Concentrations of selected immunological parameters in the serum and processing fluid of suckling piglets and the serum and colostrum of their mothers.

BACKGROUND: Blood sampling from neonatal piglets is related to multiple disadvantages. Therefore, a new, alternative matrix is required to assess piglets' early immune status efficiently. The present study aimed to assess the usefulness of processing fluid for determining selected piglets' immune parameters. 264 pigs - 31 sows, 146 male piglets, and 87 female piglets from commercial indoor farrow-to-finish pig herd were included in this study. 264 serum, 31 colostrum, and 146 processing fluid samples were collected. Serum was collected from all animals, colostrum was collected from sows, and processing fluid was collected from male piglets only. Using commercial ELISA tests, the concentration of various immunoglobulins, cytokines, and acute phase proteins was assessed in each matrix. Statistical analyses were employed to determine differences in the concentration of measured indices between piglets' serum and processing fluid and correlations in the concentration of tested indices between particular sets of matrices. RESULTS: Statistical analyses did not reveal significant differences in the IgG, IgA, IL-1ß, IL-4, IL-6, and IFN-γ concentration between piglets' serum and processing fluid (p > 0.05). A positive correlation (p < 0.05) regarding the concentration of some indices between processing fluid and samples collected from sows was also observed. CONCLUSIONS: Processing fluid can be considered a promising alternative to blood for assessing some immunological indices in piglets, such as IgG, IgA, IL-1ß, IL-4, IL-6, and IFN-γ, and, possibly, in the indirect assessment of some indices in lactating sows, including IgA, IL-1ß, IL-4, IL-6, IL-8, IFN-γ, or Pig-MAP.

Neonatal and maternal upregulation of antileukoproteinase in horses.

Introduction: The end of gestation, ensuing parturition, and the neonatal period represent highly dynamic phases for immunological changes in both mother and offspring. The regulation of innate immune cells at the maternal-fetal interface during late term pregnancy, after birth, and during microbial colonization of the neonatal gut and other mucosal surfaces, is crucial for controlling inflammation and maintaining homeostasis. Innate immune cells and mucosal epithelial cells express antileukoproteinase (SLPI), which has anti-inflammatory and anti-protease activity that can regulate cellular activation. Methods: Here, we developed and validated new monoclonal antibodies (mAbs) to characterize SLPI for the first time in horses. Peripheral blood and mucosal samples were collected from healthy adults horses and a cohort of mares and their foals directly following parturition to assess this crucial stage. Results: First, we defined the cell types producing SLPI in peripheral blood by flow cytometry, highlighting the neutrophils and a subset of the CD14+ monocytes as SLPI secreting immune cells. A fluorescent bead-based assay was developed with the new SLPI mAbs and used to establish baseline concentrations for secreted SLPI in serum and secretion samples from mucosal surfaces, including saliva, nasal secretion, colostrum, and milk. This demonstrated constitutive secretion of SLPI in a variety of equine tissues, including high colostrum concentrations. Using immunofluorescence, we identified production of SLPI in mucosal tissue. Finally, longitudinal sampling of clinically healthy mares and foals allowed monitoring of serum SLPI concentrations. In neonates and postpartum mares, SLPI peaked on the day of parturition, with mares returning to the adult normal within a week and foals maintaining significantly higher SLPI secretion until three months of age. Conclusion: This demonstrated a physiological systemic change in SLPI in both mares and their foals, particularly at the time around birth, likely contributing to the regulation of innate immune responses during this critical period.

Exploring the impact of colostrum supplementation on athletes: a comprehensive analysis of clinical trials and diverse properties.

