Neonatal Calf Diarrhea Research Articles

Detection of viral infectious agents causing calf diarrhea on dairy farms in Serbia

Neonatal calf diarrhea (NCD) is a multifactorial disease commonly occurring in unweaned calves, and one of the major causes of calflosses worldwide. In this study, we investigated the role of viral agents in neonatal calf diarrhoea from dairy farms with reported outbreaks in the winter of 2021-2022.For this study, we tested rectal swab samples from 20 commercial dairy farms with 100-1000 cows with reported acute diarrhoea in neonatal calves.From each farm, five to ten calves, up to 2 months of age, in total 154, with acute diarrhea were sampled by rectal swabbing. Out of 20 tested dairy farms, at 4 farms none of the testedviruses was detected whereas at least one of the tested viruses was detected at 16 farms (80%). As the most prevalent, mono BRV infection was detected at 10 farms (62.5%), followed by a single BCoV infection at 3 farms (18.75%). Coinfection of BVDV and BRV was demonstrated at 2 farms (12.5%), and simultaneous infection with BVDV, BRV and BCoV at one farm (6.25%). G typing of BRV revealed that 60% of the BRVs were G10, 33.3% were G6, and 16.7% were G8. P typing indicated that 66.7% of the BRVs were P[11] and that 33.3% were P[5]. This study revealed viral causative agents being the most often found in diarrheic neonatal calves in Serbia, thuscontributing to the development of more effective strategies for disease prevention and control.

Herd-level occurrence and risk factors associated with respiratory and enteric pathogens from dairy calves in Ontario: A cross-sectional study

This cross-sectional herd-level study aimed to determine the occurrence of and risk factors for pathogens associated with neonatal calf diarrhea and bovine respiratory disease on Ontario dairy farms. From April to August 2022, a convenience sample of 100 dairy farms were visited once. A questionnaire covering farm biosecurity, calving and colostrum management, preweaning nutrition, and housing was administered on-farm. At each farm visit, approximately 5 calves between 2 and 35 d old were randomly selected for fecal sampling. Furthermore, approximately 5 calves between 21 to 122 d old were randomly selected for nasopharyngeal sampling. In total, 363 fecal samples (from 83 dairy farms) and 390 nasopharyngeal swab samples (from 80 dairy farms) were collected. Fecal samples were analyzed individually using a multiplex PCR to identify bacterial and parasitic enteric pathogens. Nasopharyngeal swabs were analyzed as one pooled sample per farm using bacterial culture and real-time PCR. The most common enteric pathogens detected at herd-level were Cryptosporidium parvum (67.4%) and Escherichia coli K99+ (13.2%). The most common respiratory pathogens detected at herd-level were Pasteurella multocida (62.5%), bovine coronavirus (42.5%), and Mycoplasma bovis (21.2%). Multivariable logistic models were built to explore associations between the most common pathogens and herd-level predictors selected from the questionnaire. Herd positivity for C. parvum was positively associated with having more than 61 preweaned calves per year and feeding mainly whole milk to calves. The presence of M. bovis was positively associated with herds that combined manual and automatic milk-feeding systems, and the presence of bovine coronavirus was positively associated with having more than 98 preweaned calves during the year. Univariable Poisson regression models were built to explore the association between the most common pathogens and preweaning calf mortality. Herds that were positive for C. parvum, M. bovis, or bovine coronavirus had a greater risk of preweaning calf mortality. These results provide insights for future research on pathogens associated with NCD and BRD and offer guidance for veterinarians and dairy farmers in implementing disease control measures in dairy calf herds.

