Comparison of accuracy of ultrasonography, progesterone, and pregnancy-associated glycoprotein tests for pregnancy diagnosis in semidomesticated reindeer.

The aim of the study was to compare transrectal ultrasound with progesterone (P4) and pregnancy-associated glycoproteins (PAGs) as pregnancy detection methods for semidomesticated reindeer (Rangifer tarandus tarandus) in field conditions. Female reindeer (n=195) were scanned transrectally by a 7.5-MHz linear array transducer, and blood was sampled either in December 2005 (n=33), December 2006 (n=92), or January 2007 (n=70) during early or mid gestation. Plasma levels of P4 and PAGs were assessed by radioimmunoassay (RIA). Based on calving records, the sensitivity, specificity, predictive values, and the overall accuracy of the three tests were calculated. The overall calving rate calculated from the calving records was 86.2%. The overall accuracy of transrectal ultrasound was 99.5%. The sensitivity and specificity of transrectal ultrasound were 99.4% and 100%, respectively. In the plasma P4 test, the threshold level of 5.0 nmol/L gave the highest overall accuracy (94.9%). The sensitivity of the P4 test decreased from 96.4% to 81.5%, when the threshold level increased from 5.0 nmol/L to 8.0 nmol/L, while the specificity remained at 85.2% over the range of these cutoff values. The overall accuracy of the plasma PAG test decreased from 96.4% to 64.1% when the plasma PAG threshold level increased from 0.5 ng/mL to 3.5 ng/mL, whereas sensitivity decreased from 99.4% to 58.3%. Specificity increased from 77.8% to 100% when the plasma PAG threshold level reached 3.0 ng/mL. Transrectal ultrasound showed higher diagnostic values than those of plasma P4-RIA and PAG-RIA in diagnosing pregnancy of reindeer, with the advantage that diagnoses can be made in real time in field conditions.

Acute BRSV infection in young AI bulls: effect on sperm quality.

Bovine respiratory syncytial virus (BRSV) infection is an important part of the calf pneumonia complex, occasionally affecting even adult cattle. However, the pathogenicity of BRSV in animals older than 6 months is often neglected. Finland is free of many contagious diseases in farm animals, and this gives a good opportunity to study the effects of specific pathogens on bovine reproduction. This report describes the deteriorating effects of BRSV epizootics on sperm morphology and fertility of young dairy bulls (n = 79) at a bull station. More than half of the young bulls had a clinical respiratory disease caused by BRSV during their quarantine when they were 6 months old. Four of seven subsequent quarantine groups were affected. Six months later, when these seropositive bulls (n = 54) came into semen production, they had poorer sperm morphology, and the proportion of normal spermatozoa was 74.1% in BRSV-seropositive animals compared with 81.2% in seronegative bulls (n = 25) (p = 0.035). Field fertility was also slightly affected, the 60-day non-return rates were 75.2% and 76.8% for BRSV seropositive and seronegative bulls respectively (p = 0.014). Potential reasons for lowered sperm quality are discussed here.