Colostrum, an invaluable food produced by mammals during the postnatal period, contains important bioactive components. It is a valuable therapeutic substance that can be used to treat a variety of disorders, in addition to its primary function of providing passive immunity to newborns. Undoubtedly, a strong dedication to intense effort and demanding training schedules is necessary to succeed in today's sports environment. Peak physical fitness, strategic skill development, and mental toughness are highly valued in the environments in which athletes compete. However, the inherent difficulties brought about by athletes' intense schedules are matched with the demanding character of modern sports. The intensity of athletic activity frequently provides little time for sufficient relaxation, nutritional preparation, and overall recovery, which can contribute to mental and physical tiredness. Athletes need to develop all-encompassing strategies to overcome these obstacles. These strategies should prioritize self-care and recovery in addition to maximizing training efficiency. The bioactive components of colostrum bring forth various therapeutic effects against the challenges experienced by athletes; including diarrhea, upper respiratory tract infections, muscle injuries, intestinal disorders, etc. This review examined the different therapeutic effects of the bioactive components of colostrum on athletes, the effect of the use of colostrum as a whole on the performance of athletes, and the clinical research conducted in this field. While the majority of studies report positive effects of colostrum, further research is needed.

Evaluating smartphone-based optical readouts for immunoassays in human and veterinary healthcare: A comparative study.

Recent advances have significantly enhanced the use of smartphone devices for medical diagnostics. This study uses high-resolution cameras in mobile devices to capture and process bioassay images, enabling the quantification of diverse biomarkers across a range of diagnostic tests conducted on 96-well microplates. The study evaluates the effectiveness of this technology through protein quantification techniques and immunoassays that generate colorimetric responses at specific wavelengths. It includes the assessment of bicinchoninic acid and Bradford protein quantification methods, alongside a conventional immunoassay for detecting mare antibodies in colostrum to monitor foal immunodeficiencies. Further application involves the readout of magneto-actuated immunoassays aimed at quantifying bacteria. The results obtained from benchtop spectrophotometry at 595, 562, and 450 nm are compared with those acquired using a smartphone, which identified color intensities in shades of blue, purple, and yellow. This comparison yields promising correlations for the samples tested, suggesting a high degree of accuracy in the smartphone capability to analyze bioassay outcomes. The analysis via smartphone is facilitated by a specific app, which processes the images captured by the phone camera to quantify color intensities corresponding to different biomarker concentrations. Detection limits of 12.3 and 22.8 µg mL-1 for the bicinchoninic acid assay and 36.7 and 45.4 µg mL-1 for the Bradford are obtained for protein quantification using the spectrophotometer and the smartphone app, respectively. For mare's antibodies in colostrum, the values are 1.14 and 1.72 ng mL-1, while the detection of E. coli is performed at 2.0 x 104 and 2.9 × 104 CFU mL-1, respectively. This approach offers further advantages, including wide availability, cost-effectiveness, portability, compared to traditional and expensive benchtop instruments.

The immune response of pregnant sow after vaccination with crude fimbriae (F4) extracts vaccine and immunoprotection of nursery pig against pathogenic E. coli (F4+ETEC).