Dairy farm management factors associated with auction sale price of young dairy calves sold at auction markets in Québec, Canada. A cross-sectional study

Each year around 150,000 surplus calves are sold at auction markets in Québec, Canada. Surplus calves (male or female not kept in the herd of origin) are sold at a young age, but these animals are at risk of receiving lower quality neonatal care than replacement heifers. Knowledge of factors associated with a higher selling price could help convince farmers to spend more resources in the care surplus calves. Our objective was to explore the associations between farm management practices and the median percentile of surplus calf selling price per farm at auction markets. The price (CAD/kg of body weight) and the individual identification number of surplus calves sold in 2 auction markets in Québec during 4 sales days in the summer 2019 and in the winter 2020 were recorded. The recorded price of each surplus calf was transformed as percentile for each breed and day of sale. Farmers managing the surplus calves were contacted and interviewed on farm management practices. The data from farmer's interviews were analyzed as potential variables associated with the median percentile of calves' selling price per farm (farm level dependent variable) in a multivariable linear regression model. A total of 509 farmers were contacted, of which 433 farmers agreed to participate, and 409 interviews were retained for statistical analysis. The farms enrolled in the study had sold a median of 2 calves (range 1-19 calves) during the sale days considered. The main breed of surplus calves sold were Holstein (82%) and Angus crossbred calves (9%). The results from the multivariable model showed that median percentile of calves' selling price was positively associated with farms with an average milk production per cow superior to 11,000 L/years (β 0.13, 95% confidence interval (95% CI): 0.045, 0.221) and farms with 3 or more workers available to take care of surplus calves (β 0.08, 95% CI: 0.005, 0.167). Those results indicate that farms having an average milk production per cow superior to 11,000 L/year increase the calves' selling price by 13 percentiles (i.e., from 50th to 63rd) and that farms having at least 3 caretakers increase their median percentile calves' selling price by 8 percentiles (i.e., from 50th to 58th). Median percentile of calves' selling price was negatively associated with farms that vaccinated cows for neonatal calf diarrhea (β -0.06, 95% CI:-0.127, -0.011), that do not disinfect the navel of newborn calves (β -0.07, 95% CI:-0.133, -0.012), that allow transporters to enter the farm's building (β -0.07, 95% CI:-0.130, -0.015) and that used wood shaving as bedding for surplus calves (β -0.08, 95% CI:-0.156, -0.021). Sensitivity analyses performed on farms that have sold 2 or more surplus calves did not show significant changes in the associations found. Despite the fact that the study was based on self-reported questionnaire answers and a small number of calves per farm, it provides insight on farm management practices associated with median percentile of surplus calf selling price at the auction markets. Taking these results in consideration, farmers could potentially improve the market value of their animals.

Effects of propolis extract administration on immune parameters, faecal consistency scores, and growth performance of Holstein-Friesian calves.

The purpose of the study was to investigate the effect of Ethanolic Extract of Propolis (EEP) administration on immune parameters, faecal consistency scores, growth performance, and feed efficiency of Holstein Friesian calves. A total of 24 calves were divided into two different groups, control (n = 12) and EEP (n = 12). Both groups consisted of 6 male and 6 female calves. The calves were fed milk amounting to 10% of their birth weight each day until they reached 60days of age. Additionally, they were given starter feed and dry hay once a day. Calves assigned to the EEP group received 4ml of EEP daily. Use of EEP increased (P < 0.05) the serum IgG and IgM levels at 2months of age compared to the control group. EEP also showed efficacy (P < 0.01) in reducing faecal consistency in calves throughout the study. The levels of IL-1β, IL-6, TNF-α and NF-κB expression in calves treated with EEP were lower (P < 0.05) throughout the EEP application period. On the other hand, IGF-1 mRNA transcript levels were (P < 0.01) higher in EEP group calves than in the control group. Furthermore, EEP-fed calves consumed less dry matter for 1kg of live weight gain during the weaning-4months (P < 0.01) and birth-4months (P < 0.05) periods. These results indicate that EEP supplementation, through its immunostimulatory effects, plays a crucial role in the control of neonatal calf diarrhoea. Growth and development as well as IGF-1, which stimulates growth in almost all somatic cells, was also significantly increased by EEP supplementation. The combined effect of the rich bioactive compounds found in EEP appears to have a significant impact on health and well-being, resulting in improved early life performance in dairy calves.

Determination of G and P genotypes of bovine group A rotavirus with emergence of unusual G-and P-type combinations from neonatal calfdiarrhea in Kashmir, India.

A total of 490 diarrhoeic samples from calves aged between 0 and 6 months were screened for the presence of different G- and P-genotypes of rotavirus circulating in bovines in the Kashmir Valley. Of the 490 diarrhoeic samples, Group A rotavirus was detected in 68 (13.87%) samples by polymerase chain reaction (PCR) followed by RNA-PAGE. Genotyping analysis revealed G10, G6, G3, P[11] and P[5] to be the predominant types. The most common types of combinations detected were G10P[11] (27.90%) and G6P[11] (20.60%). The prevalence rate of G10 and P[11] decreased from 60% to 36.76% and 100%-69.11%, respectively. Genotypes G6, G3, P[1] and P[5], which were not previously reported, were detected and unusual combinations such as G6P[11], G3P[11], G10P[5], G3P[5], G6P[1], G6P[5], G6+G8P[11] were also observed for the first time. Fluctuations in the predominant types, emergence of new types and possible genetic reassortment events suggest an unstable epidemiological situation and the need for continuous surveillance of the circulating types to ensure the suitability of the vaccination programme. The present data suggests G10, G6, P[11] and P[5] genotypes could be incorporated in the polyvalent vaccine to offer increased protection against bovine rotavirus infection in India.

Determination of systemic inflammation response index (SIRI), systemic inflammatory index (SII), HMGB1, Mx1 and TNF levels in neonatal calf diarrhea with systemic inflammatory response syndrome

The objective of this study was to examine the values of MX dynamin-like GTPase 1 (Mx1), high mobility group box-1 (HMGB1), systemic inflammatory response index (SIRI), systemic inflammatory index (SII), tumor necrosis factor (TNF), and other hematological indices in calves with systemic inflammatory response syndrome (SIRS). The study material was divided into two groups: the SIRS group (comprising 13 calves) and the control group (comprising 10 calves). The independent samples t-test and Mann-Whitney U test were employed for normally distributed and non-normally distributed data, respectively. The relationship between the two groups was determined using Spearman correlation coefficient analysis. Significant differences were identified between the SIRS group and the control group with regard to white blood cell (WBC; P < 0.05), neutrophil (NEU; P < 0.01), and neutrophil-to-lymphocyte ratio (NLR; P < 0.001) values, in addition to SIRI (P < 0.05), SII (P < 0.01) values. Furthermore, HMGB1 (P < 0.001), Mx1 (P < 0.05), and TNF values (P < 0.001) demonstrated notable disparities between the two groups. As a result of this study, it was concluded that there were significant increases in inflammatory hematological indices, as well as in the levels of HMGB1, Mx1, and TNF, in calves with SIRS.

Determining genetic diversity of prevalent G and P genotype of Bovine Rotavirus A from neonatal calves of Gujarat, India.

Neonatal calf diarrhea is a major cause of mortality in newborn calves worldwide, posing a significant challenge in bovine herds. Group A Bovine Rotaviruses (BRVA) are the primary contributors to severe gastroenteritis in calves under two months old. This study examined the prevalence and molecular characterization of BRVA in neonatal calves in Gujarat, India. Sixty-nine diarrheic fecal samples were collected and subjected to various molecular methods of BRVA detection, isolation, and characterization. The latex agglutination test (LAT), electropherotyping (RNA-PAGE), and reverse transcription polymerase chain reaction revealed positivity rates of 39.13%, 20.30%, and 37.70%, respectively. RNA-PAGE identified 11 bands with a 4:2:3:2 migration pattern, indicative of the segmented genome of BRVA. BRVA was successfully isolated from LAT-positive samples, with 26 samples exhibiting clear cytopathic effects upon passage in MA-104 cell lines. Genotyping identified G10 as the predominant G genotype, with P[11] genotypes comprising 76.92% of the isolates. The most common G/P combination was G10P[11], highlighting its zoonotic potential. These findings underscore the importance of molecular detection and genotyping for effective vaccine development. This study provides crucial insights into the prevalent G and P genotypes of BRVA in Gujarat, India, aiding in the development of targeted control measures.

