Veal calves management in Québec, Canada: Part I. Association between passive immunity transfer at arrival and health disorders.

Morbidity and mortality remain important concerns for veal production which traditionally involves very young calves being transported directly from dairy farms to calf-raising facilities or sold through auction markets from dairy farms. There are few studies that examine the relationship between transfer of passive immunity and health outcomes in veal production in Québec. The objective of this study was to investigate the risk factors associated with morbidity and mortality in milk and grain-fed veal facilities in Québec. Between October 2017 and December 2018, a prospective cohort study was conducted on 59 batches of milk- and grain-fed veal calves from Montérégie and Centre du Québec regions in Québec, Canada. A total of 30 calves per batch were randomly sampled for the transfer of passive immunity (TPI) status using the Brix refractometer (serum threshold ≥ 8.4%). Throughout the production cycle, arrival, treatment, mortality, and slaughter records of each batch of calves were extracted and used to quantify individual- and group-level risk factors. Morbidity and mortality were modelled through generalized linear mixed models (GLMMs) using a logit link, as function of categorical variables (individual inadequate TPI, arrival season, purchasing sites, and arrival weights) and a continuous variable (proportion of inadequate TPI in the batch). Given that the health and performance data are usually collected retrospectively under commercial settings, incomplete data was recognized as a potential issue. Thus, multiple imputation models were used. From 59 batches where 1729 calves were sampled for measuring TPI, 1084 calves had a serum Brix% < 8.4% giving a prevalence of 62.7% of inadequate TPI. The prevalence of morbidity and mortality in those 59 batches were not associated with the batch-level inadequate TPI prevalence. On the other hand, individual calves with inadequate TPI had higher odds of morbidity (OR: 1.56; 95% CI: 1.2-2.05, P = 0.001) compared to those calves with adequate TPI. Odds of mortality, on the other hand, were not significantly affected by inadequate TPI (OR:1.27; 95% CI: 0.74-2.18, P = 0.3). Calves arriving to the facility during the winter season had lower odds of mortality than those arriving in fall (OR:0.16; 95% CI: 0.03-0.78, P = 0.02). In conclusion, this study suggests that inadequate TPI, as assessed upon arrival in veal farms, remains an important concern for negative health outcomes in veal calves.

Clinical and histopathological studies on neurodegeneration and dysautonomia in buffalo calves during foot-and-mouth disease outbreaks in Egypt.

BACKGROUND AND AIM: Signs of dysautonomia were frequently observed in calves that died during foot-and-mouth disease (FMD) virus (FMDV) outbreaks in Egypt from 2015 to 2018. This study aimed to describe the clinical and histopathological features of the central nervous system in malignant cases of FMD and excluding possible concurrent bacterial, and bovine herpes virus 4 (BHV4) infections or both. MATERIALS AND METHODS: In this study, 335 FMDV-infected buffalo calves aged 1-22 months were clinically examined and followed until recovery or death. Of the 335 calves, 134 died (malignant group) and 201 recovered after exhibiting classic symptoms of FMD (recover group). The calves were subjected to clinical examination. For the malignant group, several laboratory trials were conducted to assess the possible cause/s of dysautonomia-related viral, bacterial, or concurrent infections. Koch's postulates and polymerase chain reaction were employed. Postmortem and histopathological examinations of nervous tissue were performed. RESULTS: In the malignant group, signs of dysautonomia were observed before death, including partial or complete gut dysfunction, loss of anal sphincter tone, rapid breathing sounds, fluctuating body temperature, and cardiac arrhythmias. In the malignant group, histopathological examination of the spinal cord, pons, medulla oblongata, hypothalamus, cerebellum, and cerebrum revealed demyelination, neuronal degeneration, and focal areas of malacia and gliosis. The nervous tissue and heart samples from malignant cases were positive for serotype O FMDV. CONCLUSION: Findings revealed in this study support the existence of neurodegeneration induced by FMDV infection in buffalo calves.

Characterization of Foot and Mouth Disease Virus Serotype SAT-2 in Swamp Water Buffaloes (Bubalus bubalis) under the Egyptian Smallholder Production System.

Spontaneous mutations are a common characteristic of the foot and mouth disease virus (FMDV), leading to wide antigenic variations resulting in the emergence of new topotypes and lineages of FMDV, which contributes to occasional vaccination failures. The objectives of the present study were to genetically characterize FMDV isolated from water buffaloes and study the biochemical and histopathological indicators of infected animals. Fifty-four water buffaloes of both sexes and different ages suffered from acute symptoms of FMD were clinically examined and randomly selected for inclusion in this study. Oral desquamated epithelial and oropharyngeal fluid samples have been tested for FMDV by reverse transcriptase PCR (RT-PCR). Tissue and serum samples were also collected from the diseased buffaloes and subjected to histopathological and biochemical analysis. Our findings showed that all examined samples were confirmed to be positive to FMDV serotype SAT-2 and were adjusted to be responsible for the recent disease outbreak in this study. Phylogenetic analysis revealed that the circulating viruses were of the SAT-2 serotype, closely related to the lineage of lib12, topotype VII, with 98.9% identity. The new lineage of SAT-2 showed a high virulence resulting in the deaths of water buffaloes due to heart failure, confirmed by high serum levels of inflammatory and cardiac markers, including haptoglobin, ceruloplasmin, cardiac troponin I and creatine phosphokinase-MB, indicating an unfavorable FMD-infection prognosis. In conclusion, we document the presence of new incursions circulating in water buffalo populations in Egypt in early 2019, explaining the high morbidity rate of FMD outbreak in early 2019. Furthermore, the newly identified serotype SAT-2 lib12 lineage, topotype VII, showed an aggressive pattern in water buffaloes of the smallholder production system.

