Do modified live virus vaccines against bovine viral diarrhea induce fetal cross-protection against HoBi-like Pestivirus?

Bovine Pestivirus heterogeneity is a major challenge for vaccines against bovine viral diarrhea (BVD). In breeding herds, fetal protection is a high priority issue. To some degree, fetal infections in vaccinated heifers have been attributed to the antigenic diversity of bovine Pestiviruses. The purpose of this study was to assess fetal protection against a divergent bovine Pestivirus (Hobi-like Pestivirus, HoBiPeV) with a commercially available modified live vaccine (MLV) claiming fetal protection against BVDV 1 and BVDV 2 up to one year after the first inoculation. Five vaccinated and four unvaccinated heifers were challenged by intranasal inoculation with the HoBiPeV Italy-1/10-1 strain between 82 and 89 days after insemination, i.e. between 4 and 6 months after vaccination. At challenge, neutralizing antibody titers to HoBiPeV in vaccinated heifers were low or even undetectable. Of the four unvaccinated heifers, one control animal aborted (fetus not available) and the remaining three gave birth to HoBiPeV positive calves. Among the heifers of the vaccinated group, one aborted the fetus in the sixth month of pregnancy, which tested Pestivirus negative, while three others gave birth to healthy, HoBiPeV negative calves; the remaining heifer delivered one HoBiPeV positive calf. The results suggest that the BVDV vaccine might be able to elicit a partial fetal protection against HobiPeV, even in absence of a strong specific antibody response.

Leukocyte coping capacity chemiluminescence as an innovative tool for stress and pain assessment in calves undergoing ring castration.

Pain and stress assessment in animals is considered an imperative issue and also a difficult challenge. Unfortunately, no gold standard technique for pain and stress assessment in animals has been validated nowadays. A new tool to assess stress in animals consists of measuring the leukocyte coping capacity (LCC). The aim of this study was to evaluate the whole-blood LCC chemiluminescence as an innovative tool for stress and pain assessment in the bovine species undergoing ring castration. Twenty 2-mo-old male mix-breed Piemontese-Angus-Belgian Blue calves (Bos taurus) weighing 90 ± 4 kg were used. The animals were randomly allocated in 2 groups composed of 10 subjects each as follows: ring castration group (CAS) and sham castration group (SHAM). Blood drawing, scrotal and perineal temperature recording, scrotal lesion score, pain assessment, and LCC Chemiluminescence were performed at different time points, which were as follows: 1 h before castration/sham (-1 h), 30 min postcastration/sham (30 min), 3 d postcastration/sham (3 d), 7 d postcastration/sham (7 d), 14 d postcastration/sham (14 d). Results showed that in CAS LCC values significantly increased (P < 0.05) at 3 d and decreased at 7 d, whereas in SHAM, LCC values did not significantly vary between the study times. Significant differences in LCC values between CAS and SHAM were seen at 7 d (P < 0.0001). In the CAS group, scrotal lesion was scored as 0, 0, 3.8, 2.7, and 0.2 at -1 h, 30 min, 3 d, 7 d, and 14 d, respectively, whereas in SHAM, its score was 0 at every time point. Perineal temperatures did not vary throughout all the study times in both CAS and SHAM. Differences among the 2 groups were noted in scrotal temperatures only at 3, 7, and 14 d (P < 0.05). In CAS, the percentage of animals which obtained a pain score ≥ 1 was: 10% at -1 h, 30% at 30 min, 20% at 3 and 7 d, and 10% at 14 d, whereas in SHAM, no pain signs were noted at any time point. No significant difference between CAS and SHAM was recorded in cortisol blood level at any time point. No stress leukogram nor variation in neutrophil/lymphocyte ratio was noted at any of the time points in both CAS or SHAM. Our results suggest that ring castration might cause long-lasting pain in calves, but its magnitude is not easily detected by conventional methods. We argue that whole-blood LCC chemiluminescence might be a useful tool for detecting pain and stress in calves undergoing ring castration.