BACKGROUND: Neonatal and post-weaning diarrhea is a concern disease caused by enterotoxigenic Escherichia coli fimbriae F4 (F4+ETEC) in pig farms. Diarrhea outbreaks are often severe and costly due to the high prevalence and spread of the disease within the same herd. Vaccine is one of strategic solution in protecting pig against F4+ETEC infection in particular pig farm. In present study, we conducted two trials of vaccination with crude F4 fimbriae extract vaccine in pregnant sow and nursery pigs. METHODS: In experiment 1 (20 sows; non-vaccinated control, n=10), we vaccinated pregnant sows (n=10) twice at 4 wk and 2 wk before farrowing and evaluated impact of vaccination on maternal immunity. The sow serum and colostrum were collected before vaccination, 2 and 4 weeks after vaccination, 6 hours after farrowing, respectively, and the piglet's serum from both groups (2 piglet/sow, 10 piglets from each group) were also collected on 3 days old to measure F4 specific IgG, F4 specific IgA using in house ELISA kit. In experiment 2, to optimize doses and dosage of candidate vaccine in piglets, 18 piglets (3 piglets/group) were allocated into five immunized groups and one control group (unimmunized group), we immunized piglets twice at 4 and 6 weeks old with difference doses (i.e., 0, 50, 100, 150, 200 µg), and for a dose 150 µg, we immunized with two dosages at 1 ml and 2 ml. Piglets were challenged with a 3 ml dose of 3 × 109 CFU/ml bacterial culture of enterotoxigenic Escherichia coli (F4+ETEC) in order to evaluate the efficacy of vaccine. After challenging, the clinical sign of the piglets was daily observed and the rectal swab was performed every day for investigation of the fecal shedding of Escherichia coli (F4+ETEC) by using PCR technique. Serum were collected before, 2 and 4 weeks after vaccination and 1 week after challenge to measure F4 specific IgG, F4 specific IgA using in house ELISA kit and cytokines levels (i.e., IL-1 beta, IL-6, IL-8 and TNF alpha) before and 1 week after challenge using commercial ELISA kit. RESULTS: The levels of antibody results showed that in experiment 1, the anti-F4 antibody levels both F4 specific IgG and F4 specific IgA in serum and colostrum of vaccinated sow increased significantly after vaccination. The piglets of immunized sows have antibody level both F4 specific IgG and F4 specific IgA in their serum higher than those piglets of unimmunized sows significantly (p < 0.01). In experiment 2, irrespective of different doses and dosage, there is no difference in term of F4 specific IgG and F4 specific IgA levels among immunized groups. However, all of vaccinated piglets showed F4 specific IgG and F4 specific IgA levels higher and the elimination of Escherichia coli (F4+ETEC) in feces post challenge faster (< 3 days) than unvaccinated group (> 5 days). For cytokines levels, a higher level of IL-1 beta, IL-6, IL-8 and TNF alpha at 1 week after challenge in vaccinated groups was found when compared with the levels in non-vaccinated group. CONCLUSIONS: Our results suggest that crude F4 fimbriae extract autogenous vaccine is a candidate vaccine for protecting piglets against diarrhea disease caused by enterotoxigenic Escherichia coli (F4+ETEC) and vaccination the pregnant sow twice before farrowing is one of strategies to provide maternal derived antibody to the newborn piglets for against enterotoxigenic Escherichia coli (F4+ETEC) during early life.

Specific IgA, But Not IgG, in Human Milk From COVID-19-Infected Mothers Neutralizes SARS-CoV-2.

This study highlights the importance of human milk in providing anti-severe acute respiratory syndrome coronavirus 2 immunity to newborns. The highest protective activity of human milk against COVID-19 was found in colostrum from infected mothers. Neutralizing activity was associated with high levels of specific IgA. Depletion of IgA, but not IgG, from milk samples completely abolished the ability of human milk to neutralize severe acute respiratory syndrome coronavirus 2.

Successful transfer of passive immunity: the natural alternative to antibiotics for boosting the survival of intensively reared dairy goat kids.

In dairy operations, antibiotics have traditionally been used to treat, prevent, and control diseases. However, given the mounting global crisis of antimicrobial resistance (AMR), farmers are urged to re-assess and reduce their reliance on antibiotics. Thus, this randomized, double-blinded cohort study aimed to estimate the prevalence of failed and successful transfer of passive immunity (FTPI and STPI) in dairy goat kids reared under commercial conditions, and the effects of antibiotic metaphylaxis on the pre-weaning (≤42 d old) mortality in FTPI and STPI kids. Plasma concentration of immunoglobulin G at 1d old (pIgG-24 h) was measured in 747 male Saanen kids for the determination of FTPI and STPI (pIgG-24 h < 12 and ≥12 g/L, respectively). Kids were then randomly divided into two groups: those receiving a single penicillin injection at 1 d old (PEN), and those receiving no treatment (CTR). The mean (±SD) pIgG-24 h and initial BW (IBW) were 17 ± 9.8 g/L and 4.1 ± 0.64 kg. The prevalence of FTPI was 29% (220/747 kids). Gastrointestinal complications were the primary cause of death (41%), followed by septicemia (22%) and arthritis (17%). A single penicillin injection reduced preweaning mortality by 55% (10 vs 22%, PEN vs CTR). However, results suggest that such a decline was mainly driven by the improved survival rates among FTPI kids, which increased by 19% (from 62% in CTR-FTPI to 82% in PEN-FTPI), as opposed to an 8% increase among STPI kids (from 85% in CTR-STPI to 93% in PEN-STPI). Additionally, the odds of mortality ≤ 42 d old were threefold higher in the CTR-FTPI group when compared to both the CTR-STPI and PEN-FTPI groups, suggesting a potential parity between STPI and PEN for mortality rate reduction. Taken together, the results indicate that although metaphylactic antibiotics can halve preweaning mortality, similar improvements are likely to be achieved via increased STPI rates. Furthermore, by targeting metaphylactic interventions to high-risk groups (i.e., those displaying signs of inadequate colostrum intake and/or low birth BW), farmers could reduce treatment costs and mitigate AMR risks. While these findings carry considerable weight for commercial dairy goat practices, their applicability to other systems (i.e., extensive, semi-intensive, mohair, meat systems) warrants further investigation.

Podcast RP Convida: Boas práticas em neonatologia e aleitamento

Com o tema “Boas práticas em neonatologia e aleitamento”, o podcast RP Convida da revista Residência Pediátrica (RP) apresenta o episódio especial em alusão ao Agosto Dourado. Nesta edição, a convidada é a dra. Carmen Elias, do Departamento Científico de Aleitamento Materno da Sociedade Brasileira de Pediatria (SBP).

Colostro, leite produzido pela mulher logo após o parto, fortalece o sistema imunológico e protege a saúde do bebê

O contato pele a pele entre mulher e criança e a amamentação na primeira hora de vida, após o nascimento, também chamada de “hora de ouro”, são de grande importância para estabelecer laços entre mãe e bebê. Segundo o Fundo das Nações Unidas para a Infância (Unicef), esses também são fatores de proteção contra mortes neonatais.

A Direct MS-Based Approach to Profile Human Milk Secretory Immunoglobulin A (IgA1) Reveals Donor-Specific Clonal Repertoires With High Longitudinal Stability.

Recently, a mass spectrometry-based approach was introduced to directly assess the IgG1 immunoglobulin clonal repertoires in plasma. Here we expanded upon this approach by describing a mass spectrometry-based technique to assess specifically the clonal repertoire of another important class of immunoglobulin molecules, IgA1, and show it is efficiently and robustly applicable to either milk or plasma samples. Focusing on two individual healthy donors, whose milk was sampled longitudinally during the first 16 weeks of lactation, we demonstrate that the total repertoire of milk sIgA1 is dominated by only 50-500 clones, even though the human body theoretically can generate several orders of magnitude more clones. We show that in each donor the sIgA1 repertoire only changes marginally and quite gradually over the monitored 16-week period of lactation. Furthermore, the observed overlap in clonal repertoires between the two individual donors is close to non-existent. Mothers provide protection to their newborn infants directly by the transfer of antibodies via breastfeeding. The approach introduced here, can be used to visualize the clonal repertoire transferred from mother to infant and to detect changes in-time in that repertoire adapting to changes in maternal physiology.

Risk factors related to the appearance of umbilical disorders in dairy calves / [Fatores de risco relacionados ao surgimento de afecções umbilicais em bezerros leiteiros]

The objective of this study was to determine the types of calve housing used in dairy farms, the prevalence of umbilical disorders and related risk factors. The 16 farms studied were visited to characterize the types of installation and possible risk factors, as well as information obtained from a questionnaire applied to the farmers. 806 Holstein calves were physically examined, in addition to collecting blood samples for the evaluation of Failures in Passive Immunity Transfer (FPIT), in animals that manifested inflammatory omphalopathies, and were also submitted to ultrasound examination. The prevalence of omphalopathies was assessed by Fisher's test, and multivariate logistic regression to assess risk factors. Eight types of installation were found: tropical house, suspended cage, collective stall, collective picket, Argentinean type, single-story cage, individual stall, and collective picket with chain. Omphalopathies accounted for 6.45% of the calves. Small size farms (up to 99 lactation cows) had high risk for umbilical disorders, ground floor collective calves, without side protection, with sand floor, in closed sheds and without heatstroke were considered risk factors for omphalopathies. Adequate colostrum and umbilical antisepsis are not associated with disease, its appearance being related to the housing conditions of the animals.(AU)

O objetivo deste estudo foi determinar os tipos de alojamento para bezerros leiteiros, a prevalência de onfalopatias e os fatores de risco relacionados. As 16 fazendas estudadas foram visitadas buscando-se caracterizar os tipos de instalação e os possíveis fatores de risco, além de informações obtidas de um questionário aplicado aos fazendeiros. Foram examinados fisicamente 806 bezerros da raça Holandesa, além da coleta de amostras de sangue, para avaliação da falha de transferência de imunidade passiva (FTIP), nos animais que manifestaram onfalopatias inflamatórias, sendo submetidos também ao exame ultrassonográfico. A prevalência das onfalopatias foi avaliada por teste de Fisher, e foi feita regressão logística multivariada a fim de se avaliarem os fatores de risco. Verificou-se oito tipos de instalação: casinha tropical, gaiola suspensa, baia coletiva, piquete coletivo, bezerreiro tipo argentino, gaiola térrea, baia individual e piquete coletivo com corrente. As onfalopatias corresponderam a 6,45% dos bezerros. Os bezerreiros coletivos térreos, sem proteções laterais, com piso de areia, borracha, concreto ou madeira, em galpões fechados, sem insolação, com alta densidade animal, antissepsia umbilical realizada por três dias e FTIP acima de 50% foram considerados fatores de risco para onfalopatias e possuem relação com o bezerreiro, sendo decisivas para evitar essas condições a colostragem e a antissepsia umbilical adequadas.(AU)

Method development for the analysis of PBMC-mediated killing of K562 cells by bovine colostrum.

BACKGROUND: Colostrum is the first milk that supplies newborns with immune supporting peptides. Due to its heterogeneous and variable characteristics, standardized assays for assessment of its biological activities are a challenge. The current set of studies were aimed to investigate the immune activity of bovine colostrum blends as well as develop a method to assess variability across different lots. METHODS: Immune activity of a bovine colostrum blend was evaluated by their ability to enhance PBMC (peripheral blood mononuclear cell)-mediated killing of K562 cells. K562 cell killing was assessed by flow cytometry using DAPI. PBMCs derived from multiple healthy donors were initially investigated. Frozen PBMC aliquots from one of the highest responders were used for subsequent studies. Different doses and lots of product were assessed. Incubation time was also explored. RESULTS: Bovine colostrum blend similarly reduced K562 cells number and these effects were often greater than the IL-2 positive control. Despite consistent efficacy at enhancing PBMCs-mediated K562 killing, the degree of the effect was significantly variable across different lots. These biological effects were largely dependent on the solubility of the product. CONCLUSION: Assessment of PBMC-mediated killing of K562 cells by flow cytometry using DAPI can be a reliable method for measuring immune activity of bovine colostrum when the material is well-dissolved into solution and the same biological sample from a single donor is used.

Maternal IgA2 Recognizes Similar Fractions of Colostrum and Fecal Neonatal Microbiota.

Microbiota acquired during labor and through the first days of life contributes to the newborn's immune maturation and development. Mother provides probiotics and prebiotics factors through colostrum and maternal milk to shape the first neonatal microbiota. Previous works have reported that immunoglobulin A (IgA) secreted in colostrum is coating a fraction of maternal microbiota. Thus, to better characterize this IgA-microbiota association, we used flow cytometry coupled with 16S rRNA gene sequencing (IgA-Seq) in human colostrum and neonatal feces. We identified IgA bound bacteria (IgA+) and characterized their diversity and composition shared in colostrum fractions and neonatal fecal bacteria. We found that IgA2 is mainly associated with Bifidobacterium, Pseudomonas, Lactobacillus, and Paracoccus, among other genera shared in colostrum and neonatal fecal samples. We found that metabolic pathways related to epithelial adhesion and carbohydrate consumption are enriched within the IgA2+ fecal microbiota. The association of IgA2 with specific bacteria could be explained because these antibodies recognize common antigens expressed on the surface of these bacterial genera. Our data suggest a preferential targeting of commensal bacteria by IgA2, revealing a possible function of maternal IgA2 in the shaping of the fecal microbial composition in the neonate during the first days of life.

Diverse Immune Effects of Bovine Colostrum and Benefits in Human Health and Disease.

The health benefits of bovine colostrum have extensively been studied, including immune effects mediated by immunoglobulins, lactoferrin, and casein, as well as by certain growth factors. Some of these effects are not directly related to the absorption of proteins from the intestinal tract. The ingestion of BC can modulate the function of subsets of lymphocytes, macrophages, and dendritic cells and increase regulatory cytokines such as interleukin 10. In this review, we predominantly focused on evidence from human studies on benefits in health and disease. This review highlights that clear evidence of the prevention of infectious diseases in pre-term infants such as necrotizing enterocolitis, neonatal sepsis or prevention of cancer metastasis is lacking. This is clearly an area where translational science has to be strengthened, taking the considerable evidence from numerous ex vivo studies on cells and tissues and from animal interventions. The review focuses predominantly on human data.

Pathogenesis of a novel porcine parainfluenza virus type 1 isolate in conventional and colostrum deprived/caesarean derived pigs.

Two experimental challenge studies were conducted to evaluate the pathogenesis of a porcine parainfluenza virus type 1 (PPIV-1) isolate. Four-week-old conventional (CON) pigs were challenged in Study 1 and six-week-old caesarean derived/colostrum deprived (CDCD) pigs were challenged in Study 2. Results indicate that PPIV-1 shedding and replication occur in the upper and lower respiratory tracts of CON and CDCD pigs as detected by RT-qPCR and immunohistochemistry. Mild macroscopic lung lesions were observed in CON pigs but not in CDCD pigs. Microscopic lung lesions were mild and consisted of peribronchiolar lymphocytic cuffing and epithelial proliferation in CON and CDCD pigs. Serum neutralizing antibodies were detected in the CON and CDCD pigs by 14 and 7 days post inoculation, respectively. This study provides evidence that in spite of PPIV-1 infection and replication in challenged swine, significant clinical respiratory disease was not observed.

Milk Exosomes Transfer Oligosaccharides into Macrophages to Modulate Immunity and Attenuate Adherent-Invasive E. coli (AIEC) Infection.

Exosomes are abundance in human body fluids like urine, milk and blood. They act a critical role in extracellular and intracellular communication, intracellular trafficking and physiological regulation. Multiple immune-modulatory components, such as proteins, RNAs and carbohydrates (glycoproteins), have been found in human milk exosomes, which play immune-regulatory functions. However, little is known about oligosaccharides in milk exosomes, the "free sugars", which act critical roles in the development of infant's immature mucosal immune system. In this study, the profile of milk exosomes encapsulated human milk oligosaccharides (HMOs) was calibrated with characteristic oligosaccharides in colostrum and mature milk, respectively. The exosomes containing human milk oligosaccharides were uptaken by macrophages, which were responsible for the establishment of intestinal immunity. Furthermore, mice pretreated with exosome encapsulated HMOs were protected from AIEC infection and had significantly less LPS-induced inflammation and intestinal damage. Exosome encapsulated milk oligosaccharides are regarded to provide a natural manner for milk oligosaccharides to accomplish their critical functions in modifying newborn innate immunity. The understanding of the interaction between a mother's breastfeeding and the development of an infant's mucosal immune system would be advantageous. The transport of milk oligosaccharides to its target via exosome-like particles appears to be promising.

Interaction between the level of immunoglobulins and number of somatic cells as a factor shaping the immunomodulating properties of colostrum.

The aim of this study was to investigate the association between immunoglobulins and SCC as a factor in shaping the content of the immunostimulatory components of colostrum. Seventy-eight multiparous Polish Holstein-Friesian cows were selected for the experiment. Colostrum samples were collected immediately after calving (up to a max. of 2 h). The cows were divided into groups according to the following levels: Immunoglobulins (IG class)-(IG1) over 50 g/L, (IG2) up to 50 g/L; SCC class-(SCC1) up to 400 000/ml, (SCC2) 400-800 000/ml, (SCC3) over 800 000/ml. Colostrum assigned to the IG1 SCC1 group had a statistically significant higher (p ≤ 0.01) concentration of both whey proteins and fatty acids compared to the IG1 SCC2 and SCC3 groups. The concentration of IgG, IgM, and IgA was shown to be higher in IG1 SCC1 than IG2 SCC3 by 226%, 149%, and 115%, respectively. The concentration of lactoferrin was shown to be higher in IG1 SCC1 than IG2 SCC3 by 149%. The determination of colostrum quality based on the concentration of immunoglobulins in the colostrum may not be sufficient because serum IgG concentrations at birth show a linear increase relative to colostrum SCC. A breakdown of colostrum into quality classes, taking into account the level of SCC, should therefore be introduced.

Humoral and Cell-Mediated Immune Response in Colostrum from Women Diagnosed Positive for SARS-CoV-2.

Objective: To evaluate the immune response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in colostrum from women who tested positive for the virus. Methods: Between March and September 2020 we obtained bilateral colostrum samples collected on spot cards within 48 hours of delivery from 15 new mothers who had previously tested positive for SARS-CoV-2. Four of 15 women provided liquid colostrum, which was used for validating results obtained from spot cards. Archived bilateral colostrum samples collected from 8 women during 2011-2013 were used as pre-coronavirus disease 2019 (COVID-19) controls. All samples were tested for reactivity to the receptor binding domain (RBD) of the SARS-CoV-2 spike protein using an enzyme-linked immunosorbent assay that measures SARS-CoV-2 RBD-specific IgA, IgG, and IgM and for levels of 10 inflammatory cytokines (interferon-gamma [IFN-γ], tumor necrosis factor-alpha, interleukin [IL]-1ß, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, IL-13) using a multiplex electrochemiluminescent sandwich assay. Results: Our validation studies indicate that the levels of SARS-CoV-2-specific antibodies and the associated cytokines measured in liquid colostrum are comparable to levels eluted from spot cards. Bilateral colostrum samples from 73%, 73%, and 33% of the 15 COVID-19 mothers exhibited IgA, IgG, and IgM reactivity to RBD, respectively. In addition, symptomatic COVID-19 mothers had statistically significant elevated levels of 4 of the 10 inflammatory markers (IFN-γ, IL-4, IL-6, and IL-12) compared to asymptomatic COVID-19 mothers. Conclusions: A strong humoral immune response is present in the colostrum of women who were infected with SARS-CoV-2 before delivering. The evolution and duration of the antibody response, as well as dynamics of the cytokine response, remain to be determined. Our results also indicate that future large-scale studies can be conducted with milk easily collected on paper spot cards.

Risk factors for poor colostrum quality and failure of passive transfer in Scottish dairy calves.

Failure of passive transfer (FPT) has health, welfare and economic implications for calves. Immunoglobulin G (IgG) concentration of 370 dairy calf serum samples from 38 Scottish dairy farms was measured via radial immunodiffusion (RID) to determine FPT prevalence. IgG concentration, total bacteria count (TBC) and total coliform count (TCC) of 252 colostrum samples were also measured. A questionnaire was completed at farm enrollment to investigate risk factors for FPT and poor colostrum quality at farm-level. Multivariable mixed effect logistic and linear regressions were carried out to determine significant risk factors for FPT and colostrum quality. Prevalence of FPT at calf level was determined to be 14.05%. Of 252 colostrum samples, 111 (44.05%) failed to meet Brix thresholds for colostrum quality. Of these 28 and 38 samples also exceeded TBC and TCC thresholds, respectively. Increased time between parturition and colostrum harvesting was numerically (non-significantly) associated with a colostrum Brix result <22%, and increased time spent in a bucket prior to feeding or storing was significantly associated with high TBC (≥100 000 cfu/ml and also ≥10 000 cfu/ml). High TBC values in colostrum were significantly associated with lower serum IgG concentrations. This study highlights associations between colostrum quality and FPT in dairy calves as well as potential risk factors for reduced colostrum quality; recommending some simple steps producers can take to maximise colostrum quality on farm.