Serum amyloid A concentrations in lungs and blood in calves with respiratory disease: association with clinical signs
Abstract
Bovine respiratory disease (BRD) is a multifactorial disease complex that causes major
economic losses to farmers worldwide due to high morbidity and mortality. Several viral
agents are considered to be primary cause of BRD, but more often than not, secondary
bacterial agents are involved in the disease. Mycoplasma are also a major agent in BRD as
primary or secondary factor. Environment plays a role as a catalyst to the disease.
The present study was done to investigate the correlation of serum amyloid A (SAA)
measured from tracheobronchial lavage (TBL) and clinical signs of BRD as well as the
correlation of SAA measured from TBL fluid and SAA measured from blood serum. Samples
were collected and clinical examination was performed in 10 calves during two times three
weeks apart from 40 herds in all-in all-out calf-rearing farms in Finland. In total study
included samples from 396 calves. Only those samples where all information was available
were included in this study (450 samples, 234 from the first and 216 from the second time).
There was significant positive association found between serum amyloid A measured from
tracheobronchial lavage fluid and nasal discharge during the 1st sampling time. During the
2
nd time sampling nasal discharge was not significant anymore but fever showed tendencies
of positive association. SAA measured from serum was higher during both sampling times
compared to SAA measured from TBL fluid. Local and systemic SAA did not correlate. Veiste hingamisteede haigus (bovine respiratory disease, BRD) on paljude põhjustega
haiguste kompleks, mis põhjustab suure haigestumuse ja suremuse tõttu
põllumajandustootjatele kogu maailmas suurt majanduslikku kahju. BRD peamiseks
põhjuseks peetakse mitut viirustekitajat, kuid enamasti on haigusega seotud sekundaarsed
bakteriaalsed tekitajad. Ka mükoplasmad on primaarse või sekundaarse tegurina olulised
BRD tekitajad. Keskkond mängib rolli haiguse katalüsaatorina.
Käesolevas uuringus määrati hingamisteede haigusega vasikate trahheobronhiaalse loputuse
(TBL) vedeliku ja vere seerumi amüloid A (SAA) sisaldus ning selgitati nende võimalikke
seoseid esinevate kliiniliste tunnustega. Samuti uuriti lokaalse ja süsteemse SAA omavahelist
seost. Proovid koguti ja kliiniline läbivaatus viidi läbi 10 vasikaga 40 karjast 38 Soome
vasikakasvatusfarmis kahel korral kolme nädalase vahega. Kokku oli uuringus 396 vasikat.
Antud uuringusse kaasati nende vasikate proovid kellelt oli olemas täielikud andmed (kokku
450 proovi, 234 esimesest ja 216 teisest korrast).
Esimesel proovivõtul leiti märkimisväärne positiivne seos TBL vedeliku SAA ja ninanõre
esinemise vahel. Sellist seost ei ilmnenud teisel proovivõtmise ajal, kuid siis oli palavikuga
esinemisega olulisusele lähedane positiivne seos. Seerumist mõõdetud SAA oli mõlema
proovivõtu ajal kõrgem võrreldes TBL vedelikust mõõdetud SAA-ga. Lokaalne ja süsteemne
SAA ei olnud omavahel seoses.