Dead Calves Research Articles

Therapeutic management of pyometra in crossbred Murrah buffalo

Pus filled uterus described as pyometra. In present case a crossbred Murrah she buffalo was suffering from the pyometra and produces dead calf on calving. Clinical signs showed fever, anorexia, inactivity, mucopurulent discharge from vagina and lack of interest towards feeding. The case was treated locally and parenterally. The cow recovered successfully within 8th days without any secondary complications.

Impact of reproductive traits on productive life in Iranian Holstein dairy cows.

Enhancing reproductive performance is a key strategy to mitigate involuntary culling rates, thereby extending productive life (PL) and ultimately improving profitability in dairy cattle herds. A piecewise Weibull proportional hazards model was used to investigate the effect of several important reproductive traits on PL in Holstein dairy cows. Data comprised 200,747 lactation records from 82,505 cows sired by 1952 bulls across 36 dairy herds. PL was defined as the number of days from the first calving to the last milk record or censoring. The statistical model accounted for the time-dependent fixed effects of changes in herd size, year-season, milk production, fat and protein contents, and the time-independent fixed effect of age at first calving. Herd-year and sire effects were also included as random effects. Reproductive traits include calving traits such as calving ease (CE), calf size (CZ), and calf survival (CS), as well as female fertility traits such as number of inseminations per conception (NI), days from calving to first service (CFS), days from first service to conception (FSC), and days open (DO). All reproductive traits had a significant effect on PL (p < 0.001). Each reproductive trait was analysed separately. The relative risk (RR) of being culled increased as the severity of calving difficulties increased in both primiparous and multiparous cows. Cows that calved small or large calves showed a higher risk of being culled compared with those that calved medium size calves. The increased RR of culling was observed only for primiparous cows that gave birth to dead calves. In addition, cows that required more NI, a longer CFS, FSC, and DO had shorter longevity. These insights can deepen our comprehension of the factors affecting PL and provide information for refining management and breeding strategies, which could lead to increased profitability and sustainability in Iranian dairy farming.

Genetic diversity and phylogenetic relationships of Clostridium perfringens strains isolated from mastitis and enteritis in Egyptian dairy farms

BackgroundClostridium perfringens, a common environmental bacterium, is responsible for a variety of serious illnesses including food poisoning, digestive disorders, and soft tissue infections. Mastitis in lactating cattle and sudden death losses in baby calves are major problems for producers raising calves on dairy farms. The pathogenicity of this bacterium is largely mediated by its production of various toxins.ResultsThe study revealed that Among the examined lactating animals with a history of mastitis, diarrheal baby calves, and acute sudden death cases in calves, C. perfringens was isolated in 23.5% (93/395) of the total tested samples. Eighteen isolates were obtained from mastitic milk, 59 from rectal swabs, and 16 from the intestinal contents of dead calves. Most of the recovered C. perfringens isolates (95.6%) were identified as type A by molecular toxinotyping, except for four isolates from sudden death cases (type C). Notably, C. perfringens was recovered in 100% of sudden death cases compared with 32.9% of rectal swabs and 9% of milk samples. This study analyzed the phylogeny of C. perfringens using the plc region and identified the plc region in five Egyptian bovine isolates (milk and fecal origins). Importantly, this finding expands the known data on C. perfringens phospholipase C beyond reference strains in GenBank from various animal and environmental sources.ConclusionPhylogenetic analyses of nucleotide sequence data differentiated between strains of different origins. The plc sequences of Egyptian C. perfringens strains acquired in the present study differed from those reported globally and constituted a distinct genetic ancestor.

