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Prospective longitudinal clinicopathological study of perinatal

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					Prospective longitudinal
clinicopathological study of
perinatal mortality in dairy
calves: preliminary results
Dr. John Mee

Teagasc
Moorepark Dairy Production Research Centre
IRELAND
  Outline of Presentation
 Why  should we be interested in perinatal calf
  mortality now?
 What are the current causes of calf mortality ?
    Because…
   Increasing incidence – documented in Denmark, The Netherlands,

                             Sweden and North America.

                           - particularly in Holstein heifers

   ‘Welfare deficiency’ (WD) indicator (Sweden) - underestimation by
    up to 50%; 94% not a problem (8.8%). (Canada)

   Primary cause – traditionally dystocia

   Changing aetiology? – idiopathic, unexplained stillbirth, non-visible
    dystocia.
Recent international perspectives
   “In recent years the stillbirth rate for heifers has been close to 22-
    25%”
                                                    Benjaminsson (2007)

   The majority (53%) of Danish Holstein heifers are now assisted at
    calving
                                              Hansen et al., (2004)

   “It is not uncommon to find US herds with close to 20% stillbirths in
    heifers that have not been recognised or investigated”
                                                     McGuirk (2007)

   “ …existence of a growing number of stillbirths not associated with
    dystocia”
                                         Gustafsson et al., (2008)

   In problem herds, up to 75% of heifers’ calves can be stillborn
                                                    Muskens (2008)
Death by geography….
Country            Breed of dam       Heifers   Heifers &
                                        (%)     Cows (%)
Australia         Holstein-Friesian    10.8        5.1

Canada            Holstein-Friesian     9.0        9.6

Iceland               Icelandic         16         15

The Netherlands   Holstein-Friesian    11.4        6.9

New Zealand       H-F, J & Xbreds       7.4        7.2

Norway            Norwegian Red         3.0        2.0

Sweden             Swedish Red          5.2        4.8

UK                Holstein-Friesian    10.9        5.3

USA               Holstein-Friesian    12.1        8.0
What are the current causes
    of calf mortality ?
Recent Irish study
Materials and methods

 Case   definition: calf death within 48h of birth
  following a gestation period of >260d
 Experimental design: prospective,
  longitudinal, observational, whole-herd study
 Study period: Jan-May, 2009

 Study farms: seven spring-calving dairy herds

 Study animals: 40 calves, ~750 calvings and
  representative sample of pregnant animals.
Data collected
 Epidemiological    – carcass submission
  questionnaire: single/twin, parity, BCS, sex,
  breed, gestation length, calving date, time,
  assistance, calf clinical signs, time-of-death
 Herd micronutrient status – pregnant dam
  blood samples (5 H, 5 C; PII, Se, Cu, Mg)
 Necropsy – body and organ weights, gross
  pathology, histopathology, toxicology,
  microbiology, serology & micronutrient status
Epidemiological Results

                                       %
Singletons                            95
Pluriparous dams                      73
Holstein-Friesian sires               70
Male                                  58
Unobserved/unassisted at calving      40
Dystocia                              38
Death body weight (kg)             34.6 (8.2)
       Time-of-death

  80
  70
  60
  50
% 40
  30
  20
  10
   0
       Stillborn   1 min.-1 hr.   1-24 hr.   24-48 hr.
                        Time-of-death
Herds Micronutrient Status
Micronutrient     Normal        Herds within    Animals
                  ranges          normal     within normal
                                ranges (%)    ranges (%)
PII             60-300 ug/l         14            42

Se              0.75-3 umol/l       100           100

Cu              9.4-24 umol/l       100           100

Mg               0.73-1.31          100           95
                  mmol/l
 Calves Micronutrient
 Status

Thyroid gland weight (g)    14.1 (6.0)

Thyroid/body weight ratio      0.04

Hepatic copper (mmol/kg)    1.78 (0.74)

Hepatic cobalt (umol/kg)    0.20 (0.07)

Renal selenium (umol/kg)    9.05 (1.69)
 Microbiology Results

                                          %
Abomasal culture (significant isolates)   0
BVD (antigen)                             0
     (antibodies)                         13
Leptospira hardjo [antibodies (>1:50)]    12
Neospora caninum (antibodies)             3
Categories of Perinatal Mortality
– Foetal Disorders (43%)

  Disorder                           %
  Lethal congenital defects         12.5
  Umbilical haemorrhage             7.5
  Dead-in-utero                     7.5
  Anoxia-eutocia                    5.0
  Prematurity                       5.0
  Goitre                            2.5
  Anaemia                           2.5
Categories of Perinatal Mortality
– Calving Disorders (35%)


  Disorder                           %
  Malpresentation                   17.5
  Dystocia                          7.5
  Uterine torsion                   5.0
  Milk fever                        2.5
  Twinning                          2.5
Categories of Perinatal Mortality –
Placental (13%) and other (10%)
disorders


  Disorder                             %
  Premature placental separation      12.5
  Other                               10.0
What are the most common causes
of stillbirth? - veterinary practitioner survey

 Question
 What are the most common causes of stillbirth? - rank
 Dystocia – relative fetal oversize, twins, maldispositions…          1
 Other – unassisted calvings, milk fever, malformations, non-viable
   calves..                                                           2
  Infections – BVD, Neospora, non-specific…                           3


 Do producers in your country commonly have stillborn calves
   necropsied? yes (%)                                                3
      Preliminary Conclusions
   Epidemiology: stillborn, singleton, male, from
    pluriparae sired by Holstein-Friesian bulls

   Necropsy: without significant infections or
    micronutrient deficiencies

   Categories of loss: primarily foetal and calving
    disorders

   Clinical-pathology: value of anamnesis & necropsy
john.mee@teagasc.ie

				
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