Total and pathogen-specific serum Immunoglobulin G concentrations in neonatal beef calves, Part 1: Risk factors.

Maternal antibodies, delivered to the calf via colostrum, are crucial to prevent calfhood diseases and death. However, knowledge regarding the factors influencing this transfer of total and specific Immunoglobulin G (IgG) against common enteric and respiratory disease pathogens under current production conditions is sparse. The objectives of this study were to determine risk factors influencing total and pathogen-specific immunoglobulin G (IgG) concentrations against Escherichia coli (E. coli), bovine Rotavirus (BRoV), Cryptosporidium parvum (C. parvum), Bovine Viral Diarrhea Virus type 1 and 2 (BVDV), Parainfluenza Virus Type 3 (PI-3), Bovine Respiratory Syncytial Virus (BRSV), and Bovine Herpesvirus type 1 (BHV-1) in the serum of newborn beef calves. A total of 420 serum samples were collected from 1- to 7-day-old beef calves born on 6 farms in Alberta, Canada. Samples were analyzed by radial immunodiffusion for total IgG concentration and by enzyme-linked immunosorbent assays for pathogen-specific IgG concentrations against E. coli, BRoV, C. parvum, BVDV, PI-3, BRSV, and BHV-1. Multivariable multilevel linear and logistic regression models were built to evaluate dam- and calf-level risk factors associated with total and pathogen-specific IgG concentrations, failed transfer of passive immunity (FTPI; serum IgG < 10 g/L), and inadequate transfer of passive immunity (ITPI; serum IgG < 24 g/L). Farm was included as a random effect in all models to account for clustering at the herd level. Of the 420 calves included in this study, 5% (n = 20) and 18% (n = 75) of calves had FTPI and ITPI, respectively. Receiving colostrum intervention (i.e., being fed colostrum or colostrum product by either bottle or tube) was the most consistent risk factor for low total IgG concentration and significantly increased the odds of FTPI (Odds ratio (OR): 6.1, 95% CI: 2.0-18.9) and ITPI (OR: 4.8, 95% CI: 2.1-10.8). Calves born to cows consistently had higher pathogen-specific IgG concentrations (P < 0.0001), compared to calves born from heifers, and calves born to vaccinated dams had significantly higher BRoV, BVDV, and BHV-1-specific IgG concentrations. Interestingly, E.coli-specific IgG concentrations were associated with dam vaccination only in cows but not in heifers, which was likely due to differing vaccination strategies used. This study highlights the need to review and refine protocols with respect to dam vaccination and colostrum intervention on cow-calf operations.

Total and pathogen-specific serum Immunoglobulin G concentrations in neonatal beef calves, Part 2: Associations with health and growth.

The association of poor transfer of passive immunity (TPI) with negative health outcomes is extensively researched in dairy calves. However, few field studies have examined the effect of total and particularly pathogen-specific Immunoglobulin G (IgG) concentrations on pre-weaning health and growth of beef calves. Hence, the objective of this study was to determine the association of total and pathogen-specific IgG concentrations against selected pathogens associated with neonatal calf diarrhea (NCD) and bovine respiratory disease (BRD) and the odds of pre-weaning treatments, mortality, and the growth of newborn beef calves. A total of 420 serum samples from 1- to 7-day old beef calves born on 6 farms in Alberta, Canada, were available for this observational study. Serum samples were analyzed by radial immunodiffusion for total IgG concentration and by enzyme-linked immunosorbent assays for pathogen-specific IgG concentrations against Escherichia coli (E. coli), bovine Rotavirus (BRoV), Cryptosporidium parvum (C. parvum), Bovine Viral Diarrhea Virus (BVDV), Parainfluenza Virus Type 3 (PI-3), Bovine Respiratory Syncytial Virus (BRSV), and Bovine Herpesvirus Type 1 (BHV-1). Data about the individual dam- and calf-level risk factors, calf treatments, mortality, and birth and weaning weights were collected. Multivariable multilevel logistic and linear regression models were built to evaluate the association of total and pathogen-specific IgG concentrations with the odds of mortality and average daily gain (ADG), respectively, while their association with the odds of pre-weaning treatment was established by univariable logistic regression analysis. The odds of calves with IgG concentrations < 10 g/L of getting treated (OR 7.9, 95 % CI 2.7-23.7) and dying (OR: 18.5, 95 % CI: 3.7-93.4) were higher than for their counterparts (P < 0.0001). Calves with IgG concentrations < 24 g/L also had higher odds of dying (OR: 10.1, 95 % CI: 2.6-40.2) and had lower ADG (-0.09 kg, SE: 0.03, P < 0.002) than calves with IgG concentrations ≥ 24 g/L. Higher BVDV-specific IgG concentration was protective against mortality (OR: 0.97, 95 % CI: 0.96-0.99, P < 0.001). This study highlights the negative association of inadequate TPI with health and growth of beef calves and thus, the need to refine protocols for dam vaccination and colostrum intervention in cow-calf operations to meet these higher IgG targets.