The Waves

In August 2018, there was a female orca who carried her dead calf to the surface of the Pacific Ocean for seventeen days. This kind of behavior had never before been documented. When the orca needed to feed or rest, her pod helped her carry the burden. During this time, the pod travelled more than 1,600 kilometres with the dead calf. Researchers say the orcas were in mourning and called this time their ‘Tour of Grief.’ Orcas are enormous mammals with the capacity to feel deep emotion. To Laura Quigley, this story speaks to the enormity of a mother’s heart and her fierce strength. It also speaks to the bond of the pod and their instinct to support one another, especially in the darkest moments. When Quigley gave birth to her second baby, she was struck by how isolated she felt. She was away from colleagues and many of her friends, and she lived far from her family because of her work. In speaking with so many mothers since writing this play, she understands that she was not alone in this feeling of segregation. As new mothers, we are without pods. The Waves dives into under-represented territory: loss of identity in motherhood, postpartum depression, and the rebuilding of self after giving birth. The text is poetic, raw, and urgent and explores ways the human voice can initiate understanding and connection between performer and audience, between humans. In this way, the text contains a detailed description of vocal sounds that depart from language, invoking the performer to explore relationship and communication beyond the conventions of speech and silence.

Chloride and lactate as prognostic indicators of calf diarrhea from eighty-nine cases.

Deaths due to neonatal calf diarrhea are still one of the most critical problems of cattle breeding worldwide. Determining the parameters that can predict diarrhea-related deaths in calves is especially important in terms of prognosis and treatment strategies for the disease. The primary purpose of this study was to determine mortality rates and durations, survival status, and predictive prognosis parameters based on vital signs, hematology, and blood gas analyses in neonatal diarrheic calves. The hospital automation system retrospectively obtained data from 89 neonatal diarrheic calves. It was found that 42.7% (38/89) of the calves brought with the complaint of diarrhea died during hospitalization or after discharge. Short-term and long-term fatalities were a median of 9.25 hours and a median of 51.50 hours, respectively. When the data obtained from this study is evaluated, body temperature (°C), pH, base excess (mmol/L), and sodium bicarbonate (mmol/L) parameters were found to be lower, and hemoglobin (g/dL), hematocrit (%), lactate (mmol/L), chloride (mmol/L), sodium (mmol/L) and anion gap (mmol/L) parameters were found to be higher in dead calves compared to survivors. Accordingly, hypothermia, metabolic acidosis, and dehydration findings were seen as clinical conditions that should be considered. Logistic regression analysis showed that lactate (odds ratio, 1.429) and CI- (odds ratio, 1.232) concentration were significant risk factors associated with death in calves with diarrhea. According to the findings obtained from this study, the determination of lactate and Cl- levels can be used as an adjunctive supplementary test in distinguishing calves with diarrhea with a good prognosis.

Molecular characterization of G and F protein genes of bovine respiratory syncytial virus detected from dead calves caused by severe respiratory syndrome: emergence of novel mutations and their importance.

The online version contains supplementary material available at 10.1007/s13337-023-00846-7.

Improvement of Laboratory Diagnosis for Detection and Identification of Bovine Clostridiosis

Objective: Clostridiosis is a toxic infectious disease; the pathogenicity factor of causative agents is the secreted toxins. A characteristic feature of clostridiosis pathogens is their polytropism. They affect both humans and agricultural, domestic, and wild animals. Our research aimed to monitor Clostridium perfringens and Clostridium difficile spread among agricultural organizations of the Ural region. Materials and Methods: 137 biological samples were obtained from cattle with symptoms of clostridial infection. For PCR species and toxinotype identification commercial kits and previously described protocols were used. Results verification was conducted using MALDI-TOF MS. Results: Out of 137 samples of selected material Clostridium was detected in 40.6% of samples: Cl. difficile in 35.8%, Cl. perfringens in 25.3%, Cl. difficile+Cl. perfringens in 16.4%. Cl. difficile and Cl. perfringens were found in 30.5% of fecal samples, in pathological material from dead calves and cows – 8.7%, in milk samples – 1.4%. Conclusion: Laboratory methods made it possible to verify the diagnosis: infectious anaerobic enterotoxemia of calves in one case, necrotic enteritis in 3 animals, and intestinal toxic infection caused by Cl. perfringens type A in 2 cows and 5 calves. The diagnostics of toxinotypes of Cl. perfringens have made it possible to conduct toxin-specific vaccination against clostridial infection in farms.

Complete genome sequence of multi-drug-resistant Salmonella enterica subsp. enterica serovar Typhimurium strain Bnaya isolated from a dairy calf in Israel.

This manuscript reports the complete genome sequence of a Salmonella enterica subsp. enterica serovar Typhimurium strain (designated "Bnaya"), isolated from a dead dairy calf with severe diarrhea in Israel. The isolate exhibited multi-drug resistance, which is highly unusual in bovine Salmonella spp. in Israel, prompting further investigation.

Novel pathologic findings and viral antigen distribution in cattle and buffalo calves naturally infected with Foot-and-Mouth disease virus

The Foot-and-Mouth disease is highly contagious acute viral disease of livestock inflicting huge economic loss to the farmers. The limited knowledge regarding the pathological lesions vis-a-vis distribution of the FMDV in lesser explored endocrine glands and important vital organs other than the target organs of infected calves prompted us to take the present investigation to have detailed insight into the pathogenesis. The systematic necropsy of 37 dead calves (cattle-28 and buffalo-9) was conducted, and thin representative tissue pieces from the affected organs were collected in 10% neutral buffered formalin (NBF) for pathological and immunohistochemical investigations. The genomic detection and its serotyping were done by RT-PCR and multiplex-PCR, respectively. Necropsy examination in all cases showed myocardial lesions resembling ‘tigroid heart appearance’. Other organ specific lesions include vesiculo-ulcerative stomatitis, edema of the lungs, petechial hemorrhages, edema of the endocrines, and gastroenteritis. Histopathological examination showed varying sizes of vesicles and ulcerations in stratified squamous epithelium of the tongue, acute necrotizing myocarditis, lymphoid depletion in lymphoid tissues, hepatitis, pancreatitis, thymic hyperplasia, thyroiditis, adrenitis, and enteritis. Positive immunolabeling for viral antigens was observed in endocrine glands, lymphoid organs, lungs, liver, kidneys, and intestine, in addition to other typical locations. The thyroid, adrenal glands, and pancreas, in addition to the tongue and heart, are the tissue of choice for sampling in the field during epidemics. Further, the viral genome and serotype A was confirmed in the affected tissues. This study provides insights into novel tissue tropism and pathogenesis in young calves naturally infected with FMDV.

Nurturant behavior towards a dead calf in a Cuvier's beaked whale

Nurturant behavior towards a dead calf in a Cuvier's beaked whale

Pathogenicity and molecular characterization of Mycoplasma bovis isolate from calves in Morocco.

Bovine respiratory disease caused by Mycoplasma bovis (M. bovis) represents a major health problem for cattle worldwide that causes considerable financial losses. This study reports for the first time the molecular and pathogenic characterization of a strain of M. bovis isolated from a dead local calf with respiratory symptoms in Morocco. M. bovis was isolated from lung tissue, purified by cloning, and subtyped using MLST analysis. Experimental infection was conducted in naïve calves to evaluate pathogenicity.The isolate was identified as a new subtype ST-204 that shares similarities with the 2019-2021 Spanish strains (ST-169, ST-170, ST-171) and the 2018 Algeria isolate (ST-4). Experimental infection resulted in fever and respiratory symptoms with serous nasal discharge. At postmortem, lung lesions of congestion and hepatization were observed with lymph node enlargement and foci of necrosis. The study confirms the high pathogenicity of the isolate and the important role of M. bovis in bovine respiratory disease.

Shiga Toxin-Producing Escherichia coli (STEC) Associated with Calf Mortality in Uruguay.

