Orally administered recombinant Lactobacillus expressing PEDV neutralizing antibody protects piglets against PEDV infection.

Porcine epidemic diarrhea virus (PEDV) is a highly contagious coronavirus, causing fatal acute diarrhea in suckling pigs, with mortality rates as high as 100 % in 7-day-old piglets. Due to the challenge of quickly establishing effective active immunity, the main strategy for protecting piglets from PEDV infection relies on antibodies, particularly neutralizing antibodies, to provide passive immune protection. In this study, a recombinant Lactobacillus strain for secreting the Fab fragment of neutralizing antibody against PEDV was constructed (pPG-Fab/J31). The results showed that the Fab antibody was stably expressed by pPG-Fab/J31, and exhibit specific neutralizing effect against PEDV. Then, pPG-Fab/J31 was used for the oral administration of newborn piglets to test the protective effect against PEDV challenge. The findings demonstrated that piglets in the antibody administration group exhibited an alleviation of clinical symptoms, a smaller decrease in weight, significant reduction in viral shedding, and attenuation of intestinal lesions. Additionally, the survival rate of piglets orally administered pPG-Fab/J31 was 100 %. Thus, PEDV neutralizing antibody expressed by recombinant Lactobacillus hold promise as a passive protective candidate, providing a new idea for the prevention and treatment of viral infections.

Persistence of maternal antibodies against goat pox virus in goat kids.

BACKGROUND: In goat kids, choosing the appropriate age to administer the first dose of goat pox disease (GTP) vaccine requires knowing when maternal antibody decline concentrations. OBJECTIVE: Determine the persistence of maternal antibodies against goat pox virus (GTPV) in goat kids. ANIMALS: Twenty Saanen goat kids from birth to 120 days old. METHODS: In 2 groups, including: control (receiving colostrum from nonvaccinated does) and treatment (receiving colostrum from vaccinated does). On zero, 3, 7, 14, 21, 28, 42, 56, 70, 100 and 120 days after the birth, virus neutralization test was used to measure the serum concentration of antibodies against GTPV. RESULTS: At the age of 56 days, the first seronegative goat kids (n = 2) were recorded in the treatment group. At the age of 120 days, all the goat kids in the treatment group were seronegative. The average virus neutralization index (VNI) of the goat kids became negative at the age of 100 to 120 days. All goat kids in the control group were negative at all times. CONCLUSIONS AND CLINICAL IMPORTANCE: One hundred to 120 days of the age seems to be the time to administer the first GTP vaccine in the goat kids with passive immunity against goat pox.

Effect of suckler cow breed type and parity on the development of the cow-calf bond post-partum and calf passive immunity.

BACKGROUND: Development of the cow-calf bond post-partum and passive immunity of calves from spring-calving beef × beef (B×B) and beef × dairy (B×D) cow genotypes was determined using primiparous and multiparous (Experiment 1), and primiparous and second-parity (Experiment 2) animals. In Experiment 1, calves either suckled colostrum naturally ('natural-suckling') (n = 126), or were fed colostrum, using an oesophageal-tube ('artificially-fed') (n = 26), from their dam within 1-h post-partum. In Experiment 2, all calves (n = 60) were artificially-fed colostrum from their dam. Prior to colostrum suckling/feeding, colostrum was sampled for IgG analysis. The cow-calf bond was assessed using CCTV recordings during the first 4-h post-partum. Calves were blood sampled at 48-h post-partum to determine IgG and total protein (TP) concentrations, and zinc sulphate turbidity (ZST) units. RESULTS: There was no difference (P > 0.05) in cow licking behaviours and calf standing and suckling behaviours between the genotypes, except in Experiment 2 where B×D calves had more attempts to suckle before suckling occurred (P ≤ 0.05) compared to B×B calves. In Experiment 1, multiparous cows licked their calves sooner (P ≤ 0.05) and for longer (P < 0.01), and their calves had fewer attempts to stand (P < 0.001), stood for longer (P = 0.05), and had fewer attempts to suckle before suckling occurred (P < 0.001) than primiparous cows; there was no parity effect on cow-calf behaviour in Experiment 2. Colostrum IgG concentrations and measures of calf passive immunity did not differ (P > 0.05) between the genotypes in either Experiment. In Experiment 1, colostrum IgG concentrations were greater (P ≤ 0.05) in multiparous compared to primiparous cows and their calves had superior (P ≤ 0.05) passive immunity; no effect of parity was found in Experiment 2. Passive immunity did not differ (P > 0.05) between suckled and artificially-fed calves in Experiment 1. CONCLUSIONS: Cow genotype had little effect on cow-calf behaviours, but under 'natural-suckling' conditions primiparous cows expressed maternal inexperience and their calves were less vigorous than multiparous cows. Colostrum IgG concentration and calf passive immunity measures were unaffected by genotype, but under 'natural-suckling' conditions calves from primiparous cows had lower passive immunity.