Comparison of the levels of selected specific antibodies in the immunoglobulin G of colostrum versus milk and serum in dairy cows (Bos taurus).

Commercial products containing immunoglobulin G (IgG) sourced from colostrum, milk, and/or serum may be used to supplement or replace maternal colostrum in newborn dairy calves. To determine if antibody specificities in bovine milk and serum IgG differ from colostrum IgG, we sampled serum, colostrum (1 to 2 hours post-partum), and milk (day 5 post-partum) from 24 dairy heifers or cows. Specific antibodies [IgG class (H&L)] to 8 common pathogens were measured using enzyme-linked immunosorbent assays (ELISAs). Immunoglobin G1 and IgG2 subclass-specific ELISAs were performed for 3 of these pathogens. Colostrum-derived IgG contained more specific antibodies to rotavirus [IgG (H&L) and IgG1] and to IgG (H&L) of bovine respiratory syncytial virus (BRSV), bovine parainfluenza-3 virus (BPI3V), Staphylococcus aureus, Escherichia coli F5 (K99), and bovine coronavirus than milk IgG. Colostral IgG contained more antibodies to BRSV (IgG1), rotavirus (IgG1), and IgG (H&L) specific for BRSV, bovine herpesvirus-1 (BHV-1), BPI3V, E. coli F5 (K99), and Streptococcus uberis than serum IgG. Compared to serum, milk contained more IgG (H&L) antibody to BRSV, BHV-1, and BPI3V, IgG1-specific BRSV, and rotavirus. These data indicate that IgG derived from colostrum delivers more specific antibodies to these endemic pathogens of calves compared to IgG sourced from milk or serum. In addition, the IgG1 subclass predominates in milk and colostrum, and both deliver a similar spectrum of antibodies.

Les produits commerciaux contenant de l'immunoglobuline G (IgG) provenant du colostrum, du lait et/ou du sérum peuvent être utilisés pour compléter ou remplacer le colostrum maternel chez les veaux laitiers nouveau-nés. Pour déterminer si les spécificités des anticorps dans le lait de vache et les IgG sériques diffèrent des IgG du colostrum, nous avons prélevé du sérum, du colostrum (1 à 2 heures après le vêlage) et du lait (5 jours après le vêlage) de 24 génisses ou vaches laitières. Des anticorps spécifiques [classe IgG (H&L)] dirigés contre huit agents pathogènes courants ont été mesurés par dosages immuno-enzymatiques (ELISA). Des tests ELISA spécifiques aux sous-classes d'IG1 et d'IgG2 ont été effectués pour trois de ces agents pathogènes. Les IgG dérivées du colostrum contenaient plus d'anticorps spécifiques contre le rotavirus [IgG (H&L) et IgG1] et des IgG (H&L) contre le virus respiratoire syncytial bovin (BRSV), le virus parainfluenza bovin 3 (BPI3V), Staphylococcus aureus, Escherichia coli F5 (K99) et le coronavirus bovin que les IgG du lait. Les IgG du colostrum contenaient plus d'anticorps dirigés contre le BRSV (IgG1), le rotavirus (IgG1) et des IgG (H&L) spécifiques contre BRSV, l'herpèsvirus bovin-1 (BHV-1), le BPI3V, E. coli F5 (K99) et Streptococcus uberis que les IgG du sérum. Comparé au sérum, le lait contenait plus d'anticorps IgG (H&L) contre le BRSV, le BHV-1 et le BPI3V, des IgG1 spécifiques au BRSV et au rotavirus. Ces données indiquent que les IgG dérivées du colostrum fournissent des anticorps plus spécifiques contre ces agents pathogènes endémiques des veaux que les IgG provenant du lait ou du sérum. De plus, la sous-classe IgG1 prédomine dans le lait et le colostrum, et les deux fournissent un spectre similaire d'anticorps.(Traduit par Docteur Serge Messier).

Assessment of Brix refractometry to estimate immunoglobulin G concentration in beef cow colostrum.

BACKGROUND: Brix refractometry can be used to assess colostral immunoglobulin G (IgG) concentration, but studies identifying Brix percentages to detect high- and low-IgG colostrum are lacking for beef cows and interlaboratory agreement is unknown. OBJECTIVES: Evaluate Brix refractometer performance and interlaboratory agreement for assessing beef cow colostrum IgG concentration, including determination of thresholds to identify colostrum containing IgG concentrations <100 g/L and ≥150 g/L. ANIMALS: Beef cows (n = 416) from 11 cow-calf operations in Alberta, Canada. METHODS: Colostral IgG concentrations were measured using radial immunodiffusion (RID) and estimated by Brix refractometry for this retrospective study. Spearman correlation coefficients were assessed between RID and Brix refractometry. Likelihood ratios and misclassification cost-term analysis were used to determine optimal Brix percentages for detecting colostrum containing IgG concentrations <100 g/L and ≥150 g/L. Concordance correlation coefficient (CCC) and Bland-Altman analyses were performed for Brix percentages obtained at 3 different laboratories. RESULTS: Brix percentages obtained at 3 laboratories were positively correlated with IgG results (r = 0.72, 0.68, and 0.76, respectively). Colostrum Brix percentages of <24% and ≥30% were optimal for indicating IgG concentrations of <100 g/L and ≥150 g/L, respectively. Interlaboratory agreement was substantial, with CCC ranging from 0.89 to 0.96 and Bland-Altman analysis showing small mean differences (-1.2% to 0.09% Brix) and narrow limits of agreements (-4.8% to 2.4% Brix) among laboratories. CONCLUSIONS AND CLINICAL IMPORTANCE: Brix refractometry shows good potential for reliably estimating IgG concentrations in beef cow colostrum across multiple laboratories and can be recommended to aid colostrum management decisions on farms.

Effect of vaccination of pregnant beef heifers on the concentrations of serum IgG and specific antibodies to bovine herpesvirus 1, bovine viral diarrhea virus 1, and bovine viral diarrhea virus 2 in heifers and calves.

The objective of this study was to evaluate the effect of late-gestation vaccination of beef heifers with 2 doses of a killed-virus (KV) vaccine containing bovine herpesvirus 1 (BoHV-1), bovine viral diarrhea virus 1 (BVDV-1), and bovine viral diarrhea virus 2 (BVDV-2) on the serum concentrations of antibody against BoHV-1, BVDV-1, and BVDV-2 in heifers and their calves and on the IgG concentration in the calves. Of the 47 pregnant beef heifers selected, 26 received 2 doses of the vaccine at 6.5 to 8 mo of gestation (at pregnancy check), and 21 received 2 doses of saline. The mean log2 serum titers of neutralizing antibody against BoHV-1, BVDV-1, and BVDV-2 before vaccination did not differ significantly between the treatment groups; however, at calving all 3 mean titers were significantly greater (P < 0.05) in the vaccinated heifers than in the control heifers. At 24 h after birth the mean serum IgG levels in the calves did not differ significantly between the 2 groups, at 30.18 and 32.28 g/L, respectively (P < 0.05); however, the mean log2 serum titers of antibody to all 3 viruses were greater in the calves nursing colostrum from the vaccinated heifers than in the calves nursing colostrum from the nonvaccinated heifers and significantly so for BoHV-1 and BVDV-1 (P < 0.001 and P = 0.009, respectively). Thus, late-gestation vaccination of beef heifers could result in a greater and more consistent deposition of specific antibodies in colostrum, reducing the variability of initial titers in calves and increasing the duration of maternal immunity.

L'objectif de la présente étude était d'évaluer les effets, sur des taures d'embouche, de la vaccination en fin de gestation avec deux doses d'un vaccin contenant les virus tués suivants herpesvirus bovin-1 (BHV-1), virus de la diarrhée virale bovine 1 (BVDV-1), et le virus de la diarrhée virale bovine 2 (BVDV-2) sur les concentrations sériques d'anticorps contre BHV-1, BVDV-1, et BVDV-2 chez des taures et leurs veaux ainsi que sur la concentration d'IgG chez les veaux. Parmi les 47 taures d'embouche gestantes sélectionnées, 26 reçurent deux doses du vaccin à 6,5 et 8 mo de gestation (à la vérification de la gestation), et 21 reçurent deux doses de saline. Les titres sériques moyens log2 d'anticorps neutralisants contre BHV-1, BVDV-1, et BVDV-2 avant la vaccination ne différaient pas de manière significative entre les deux groupes de traitement; toutefois, au moment du vêlage les trois titres moyens étaient significativement plus élevés (P < 0,05) chez les taures vaccinées que chez les taures témoins. Vingt-quatre heures après la naissance, les quantités moyennes d'IgG sériques chez les veaux ne différaient pas significativement entre les deux groupes, à 30,18 et 32,28 g/L, respectivement (P < 0,05); toutefois, les titres sériques moyens log2 d'anticorps contre les trois virus étaient plus grands chez les veaux nourris avec du colostrum des taures vaccinées que chez les veaux se nourrissant de colostrum des taures non-vaccinées et de manière significative pour BHV-1 et BVDV-1 (P < 0,001 et P = 0,009), respectivement. Ainsi, la vaccination en fin de gestation chez des taures d'embouche pourrait résulter en une plus grande et constante déposition d'anticorps spécifiques dans le colostrum, réduisant la variabilité dans les titres initiaux chez les veaux et en prolongeant la durée de l'immunité maternelle.(Traduit par Docteur Serge Messier).

Bovine respiratory syncytial virus-specific IgG-1 in nasal secretions of colostrum-fed neonatal calves.

In order to determine whether nasal secretions of young calves contain passively derived antibodies to bovine respiratory syncytial virus (BRSV) and if there are differences in presence and/or subclass of these antibodies between calves fed different colostrum replacement products, 17 Holstein calves were fed 150 g of IgG in either a sprayed-dried colostrum-based (CR; n = 8) or a plasma-based colostrum replacement product (PR; n = 9) within 6 h of birth. Venous blood and nasal secretions obtained before feeding and at 24 h of age were assayed for total IgG (serum) by radial immunodiffusion and for BRSV-specific total IgG, IgG-1, and IgG-2 by indirect enzyme-linked immunosorbent assay (ELISA). Calves that were fed a CR had higher concentrations of BRSV-specific IgG and IgG-1 in their serum and nasal secretions compared to calves fed product PR; calves fed the PR had higher levels of serum BRSV-specific IgG-2. The only subclass of antibodies detected in nasal secretions was IgG-1. Re-secretion of passive IgG with neutralizing activity, onto the nasal mucosa could contribute to BRSV-associated disease-sparing observed in the laboratory and in the field. Use of PR will result in lower nasal antibodies since IgG-2 is not re-secreted.

IgG-1 spécifique au virus respiratoire syncytial bovin dans les sécrétions nasales des veaux néonataux nourris au colostrum. Afin de déterminer si les sécrétions nasales des jeunes veaux contenaient des anticorps dérivés passivement envers le virus respiratoire syncytial bovin (VRS) et s'il y a des différences dans la présence et/ou la sous-catégorie de ces anticorps entre les veaux nourris avec différents produits de remplacement du colostrum, 17 veaux Holstein ont été nourris avec 150 g d'IgG soit sous forme de produit vaporisé-séché à base de colostrum (CR; n = 8) ou d'un produit de remplacement de colostrum à base de plasma (PR; n = 9) au cours des 6 premières heures après la naissance. Du sang veineux et des sécrétions nasales obtenus avant le nourrissage et à l'âge de 24 h ont été analysés pour obtenir la quantité d'IgG totale (sérum) par immunodiffusion radiale et le total des quantités d'IgG, d'IgG-1 et d'IgG-2 spécifiques au VRS par ELISA indirecte. Les veaux qui avaient été nourris d'un CR avaient des concentrations supérieures d'IgG et dIgG-1 spécifiques au VRS dans leur sérum et les sécrétions nasales comparativement aux veaux nourris de produits PR; les veaux nourris d'un PR avaient des niveaux supérieurs d'IgG-2 sérique spécifique au VRS. La seule sous-catégorie d'anticorps détectée dans les sécrétions nasales était l'IgG-1. La re-secrétion passive d'IgG avec de l'activité neutralisante sur les muqueuses nasales pourrait contribuer à l'immunité associée au VRS observée en laboratoire et sur le terrain. L'usage de PR produira des anticorps nasaux inférieurs vu que l'IgG-2 n'est pas re-secrété.(Traduit par Isabelle Vallières).

Application of transmission infrared spectroscopy and partial least squares regression to predict immunoglobulin G concentration in dairy and beef cow colostrum.

The objective of this study was to explore the potential of transmission infrared (TIR) spectroscopy in combination with partial least squares regression (PLSR) for quantification of dairy and beef cow colostral immunoglobulin G (IgG) concentration and assessment of colostrum quality. A total of 430 colostrum samples were collected from dairy (n = 235) and beef (n = 195) cows and tested by a radial immunodiffusion (RID) assay and TIR spectroscopy. Colostral IgG concentrations obtained by the RID assay were linked to the preprocessed spectra and divided into combined and prediction data sets. Three PLSR calibration models were built: one for the dairy cow colostrum only, the second for beef cow colostrum only, and the third for the merged dairy and beef cow colostrum. The predictive performance of each model was evaluated separately using the independent prediction data set. The Pearson correlation coefficients between IgG concentrations as determined by the TIR-based assay and the RID assay were 0.84 for dairy cow colostrum, 0.88 for beef cow colostrum, and 0.92 for the merged set of dairy and beef cow colostrum. The average of the differences between colostral IgG concentrations obtained by the RID- and TIR-based assays were -3.5, 2.7, and 1.4 g/L for dairy, beef, and merged colostrum samples, respectively. Further, the average relative error of the colostral IgG predicted by the TIR spectroscopy from the RID assay was 5% for dairy cow, 1.2% for beef cow, and 0.8% for the merged data set. The average intra-assay CV% of the IgG concentration predicted by the TIR-based method were 3.2%, 2.5%, and 6.9% for dairy cow, beef cow, and merged data set, respectively.The utility of TIR method for assessment of colostrum quality was evaluated using the entire data set and showed that TIR spectroscopy accurately identified the quality status of 91% of dairy cow colostrum, 95% of beef cow colostrum, and 89% and 93% of the merged dairy and beef cow colostrum samples, respectively. The results showed that TIR spectroscopy demonstrates potential as a simple, rapid, and cost-efficient method for use as an estimate of IgG concentration in dairy and beef cow colostrum samples and assessment of colostrum quality. The results also showed that merging the dairy and beef cow colostrum sample data sets improved the predictive ability of the TIR spectroscopy.

Evaluation of the effects of colostrum replacer supplementation of the milk replacer ration on the occurrence of disease, antibiotic therapy, and performance of pre-weaned dairy calves.

The objective of this study was to evaluate the effects of colostrum supplementation of the milk replacer ration on disease occurrence, antibiotic therapy, and performance of pre-weaned dairy calves with adequate transfer of passive immunity. Two hundred and two 1-d-old Holstein dairy calves were assigned to 1 of 2 groups after arrival to a dairy calf rearing facility. Calves assigned to the control group (n = 100) received milk replacer (28% crude protein and 20% crude fat) without colostrum inclusion twice daily. Calves assigned to the treatment group (n = 102) received 150 g of supplemental colostrum replacer powder added to their milk replacer twice daily for the first 14 d of life. Before group assignment, serum samples were collected from all calves to confirm transfer of passive immunity. Calves were evaluated daily until weaning (56 d of life) for signs of clinical disease as well as any treatment with antibiotics. Presentation of clinical disease and antibiotic treatment was recorded daily by personnel blinded to treatment allocation. Adequate transfer of passive immunity was confirmed in all calves at the start of the study and mean serum IgG values were similar among calves from treatment and control groups. The odds ratios of having abnormal feces and abnormal respiration during the pre-weaning period for calves from the treatment group were 0.15 and 0.46 the odds ratios of calves from the control group, respectively. The odds ratios of receiving antibiotic therapy during the pre-weaning period for calves from the treatment group were 0.09 the odds ratios of calves from the control group. Mean body weight and average daily gain at weaning were not significantly different among calves from the treatment and control groups. Colostrum replacer supplementation of the milk replacer ration was effective in reducing antibiotic therapy and occurrence of disease during the pre-weaning period.

The effect of dystocia on physiological and behavioral characteristics related to vitality and passive transfer of immunoglobulins in newborn Holstein calves.

The objective of this study was to examine the effect of calving difficulty or dystocia on the vitality of newborn calves and its association with blood pH, the apparent efficiency of immunoglobulin G (IgG) absorption (AEA), and weight gain. A total of 45 calving events (N = 48 calves) were monitored from the first sight of fetal membranes. All calves were assessed at the time of first attaining sternal recumbency (SR), at 2 and 24 h, and at 7 and 14 d of age. Measurements included time to SR, rectal temperature, respiration and heart rate, analysis of blood gases and other blood measures, suckling response, time to standing, passive transfer of IgG, and weight gain. Calves were separated from their dam 2 h after birth and fed a commercial colostrum replacer containing 180 g of IgG by esophageal tube feeder. Calves born following dystocia had lower venous blood pH and took longer to attain SR and attempt to stand than those born unassisted. Duration of calving interacted with the number of people required to extract the calf by pulling as a significant predictor of pH at SR. No association was found between pH at SR and AEA. However, reduced AEA was found in calves that were female and in calves that did not achieve SR within 15 min of birth. A longer calving duration, being born in July or August rather than June, and a shorter time spent standing in the first 2 d of life were significantly associated with reduced weight gain to 14 d. It was concluded that factors at calving impact the physiology, vitality, and subsequent weight gain of newborn calves.

L'objectif de la présente étude était d'examiner les effets des difficultés au moment du vêlage ou dystocie sur la vitalité de veaux nouveaunés et l'association avec le pH sanguin, l'efficacité apparente d'absorption des immunoglobulines G (IgG) (EAA), et le gain de poids. Quarante-cinq vêlages (N = 48 veaux) furent surveillés à partir de la première visualisation des membranes foetales. Tous les veaux furent évalués au moment de la première fois qu'ils étaient en décubitus sternal (DS), à 2 et 24 h, et à 7 et 14 jours d'âge. Les données recueillies incluaient le délai pour atteindre le DS, la température rectale, les rythmes respiratoire et cardiaque, l'analyse des gaz sanguins et d'autres mesures sanguines, la réponse de tétée, le délai pour se tenir debout, le transfert passif d'IgG et le gain de poids. Les veaux furent séparés de leur mère 2 h après la naissance et nourris par tube oesophagien avec un substitut commercial du colostrum contenant 180 g d'IgG. Les veaux nés suivant une dystocie avaient un pH sanguin veineux plus bas et ont pris plus de temps pour atteindre le DS et tenter de se lever que ceux nés sans assistance. La durée du vêlage a interagit avec le nombre de personnes requis pour extraire le veau en tirant comme un prédicteur significatif du pH à DS. Aucune association ne fut trouvée entre le pH à DS et l'EAA. Toutefois, une EAA réduite fut notée chez les génisses et chez les veaux qui n'étaient pas en DS à l'intérieur d'un délai de 15 min suivant la naissance. Une durée plus longue du vêlage, une naissance en juillet ou août plutôt qu'en juin, et un temps plus court à se tenir debout pendant les deux premières journées de vie étaient associés significativement avec un gain de poids moindre après 14 j. Il a été conclu que des facteurs au moment du vêlage ont un impact sur la physiologie, la vitalité et le gain de poids à venir de veaux nouveau-nés.(Traduit par Docteur Serge Messier).

Innate and adaptive immune responses of snatch-farrowed porcine-colostrum-deprived pigs to Mycoplasma hyopneumoniae vaccination.

BACKGROUND: The snatch-farrowed porcine-colostrum-deprived (SF-pCD) pig model, in which neonates are raised on commercially available bovine colostrum, is an alternative model for porcine infectious disease research. It is not known if SF-pCD pigs possess growth performance and immunity comparable to conventional, farm-raised pigs. The current experiment compared growth performance and immune responses of SF-pCD pigs to their farm-raised siblings following Mycoplasma hyopneumoniae (Mhyo) vaccination. Twelve SF-pCD and 13 farm-raised siblings were vaccinated on day 7 (D7) and D26 of age. Body weights were measured once or twice weekly and average daily gain (ADG) was calculated. Peripheral blood mononuclear cells (PBMC) were isolated on D40. Cytokine secretion from PBMC stimulated with Mhyo antigen or phorbol myristate acetate plus ionomycin (PMA/Iono) was assessed using a multiplexed fluorescent microsphere immunoassay (FMIA). Additionally, interferon gamma (IFNγ) secretion from stimulated PBMC was assessed using ELISPOT. Mhyo IgG titers were measured by an ELISA in D40 sera. RESULTS: Growth performance did not differ between groups before weaning, but SF-pCD pigs had higher ADG after weaning. In response to Mhyo stimulation, numbers of IFNγ secreting PBMC and levels of interleukin 8 (IL8) and IL10 in PBMC supernatants were significantly higher in SF-pCD pigs, as were Mhyo antibody levels in sera, and levels of IL1ß, IL8 and IL12 in supernatants of PMA/Iono stimulated PBMC. CONCLUSIONS: Under the conditions of this experiment, SF-pCD pigs demonstrated superior growth performance and enhanced humoral and cell-mediated immunity following vaccination. Whether or not this reflects greater resistance or tolerance to infection is unknown but the ability to react positively to the vaccination provides evidence that SF-pCD pigs are a suitable alternative model for swine disease research.

