Seasonal and Age-Associated Pathogen Distribution in Newborn Calves with Diarrhea Admitted to ICU

Immunophenotyping of peripheral circulating lymphocytes and serum selenium levels in calves with neonatal diarrhea

This work aims to: (1) elucidate the immune response exhibited by CD4 + and CD8 + T lymphocyte cells in response to various infectious agents in calves suffering with neonatal diarrhea; and (2) determine and investigate the association between serum selenium levels and T lymphocyte subtypes in neonatal calves afflicted with neonatal diarrhea and infected with various infectious agents. The study encompassed a cohort of 50 calves, encompassing both sexes and various breeds, within the neonatal age range (1-28 days old). Subdivided into distinct groups, the calves were categorized based on the causative agents of neonatal diarrhea, including Rotavirus (n = 10), Cryptosporidium parvum (C.parvum) (n = 10), Coronavirus (n = 5), Rotavirus+C.parvum (n = 5), and a Control group (n = 20). Blood samples were meticulously obtained from the vena jugularis of all animals utilizing specific techniques-8 ml in tubes devoid of anticoagulant and 3 ml in blood collection tubes containing EDTA. Serum selenium levels were analyzed by ICP-MS. Flow Cytometry device was used to determine CD4 + and CD8 +T lymphocyte levels. In this study, although there was no statistically significant difference in serum selenium levels between all study groups, it was found that the selenium level in the control group was not sufficient. CD4 T lymphocyte levels, the rotavirus+C.parvum group exhibited a statistically significant elevation compared to the coronavirus group. Regarding CD8 + T lymphocyte levels, the coronavirus group demonstrated a statistically significant increase when compared to the control group. In intragroup analyses of CD8 + T lymphocyte levels, the coronavirus group exhibited a significant elevation compared to the rotavirus group, C.parvum group, and the C.parvum + Rotavirus group. A significant negative correlation was detected between selenium levels and CD4 + T lymphocytes, while no correlation was found between CD8 + T lymphocytes. Fibrinogen concentration exhibited statistical significance, being higher in the Rotavirus group (p < 0.008) compared to the control group, in the C.parvum group (p < 0.004) compared to the control group, and in the Coronavirus group (p < 0.001) compared to the control group. The leukocyte count demonstrated statistical significance, being higher in the Rotavirus group compared to the control group (p < 0.001), in the Rotavirus+C.parvum group compared to the control group (p < 0.002), and in the Coronavirus group compared to the control group (p < 0.011). In conclusion, the data derived from this study illuminate discernible disparities in CD4 + and CD8 + T lymphocyte immune responses, contingent upon the specific etiological agent associated with neonatal diarrhea. Furthermore, the study underscores the importance of considering selenium deficiency as a relevant factor in calves affected by neonatal diarrhea.

Prognostic potential of inflammatory markers, oxidative status, thrombocyte indices, and renal biochemical markers in neonatal calf diarrhoea-induced systemic inflammatory response syndrome

The study aimed to assess the prognostic value of inflammatory markers, indicators of oxidative stress, thrombocyte indices, and renal biochemical markers in neonatal calf diarrhoea (NCD) induced by systemic inflammatory response syndrome (SIRS) upon admission. A prospective, observational, and case-control study was conducted on 56 calves diagnosed with NCD. Mean concentrations of interleukin-6 (IL-6), malondialdehyde (MDA), glutathione (GSH), mean platelet volume (MPV), platelet distribution width (PDW), blood urea nitrogen (BUN), and creatinine (Crea) were measured. Furthermore, the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) were also calculated for SIRS survivors [SIRS (survivor)] and non-survivors [SIRS (non-survivor)] induced by NCD. A prognostic cut-off value for predicting the prognosis of the SIRS's induced by NCD was obtained via receiver operating characteristic (ROC) curve analysis. Upon admission, the SIRS (non-survivor) calves had significantly higher (P < .001) average levels of IL-6, MDA, BUN, Crea, MPV, and PDW compared to the SIRS (survivor) calves and significantly lower (P < .001) average levels of GSH. Despite an apparent increase in the NLR and PLR values of calves diagnosed with SIRS, no significant difference was found between the survival and non-survivor SIRS cases. Positive predictive values (PPVs) for survival were determined as 100 %, 100 %, 80 %, 100 %, 80 %, and 80 %, respectively, using cut-off values of IL-6 (≤259.67 ng/L), MDA (≤2.87 nmol/mL), MPV (≤12.5 fL), PDW (≤34.25 %), BUN (≤168.3 mg/dL), and Crea (≤2.11 mg/dL). The determined threshold values are those obtained upon admission to the hospital. Based on the sensitivity, specificity, and PPVs derived from the ROC analysis, it has been concluded that IL-6, MDA, MPV, PDW, BUN, and Crea are the most relevant biomarkers used for predicting the prognosis of NCD-induced SIRS in calves. Furthermore, it is also noteworthy that IL-6 exhibited the highest effectiveness among all biomarkers.