Timing of maternal vaccination against COVID-19 for effective protection of neonates: cohort study.

Introduction: Although the safety and effectiveness of COVID-19 vaccination during pregnancy have been proven, there is still little data explaining neonatal outcomes of maternal pre-pregnancy vaccination. Methods: Here, we investigated the impact of vaccination and SARS-CoV-2 infection on maternal-neonate immune response in a cohort study involving 141 pregnant individuals, and defined the importance of maternal COVID-19 vaccination timing for its effectiveness. Results and discussion: Our data indicate that vertically transferred maternal hybrid immunity provides significantly better antiviral protection for a neonate than either maternal post-infection or post-vaccination immunity alone. Higher neutralization potency among mothers immunized before pregnancy and their newborns highlights the promising role of pre-pregnancy vaccination in neonatal protection. A comparison of neutralizing antibody titers calculated for each dyad suggests that infection and pre-/during-pregnancy vaccination all support transplacental transfer, providing the offspring with strong passive immunity against SARS-CoV-2. Analysis of neutralizing antibody levels in maternal sera collected during pregnancy and later during delivery shows that immunization may exert a positive effect on maternal protection.

KD-409, a Respiratory Syncytial Virus FG Chimeric Protein without the CX3C Chemokine Motif, Is an Efficient Respiratory Syncytial Virus Vaccine Preparation for Passive and Active Immunization in Mice.

Although respiratory syncytial virus (RSV) vaccine development initiatives have existed for half a century, no candidate has been approved for application at all ages from neonates to children. Developing an effective and safe RSV vaccine for pediatric use is challenging owing to RSV-associated disease and vaccine-enhanced disease (VED). We aimed to design an RSV vaccine, KD-409, by structurally incorporating the F ectodomain and G protein central conserved domain without the CX3C chemokine motif and test its efficacy and safety. KD-409 formed rosette particles or trimmers. KD-409 immunization of mice mainly induced anti-RSV F protein IgG. The induced anti-F antibodies had a higher IgG2a/IgG1 ratio than pre-fusion F, suggesting that they induced Th1-dominant immunity. Active and passive immunities were assessed by analyzing the viral titers in BALB/c mice intranasally challenged with RSV after intramuscular KD-409 immunization and pups derived from mothers who were intramuscularly vaccinated with KD-409 twice, respectively. KD-409 was more effective than post-fusion F and had a lower minimum effective dose than pre-fusion F. Thus, KD-409 demonstrated great potential as a novel RSV vaccine candidate, outperforming existing RSV F-based candidates. Our findings provide a promising strategy to overcome RSV-associated acute lower respiratory infections without the risk of VED associated with traditional approaches.

Passive Immunization Strategies to Prevent Severe Respiratory Syncytial Virus Infection Among Newborns and Young Infants.

Newborns and young infants are at risk for severe respiratory syncytial virus (RSV) lower respiratory tract infection. Passive immunity is the mainstay of infection prevention in this cohort. Transplacental transfer of maternal antibodies provides the newborn with immediate protection from life-threatening infections, however, is dependent upon gestational age, birth weight, mother's age, recent maternal vaccination, maternal nutritional status, maternal immunocompetence and medical conditions, and placental integrity. Efficient transplacental transfer of RSV-neutralizing antibodies have led to the development and approval of maternal RSV immunization for the protection of the newborn. Additionally, administration of RSV-specific antibodies to infants leads to high serum titers of RSV-neutralizing antibodies and further protection from severe disease.

Assessing the impact of colostrum feeding delay on serum immunoglobulin G and total protein in dairy goat kids.

This experiment was motivated by the need to understand the impacts of delaying the first colostrum feeding on the prevalence of failed transfer of passive immunity (FTPI). A cohort of 216 kids was stratified into groups based on the colostrum feeding delay postbirth: 0-4 h, 4-8 h, 8-12 h, and 12-16 h. All kids received a single colostrum meal of 300 mL, and blood samples were collected approximately 36 h after feeding. Serum immunoglobulin G (SIgG) was measured using ELISA, and serum total protein (STP) was assessed using the Bradford method and refractometry (STPb and STPr). Statistical methods like Pearson correlations, Bland-Altman plots, and Lin's concordance coefficient were employed to assess associations and agreements between SIgG, STPb and STPr. Receiver operator characteristic analysis was employed to determine optimal STPb and STPr thresholds for predicting FTPI (SIgG < 12 g/L). Subsequently, areas under the curve, sensitivity, and specificity were examined to assess the accuracy of these thresholds. Our results showed that for each hour's delay from birth to colostrum intake (up to 16 h), IgG apparent efficiency of absorption (AEA) decreases at an approximate rate of 2.0% per hour, and SIgG decreases at an approximate rate of 1.0 g/L per hour. However, this decline is not constant over time but intensifies progressively with increased feeding delay. Specifically, reductions in IgG AEA were 1.3, 2.9, and 5.9% per hour, and decreases in SIgG were 0.2, 0.3, and 0.7 g per hour for SIgG across the time intervals of 0-4 to 4-8 h, 4-8 to 8-12 h, and 8-12 to 12-16 h, respectively. Additionally, there was an increase in SIgG of 1.2 g/dL but a decrease in IgG AEA of 1.9% for each gram per kg of BW increase in IgG intake. The correlations between SIgG and STPr and STPb were 0.62, and 0.36, respectively. Optimal STPr and STPb thresholds predicting FTPI were determined to be 4.6 and 6.2 g/dL. The prevalence of FTPI, according to SIgG, STPr, and STPb thresholds were 63, 62, and 45%. Overall, STPr showed higher values for key performance metrics (i.e., sensitivity, likelihood ratio of positive tests, overall accuracy, and Youden's index), indicating better prediction ability than STPb. Our findings corroborate the critical importance of swift colostrum administration, ideally occurring no later than 12 h postbirth. Moreover, our research validates the effectiveness of Brix refractometry as a practical, on-farm method for assessing FTPI in goat kids.

Association of morbidity, mortality, and average daily gain with transfer of passive immunity in dairy-beef crossbred calves up to 60 days of life.

Adequate transfer of passive immunity (TPI) is a cornerstone for a proper health status of calves. In the literature, there is limited information on the prevalence of failure of TPI in dairy-beef crossbred calves and its effect on morbidity, mortality, and ADG during the preweaning period. Therefore, this study aimed to evaluate the association between TPI with morbidity, mortality, and ADG in preweaning dairy-beef crossbred calves. A total of 1,055 newborn dairy-beef crossbred calves were enrolled upon arrival at a calf-raising facility in California from January to August 2021. Farm of origin, genetic breed group, sex, and BW were recorded upon arrival. Blood was collected at 24 ± 1 h after arrival to evaluate serum IgG concentration, serum total protein (TP), and packed cell volume. Morbidity (diarrhea and respiratory treatment records) and mortality were recorded daily until 60 d of life. Calves were grouped into 2 genetic breed groups: Holstein × Beef (Ho × Be, 49.6%) and Jersey × Beef crossbred calves (Je × Be, 50.4%). Descriptive statistics and Cox proportional hazard models were created to evaluate the association of TPI categories for serum IgG (TPI-IgG: poor: <10.0 g/L, fair: 10.0-17.9 g/L, good: 18.0-24.9 g/L, and excellent: ≥25.0 g/L) and TP (TPI-TP: poor: <5.1 g/dL, fair: 5.1-5.7 g/dL, good: 5.8-6.1 g/dL, and excellent: ≥6.2 g/dL), sex, and genetic breed group with morbidity and mortality. Additionally, a mixed linear regression was performed to evaluate the association of sex, genetic breed group, and TPI categories with ADG. Overall morbidity and mortality were 84.8% (n = 895) and 2.5% (n = 26). Calves classified as TPI-IgG excellent were associated with the lowest (43.2% less) hazard of being treated compared with TPI-IgG poor calves. For mortality, dairy-beef crossbred calves with TPI-IgG excellent were associated with a reduction of 82.0% in the hazard of dying compared with TPI-IgG poor. The TPI-IgG poor and TPI-IgG fair calves were associated with a decreased ADG of 101.0 and 98.8 g/d, respectively, in comparison with TPI-IgG good calves. Average daily gain of TPI-IgG good and TPI-IgG excellent calves were not different. In our study, dairy-beef crossbred calves enrolled may have endured challenging conditions that increased morbidity. This reinforces the importance of high IgG levels to decrease morbidity and mortality and maximize ADG in dairy-beef crossbred calves raising systems. Further research should evaluate the long-term effects of TPI categories on the health and performance of dairy-beef crossbred calves.

Persistence of passive immunity in calves receiving colostrum from cows vaccinated with a live attenuated lumpy skin disease vaccine and the performance of serological tests.

This study aimed to determine the persistent duration of maternal immunity against lumpy skin disease virus (LSDV) in dairy calves born from vaccinated cows using a virus neutralization test (VNT). The performance of the VNT and an in-house-ELISA test was also determined. Thirty-seven pregnant cows from 12 LSD-free dairy farms in Lamphun province, Thailand were immunized with a homologous Neethling strain-based attenuated vaccine and calved from December 2021 to April 2022. Blood samples from dam-calve pairs were collected within the first week after calving. Subsequently, blood samples were taken from the calves at monthly intervals over a period of 4 months and tested for the humoral immune response using a VNT. The calf sera were also tested with an in-house ELISA test to estimate the accuracy of both tests using a Bayesian approach. For the results, antibodies against LSDV can persist in cows for 4-9 months post-vaccination. Moreover, neutralizing antibodies and LSDV-specific antibodies against LSDV were detected in the majority of calves (75.68%) during the first week after colostrum intake. However, the percentage of seropositive calves declined to zero by day 120, with seropositivity dropping below 50% after day 60. Only a small number of seropositive calves (approximately 13.51%) were observed on day 90. These findings indicated that passive immunity against LSDV can last up to 3 months. The median of posterior estimates for sensitivity (Se) and specificity (Sp) of the VNT were 87.3% [95% posterior probability interval (PPI) = 81.1-92.2%] and 94.5% (95% PPI = 87.7-98.3%), respectively. The estimated Se and Sp for the ELISA test were 83.1% (95% PPI = 73.6-92.6%) and 94.7% (95% PPI = 88.4-98.5%), respectively. In conclusion, this study illustrates the transfer and persistence of maternal passive immunity against LSDV to calves under field conditions. This highlights a potential three-month vaccination gap in calves born from vaccinated cows, while an in-house ELISA test can be used as an ancillary test for LSDV immune response detection. However, further research is required to assess the vaccination protocols for calves as young as 2 months old to precisely determine the duration of maternal immunity.

Salivary IgG and IgA in newborn calves and the possible role in the assessment of passive immunity transfer.

Introduction: The transfer of immunoglobulins from the mother to newborns is widely recognized as a critical event for safeguarding offspring against potentially life-threatening infectious diseases. Mainly for this reason, this study aimed to assess the concentrations of immunoglobulin G (IgG) and immunoglobulin A (IgA) in the saliva of newborn calves and explore its potential use for monitoring passive immunity transfer from cows to calves, as also to evaluate how colostrum intake affects serum and saliva IgG and IgA concentrations. Methods: The quality of colostrum samples was evaluated using an optical refractometer before administration to the calves. Saliva and blood samples from 24 calves were obtained at the day of birth (T0) and 2 days after (T2) for determination of serum concentrations of total protein by refractometer, IgG and IgA (both on serum and saliva) by ELISA test. Results: Positive correlations were observed between salivary IgA at T2 and salivary IgG at T2. A significant increase in both IgG and IgA levels in calf serum and saliva was noted. Salivary IgA levels can reflect salivary IgG levels. Discussion: These findings suggest the potential utility of IgA in monitoring passive immunity transfer, and do not exclude saliva as an alternative, practical, and non-invasive matrix for assessing passive immunity transfer.

Rapid development and mass production of SARS-CoV-2 neutralizing chicken egg yolk antibodies with protective efficacy in hamsters.

Despite the record speed of developing vaccines and therapeutics against the SARS-CoV-2 virus, it is not a given that such success can be secured in future pandemics. In addition, COVID-19 vaccination and application of therapeutics remain low in developing countries. Rapid and low cost mass production of antiviral IgY antibodies could be an attractive alternative or complementary option for vaccine and therapeutic development. In this article, we rapidly produced SARS-CoV-2 antigens, immunized hens and purified IgY antibodies in 2 months after the SARS-CoV-2 gene sequence became public. We further demonstrated that the IgY antibodies competitively block RBD binding to ACE2, neutralize authentic SARS-CoV-2 virus and effectively protect hamsters from SARS-CoV-2 challenge by preventing weight loss and lung pathology, representing the first comprehensive study with IgY antibodies. The process of mass production can be easily implemented in most developing countries and hence could become a new vital option in our toolbox for combating viral pandemics. This study could stimulate further studies, optimization and potential applications of IgY antibodies as therapeutics and prophylactics for human and animals.

Evaluation of longitudinal passive immunity transfer against lumpy skin disease virus in calves by different serological methods.

To implement effective lumpy skin disease (LSD) control measures, such as timely vaccination, particularly in calves and serological monitoring, it is necessary to evaluate immune response after vaccination, both in adult cattle and in their calves. The aim of this study was to evaluate passive immunity transfer and duration of maternal antibodies against lumpy skin disease virus (LSDV) in calves born to vaccinated cows by two different serological methods. The longitudinal study was carried out on two farms in Serbia where no cases were reported during LSD outbreak in 2016. Fifteen cows on each farm were vaccinated and revaccinated with attenuated vaccine - Neethling strain. A total of 30 cows and 30 calves on both farms were included in the study. Serum samples from cows were collected on calving day and serum samples from their respective calves on days 10, 20, 30, 45, 60, 75, 90, 105 and 120 after birth. Colostrum samples were collected only from 15 cows on one farm. In order to determine the presence of antibodies against LSDV a total of 30 cow sera samples, 15 colostrum samples and 270 calf sera samples were examined by commercial enzyme-linked immunosorbent assay (ELISA) and modified virus neutralization test (VNT). Overall, the performance of both serological tests was very satisfactory. The results of this longitudinal study showed that persistence of passive immunity in calves is less than 4 months, and that most calves are not protected against LSDV at that age. Since the vaccination is the most important control measure against LSDV, the recommended age of six months for vaccination of calves born to vaccinated cows should be reassessed to achieve the most optimal protection against LSD.

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.

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

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

Absence of blood donors' anti-SARS-CoV-2 antibodies in pre-storage leukoreduced red blood cell units indicates no role of passive immunity for blood recipients.

Transfer of vaccine antibodies (Ab) from donors to recipients after transfusion of packed red blood cells (RBC) is supposed, thus affecting the recipients' response to vaccinations. In this prospective study, SARS-CoV-2 IgG level in donors' serum and RBC supernatant samples was assessed. Among 346 subjects, 280 were referred for hyperimmune plasma donation and 30 for whole blood donations. All units underwent pre-storage filtration, and residual plasma volume was 18±18 mL. The mean total IgG and IgM levels were 171.43 ± 48.79 and 11.43 ± 10.69 mg/dL respectively, with significant reduction after plasma depletion and filtration (IgG 5.86 ± 5.2 and IgM 1.43 ± 3.78, p < 0.05). Anti-COVID-19 Ab were identified in serum of 28/30 (93.5%) blood donors but were absent in all blood units. The mean value of anti-SARS-CoV-2 IgG level in donors' serum samples and in RBC units was 8.80 S/C (range 0.01-23.4) and 0.11 (range 0.01-0.37) S/C, respectively (p<0.05). This study shows deplasmation and leukodepletion of RBC units ensured removal of IgG content and no red blood cell unit was reactive for anti-COVID-19 antibodies even from donors with high serum titre. These findings demonstrate that deplasmated and leukodepleted RBCs are not to be considered blood products containing substantial amounts of immune globulin, and differently from other blood derived-products containing Ab, transfusions with deplasmated and leukodepleted RBCs do not require delayed vaccinations and a revision of current recommendations is requested.

Condition of surplus dairy calves during marketing: A cross-sectional study.

In North America, surplus dairy calves are sold soon after birth and often marketed through a third party (e.g., live auction, livestock dealer) before entering veal or dairy beef production. Previous work has demonstrated that a percentage of calves have failed transfer of passive immunity (FTPI) and clinical signs of disease on arrival at calf-raising facilities, but little is known regarding calf condition during marketing. The objectives of this cross-sectional study were to (1) estimate the prevalence of FTPI and poor health outcomes in surplus calves on arrival at livestock dealers, and (2) investigate the association between calf-level variables (body weight, sex, source) and health outcomes. Two livestock dealers in Ohio were visited 2 to 3 times per week, with approximately 28 calves enrolled in the study per visit for a total of 1,119 calves. One blood sample per calf was obtained to evaluate FTPI by measuring serum total protein concentrations (using a cutoff <5.1 g/dL). Calves were clinically evaluated for signs of arthritis, broken ribs or tail, dehydration, depression, diarrhea, fever, navel inflammation, and respiratory disease by 2 observers; health outcomes were dichotomized using clinically relevant cut points. Descriptive statistics were used to estimate the prevalence of calves with poor health outcomes. Multivariable logistic regression models were built to investigate the effect of body weight, sex, and source on health outcomes. Nineteen percent (206/1,091) of calves had FTPI.

Revisão de literatura sobre os aspectos fisiológicos e nutricionais em bezerros alimentados com colostro acidificado / Literature review on physiological and nutritional aspects in calves fed acidified colostrum / Revisión de la literatura sobre aspectos fisiológicos y nutricionales en terneros alimentados con calostro acidificado

A colostragem é essencial para a saúde dos bezerros neonatos, uma vez que não há a transferência de imunidade através da placenta, ou seja, o contato inicial do organismo com anticorpos se dá através da primeira mamada, onde há transferência da imunidade passiva. Sendo assim, o objetivo do trabalho é revisar os benefícios da acidificação ou silagem do colostro para otimizar a conservação da dieta líquida em fazendas; analisar o impacto no desempenho de bezerros em comparação com o colostro tradicional refrigerado em aleitamentos convencionais. O volume ideal preconizado é, no mínimo, 10% do peso vivo do animal nas primeiras duas horas e mais 5% do peso vivo nas seis a oito horas seguintes a primeira ingestão, para que se obtenha um bom desenvolvimento durante o crescimento, caso contrário, a falta da administração do colostro nas primeiras horas de vida predispõe enfermidades, tais como pneumonia e diarreia, prejudicando assim a saúde e consequentemente o desempenho em relação a outros animais que receberam uma colostragem adequada. Problemas com a qualidade do colostro surgem devido ao armazenamento inadequado, especialmente em propriedades sem refrigeração. A falta de sistemas de congelamento resulta em administração de leite em temperatura ambiente por períodos prolongados, prejudicando assim a imunidade e nutrição dos bezerros durante a colostragem. Todavia, há alternativas para o problema tal como o fornecimento de silagem de colostro. Em alguns casos, o processo de acidificação demanda a adição de ácidos no leite, a fim de evitar o crescimento de microrganismos patogênicos. O principal aspecto positivo do leite acidificado é a manutenção em temperatura ambiente, ou seja, não há a necessidade de passar por processos de refrigeração.

Colostrum is essential for the health of newborn calves, since there is no transfer of immunity through the placenta, that is, the body's initial contact with antibodies occurs through the first feeding, where there is a transfer of passive immunity. Therefore, the objective of the work is to review the benefits of acidifying or colostrum silage to optimize the conservation of liquid diets on farms; analyze the impact on calf performance compared to traditional refrigerated colostrum in conventional sucklers. The recommended ideal volume is at least 10% of the animal's live weight in the first two hours and a further 5% of its live weight in the six to eight hours following the first ingestion, so that good development is achieved during growth, otherwise, the lack of colostrum administration in the first hours of life predisposes diseases, such as pneumonia and diarrhea, thus harming health and consequently performance in relation to other animals that received adequate colostrum. Problems with colostrum quality arise due to inadequate storage, especially in unrefrigerated properties. The lack of freezing systems results in milk being administered at room temperature for prolonged periods, thus damaging the calves immunity and nutrition during colostrum. However, there are alternatives to the problem such as the supply of colostrum silage. In some cases, the acidification process requires the addition of acids to the milk in order to prevent the growth of pathogenic microorganisms. The main positive aspect of acidified milk is that it remains at room temperature, that is, there is no need to undergo refrigeration processes.

El calostro es esencial para la salud de los terneros recién nacidos, ya que no existe transferencia de inmunidad a través de la placenta, es decir, el contacto inicial del cuerpo con los anticuerpos ocurre a través de la primera alimentación, donde existe una transferencia de inmunidad pasiva. Por lo tanto, el objetivo del trabajo es revisar los beneficios de acidificar o ensilar el calostro para optimizar la conservación de dietas líquidas en granjas; analizar el impacto en el rendimiento de los terneros en comparación con el calostro refrigerado tradicional en lechones convencionales. El volumen ideal recomendado es al menos el 10% del peso vivo del animal en las dos primeras horas y otro 5% de su peso vivo en las seis a ocho horas siguientes a la primera ingesta, para que se consiga un buen desarrollo durante el crecimiento, en caso contrario. la falta de administración de calostro en las primeras horas de vida predispone a enfermedades, como neumonía y diarrea, perjudicando la salud y consecuentemente el rendimiento en relación a otros animales que recibieron el calostro adecuado. Los problemas con la calidad del calostro surgen debido a un almacenamiento inadecuado, especialmente en propiedades no refrigeradas. La falta de sistemas de congelación provoca que la leche se administre a temperatura ambiente durante períodos prolongados, dañando así la inmunidad y la nutrición de los terneros durante el calostro. Sin embargo, existen alternativas al problema como el suministro de ensilaje de calostro. En algunos casos, el proceso de acidificación requiere la adición de ácidos a la leche para evitar el crecimiento de microorganismos patógenos. El principal aspecto positivo de la leche acidificada es que se mantiene a temperatura ambiente, es decir, no es necesario someterse a procesos de refrigeración.

Identificación de la proteína "Spike" en sangre de cordón umbilical de recién nacidos de madres vacunadas contra SARS-CoV-2 durante el embarazo / Identification of the "Spike" protein in umbilical cord blood of newborns from mothers vaccinated against SARS-CoV-2 during pregnancy

Resumen OBJETIVO: Identificar la coexistencia de anticuerpos contra la proteína "Spike" del SARS-CoV-2 en sangre del cordón umbilical de recién nacidos de madres vacunadas contra la COVID-19 durante el embarazo. MATERIALES Y MÉTODOS: Estudio transversal, llevado a cabo en un centro de atención privada de la Ciudad de México, entre junio del 2021 y febrero del 2022, al que se incluyeron mujeres que completaron el esquema de vacunación contra SARS-CoV-2 durante el embarazo y en quienes en el trascurso de la finalización del embarazo parto o cesárea se haya obtenido una muestra de sangre de cordón umbilical para identificar la proteína Spike. RESULTADOS: Se registraron 219 pacientes y se analizaron 5 tipos de vacuna de dos plataformas diferentes; Pfizer®, Moderna®, AstraZeneca®, J&J/Janssen® y Sputnik®. La concentración de anticuerpos fue mayor en pacientes vacunadas con Moderna® y Sputnik®. Mediante el análisis de regresión de Cox se evaluó un modelo predictivo, sin mostrar diferencia estadísticamente significativa en la cantidad de anticuerpos generados luego de la primera y segunda dosis de la vacuna. CONCLUSIONES: La vacunación prenatal contra la COVID-19 induce una fuerte respuesta humoral materna, que se transfiere de manera efectiva al feto, incluso con una sola dosis.

Abstract OBJECTIVE: Identification of the presence of SARS-CoV-2 Spike protein antibodies in cord blood of newborns following maternal COVID-19 vaccination during pregnancy. MATERIALS AND METHODS: Cross-sectional study in vaccinated women during pregnancy who had a cord blood sample taken during the surgical procedure Vaginal birth/Cesarean section to measure spike protein antibodies. RESULTS: We registered 219 patients in the study: five types of vaccines, from two different platforms, were tested: Pfizer®, Moderna®, AstraZeneca®, J&J/Janssen® and Sputnik®. The levels of antibodies were greater in those patients vaccinated with Moderna® and Sputnik®. Through a Cox regression we made a predictive model where we observed that there are no differences in the number of antibodies generated after the first and second vaccine dose. CONCLUSIONS: Prenatal vaccination against COVID-19 induces a strong maternal humoral response that is effectively transferred to the fetus, even with a single dose.

Associations of serostatus upon arrival with clinical respiratory disease, lung consolidation, and growth in veal calves.

Respiratory tract infections remain a major problem during calf rearing, especially among milk (formula)-fed veal. Preconditioning of calves through appropriate colostrum management and vaccination could be helpful to address this issue. The objective of this study was to investigate whether the presence of serum antibodies against major respiratory tract pathogens (bovine respiratory syncytial virus, parainfluenza 3 virus, bovine coronavirus, Mycoplasmopsis bovis, Histophilus somni, Pasteurella multocida, and Mannheimia haemolytica) and total serum IgG concentration in calves upon arrival at the veal facility were associated with the occurrence of clinical bovine respiratory disease (BRD) or lung consolidation in the first 3 wk, as assessed by both the Wisconsin BRD scorecard (based on 5 clinical signs: cough, rectal temperature, ear position, and nasal and ocular discharge) and by quick thoracic ultrasound scanning. Additionally, the association between calves' serostatus production parameters were explored. A prospective cohort study was conducted among 442 male dairy calves on a large veal calf facility in Belgium. Both clinical scoring and quick thoracic ultrasound scanning were performed on all calves at 4 key moments in the production cycle: arrival at the facility, initiation of first metaphylactic antimicrobial treatment at peak incidence of BRD (wk 1), end of the first metaphylactic treatment (short-term evaluation) and at wk 10 (long-term evaluation). Mixed effects logit regression models were fitted to quantify relationships. The outcomes of interest were clinical respiratory disease (Wisconsin BRD scorecard positive), lung consolidation (≥1 cm or ≥ 3 cm), average daily weight gain, and cold carcass weight. In the first week of production, incidence of lung consolidation (≥1 cm) quickly increased from 14.9% upon arrival to 43.0% at the peak of the BRD incidence, while clinical BRD increased from 3.6% to 16.1%. The main finding of this study was that calves who were seropositive for bovine respiratory syncytial virus and bovine coronavirus at arrival had reduced odds of developing lung consolidation at the peak of the outbreak, 0.58 odds ratio (95% CI: 0.38-0.89) and 0.37 odds ratio (95% CI: 0.20-0.69), respectively. No relationships between serum IgG concentration at arrival and the development of lung consolidations or clinical respiratory disease were found. Nevertheless, on average, throughout the first 10 wk of the fattening cycle, calves with failed transfer of passive immunity (serum IgG < 7.5 g/L) gained 40 g/d (95% CI: 10-70 g/d) less weight (average daily gain). Hence, ensuring that calves have a positive serostatus for these respiratory tract pathogens before entering the facility may help lower the incidence of lung consolidations, subsequently reducing treatment incidence and the adverse effects on primary economic outcomes.

Determination of minimum individual cow colostral immunoglobulin G concentration required to provide adequate total immunoglobulin G mass in pooled colostrum fed to Jersey calves.

OBJECTIVE: Quantify the minimum individual cow colostral immunoglobulin G (IgG) concentration required for pooling to achieve adequate transfer of passive immunity in calves. ANIMALS: 201 Jersey cows. METHODS: Colostrum was collected from 28 pools and heat treated before being fed to calves or stored. Parity, total number of cows contributing to the pool, individual cow colostral volume contributions, and total volume of each colostrum pool were recorded. Colostrum IgG concentrations in individual and pooled (pre- and post-heat treatment) samples were analyzed by radial immunodiffusion and Brix refractometry. Colostral IgG concentration of ≥ 50g/L was considered the current recommended dairy industry standard for acceptable colostrum quality. Multivariable models were performed to determine factors affecting pooled colostral IgG concentrations. The minimum colostral IgG concentration required for pooling to achieve the recommended total mass of at least 200g IgG to be fed to a calf was calculated. RESULTS: Total pool volume and the number of cows contributing to the pool were significant factors affecting IgG concentration. Colostrum pools from ≤ 7 cows, with a minimum pool IgG concentration of 70.4 g/L (22.9% Brix) or colostrum pool volume ≤ 40 L, with a minimum pool IgG concentration of 66.2 g/L (21.8% Brix) achieved the recommended total mass of at least 200g IgG in 4L of colostrum. CLINICAL RELEVANCE: When feeding pooled colostrum, IgG concentrations higher than the industry standard of 50 g/L is recommended to reduce the risk of failure of transfer of passive immunity in calves.