Effect of Three Colostrum Diets on Passive Transfer of Immunity and Preweaning Health in Calves on a California Dairy following Colostrum Management Training.

Following colostrum management training, a randomized field trial was conducted on a California dairy to determine the effect of supplementing pooled colostrum with either colostrum-derived replacer (CDR) or second-milking colostrum (transition milk) on failure of passive transfer (FPT) and preweaning morbidity risks. A total of 166 calves were randomly assigned to 4L first-milking pooled colostrum (treatment 1), 2L first-milking pooled colostrum and 2L of CDR (treatment 2), or 2L first-milking pooled colostrum and 2L second-milking pooled colostrum (treatment 3). Mean 24-hour serum TP and IgG for treatments 2 (TP 5.2 g/dL, IgG 15.9 g/L) and 3 (TP 5.4 g/dL, IgG 18.3 g/L) did not statistically differ but were significantly lower than for treatment 1 (TP 5.9 g/dL, IgG 24.6 g/L). Risk of FPT did not differ for treatments 1, 2, and 3 (0.0%, 9.3%, and 1.9%, resp.). Similarly, the preweaning risk of diarrhea (81.0%, 92.5%, and 87.0%, resp.) or pneumonia (6.9%, 13.2%, and 18.5%, resp.) did not differ between treatments. Feeding 4L first-milking pooled colostrum resulted in adequate passive transfer. When first-milking pooled colostrum quantity is inadequate, CDR or second-milking pooled colostrum can be used to supplement the required colostrum volume and IgG mass without adversely affecting the risks of FPT or preweaning diarrhea and pneumonia.

Comparison of levels and duration of detection of antibodies to bovine viral diarrhea virus 1, bovine viral diarrhea virus 2, bovine respiratory syncytial virus, bovine herpesvirus 1, and bovine parainfluenza virus 3 in calves fed maternal colostrum or a colostrum-replacement product.

Colostrum-replacement products are an alternative to provide passive immunity to neonatal calves; however, their ability to provide adequate levels of antibodies recognizing respiratory viruses has not been described. The objective of this study was to compare the serum levels of IgG at 2 d of age and the duration of detection of antibodies to bovine viral diarrhea virus 1 (BVDV-1), bovine viral diarrhea virus 2 (BVDV-2), bovine respiratory syncytial virus (BRSV), bovine herpesvirus 1 (BHV-1), and bovine parainfluenza virus 3 (BPIV-3) in calves fed maternal colostrum (MC) or a colostrum replacement (CR) at birth. Forty newborn male Holstein calves were assigned to the CR or the MC group. Group CR (n = 20) received 2 packets of colostrum replacement (100 g of IgG per 470-g packet), while group MC (n = 20) received 3.8 L of maternal colostrum. Blood samples for detection of IgG and virus antibodies were collected from each calf at birth, at 2 and 7 d, and monthly until the calves became seronegative. Calves in the MC group had greater IgG concentrations at 2 d of age. The apparent efficiency of absorption of IgG was greater in the MC group than in the CR group, although the difference was not significant. Calves in the CR group had greater concentrations of BVDV neutralizing antibodies during the first 4 mo of life. The levels of antibodies to BRSV, BHV-1, and BPIV-3 were similar in the 2 groups. The mean time to seronegativity was similar for each virus in the 2 groups; however, greater variation was observed in the antibody levels and in the duration of detection of immunity in the MC group than in the CR group. Thus, the CR product provided calves with more uniform levels and duration of antibodies to common bovine respiratory viruses.

