.023
Effect of experimental treatment on VIGOR score
*1-6 h post treatment
Calves who received Metacam® following birth had a significant improvement in VIGOR score from the 1st to the 2nd assessment than placebo treated calves, controlling for farm and the time after birth of VIGOR assessment (P=0.023)
Study Results
0
1
2
3
4
5
6
7
8
9
0 5 10 15 20
Seru
m T
ota
l Pro
tein
(g/
dL)
VIGOR Score
VIGOR score was not significantly associated with STP, after controlling for farm and age at blood sampling for STP (β=-0.15; 95% CI=-0.55 to 0.25; P=0.46)
Study Results
Meloxicam (Mean±SD) Placebo (Mean±SD) P-value
n 19 15
Finger Test (1-3)
*Pre-treatment 1.63±0.60 1.53±0.52 0.60
†Post-treatment 2.19±0.68 1.60±0.74 0.024
Difference 0.75±0.79 0.067±0.59 0.014
Manometer Suckling Pressure (psi)
*Pre-treatment 0.57±0.63 0.67±0.51 0.67
†Post-treatment 0.99±1.08 0.67±0.65 0.11
Difference 0.41±0.77 -0.0013±0.46 0.072
Effect of treatment on suckling reflex
*1-2 h from birth †1-6 h post treatment
Study Results
Average Milk Intake (L/d)
Coefficient 95% Confidence Interval P-value
lower limit upper limit
Treatment
Metacam® 0.03 0.0016 0.057 0.039
Placebo ref - - -
Total 8 Week
Health Score
-0.0093 -0.016 -0.0034 0.002
Average # of
Rewarded Visits to
Milk Feeder
2 ref - - -
4 0.080 0.050 0.11 <0.001
5 0.055 0.0093 0.10 0.019
Farm
2 0.61 0.53 0.69 <0.001
1 ref - - -
Study Results
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
Observed butUnassisted
Unobserved Assisted
We
igh
t G
ain
in W
ee
k 1
(kg
)
Calving Assistance
Metacam
Placebo
n=63
n=166
n=150
n=92
n=100
n=55
Study Results
Treatment Metacam® -0.36 -0.64 -0.073 0.014 Placebo ref - - -
Season of Birth
Spring 1.21 0.082 2.34 0.036 Summer -0.16 -0.57 0.25 0.44 Winter 1.40 1.06 1.74 <0.001 Fall ref - - -
Time colostrum fed after birth
<2hrs ref - - - 3-4 h -0.15 -0.54 0.25 0.43 5-6 h -0.27 -0.98 0.45 0.46 7-12 h 1.20 0.21 2.10 0.018
Total Health Score
Coefficient 95% Confidence Interval lower limit upper limit
P-value
Outline
Dystocia: effects on the calf
Causes of reduced newborn vitality
Consequences of reduced vitality
Vitality scoring
Methods to improve calf vitality
Study results
Biomarker for calf vitality and long-term health
Haptoglobin
Major bovine acute phase protein
Produced in response to a bacterial or viral challenge
Works by binding free hemoglobin in plasma to reduce the pro-oxidative and pro-inflammatory stress associated with hemolysis
Can be used as a quantifiable indicator of tissue damage, including infection, neoplasia or trauma
(Gruys et al., 1994; Murata et al., 2004; Petersen et al., 2004)
Haptoglobin – Indicator of Inflammation at calving
0
0.05
0.1
0.15
0.2
0.25
Observed butUnassisted
(N=146)
Unobserved(N=533)
Easy Pull(N=356)
Hard Pull(N=44)
Malpresented(N=23)
Surgery(N=7)
Me
an H
apto
glo
bin
(g
/L)
Assistance at Birth
Haptoglobin – Indicator of Health
0
0.05
0.1
0.15
0.2
0.25
0(N=186)
1(N=629)
2(N=227)
3(N=65)
≥4 (N=43)
Me
an H
apto
glo
bin
(g/
L)
Event 1 Health Score
P<0.001, accounting for farm as a random effect
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
0.18
No (N=890) Yes (N=312)
Me
an H
apto
glo
bin
(g/
L)
Treated for BRD in 1st 4 Months
P<0.05, accounting for farm as a random effect
Haptoglobin – Predictor of Health
0
0.05
0.1
0.15
0.2
0.25
No (N=1070) Yes (N=132)
Me
an H
apto
glo
bin
(g/
L)
Treated for Diarrhea in the 1st 4 Months
P<0.001, accounting for farm as a random effect
Haptoglobin – Predictor of Health
0
0.05
0.1
0.15
0.2
0.25
No(N=1158)
Yes(N=55)
Me
an H
apto
glo
bin
(g/
L)
Dead
P=0.001, accounting for farm as a random effect
Haptoglobin –Predictor of Mortality
Mortality Odds Ratio 95% CI P-value
Lower Limit Upper Limit
Hp (g/L) 4.29 1.07 17.18 0.04
Passive Transfer
Pass (>5.4g/dl) Ref
Intermediate (5.2-5.4g/dl) 0.43 0.13 1.47 0.18
Fail (<5.2g/dl) 2.22 1.2 4.11 0.01
Treated for BRD once or more
during study period
No Ref - - -
Yes 2.77 1.56 4.92 0.001
Treated for scours once or more
during study period
No Ref - - -
Yes 3.26 1.72 6.18 <0.001
Treated for other disease once
or more during the study period
No Ref - - -
Yes 2.06 1 4.22 0.049
Haptoglobin –Predictor of Mortality
Conclusions
Effects of dystocia: pain, fractures, trauma, hypoxia & impaired thermoregulation lead to reduced calf vigor & failure of passive transfer
Newborn calf vitality assessed through modified APGAR scores are well correlated to the degree of calving assistance using practical on farm measures
NSAIDs following dystocia my improve calf vitality, health and growth
Haptoglobin may be a biomarker for inflammation at calving and subsequent risk of morbidity and mortality
Acknowledgements
Advisory committee:
Ken Leslie – Professor Emeritus
Todd Duffield – Professor, Dairy Health Management
Derek Haley – Assistant Professor, Animal Welfare
David Pearl – Associate Professor, Epidemiology
Doug Veira – Senior Scientist, AAFC, Agassiz BC
Kathleen Shore – Nutritionist, Grober/New-Life Mills
Funding & support provided by: