Efficacy of prepartum vaccination against neonatal calf diarrhea in Nelore dams as a prevention measure.

BACKGROUND: Neonatal calf diarrhea (NCD) is the leading cause of calf morbidity and mortality in beef cattle. Cow's vaccination in last stage of pregnancy is one of the most important measures to mitigate the risk of NCD outbreaks. The aim of this study was to evaluate the efficacy of prepartum single dose vaccination against NCD, especially Bovine Rotavirus type A (BoRVA) and Bovine Coronavirus (BCoV), in Nelore dams and offspring. A total of 117 pregnant cows (n = 81) and heifers (n = 36) were distributed in two groups, vaccinated (VAC: cows = 40; heifers = 19) and non-vaccinated (NVAC: cows = 41; heifers = 17). Vaccination occurred between 60 to 50 days before the expected calving date with a single dose of a water-in-oil (W/O) vaccine, and NVAC group received a dose of saline solution 0.9%. Blood samples were collected before vaccination and 30 days after to evaluate the antibody (Ab) response. Specific IgG1 Abs against BoRVA and BCoV were measured by using an Enzyme Linked Immuno Sorbent Assay (ELISA). Calves' births were monitored, and the transference of passive immunity was evaluated. Diarrhea was monitored in the first 30 days of age, and fecal samples were collected for identification of the etiological agent. RESULTS: Higher titers of IgG1 Ab against BoRVA and BCoV was observed in the VAC group than NVAC group in the cow (P < 0.0001) and total dams categories (P < 0.0001). The titer of specific IgG1 Abs in the calves' serum reflected the dams response, observing higher IgG1 Ab titers for BoRVA (P < 0.0016) and BCoV (P < 0.0095) in the offspring born to VAC cows and higher IgG1 Ab titers for BoRVA(P < 0.0171) and BCoV (P < 0.0200) in the offspring born to VAC total dams. The general incidence of diarrhea observed was 18.6% (11/59) and 29.3% (17/58) in the calves born to the VAC and NVAC group, respectively. CONCLUSIONS: Prepartum vaccination with a single dose of the vaccine tested increased the titers of IgG1 Ab against BCoV and BoRVA, and it could be used as a preventive strategy to decrease the NCD occurrence in Nelore calves.

Diagnostic accuracy of Wisconsin and California scoring systems to detect bovine respiratory disease in preweaning dairy calves under subtropical environmental conditions.

Bovine respiratory disease (BRD) is a multifactorial disease which causes short- and long-term negative effects. Early detection is crucial for a prompt response to therapy, as well as to decrease mortality risk. Clinical scoring systems have been developed mostly in North America for screening calves at risk or suspected of having BRD, and these tools have also been applied in subtropical and tropical countries. However, it has been unknown whether these scoring systems had the same accuracy in tropical environmental conditions. Therefore, this study evaluated the accuracy of 4 different field techniques, as well as serum haptoglobin (HAP), to diagnose BRD in Holstein dairy calves in subtropical conditions. The tests used to diagnose BRD were thoracic ultrasound (TUS; positive if consolidation depth ≥1 cm), thoracic auscultation (AUSC; positive if crackles, wheezes, or silent areas were present), Wisconsin score (WISC; ≥2 categories with scores of ≥2), and California score (CALIF; positive if total score ≥5). Also, HAP was measured and classified as positive if ≥15 mg/dL. Heifers between 30 d of age and weaning (n = 482), residing on 17 commercial dairies in São Paulo state, were enrolled in this study. Bayesian latent class models were used with informative priors to evaluate the accuracy of TUS, AUSC, and HAP, and noninformative priors for the accuracy of WISC and CALIF. The percentage of calves positive for each test on each farm ranged from 0 to 56% for WISC, 11-51% for CALIF, 0-72% for TUS, 0-32% for AUSC, and 0-100% for HAP. The sensitivity (Se; 95% credible interval) and specificity (Sp) for WISC were 77.9% (64.8-90.2) and 81.9% (76.3-88.2). For CALIF, the Se was 67.1% (53.6-80.1) and Sp 79.1% (73.9-84.6). For TUS Se was 59.8% (46.5-73.1) and Sp was 84.8% (80.0-89.5), and for AUSC, Se was 58.8% (41.3-79.8) and Sp was 98.6% (95.7-99.9). The Se and Sp of HAP was 67.6% (55.3-78.8) and 46.7% (41.4-52.2), respectively. The performance of the scoring systems was similar to, or better than, the performance found in North American studies, despite the fact that calves were in a tropical environment.

Influence of Mycoplasma bovis infection on milk production and quality of Holstein dairy cows.

We wished to determine if Mycoplasma bovis infection can negatively impact milk quality and production in Holstein dairy cows. For this Research Communication, milk samples (271) from Holstein cows from 3 herds were screened for M. bovis by real-time PCR. Positive (n = 21) and negative animals (n = 21) were matched by herd, age, lactations and days in milk (DIM). Pairs were evaluated in 7 stages of lactation: D1-50, D51-100, D101-150, D151-200, D201-250, D251-300, and D ≥ 301. A mixed model was used to assess the effect of groups (M. bovis+ × M.bovis-), time (lactation) and groups × time interaction. Cows positive for M. bovis had lower average milk production per day and high somatic cells count (SCC).

Effect of selenium and vitamin E supplementation on the metabolic status of dairy goats and respective goat kids in the peripartum period.

This study aimed to examine the effects of selenium (Se) and vitamin E (vitE) supplementation on blood cell counts and blood metabolite concentrations in goats and their kids. Fifteen Saanen goats (average age 6 years of age; average initial body weight of 70 ± 10 kg) and 21 ½ Saanen × ½ Pardo Alpine crossbred goat kids (average body weight of 3.70 ± 0.64 kg) were used. Animals were distributed in a completely randomized design with five replicates per diet for mother goats and seven for goat kids and randomly assigned into three groups in the following diets: CON, control basal diet; Se, inclusion of 3.2 mg of Se/kg DM; SevitE, inclusion of 3.2 mg Se/kg DM and 1145 IU/day vitE/kg DM. Effects of time were observed on red blood cells, hemoglobin, hematocrit, mean corpuscular volume, and mean corpuscular hemoglobin in goats and goat kids. Effects of time were observed on differential counts of leucocytes, lymphocytes, and monocytes in goat kids. Interaction was observed for high-density lipoprotein and total protein in goats and for triglycerides, beta-hydroxybutyrate (BHBA), and gamma-glutamyltransferase (GGT) in goat kids. Effects of time were observed on low-density lipoprotein, triglycerides, glucose, lactate, BHBA, non-esterified fatty acids (NEFA), creatinine, aspartate-aminotransferase, and GGT in goats and all blood metabolites in goat kids. Selenium, vitE, or association in the evaluated levels are not sufficient to change blood cell counts when supplied in diets for goats or goat kids. However, the effect of time or interaction between time and diets change the blood metabolite concentrations in the animals.

Somatic cell count in buffalo milk using fuzzy clustering and image processing techniques.

This research communication presents an automatic method for the counting of somatic cells in buffalo milk, which includes the application of a fuzzy clustering method and image processing techniques (somatic cell count with fuzzy clustering and image processing|, SCCFCI). Somatic cell count (SCC) in milk is the main biomarker for assessing milk quality and it is traditionally performed by exhaustive methods consisting of the visual observation of cells in milk smears through a microscope, which generates uncertainties associated with human interpretation. Unlike other similar works, the proposed method applies the Fuzzy C-Means (FCM) method as a preprocessing step in order to separate the images (objects) of the cells into clusters according to the color intensity. This contributes signficantly to the performance of the subsequent processing steps (thresholding, segmentation and recognition/identification). Two methods of thresholding were evaluated and the Watershed Transform was used for the identification and separation of nearby cells. A detailed statistical analysis of the results showed that the SCCFCI method is able to provide results which are consistent with those obtained by conventional counting. This method therefore represents a viable alternative for quality control in buffalo milk production.

Influence of bovine pestivirus heterogeneity on serological responses to 10 different commercial vaccine formulation.

Bovine Pestivirus typically involves one or more organ systems, with clinical manifestations ranging from mild to severe fatal systemic illness that lead to significant reproductive, productive, and economic losses. Vaccines face the challenge of addressing the significant variability of pestiviruses, which affects the interaction between viral antigens and the immune system's ability to provide protection. This study aimed to evaluate the serological responses against bovine viral diarrhea virus 1 (Pestivirus A) and Pestivirus B induced by 10 commercial vaccines, including one recombinant (vaccine E), two modified live (MLV multivalent, vaccine I, and MLV monovalent, vaccine J), and seven killed vaccines (KLV, vaccines A to H). Additionally, we evaluated the cross-reactivity between Pestivirus A and B from vaccines and HoBi-like pestivirus (Pestivirus H). In Phase 1, guinea pigs were used to screen for non-MLVs. They were divided into nine groups (n=6 each) and received two doses (⅕ of bovine dose) of eight different non-MLV on Days 0 and 21. Serum samples were collected on Days 0 and 30 for serological analyse. In Phase 2, Holstein × Gir heifers (n= 45) were divided into five groups, comprising 6-9 animals. They were vaccinated either once with MLVs or twice with the top non-MLVs screened in Phase 1. Serum samples were harvested on d0 (vaccination day) and d60 (60 days after the first dose) for MLV and non-MLV. Specific antibody titers were assessed virus neutralization (VN) and transformed in log2 for statistical analysis using PROC-MIXED. Significant effects were observed for vaccine groups, time points, and their interactions concerning neutralizing antibodies against Pestivirus A and B in both Guinea pigs and heifers. The Phase 1 study revealed serological responses against Pestivirus A exclusively in non-MLV D (85.33±13.49) and E (72.00±19.26). In the bovine study, the KLD vaccine D (72.00±15.10), recombinant vaccine E (90.66±25.85), and MLV I (170.66±28.22) resulted in an average of neutralizing antibodies against Pestivirus A that exceeded the protective threshold (≥ 60). However,individual analysis of heifers showed a higher frequency of animals presenting titers of Pestivirus A Ab surpassing 32 following vaccination with MLV I and J. None of the vaccine formulations in either study elicited a protective immune response against Pestivirus B or demonstrated cross-reactivity against Pestivirus H.

Serological Responses of Guinea Pigs and Heifers to Eight Different BoAHV-1 Vaccine Formulations.

Bovine alphaherpesvirus 1 (BoAHV-1) infection affects the production and reproductive performance of dairy and beef livestock, resulting in considerable economic losses. In addition to biosecurity measures, vaccination programs are effective strategies for controlling and preventing BoAHV-1 infection and transmission. We evaluated the serological immune response against BoAHV-1 induced by eight different formulations of commercial vaccines: three modified live vaccines and five killed vaccines containing BoAHV type 1 or types 1 and 5. In the first experiment, 50 BoAHV-1-seronegative guinea pigs were assigned to eight groups; each individual in the treatment groups received two doses (one-fifth of the bovine dose). The second experiment was conducted using 29 crossbred Holstein × Gir heifers in four groups of six to nine animals each. The serological immune response against BoAHV-1 was measured using virus neutralization and enzyme-linked immunosorbent assays to measure the total IgG against BoAHV. We evaluated the effects of the vaccine, time, and interaction of the vaccine and time on neutralizing antibodies against BoAHV-1. Killed vaccines produced low levels of antibodies against BoAHV-1, whereas modified live vaccines produced high levels of antibodies capable of providing neutralizing titers in the vaccinated animals, with the thermosensitive modified live vaccine showing the highest levels of antibodies.

Effects of dam metabolic profile and seasonality (Spring vs. Winter) on their offspring' metabolism, health, and immunity: maternal factors in dairy calves' analytes.

Maternal status during the transition period can significantly impact the health and performance of Holstein dairy calves, with lasting effects on various variables. However, the relationship between maternal late gestation metabolic status, seasonality, and their impact on offspring remains unclear. This study aimed to assess the influence of maternal variables at calving on the performance, metabolism, and immunity of 28 dairy calves during their first month of life. Blood samples were collected from 28 Holstein cows at calving. Median results for maternal variables including non-esterified fatty acids (NEFA), ß-hydroxybutyrate (BHB), glucose, total protein (TP), albumin, triglycerides (TG), total cholesterol (TC), haptoglobin (Hp), body weight (BW), and body condition score (BCS) were determined. These median values served as a basis for categorizing the offspring into two groups based on their dams' high or low degree of each maternal variable. Additionally, calves were categorized by the season of birth (Spring vs. Winter), with 14 in each. Blood samples were collected from the calves at birth and on days 1, 7, 14, and 28 to assess IgG, biochemical parameters, and haptoglobin concentration. Reactive oxygen species (ROS) production by polymorphonuclear cells stimulated by various agents was also evaluated. Clinical assessments were conducted for diarrhea and bovine respiratory disease frequencies. Despite the overall health of the cows, differences were observed in the calves between maternal groups. Heavier cows with high maternal BCS tended to have larger offspring, while high maternal BCS was associated with increased diarrhea prevalence. Low maternal BCS resulted in a stronger innate immune response, indicated by higher ROS production. Calves from cows experiencing metabolic changes during calving displayed elevated Hp concentrations. Spring-born calves were larger but had lower serum IgG concentration and reduced innate immune response compared to winter-born calves. Additionally, spring-born calves exhibited higher Hp and increased diarrhea prevalence on day 28. These findings underscore the importance of the prenatal period in determining neonatal health and suggest further research to elucidate the long-term clinical implications of maternal effects on offspring health and growth. Investigating offspring constituents later in life can provide insight into the persistence of maternal effects over time.

Vertical transfer of gut microbiota from dam to neonate calf in the early of life.

The aim of this study was to investigate the vertical transfer of microbiota from dams to the offspring. We studied a pair of 20 dams and its offspring. Maternal sources (colostrum, feces and vaginal secretion) and newborn fecal samples were analyzed using 16S rDNA amplicon sequencing on days 1, 3, 7, 14 and 28. Overall, newborns were maintained healthy and did not receive antimicrobial therapy. The Source Tracker analysis indicated that the newborn fecal microbiota was similar to colostrum and vaginal secretion from day 1 up to 7. However, an unknown source (probably from the environment) showed a gradual increase in its similarity with fecal samples from calves measured from day 3 to 28. The most abundant bacteria groups on meconium (day 1) and calf fecal samples on day 3 were Escherichia-Shigella and Clostridium, respectively. On day 7, the predominant genus were Bifidobacterium and Lactobacillus, while Fusobacterium was the most abundant genus on day 14, coinciding with the diarrhea peak. Faecalibacterium showed a gradual increase throughout the neonatal period. Maternal sources contribute to the neonatal microbiota, however other unknown sources (probably environment) had a strong influence on development of the gut microbiota later in the neonate period.

A comparative study across mule, equine and equine clone pregnancies regarding the determination of the day of birth.

Monitoring equine parturition effectively is essential for preemptive intervention in periparturient issues and ensuring the overall well-being of both mares and foals. However, its implementation in breeding farms is challenging due to variable gestational lengths and nocturnal births. Predictive techniques have the potential to streamline the monitoring process, reduce labor intensity, and minimize costs. Research on foaling prediction in mares carrying mule or equine clone fetuses is scarce. Therefore, this study aimed to comparatively analyze foaling prediction parameters in mares pregnant with mule, equine, or equine clone fetus. The study included vulvar relaxation, sacroiliac ligament tension, pH, BRIX index, and concentrations of calcium, phosphorus, magnesium, sodium, and potassium in prepartum mammary secretions. Sixty pregnant mares were used for this study and grouped as follows: 25 mares with mule fetuses (MF), 20 with equine clone fetuses (CF), and 15 with equine control fetuses (EF). Results showed significant differences in vulvar relaxation and sacroiliac ligament tension only in MF group (p < 0.05) on the day of parturition compared to the other days evaluated, different from the other groups. Levels of pH notably decreased on parturition day (mean 5.7 ± 0.04, p < 0.0001), with lower values in MF (6.05 ± 0.02) and CF (6.08 ± 0.04) compared to EF (6.26 ± 0.04) (p < 0.03). The BRIX index showed variation across mares and was not a good parameter for foaling prediction. Electrolytes correlated positively with impending parturition, showing no significant differences among groups. The MF and CF groups exhibited a substantial increase (102.13 % and 110.66 %, respectively) in mean calcium concentrations on the day before foaling, unlike EF (38.29 %). In conclusion, the pH values were different in mammary secretions between mares carrying mule and clone fetuses, in contrast to equine control fetuses. Nevertheless, there was a trend of decreasing pH values closer to parturition in all groups. Conversely, the BRIX index serves as a valuable indicator of colostrum quality yet does not offer insights into the proximity of parturition. While electrolyte concentrations did not reveal significant differences among groups, it is worth noting that the evaluation of phosphorus emerges as a new parameter to explore in mares nearing parturition, since it obtained a pattern similar to calcium.

Biosecurity practices in the dairy farms of southern Brazil.

Biosecurity refers to a set of practices that prevents and/or controls the introduction, spread, and elimination of harmful biological agents in a production system. In this study, we aimed to survey the biosecurity practices and determine their correlation with the size of production systems. A biosecurity assessment form was provided to 69 farms in the Campos Gerais region of Paraná, Brazil. The questionnaire was divided into two sections: general and bovine viral diarrhea virus- and bovine herpesvirus type-1-specific sections. The general section covered topics on traffic control, quarantine and animal isolation, hygiene practices, carcass disposal, and disease monitoring/control. The specific section consisted of questions on the reproductive and respiratory factors, use of antimicrobials, and vaccination schedule. The 69 farms were also classified into small (≤ 61), medium (62-201), and large (≥ 202) size farms based on the number of lactating cows. Moreover, multiple correspondence analysis (MCA) was performed between the biosecurity measures and farm size. The main risk factors and variability were related to the traffic control of people, animals, and vehicles/equipment, animal quarantine/isolation, and hygiene practices. MCA revealed that the small farms exhibited a lack of biosecurity measures, including those related to traffic control, animal quarantine, and hygiene. In medium-size farms, contact between bovine animals of different ages and difficulty in animal isolation in the quarantine system were among the main risk factors. In contrast, isolation of sick animals was easy, but the need to frequently purchase cattle was an important risk factor in large farms. These results highlight the relationship between biosecurity measures and farm size, providing valuable insights for the development of better biosecurity plans for production systems.

Effect of Prepartum Maternal Supplementation with Diphenyl Diselenide on Biochemical, Immunological, and Oxidative Parameters of the Offspring.

This study aimed to assess the impact of prepartum maternal diphenyl diselenide (PhSe)2 supplementation on the development, biochemical, immune, and antioxidant parameters of calves. Eighteen Holstein breed calves were used, born to females who were or were not subjected to supplementation, at 42, 28, and 14 days prior to calving. The (PhSe)2 group (DDG) was administered 3 µmol/kg of (PhSe)2 in 4 mL of dimethyl sulfoxide (DMSO), while the DMSO and NaCl groups were administered 4 mL of DMSO and 0.9% NaCl, subcutaneously. The calves were evaluated based on their weight, withers height, body condition score 24 h post-birth (0), as well on days 14, 28, 42, 56, 70. Blood samples were also taken to determine serum variables. Calves on the DDG showed higher average levels of total protein, albumin, and globulins on day 0, and the immunoglobulin G level was significantly higher than the other groups on days 0, 14, 56, 70. Maternal supplementation showed immunomodulatory effect on calves, evidenced by the exceptional rates of passive immunity transfer, as well as the enhancement of humoral immunity. Our research offers fresh insights into the immunomodulatory potential of (PhSe)2, making it a viable alternative in facing this challenging phase, rearing dairy calves.

Hematologic profiles and development of innate immune function in healthy Holstein calves during the pre-weaning period.

BACKGROUND: The development and state of innate immune cell function during the first 90 days of life in dairy calves have not been fully described. OBJECTIVE: This transversal study attempted to examine the changes that occur in circulating blood cells and the innate immune response in healthy calves from birth to 89 days of age. METHODS: Healthy Holstein calves represent three windows of development, G1 from 1 to 7 days old (n = 26), G2 from 30 to 40 days old (n = 28), and G3 from 60 to 89 days old (n = 36) were sampled once each from a single herd. A few biomarkers of the general health and innate and inflammatory immune responses were measured. RESULTS: The youngest calves had the lowest red blood cell (RBC) counts, cell hemoglobin concentration means (CHCMs), red cell distribution widths (RDWs), and cell hemoglobin contents of mature red blood cells (CHm) compared with the other groups. They also had the lowest iron concentrations and highest intracellular myeloperoxidase indices. However, white blood cell (WBC) and lymphocyte concentrations gradually increased from G1 to G3. G2 calves had the lowest serum protein concentrations and highest number of innate immune cells compared with the other groups. Calves were able to mount phagocytic and ROS responses from birth. CONCLUSIONS: The physiologic responses of circulating blood cells and innate immune responses in dairy calves are shown according to age. Neonates had limitations in several RBC and WBC indices and immunologic responses that would likely impact overall vigor and health. Fortunately, these limitations resolve by 90 days of age.

Effect of prophylactic use of tulathromycin on gut bacterial populations, inflammatory profile and diarrhea in newborn Holstein calves.

This objective of this study was to evaluate the use of tulathromycin on the timing of appearance and number of four indicator organisms representing the gastrointestinal microbial community, the incidence of diarrhea and a measure of the systemic inflammatory profile in Holstein heifers. Twenty-six Holstein heifer calves were distributed between receiving (ATB+) or not receiving (ATB-) tulathromycin at a dose of 2.5 mg/kg by 12 h of age. Samples from the calves were collected at six times during the neonatal period. Stool samples were used to determine the dry matter content and quantitative analysis of specific indicator bacterial populations. Samples of whole blood and serum were collected to determine the total number of neutrophils, the number of CD62L+ neutrophils, quantity of haptoglobin, and to allow for ex vivo measurement of reactive oxygen species. A higher frequency of diarrhea was detected in the ATB+ calves (84.6%) than ATB- (53.8%) on days 13-15 (P = 0.084). ATB- calves had a greater number of Bifidobacterium in stool on day 3-5 (P = 0.002), and on days 7-9 (P = 0.018). The ATB+ calves tended to have a higher number of Escherichia coli in stool on days 20-23 and days 27-30 (P = 0.052 and P = 0.072). Both the total number of neutrophils (P = 0.013) and the capacity for ROS production was higher in ATB- (P = 0.038) than ATB+ calves at all points tested. ATB+ calves had higher levels of haptoglobin (P = 0.032) on days 13-15. Administration of tulathromycin appeared to negatively impact the establishment of a normal microbiome and to modulate the development of innate immune function.

Relationships among Indicators of Metabolism, Mammary Health and the Microbiomes of Periparturient Holstein Cows.

During the period called "transition", from the ceasing of milk production to the reestablishment of full milk production, it is postulated that the microbiota of cows undergo changes in composition driven by the fluxes in systemic energetics and that these changes appear to impact the health of cows. The primary objective of this study was to document the make-up of the microbiota in the mammary gland compared with those in the vagina and in feces in an attempt to determine any correlations between the composition of the microbiota, the impact of blood indicators of energetic metabolites and the health of the mammary gland at the time of calving. Samples were collected from 20 Holstein dairy cows immediately following calving to assess their general health and measure the microbiomes associated with each cow using 16S rRNA sequencing. The results indicated that the microbiomes found within each maternal niche were different. A set of significant negative associations between the blood energetic biomarkers (NEFAs, BHB, triglycerides and cholesterol) and the taxa Pseudomonas, Christensenellaceae and Methanobrevibacter were observed in this study. In contrast, Escherichia and Romboutsia were positively correlated with the same energetic metabolites. Therefore, it was concluded that there appears to be a set of relationships between the microorganisms that colonize several niches of cows and the sufficiency of systemic energy metabolism. Furthermore, both the microbiome and energy dynamics impact the health of the mammary gland of the host.

Influence of feeding fresh colostrum from the dam or frozen colostrum from a pool on indicator gut microbes and the inflammatory response in neonatal calves.

The aim of this study was to evaluate the capacity of cells from colostrum to modulate the intestinal microbial colonization, the activity of the inflammatory response, and for their influence on the development of diarrheal disease in calves. Twenty calves were distributed into two groups: COL+ (n = 10) receiving fresh whole colostrum; COL- (n = 10) receiving pooled frozen colostrum, containing no viable cells. All assessments were made before colostrum intake (D0), the next day (D2), and weekly on the 7th (D7), 14th (D14), 21st (D21) and 28th (D28) day of age. Diarrhea was assessed using a fecal score, and the systemic inflammatory status was assessed using a combination of temperature, anemia, total serum iron level, total haptoglobin concentration and the need for systemic antimicrobial treatment. The number of indicator bacteria present in the fecal population was estimated using qPCR. However, COL- calves presented more frequent signs of systemic inflammatory response including, fever at D7 (P = 0.011); indicator haptoglobin levels on D7 and D14, and lower levels of iron on D7, D14. Anemia was detected more often in the COL- calves on D21 (P = 0.043) and D28 (P = 0.016). COL- calves had a 1.66 greater chance of having elevated haptoglobin and a 1.8 greater chance of needing treatment with antimicrobials than COL+. A lower number of DNA copies of Clostridium perfringens were detected in COL+ calves on D2 (P = 0.088) and D7 (P = 0.040). Similarly, a low number of DNA copies was observed for Escherichia coli and Lactobacillus spp. (P = 0.012) in the fecal samples of COL+ calves on D7.

An Assessment of Secondary Clinical Disease, Milk Production and Quality, and the Impact on Reproduction in Holstein Heifers and Cows from a Single Large Commercial Herd Persistently Infected with Bovine Viral Diarrhea Virus Type 2.

The aim of this study was to evaluate secondary clinical disease, milk production efficiency and reproductive performance of heifers and cows persistently infected (PI) with bovine viral diarrhea virus type 2 (BVDV type 2). PI animals (n = 25) were identified using an antigen capture ELISA of ear notch samples. They were distributed into three age groups: ≤ 12 (n = 8), 13 to 24 (n = 6) and 25 to 34 (n = 11) months old. A control group of BVDV antigen ELISA negative female cattle that were age matched to the PI animals was utilized from the same herd. The PI group had a 1.29 higher odds ratio for diarrhea than controls (p = 0.001, IC95% = 1.032-1.623) and 1.615 greater chance of developing bovine respiratory disease (BRD) (p = 0.012, IC95% = 1.155-2.259). The age at first insemination (p = 0.012) and number of insemination attempts required to establish the first pregnancy (p = 0.016) were both higher for PI than controls. Milk production was higher for control cows than PI cows during most of the sampling periods. Somatic cell counts (SCC) were higher in PI cows than the controls at all sampling points across lactation (p ≤ 0.042). PI cattle had a higher incidence of disease, produced less milk, a higher SCC, and poorer reproductive performance than control cattle in this study.

Effects of 3 Different Commercial Vaccines Formulations against BVDV and BHV-1 on the Inflammatory Response of Holstein Heifers.

After vaccination, vaccine components must activate the immune response, but the ideal vaccine should not result in undesirable effects in cattle. The aim of this study was to evaluate the inflammatory and humoral responses and adverse reactions induced by three adjuvanted commercial vaccines against bovine viral diarrhea virus (BVDV) and bovine herpesvirus 1 (BHV-1). Holstein heifers (n = 35) were divided into four groups by adjuvant compounds: Vaccine A (Alum; n=9), Vaccine B (Oil-in-water; n=10), Vaccine C (Amphigen/Quil A cholesterol and dimethyl-dioctadecyl ammonium (DDA) bromide (QAD; n=10), and Control (n=6). Heifers were assessed at 0 h, 6, 24, 48, 72 and 168 h post-vaccination; serology was evaluated at first dose (D0), booster (D21) and D42. Heifers vaccinated with Vaccine B (p= 0.0001) and C (p= 0.0001) had a more intense local reaction, while there was a higher rectal temperature detected in heifers vaccinated with Vaccine C (p= 0.020). There was greater systemic reaction observed for heifers vaccinated with Vaccines B and C at 48h (p= 0.002) after a second dose. Clinical pathology parameters [white blood count (WBC) (p = 0.001), neutrophils (p = 0.0001) and haptoglobin concentrations (p = 0.0001)] were higher in animals vaccinated with Vaccine C. Neutralizing Abs against BVDV type 1 strains, NADL and Singer, were detected in animals vaccinated with Vaccines A or C at D42, while BVDV-2 antibodies were detected only in animals vaccinated with Vaccine C. A BHV-1 antibody was detected in all three vaccine groups (Vaccines A, B or C) at day 42 (21 days post booster vaccination). The findings of this research were based on three different commercial laboratory formulations and also according to the conditions which the study was conducted. In this context, vaccine containing mineral oil or Amphigen/QAD presented greater local reactivity and induced a significant systemic inflammatory response. Vaccinated heifers with Alum and Amphigen/QAD commercial vaccines enhanced humoral immune response against BVDV and BHV-1.

Innate immune response in neonate Holstein heifer calves fed fresh or frozen colostrum.

The aim of this research was to evaluate the influence of maternal cells from colostrum on the development and function of the innate immune response in Holstein calves. Calves were divided into 2 groups: COL+ (n=10) received fresh colostrum; and COL- (n=10) which received frozen colostrum containing no viable cells. The calves were assessed before colostrum intake (D0), 48h of age (D2), and weekly from D7 up to D28. Blood samples were collected for analysis of the distribution of leukocytes, cellular phenotype and in vitro granulocyte function. COL+ calves tended to have a high number of neutrophils on D7 (p=0.073). COL- calves took up significantly more Escherichia coli (measured as MFI) on D7 (p=0.034). Endogenous production of radicals (as percentage of cells) tended to be higher in COL- calves on D14 (p=0.061). The intensity of endogenous reactive oxygen species (ROS) produced by granulocytes tended to be higher in COL+ calves on D21 (p=0.094). Overall, ROS production (percent of cells, and MFI) induced by Staphylococcus aureus and Escherichia coli were higher in COL+ calves than COL- calves. It was our observation that COL+ calves developed an innate immune response more quickly and efficiently after natural exposure to pathogens after birth. In contrast, COL- calves mounted an innate response more slowly that yielded a persistent inflammatory response after natural exposure to these bacteria agents. This research provides evidence of an advantage to the calf of receiving fresh colostrum on the development and function of the innate immune system.

Effect of maternal cells transferred with colostrum on the health of neonate calves.

The objective of this research was to evaluate the influence of cells from colostrum on the health of neonate calves. Animals were distributed in 2 groups: COL+ (n=9) which received fresh colostrum from their own damns; and COL- (n=10) which received frozen colostrums from donors. Heifers were assessed before colostrum intake - D0; D2; D7; D14; D21 and D28. Heifers were monitored by clinical examination, hematological profile and serum iron. COL- had a higher diarrhea intensity score (typically 3) on D7. Moreover, a single case each of bronchopneumonia and navel inflammation were observed in COL- calves. COL- had fewer red blood cells (RBC) (6.5±0.8×106/µL) and less hemoglobin (Hgb) (8.3±1.4g/dL) than COL+ (RBC=7.2±0.8×106/µL; Hgb=9.6±1.3g/dL) at D14 (P≤0.05). COL- had more anemia on D21 (P=0.03) and on D28 (P=0.02). Iron was lower in COL- (5.6±2.7µM/L) than COL+ (10.7±6.2µM/L) (P=0.03) on D7. Lymphocytes was lower in COL- than COL+ on D7 (3.8±1.0×103/µL COL+ and 5.4±2.2×103/µL COL-, P=0.02). COL- calves had more anemia and lower serum iron concomitant with diarrhea on D7. The number of leukocytes was relatively consistent in the COL+ calves, while COL- calves showed an increasing number of of lymphocytes starting on D7.