In Uruguay, the mortality of dairy calves due to infectious diseases is high. Escherichia coli is a natural inhabitant of the intestinal microbiota, but can cause several infections. The aim of the work was to characterize E. coli isolates from intestinal and extraintestinal origin of dead newborn calves. Using PCR, virulence gene characteristics of pathogenic E. coli were searched. The pathogenic E. coli were molecularly characterized and the phylogroup, serogroup and the Stx subtype were determined. Antibiotic susceptibility was determined using the Kirby-Bauer disk diffusion method and plasmid-mediated quinolone resistance (PMQR) genes with PCR. Finally, clonal relationships were inferred using PFGE. Gene characteristics of the Shiga toxin-producing E. coli (STEC), Enteropathogenic E. coli (EPEC) and Necrotoxigenic E. coli (NTEC) were identified. The prevalence of the iucD, afa8E, f17, papC, stx1, eae and ehxA genes was high and no f5, f41, saa, sfaDE, cdtIV, lt, sta or stx2 were detected. The prevalence of STEC gene stx1 in the dead calves stood out and was higher compared with previous studies conducted in live calves, and STEC LEE+ (Enterohemorrhagic E. coli (EHEC)) isolates with stx1/eae/ehxA genotypes were more frequently identified in the intestinal than in the extraintestinal environment. E. coli isolates were assigned to phylogroups A, B1, D and E, and some belonged to the O111 serogroup. stx1a and stx1c subtypes were determined in STEC. A high prevalence of multi-resistance among STEC and qnrB genes was determined. The PFGE showed a high diversity of pathogenic strains with similar genetic profiles. It can be speculated that EHEC (stx1/eae/ehxA) could play an important role in mortality. The afa8E, f17G1 and papC genes could also have a role in calf mortality. Multidrug resistance defies disease treatment and increases the risk of death, while the potential transmissibility of genes to other species constitutes a threat to public health.

Dead newborn calf affects behavior, cortisol, milk production, and reproductive performance in primiparous dairy cows

Little is known about the long-term effects of stillbirth on dairy cows. This study compared the behavior, serum and hair cortisol concentrations, production and quality of milk, and reproductive performance in primiparous dairy cows that delivered dead or live newborn calves. Forty-four Holstein cows housed in an earth-flooring corral (42.66 m2/cow) were studied for 90 days and classified into two groups: 29 cows with alive newborn calves (AC group) and 15 cows with dead newborn calves (DC group). On the first day of lactation and on the 30th, 60th, and 90th day, hair and serum cortisol concentrations were measured using radioimmunoassay as reliable stress indicators. Social, sexual, and maintenance behaviors were observed daily for 4 h. Milk yield was measured three times a day in a milking parlor, and somatic cell counts were compared at three and nine months of lactation. Milk quality and body condition were also recorded. Cows in the AC group spent more time lying, ruminating, and drinking than cows in the DC group, which received and exhibited significantly less aggression. No differences were observed between the groups in the proportion of time spent standing, walking, or eating. Serum and hair cortisol concentrations were significantly higher in DC cows than in AC cows on day 60 of lactation. No differences were observed in the body condition or reproductive performance. As expected, the milk quality was higher in AC cows than in DC cows. Our study shows that the delivery of dead newborn calves by primiparous cows has a clear negative effect on long-term behavior, hair and serum cortisol concentrations, and milk production. These findings highlight the role of delivery pathology in primiparous cows.

Analysis of Calving Ease and Stillbirth and Their Impact on the Length of Functional Productive Life in Slovak Holstein Cattle.

The aim of the study was to determine the frequency of births according to the categories of calving difficulty and stillbirths and to evaluate the effect of these factors on the longevity of cows. Longevity is one of the traits that affect the overall profit in the dairy industry. A Weibull proportional hazard model was used to evaluate the influence of functional traits such as calving ease and stillbirth. Longevity was expressed as the length of a functional, productive life from the first calving to death or censoring, which was corrected for milk yield. The database included 918,568 calvings, where calving without assistance represented 83.34%, calving with the assistance of one person or the use of a slight mechanical pull represented 14.47%, difficult calving with the assistance of several people, the use of mechanical traction or the intervention of a veterinarian represented 2.16%, and cesarean section represented 0.03%. The mortality of calves, stillborn or dead within 48 h of birth, represented 1.07% and 6.59%, respectively. The frequency of alive female calves was higher (46.84%) than male calves (45.50%). Cows with higher lactations had almost half as many stillborn calves as heifers. The most stillborn calves were found in difficult births (59.48%). In easy calving, this proportion was 2.48%. Using survival analysis, we estimated the significant influence of the factors such as parity, milk production, herd size, age at first calving, herd × year × season, sex of calf, calving ease, and stillbirth on the length of the functional, productive life of cows. The risk of early culling of the cows with moderately difficult calving was 1.259 times higher than in the cows with easy calving. Difficult calving and cesarean section shorten the productive life, and the risk of culling reached 1.711 and 1.894, respectively. Cows that gave birth to a dead calf achieved a 2.939 times higher risk of culling compared to cows that gave birth to a live calf. In this study, a higher risk of early culling was found in cows that gave birth to a male calf. Evaluation of the calving ease and stillbirth can be used as indirect indicators at an earlier age of the animal in the selection process for long-lived animals with good productive and reproductive performance.

THE PRODUCTIVITY OF THE FIRST CALVING COWS OF DIFFERENT CONDITIONS GROWING AND HOUSING

Introduction. The purpose of the work was to study the influence of different conditions of rearing and housing of the first calving cows on their productivity, reproductive capacity and stayability during lactation at the current stage of breeding. Materials and methods of research. The work was carried out based on the data of four breeding plants for the breeding of Ukrainian black and white dairy cows. The data of 3.610 first calving cows that calved during the last six years were analyzed. Statistical processing of the obtained data was carried out by the method of two-factor variance analysis using computer programs. During the analysis, the data were divided by the age of first fertilization and the average daily gain before fertilization. Only animals with a duration of lactation of more than 200 days were selected to determine productivity indicators for lactation. The stayability was determined for the first 10 months of lactation. In determining the probability of abortion and stillbirth, calvings with stillborn calves and abortions after which lactation began are taken into account. Research results. It was established that the live weight of first calving cows, regardless of the housing, increased proportionally to the intensity of their growing. In stall housing, the live weight of first servis that were fertilized at different ages had no significant differences, while in free stall housing, the first calving cows that were inseminated before the age of 470 days had an advantage of 12–19 kg. In terms of milk yield for 305 days of lactation, the first calving cow that were kept tethered and were fertilized at an earlier age exceeded the animals of other groups by 29–148 kg of milk, and those kept without tethering by 564–989 kg. Intensively reared animals produced 244–539 kg of milk more when tethered, and when tethered, this difference was significantly greater and amounted to 530–1081 kg, compared to first calving cow with an increase of less than 800 g. A reading has been established for the trend of increasing the milk yields from the changes in the first fertilization. The intensity of the growth of the heifers before the flooding also has a positive impact on their day milk yield. The probability of unsuccessful calving does not depend on the age of the first insemination in stall housing, but in free housing, animals that were inseminated before 470 days of age had 36–46% more unfavorable results with calving than those that were inseminated in older age The probability of abortion and the birth of a dead calf during stall housing heifers with different intensities of growing before fertilization also had no significant differences, and during free housing heifers with an average daily gain of more than 800 g had 7–9 more cases of unsuccessful calving, calculated on 100 animal compared to heifers with a lower intensity of growing. Conclusions. Increasing the intensity of raising heifers and reducing the age of first insemination contribute to increasing their productivity. It is necessary to carry out constant monitoring of repair youngsters for fatness and to prevent obesity. It leads to a decrease in reproductive capacity, unfavorable calving and, as a result, an increase in the probability of culling in the first lactation, especially in in free housing.

Pregnancy and parturition in dromedary camels III. Incidence, timing and factors affecting abortions and perinatal mortality under intensive management

In this study, the incidence, timing and risk factors associated with abortion and perinatal mortality (PM) were described in dromedary camels under intensive management. In addition, overall pregnancy losses were also summarized and weekly risk of pregnancy wastage was determined throughout gestation. Data were collected over 11 breeding seasons from September 2006 through June 2017 at the world's largest camel dairy farm. A total of 229 abortions were observed (5.05%) out of 4533 pregnancies after 60 days (d) of gestation. Most abortions were singleton (n = 199, 86.9%), but twin abortions were also recorded in 30 cases (13.1%). Abortions showed a pronounced seasonal distribution, with a peak in August. The age category (P < 0.01), breed or ecotype of the female (P < 0.05) and bull influenced the occurrence of singleton abortions. Dromedaries with twins tended to abort earlier than those with a singleton fetus (median = 232.5 d vs. 257 d, P = 0.053). Perinatal mortality was observed in 174 cases (3.84%) out of 4533 pregnancies after 60 d of gestation. The condition included the premature birth of non-viable calves after shorter than normal gestation (330–350 d, n = 26, 14.9%), the birth of well-developed but dead calves after normal gestation length (n = 120, 69.0%) and neonates that died within 48 h after delivery (n = 28, 16.1%). The frequency distribution of PM was parallel with that of parturitions. The most important predisposing factor for PM was difficult calving. Thirty-nine percent (68 out of 174) of these losses were associated with dystocia. In addition, age category (P < 0.05) and parity of the female (P < 0.01), month of delivery (P < 0.05) and breeding season (P < 0.05) also affected the incidence of PM. The cause of 60 cases of PM (1.4% of all deliveries) could not be determined and was considered idiopathic. In conclusion, one-third of total pregnancy losses occurred during mid to late gestation. Approximately 10% of pregnancies after Day 60 failed, and 90% resulted in the birth of a live calf that survived beyond 48 h. More than half of these pregnancy losses were abortions before 330 d of gestation, and approximately 40% were classified as PM. The weekly mean risk of pregnancy loss after 100 d of gestation remained only a fraction of that observed during the first 2–3 months.

First DNA sequence proof for the occurrence of bovine adenovirus types 10 and 11 in continental Europe.

Bovine adenoviruses (BAdV) are known to cause respiratory and/or intestinal disease in calves. Infection can manifest as acute outbreaks, but more often only sporadic cases occur. Here we describe the PCR detection and partial sequence characterization of several BAdVs found in sick or dead calves on different farms in Western Hungary. Intermittent diarrhoeal illnesses occurred after weaning among calves on several farms located up to 40km apart. A high-sensitivity, broad-spectrum nested PCR, developed for the general detection of adenoviruses, gave positive results in four independent cases. Direct sequencing of PCR products showed clear results from only two samples, whereas sequences from the other two amplicons were mixed. Molecular cloning of these heterogeneous PCR products was performed to separate each DNA fragment therein. By sequencing several plasmid clones from both mixed samples, we were able to detect the simultaneous presence of two different BAdV types, namely types 6 and 10 classified into two separate (Atadenovirus and Mastadenovirus) genera. The sequence of one homogenous sample was identified as being derived also from BAdV-10, whereas the other sample contained a novel type, proposed to be BAdV-11. We demonstrated, for the very first time, the occurrence of the two latter virus types in continental Europe. Their appearance in Hungary marks a significant shift in the types of BAdVs actually circulating in the country. Considering the similarity of the pathological findings to those, attributed to BAdV-10 infections reported to date, the causative role of the viruses in these cases seems to be plausible. Phylogeny reconstruction further confirmed that BAdVs represent multiple genetic lineages.

Calf care workers' attitudes and personality and their association with calf mortality in large-scale dairy farms.

Although calf mortality is a multifactorial problem, little is known about the attitudes and personalities of calf care workers (CCWs) and their association with calf mortality. This study aimed to describe the attitudes, satisfaction, and personality of CCWs in large Estonian dairy herds and to analyze their associations with herd calf mortality. A questionnaire registering CCWs' attitudes toward their work and calf mortality, personality characteristics, satisfaction and importance of different job-related factors was developed. In total, completed questionnaire data of 161 CCWs from 108 large (>100 cows) Estonian dairy farms were analyzed. Herd-level yearly calf mortality risk (MR) was calculated. Cluster analysis and variance partitioning analysis were applied to reveal the explanatory capacity of CCWs' attitudes and personalities on calf mortality. The mean yearly herd-level calf MR was 5.4% during the first 21 days of life and 2.7% during 22–90 days of life. Although good calf health and low calf mortality was important for CCWs, dead calves were often seen as inevitable. CCWs were generally doubtful regarding their capacity and available knowledge to influence calf mortality. In high-mortality herds, CCWs were dissatisfied with the calf health situation and farm working equipment and felt that the situation was out of their control. Despite striving, they had less faith that farmworkers could affect the outcomes, such as calf mortality. CCWs' personality domains explained <5% of the variance in the herd's calf MR, whereas their attitudes and satisfaction explained 20% of the variability in calf MR. The current study revealed the importance of the attitudes and satisfaction of CCWs on calf mortality and highlighted the need to allocate proficient assistance to herds with high calf mortality to mitigate calf health problems and the resulting consequences for CCWs.