Investigation of Etiological Prevalence of Neonatal Calves with Acute Diarrhea in Şanlıurfa Province with Immunochromatographic Test

Neonatal calf diarrhea is a significant global concern, frequently causing morbidity and mortality and resulting in substantial economic losses. This study aimed to assess the prevalence of E. coli F5, Clostridium perfringens, Cryptosporidium spp., Rotavirus, Coronavirus, and Giardia spp. as contributors to diarrhea in neonatal calves in Şanlıurfa province. We also evaluated the clinical severity associated with these etiological agents. The study involved 123 neonatal calves (62 males, 61 females) aged 1-28 days from Şanlıurfa province with acute diarrhea. Calf Health Scores (CHS) were assigned based on clinical examination data. Rapid diagnostic tests were conducted on stool samples to identify E. coli F5, Clostridium perfringens, Cryptosporidium spp., Rotavirus, Coronavirus, and Giardia spp. regardless of mono or co-infection status, the rapid test results showed a prevalence of 9.76% for E. coli F5, 41.46% for C. perfringens, 30.89% for Cryptosporidium spp., 16.26% for Rotavirus, 13% for Coronavirus, and 27.64% for Giardia spp. CHS varied, with the highest score observed in E. coli F5 + Giardia spp. co-infection (CHS: 7) and the lowest in Coronavirus + Rotavirus co-infection (CHS: 4). In Şanlıurfa province, C. perfringens and Cryptosporidium spp. were identified as the most common agents. It has been determined that as the etiological factor diversity increases CHS may increase but there may be different variables that change CHS. These results are significant for developing effective diagnosis and control strategies for the prominent etiologies of diarrhea in calves.

Designing a multiepitope mRNA-based vaccine against enterotoxigenic Escherichia coli infection in calves: Immunoinformatics and molecular modeling approach.

Escherichia coli is one of the serious pathogens causing various infections in the animal field, such as neonatal calf diarrhea, which is responsible for mortality associated with diarrhea during the first days of life. Current work is aimed at designing an effective and safe multiepitope vaccine candidate against E. coli infection in calves based on the fimbrial protein K99 of Enterotoxigenic E. coli (ETEC) and Immuno-informatics. A conserved sequence of K99 protein was generated, and then highly antigenic, nonallergic, and overlapped epitopes were used to construct a multiepitope vaccine. Five THL, six MHC II, and four beta cell epitopes were targeted to create the candidate. The candidate vaccine was produced utilizing 15 epitopes and three types of linkers, two types of untranslated region (UTR) human hemoglobin subunit beta (HBB), UTR beta-globin (Rabb), and RpfE protein as an immunomodulation adjuvant. Immuno-informatics analysis of the constructed protein showed that the protein was antigenic (antigenic score of 0.8841), stable, nonallergen, and soluble. Furthermore, the Immuno-informatics and physiochemical analysis of the constructed protein showed a stable, nonallergic, soluble, hydrophilic, and acidic PI (isoelectric point). of 9.34. Docking of the candidate vaccine with the toll-like receptor TLR3 was performed, and results showed a strong interaction between the immune receptor and the vaccine. Finally, the expression efficiency of the construct in E. coli was estimated via computational cloning of the vaccine sequence into Pet28a. Results of immunoinformatics and in silico approaches reveal that the designed vaccine is antigenic, stable, and able to bind to the immune cell receptors. Our results interpret the proposed multiepitope mRNA vaccine as a good preventive option against E. coli infection in calves.

Prevalence of Salmonella spp. in Neonatal Calves with Acute Diarrhea: A Study in Şanlıurfa Province, Southeastern Anatolia, Türkiye

Diarrhea is one of the most important health problems in neonatal calves. Salmonellosis, one of the causes of diarrhea in neonatal calves, continues to be one of the major health problems worldwide. Prevalence data on enteropathogens can provide basic information for control and prevention strategies. The aim of this study was to determine the prevalence of Salmonella spp. in neonatal calves with acute diarrhoea in Şanlıurfa province located in the Southeastern Anatolia Region of Türkiye. The animal material of the study consisted of 100 neonatal calves with acute diarrhoea aged 1-28 days. The presence of Salmonella spp. was determined by PCR method from rectal fecal samples taken from the calves included in the study. As a result of the study, 5% prevalence of Salmonella spp. was determined. This study showed that there is a potential risk of zoonotic Salmonella spp. infection in neonatal calves with acute diarrhoea in the region and an original contribution was made to determine the prevalence of Salmonella spp. in Türkiye. It was emphasized that treatment for the causative agent and necessary protective measures should be taken in the region. In addition, further studies with multifocal serotyping in human and animal populations living in this region and other regions of Türkiye are needed in terms of the epidemiology of zoonotic Salmonella spp.