Obstructive urolithiasis in buffalo calves (Bubalus bubalis): Serum changes of Vitamins A and D and efficacy of surgical management using tube cystostomy.

BACKGROUND AND AIM: Obstructive urolithiasis is one of the major health problems in livestock animals, mainly in young calves. The present study was designed first to investigate the changes in the serum levels of Vitamins A and D in buffalo calves (Bubalus bubalis) with obstructive urolithiasis and second to investigate the efficacy of tube cystostomy technique in management of such condition. MATERIALS AND METHODS: One hundred and forty-nine buffalo calves of variable ages ranged from 3 to 7 months with a history of retained urine were examined clinically and ultrasonographically. Then, they were subjected to surgical treatment using the tube cystostomy technique. The serum levels of Vitamins A and D were investigated in retained urine calves in addition to 10 clinically healthy calves of the same age used as a control group. RESULTS: Based on clinical and ultrasonographic findings, the calves were diagnosed as obstructive urolithiasis with intact bladder (n=64 calves) or with bladder rupture (n=85 calves) with the peak incidence in winter months. Tube cystostomy was an efficient and quick surgical technique for the management of such condition and 95.3% of calves returned their normal urination within 7-14 days after surgery. Significant hypovitaminoses A and D were found between retained urine calves and control ones (p= 0.01 and 0.002, respectively). CONCLUSION: Hypovitaminoses A and D suggested predisposing obstructive urolithiasis in buffalo calves, but further clinical studies are recommended for more confirmation. Surgical treatment using tube cystostomy technique is recommended for the management of obstructive urolithiasis in buffalo calves.

Serological and Molecular Characterization of Mycobacterium avium Subsp. paratuberculosis (MAP) from Sheep, Goats, Cattle and Camels in the Eastern Province, Saudi Arabia.

The objectives of the present study were to characterize Mycobacterium avium subsp. paratuberculosis (MAP) infection using serological and molecular tools and investigate the distribution and molecular characterization of MAP strains (cattle (C) and sheep (S) types) in sheep, goat, cattle, and camel herds in Eastern Province, Saudi Arabia. Serum and fecal samples were collected from all animals aged >2 years old in 31 herds (sheep = 8, goats = 6, cattle = 8 and camels = 9) from January to December 2019. Serum samples were tested by ELISA for the detection of MAP antibodies. Fecal samples were tested by PCR for the detection of MAP IS900 gene and the identification of MAP strains. MAP antibodies were detected in 19 (61.3%) herds. At the animal level, antibodies against MAP were detected in 43 (19.5%) sheep, 21 (17.1%) goats, 13 (19.7%) cattle and 22 (9.1%) camels. The IS900 gene of MAP was detected in 23 (74.2%) herds and was directly amplified from fecal samples of 59 (26.8%) sheep, 34 (27.6%) goats, 20 (30.3%) cattle and 36 (15.0%) camels. The S-type was the most prevalent MAP type identified in 15 herds, and all were identified as type-I, while the C-type was identified in only 8 herds. The IS900 sequences revealed genetic differences among the MAP isolates recovered from sheep, goats, cattle and camels. Results from the present study show that MAP was prevalent and confirm the distribution of different MAP strains in sheep, goat, cattle and camel herds in Eastern Province, Saudi Arabia.

Determination of the dynamics of respiratory diseases using thoracic ultrasonographic examination in preweaned dairy calves.

This study aimed to explore the dynamics of lung consolidation in preweaned calves and the association between ultrasonographic findings and prognosis (defined as the time until first consolidation occurrence during the preweaning period) and average daily gain. Two dairy herds were visited weekly for 9 weeks. The preweaned dairy heifers were: examined for bovine respiratory disease using thoracic ultrasonography and the calf respiratory scoring criteria, weighed, and had blood samples checked for passive immunity transfer status. A total of 57 preweaned dairy calves were examined. Prevalence of lung consolidation increased from the first week of age (12.5%) and peaked (90%) by 10 weeks of age. In a subgroup of 25 calves monitored from birth, lung consolidation appeared as soon as a few hours after birth (1 cm consolidation depth) and by the 17th day of age (3 cm consolidation depth). Lung consolidation can be detected early by routine thoracic ultrasonography in preweaned dairy calves and is therefore valuable for use in farms with a high risk of pneumonia in preweaned calves.

Détermination de la dynamique des maladies respiratoires par examen échographique thoracique chez des veaux laitiers pré-sevrés. L'étude visait à explorer la dynamique de la consolidation pulmonaire par ultrasons chez les veaux pré-sevrés et l'association entre les résultats de l'échographie et le pronostic (défini comme le délai avant la première consolidation pendant la période de pré-sevrage) et le gain quotidien moyen. Deux troupeaux laitiers ont été visités chaque semaine pendant neuf semaines, toutes les génisses pré-sevrées ont été examinées par échographie thoracique. Les scores cliniques respiratoires à des veaux, et des échantillons de sang ont été prélevés pour vérifier leur statut de transfert d'immunité passive. Un total de 57 veaux laitiers pré-sevrés ont été examinés. La prévalence de la consolidation pulmonaire a augmenté dès la première semaine d'âge (12,5 %) jusqu'à son maximum (90 %) à l'âge de 10 semaines. Dans un sous-groupe de 25 veaux suivis depuis la naissance, la consolidation pulmonaire est apparue quelques heures après la naissance (consolidation DEPTH 1 cm) et au 17ème jour (consolidation DEPTH 3 cm). Une détection précoce des lésions pulmonaires peut être réalisée par échographie thoracique systématique ce qui démontre une application potentielle dans les fermes au risque élevé de pneumonie pré-sevrage.(Traduit par les auteurs).