Impact of dystocia and cow/calf characteristics on mortality from 0 to 120 days of age in Japanese Black calves in commercial cow-calf operations

Calf mortality severely affects productivity in the beef industry. The present study was conducted to assess the calf mortality risk (CMR) in Japanese Black calves and investigate potential associations between calf/cow information and the CMR. Records for calves born between April 2006 and March 2010 were extracted from an existing database, which included production data on commercial cow-calf operations in Miyazaki, Japan. The study group comprised 40,462 calves born to 15,600 cows on 908 farms. Because calves on the studied farms were weaned at approximately 4 months of age, the calf records were collected from birth to 120 days. The CMR was calculated as the number of dead calves divided by the number of surviving calves. Mixed-effect multivariable logistic regression modeling was used to determine potential associations between the CMR and the factors hypothesized to influence that risk. CMR analyses were performed separately for the following production stages: days 0–30, days 31–60, days 61–90 and days 91–120 after birth. Of the 40,462 calves, 1465 died during days 0–120 after birth, and the CMR was 3.6 %. Of the 1465 dead calves, 35.9 % died within 10 days after birth. During the 0–30-day period, the CMR was associated with dam parity, calving status, gestation length, sex, birth season and twin births (P < 0.05), but not with the number of inseminations to conception. Low parity, dystocia, gestation lengths < 280 days and > 301 days, male calves, calves born in autumn and winter and twin births yielded higher CMRs. Low dam parity also yielded higher CMRs during the 31–60-day, 61–90-day and 91–120-day periods (P < 0.05), but no other factors were associated with the CMR during these periods. Thus, various cow and calf factors were shown to be associated with CMRs in Japanese Black calves, and calves with these factors should be considered high-risk calves.

Novel pathological findings and immunohistochemical detection of FMDV antigens in the brain of calves naturally infected with foot-and-mouth disease

Foot-and-mouth disease (FMD) is an extremely contagious and economically devastating viral disease of cloven-hoofed domestic and wildlife animals. The disease is endemic in India and other developing countries of the world. The disease is mainly characterized by the presence of vesicular lesions and “tigroid heart” in calves. The current report describes the novel pathologic findings along with the distribution of FMDV antigens in brain of young calves naturally infected with FMDV. The carcasses of 37 calves suspected to have died from FMD were presented for postmortem investigation. Out of 37 dead calves, 10 calves showed the clinical signs of neurological abnormalities like opisthotonos, muscle twitching and tremor in hind limbs, stiffening of the neck followed by death. Microscopically, the meninges were congested, hemorrhagic, and infiltrated with mononuclear cells. The various sub anatomical sites of the brain showed the varying degrees of vascular changes, perivascular cuffing, focal to diffuse gliosis as well as degeneration and neuronal necrosis, indicating the nonsuppurative encephalitis. The immunolabeling of FMDV antigen was demonstrated in the neurons, inflammatory cells, and microglial cells besides its typical locations. The neurons of the brain also showed strong immunopositivity for caspase-3, caspase-9 and p53 and negative for Bcl-2 and apoptosis-inducing factor (AIF) by both immunohistochemistry and western blotting indicating the role of caspase mediated intrinsic, and p53 dependent apoptotic pathway. Further, the TUNEL assay also confirmed the apoptosis in the neurons and glial cells of the brain of naturally infected calves. This study in calves establishes a basis for resemblance to other members of Picornaviruses, such as Enterovirus 71 and Coxsackievirus of humans and showing the neuropathological alterations along with the distribution of FMDV antigens associated with apoptosis in younger calves.