Prevalence of rotavirus, coronavirus, Cryptosporidium spp, Escherichia coli K99 and Giardia lamblia in neonatal calves with diarrhea in Burdur and its districts

TThe aim of this study is to determine the prevalence of pathogens such as Rotavirus, Coronavirus, Cryptosporidium spp, Escherichia coli K99, and Giardia lamblia in neonatal calves with diarrhea in Burdur and its districts. The study material consisted of 96 diarrheic calves aged between 1 and 28 days from different cattle farms in the Burdur region. Fecal samples were collected, and the causative agents were identified using rapid diagnostic kits (BoviD-5 Ag Test Kit- BIONOTE). In the study, among the 96 diarrheic calves, a single enteropathogen was detected in 61 (63.54%), and 25 (26.04%) of these calves were positive for Cryptosporidium, 12 (12.5%) for E. coli K99, 11 (11.45%) for Rotavirus, 7 (7.29%) for Coronavirus, and 6 (6.25%) for Giardia lamblia, respectively. Multiple enteropathogens were responsible for diarrhea in 18 calves, and 2 (2.08%) of them were Cryptosporidium spp.+Giardia lamblia, 8 (8.33%) Cryptosporidium spp.+Rotavirus, 3 (3.12%) Coronavirus+Rotavirus, with 1 (1.04%) Coronavirus+Cryptosporidium spp., 2 (2.08%) Rotavirus+E. coli, and 1 (1.04%) of them was E. coli+Cryptosporidium spp.+Rotavirus. Among the 96 diarrheic calves with mixed infections or a single enteropathogen, 38 (39.58%) had Cryptosporidium, 15 (15.62%) had E. coli K99, 26 (27.08%) had Rotavirus, 12 (12.50%) had Coronavirus, and 8 (8.33%) had Giardia lamblia. However, in 17 of the 96 diarrheic calves, neither mono- nor multiple enteropathogens were detected, suggesting that other factors might have caused diarrhea. Finally, this research provides valuable information for faster diagnosis, prevention, control, and treatment of enteropathogens causing diarrhea in neonatal calves in the Burdur region, contributing to reducing calf losses. It is believed that the research findings will shed light on future studies.

Health-associated changes of the fecal microbiota in dairy heifer calves during the pre-weaning period.

Neonatal calf diarrhea is a multifactorial condition that occurs in early life when calves are particularly susceptible to enteric infection and dysbiosis of the gut microbiome. Good calf health is dependent on successful passive transfer of immunity from the dam through colostrum. There are limited studies on the developing gut microbiota from birth to weaning in calves. Therefore, the objective of this study was to examine the effect of immune status and diarrheal incidence on the development of the fecal microbiota in Jersey (n = 22) and Holstein (n = 29) heifer calves throughout the pre-weaning period. Calves were hand-fed a colostrum volume equivalent to 8.5% of their birthweight, from either the calf's dam (n = 28) or re-heated mixed colostrum (≤2 cows, ≤1d; n = 23) within 2 h of birth. All calves were clinically assessed using a modified Wisconsin-Madison calf health scoring system and rectal temperature at day (d) 0, d7, d21, or disease manifestation (DM) and weaning (d83). Weights were recorded at d0, d21, and d83. Calf blood samples were collected at d7 for the determination of calf serum IgG (sIgG). Fecal samples were obtained at d7, d21/DM [mean d22 (SE 0.70)], and at weaning for 16S rRNA amplicon sequencing of the fecal microbiota. Data were processed in R using DADA2; taxonomy was assigned using the SILVA database and further analyzed using Phyloseq and MaAsLin 2. Significant amplicon sequence variants (ASVs) and calf performance data underwent a Spearman rank-order correlation test. There was no effect (p > 0.05) of colostrum source or calf breed on serum total protein. An effect of calf breed (p < 0.05) was observed on sIgG concentrations such that Holstein calves had 6.49 (SE 2.99) mg/ml higher sIgG than Jersey calves. Colostrum source and calf breed had no effect (p > 0.05) on health status or the alpha diversity of the fecal microbiota. There was a relationship between health status and time interaction (p < 0.001), whereby alpha diversity increased with time; however, diarrheic calves had reduced microbial diversity at DM. No difference (p > 0.05) in beta diversity of the microbiota was detected at d7 or d83. At the genus level, 33 ASVs were associated (adj.p < 0.05) with health status over the pre-weaning period.

Development and application of one-step multiplex Real-Time PCR for detection of three main pathogens associated with bovine neonatal diarrhea.

Neonatal calf diarrhea (NCD) is one of the most common diseases in calves, causing huge economic and productivity losses to the bovine industry worldwide. The main pathogens include bovine rotavirus (BRV), bovine coronavirus (BCoV), and Enterotoxigenic Escherichia coli (ETEC) K99. Since multiple infectious agents can be involved in calf diarrhea, detecting each causative agent by traditional methods is laborious and expensive. In this study, we developed a one-step multiplex Real-Time PCR assay to simultaneously detect BRV, BCoV, and E. coli K99+. The assay performance on field samples was evaluated on 1100 rectal swabs of diseased cattle with diarrhea symptoms and compared with the conventional gel-based RT-PCR assay detect BRV, BCoV, and E. coli K99+. The established assay could specifically detect the target pathogens without cross-reactivity with other pathogens. A single real-time PCR can detect ~1 copy/µL for each pathogen, and multiplex real-time PCR has a detection limit of 10 copies/µL. Reproducibility as measured by standard deviation and coefficient of variation were desirable. The triple real-time PCR method established in this study was compared with gel-based PT-PCR. Both methods are reasonably consistent, while the real-time PCR assay was more sensitive and could rapidly distinguish these three pathogens in one tube. Analysis of surveillance data showed that BRV and BCoV are major enteric viral pathogens accounting for calves' diarrhea in China. The established assay has excellent specificity and sensitivity and was suitable for clinical application. The robustness and high-throughput performance of the developed assay make it a powerful tool in diagnostic applications and calf diarrhea research. ​.

Management of bacterial neonatal diarrhea in calves

Diseases such as neonatal diarrhea are common in poorly managed herds and can cause major losses in any cattle breeding system in the world, especially in intensive systems, accounting for 2% of herd losses. As soon as the calf is born, it is exposed to numerous factors, such as agents, the host and the environment, which together can favor the onset of this disease because, due to the reproductive characteristics of the female bovine, there is no transfer of transplacental immunity to the newborn.

Association of passive immunity and genetic composition, health, and performance of tropical dairy calves

This retrospective cohort study aimed to identify risk factors for the failure of transfer of passive immunity (FPI) in preweaned dairy calves, explore its associations with morbidity, mortality, genetics, and determine a standardized cut-off point for FPI. Analyzing data from 6011 calves, factors such as sire predicted transmitted ability for milk (PTA), birth season, retained placenta (RP), total serum protein concentration (TSP), morbidity (neonatal calf diarrhea - NCD, bovine respiratory disease - BRD, tick-borne disease - TBD), mortality, and average daily weight gain (ADG) were considered. The calves were categorized into predominantly Gyr (PG) and predominantly Holstein (PH) genetic composition groups. Multivariate mixed logistic regression revealed optimal TSP cut-off points for predicting morbidity (7.6 g/dL) and mortality (6.9 g/dL). PH calves exhibited 1.35 times higher odds of FPI and 1.48 times greater odds of disease. Calves from multiparous cows and those born to dams with RP had increased FPI odds. Disease prevalence was 53%, with 41% NCD, 18% BRD, and 10% TBD. Season, parity, PTA, and birth weight were associated with disease odds, though FPI was not a reliable predictor. The mortality percentage was 6%, with PH calves and those with a positive PTA having higher odds. The ADG was 0.64 kg, and FPI-affected calves gained less weight. The study compared and identified various risk factors that potentially impact calf immunity. However, the use of a standardized cut-off point for FPI assessment was not effective in predicting morbidity and mortality at this specific farm.

The first commercially approved efficacious cryptosporidium vaccine protecting New-Born calves from severe diarrhea

Neonatal calf diarrhea (NCD) is an important cause of morbidity and mortality in calves. Four major pathogens, including Enterotoxigenic Escherichia coli (ETEC), bovine rotavirus (BRV), bovine coronavirus (BCV), and Cryptosporidium spp., are associated with NCD, with Cryptosporidium parvum (C. parvum) recognized as a major contributor. Despite various treatment options available, there is no effective vaccine for bovine cryptosporidiosis yet. In this study, recombinantly expressed C. parvum gp40 was evaluated as a candidate vaccine in pregnant animals. The vaccine was administered to pregnant cows during the last trimester of their pregnancy resulting in highly statistically significantly increased anti-gp40 antibody titers. The resulting anti-gp40 antibodies were transmitted to the calves via colostrum. Both suckling (n = 29; test:14, control:15) and non-suckling (n = 16; 8 per group) calves were challenged with live C. parvum oocysts. The calves that received the colostrum from gp40 vaccinated cows showed a highly statistically significant improvement in health (p < 0.0001), reduced incidence (p < 0.0001), and duration of severe diarrhea (p < 0.001) and increased weight gain in suckling calves (p < 0.0001). This study demonstrates that immune bovine colostrum, induced by immunization of late-gestation cows with C. parvum gp40, provided substantial protection to calves against cryptosporidiosis. These findings suggest that the gp40 vaccine has potential for preventing outbreaks of neonatal diarrhea associated with cryptosporidiosis in calves, thereby improving animal welfare and performance.

Neonatal Calf Diarrhea and Gastrointestinal Microbiota: Etiologic Agents and Microbiota Manipulation for Treatment and Prevention of Diarrhea.

Neonatal calf diarrhea is the leading cause of neonatal morbidity and mortality globally. The changes associated with the gastrointestinal microbiota in neonatal calves experiencing diarrhea and its etiology are not fully understood or completely defined in the literature. Several studies have demonstrated that the fecal microbiota of calves that experience diarrhea substantially deviates from that of healthy age-matched calves. However, one key question remains: whether the changes observed in the bacterial communities (also known as dysbiosis) are a predisposing factor for, or the consequence of, gastrointestinal inflammation caused by the pathogens associated with calf diarrhea. The first objective of this literature review is to present the current information regarding the changes in the fecal microbiota of diarrheic calves and the impact of the pathogens associated with diarrhea on fecal microbiota. Modulation of the gastrointestinal microbiota using pre- and probiotics, colostrum feeding, and fecal microbiota transplantation (FMT) has been used to treat and prevent gastrointestinal diseases in humans and dogs. Although information regarding the use of probiotics for the prevention of diarrhea is available in cattle, little information is available regarding the use of these strategies for treating calf diarrhea and the use of prebiotics or FMT to prevent diarrhea. The second objective of this literature review is to summarize the current knowledge regarding the impact of prebiotics, probiotics, synbiotics, colostrum feeding, and FMT for the treatment and prevention of calf diarrhea.

Effect of Dietary Supplementation of Chestnut and Quebracho Tannin Supplementation on Neonatal Diarrhoea in Preweaning Calves.