Genome characterization of a Turkish bovine rotavirus field isolate by shotgun metagenomics

A bovine rotavirus (BRV) isolate from Kirsehir was isolated from feces of a neonatal calf with diarrhea, identified, and sequenced by shotgun sequencing. Its genotype constellation is G10-P[5]-I2-R2-C2-M2-A3-N2-T6-E2-H3. The structural genes and the non-structural genes NSP1, NSP3, and NSP4 of the Kirsehir isolate were similar in sequence to those of BRVs identified in Turkey. However, VP2, NSP2, NSP4, and NSP5/6 showed similarity to those of rotaviruses from different animal hosts. These findings not only expand our current understanding of the diversity of rotaviruses but also contribute to our understanding of the evolution of rotaviruses at both the national and global levels and reinforce the significance of conducting further research on rotaviruses in Turkey.

Improving beef calf health: frequency of disease syndromes, uptake of management practices following calving, and potential for antimicrobial use reduction in western Canadian herds

Bovine respiratory disease (BRD), calf diarrhea (CD), and navel infections are the most commonly reported diseases of western Canadian beef calves. The objectives of this study were to estimate the frequency of treatment for these diseases for specific age cohorts and identify potential opportunities for reducing antimicrobial use. Producers representing 89 western Canadian cow-calf herds completed a survey describing calfhood diseases and management. The most common reason for calf treatment before weaning was BRD (4.9%), and BRD treatment was described in 51% of reporting herds before 2 months of age. Calf diarrhea (2.9%) and navel infection (2.0%) were the second and third most common reasons for treatment. Most calves were treated for CD between 6 days and 1 month of age. Almost one in five herds reported routinely administering antimicrobials at birth. Calving heifers and cows together were all associated with an increased treatment risk for BRD in calves from birth to 2 months (OR 3.55, 95%CI 2.13-5.94, P < 0.0001), CD from 1 month to weaning (OR 3.94, 95%CI 1.29-12.0, P = 0.02), and navel infection (OR 4.55, 95%CI 1.78-11.6, P = 0.002). Failure to sort cow-calf pairs out of the calving area was also associated with an increased treatment risk for BRD from 4 months to weaning (OR 4.89, 95%CI 1.96-12.2, P = 0.0006) and CD from 24 h to 5 days (OR 2.82, 95%CI 1.03-7.75, P = 0.04), and not using the Sandhills system was associated with an increased treatment risk for navel infection (OR 4.55, 95%CI 1.78-11.6, P = 0.002). Other potentially modifiable factors associated with an increased risk of BRD in calves from birth to 2 months were winter feeding and calving in one area (P < 0.0001), heifers calving in a higher density area (P = 0.01), and an increasing number of times cow-calf pairs were gathered before turn out to summer pasture (P = 0.0005). The purchase of any cows during the calving or prebreeding period was associated with an increased risk of BRD from birth to 2 months (P < 0.0001) and from 2 to 4 months (P < 0.0001). A history of respiratory bacterin vaccines administered to the dams was associated with a decreased risk of BRD in calves from 4 months to weaning (P = 0.01). Cows calving in a higher density area was associated with an increased risk of CD from 1 month to weaning (P = 0.02). These practices present opportunities for investigation of approaches to disease management that could support the judicious use of antimicrobials.