Neonatal calf diarrhoea (NCD) poses a significant health challenge in cattle herds, resulting in considerable economic losses and antimicrobial use. In response to the escalating threat of antimicrobial resistance, viable alternatives are imperative, aligning with European policies. This study evaluated the in-milk supplementation of the chestnut and quebracho tannin extract in preweaning calves on performance, diarrhoea occurrence, Cryptosporidium spp. shedding, protein digestibility, and intestinal health. Twenty newborn calves were divided, after colostrum administration, into two experimental groups for 30 days as follows: the control (CTRL) was fed with whole milk and solid feed, and tannins (TAN) were fed whole milk supplemented with 6/g day of tannin extract and solid feed. Faecal samples were collected on days 0, 3, 7, 14, and 30 for the evaluation of Cryptosporidium oocyst shedding and protein digestibility. Faecal consistency was evaluated during the sampling using the faecal score scale (0-3 scale, considering diarrhoea > 1). The results showed a significant reduction in diarrhoea frequency in the TAN compared to the CTRL group (p < 0.05) over 30 days of the trial. The prevalence of Cryptosporidium spp. was generally low (12%), considering all analysed samples. Protein digestibility revealed comparable values for the TAN and CTRL groups, suggesting that tannins did not negatively affect milk protein availability. In conclusion, the in-milk supplementation of 6/g day of the chestnut and quebracho tannin extract could be considered a valuable functional feed additive to decrease NCD occurrence, thus supporting animal health and decreasing antibiotic use in livestock.

Effects of a commercial feed additive used for prophylactic purposes on health and blood parameters in neonatal calves.

Neonatal calf diarrhea is commonly observed worldwide and leads to significant economic losses. The objective of this study was to investigate the effect of a feed additive supplemented with milk on the incidence of diarrhea days with scours, fecal score, average daily gain, fecal bacterial concentration, and blood parameters in neonatal calves. Forty Holstein-Friesian crossbreed (HF x Montbeliarde) calves were divided into control (C) and experimental (E) groups, each containing 20 calves. The study was conducted over a period of 10 days. The control group was fed whole milk twice daily. The experimental group was fed the same whole milk supplemented with feed additive once in the morning at 100 g/calf/day. At the end of the study, it was determined that the feed additive in the milk affected fecal score, blood pH, pCO2, cHCO3 -, K+, cHgb, and plasma glucose levels (p<0.05), but did not affect the incidence of diarrhea, average daily gain, days with scours, and other blood parameters (p>0.05). Rotavirus was the main pathogen found in the fecal samples of calves with diarrhea. Higher concentrations of Escherichia coli, Salmonella spp., and Clostridium perfringens were detected in the feces of experimental calves (p<0.001). The findings indicate that this feed additive improves fecal score, some blood parameters, and fecal concentration of pathogenic bacteria in feces. Additionally, it shows a favorable effect on both diarrhea incidence and the days with scours, suggesting its potential efficacy in preventing diarrhea in neonatal calves. Preventing diarrhea during this crucial stage of life can contribute to the health and productivity of animals and play a role in preventing antibiotic resistance by reducing reliance on antibiotics.

Detection of Antimicrobial Resistance by Phenotypic and Genotypic Methods in E. coli Isolated from Diarrhea of Cattle Calves in Mhow, Indore

Background: Neonatal calf diarrhoea, a complex illness, continues to be the leading cause of neonatal calf deaths. The complex pathophysiology of infectious calf diarrhoea results in severe losses to the dairy sector, either directly via mortality or indirectly through the costs of prophylaxis and slowed growth in infected calves. Neonatal calf diarrhoea during the first month of life causes between 80 to 85 per cent of all deaths in India. Methods: A total 137 cattle calve diarrhea samples were collected from calves that show clinical signs of diarrhea. Swabs of the rectum were taken directly from diarrhoeic calves and collected in sterile test tubes. They were then immediately transported to the laboratory for the isolation of E. coli. Result: A total 64 E. coli isolates were detected and identified from samples via biochemical and molecular assays employing PCR targeting the E. coli specific 16s rRNA gene. The result of antibiotic sensitivity of 64 isolated strains of E. coli to 15 antimicrobial drugs shows highest sensitivity towards antibiotic gentamycin (68.75%) followed by sulfadiazine and co-trimoxazole (39.06), ciprofloxacin (32.81%) and highest resistance against ampicillin (87.5%) followed by ceftriaxone (82.813%), ceftazidime plus clav (81.25%). There is the variation in the expression of the AMR genes in the isolated E. coli strains. The detection rate of AMR gene blaTEM was highest 90% and that of aadA was the lowest (0%). The other AMR genes blaCTX-M, blaSHV, sul1 and tetA showing 50%, 20%, 50% and 30%.