Les produits de remplacement du colostrum sont une alternative pour fournir une immunité passive aux veaux nouveau-nés; toutefois, leur capacité à fournir des niveaux adéquats d'anticorps reconnaissant les virus respiratoires n'a pas été décrite. L'objectif de la présente étude était de comparer les niveaux d'IgG sériques à 2 jours d'âge et la durée de détection des anticorps contre le virus de la diarrhée virale bovine de type 1 (BVDV-1), le virus de la diarrhée virale bovine de type 2 (BVDV-2), le virus respiratoire syncitial bovin (BRSV), l'herpesvirus bovin de type 1 (BHV-1), et le virus parainfluenza bovin de type 3 (BPIV-3) chez des veaux nourris avec du colostrum maternel (MC) ou du colostrum de remplacement (CR) à la naissance. Quarante veaux nouveau-nés mâles de race Holstein ont été assignés soit au groupe CR ou MC. Les animaux du groupe CR (n = 20) ont reçu deux paquets de substitut de colostrum (100 g d'IgG par paquet de 470 g), alors que les animaux du groupe MC (n = 20) ont reçu 3,8 L de colostrum maternel. Des échantillons sanguins pour la détection d'IgG et d'anticorps contre les virus ont été prélevés de chaque veau à la naissance, à 2 et 7 j d'âge, et à chaque mois jusqu'à ce que les veaux deviennent séronégatifs. Les veaux dans le groupe MC avaient des concentrations d'IgG plus élevées à 2 j d'âge. L'efficacité d'absorption apparente d'IgG était plus grande dans le groupe MC que dans le groupe CR, bien que la différence ne fût pas significative. Les veaux dans le groupe CR avaient des concentrations plus élevées d'anticorps neutralisants envers BVDV durant les 4 premiers mois de vie. Les niveaux d'anticorps contre BRSV, BHV-1, et BPIV-3 étaient similaires dans les deux groupes. Le temps moyen pour atteindre la séronégativité était similaire pour chaque virus dans les deux groupes; toutefois, de plus grandes variations étaient observées dans les niveaux d'anticorps et la durée de détection de l'immunité dans le groupe MC comparativement au groupe CR. Ainsi, le produit CR a fourni des veaux avec des niveaux d'anticorps contre les virus respiratoires bovins communs plus uniformes et de plus longue durée.(Traduit par Docteur Serge Messier).

The effect of bovine colostrum supplementation in older adults during resistance training.

Bovine colostrum is the first milk secreted by cows after parturition and has high levels of protein, immunoglobulins, and various growth factors. We determined the effects of 8 weeks of bovine colostrum supplementation versus whey protein during resistance training in older adults. Males (N = 15, 59.1 ± 5.4 y) and females (N = 25, 59.0 ± 6.7 y) randomly received (double-blind) 60 g/d of colostrum or whey protein complex (containing 38 g protein) while participating in a resistance training program (12 exercises, 3 sets of 8-12 reps, 3 days/ week). Strength (bench press and leg press 1-RM), body composition (by dual energy x-ray absorptiometry), muscle thickness of the biceps and quadriceps (by ultrasound), cognitive function (by questionnaire), plasma insulin-like growth factor-1 (IGF-1) and C-reactive protein (CRP, as a marker of inflammation), and urinary N-telopeptides (Ntx, a marker of bone resorption) were determined before and after the intervention. Participants on colostrum increased leg press strength (24 ± 29 kg; p < .01) to a greater extent than participants on whey protein (8 ± 16 kg) and had a greater reduction in Ntx compared with participants on whey protein (-15 ± 40% vs. 10 ± 42%; p < .05). Bench press strength, muscle thickness, lean tissue mass, bone mineral content, and cognitive scores increased over time (p < .05) with no difference between groups. There were no changes in IGF-1 or CRP. Colostrum supplementation during resistance training was beneficial for increasing leg press strength and reducing bone resorption in older adults. Both colostrum and whey protein groups improved upper body strength, muscle thickness, lean tissue mass, and cognitive function.

Snatch-farrowed, porcine-colostrum-deprived (SF-pCD) pigs as a model for swine infectious disease research.

The current study tested the benefit of commercially available spray-dried bovine colostrum (The Saskatoon Colostrum Company, Saskatoon, Saskatchewan) in raising snatch-farrowed, porcine-colostrum-deprived (SF-pCD) pigs. In experiment 1, 12 SF-pCD pigs received a liquid diet composed mainly of bovine colostrum from birth to day 10; 6 remained on the same liquid diet (COL), and the other 6 were fed a diet composed mainly of milk replacer (RPL) until weaning. In experiment 2, 12 SF-pCD pigs were fed mainly bovine colostrum before weaning; after weaning, 6 were fed a starter diet containing 20% (w/w) bovine colostrum powder (STARTER-COL), and the other 6 were fed a starter diet without any bovine colostrum (STARTER-CTRL) until termination (day 42 or day 49). In experiment 1 the COL pigs had significantly fewer fever-days than did the RPL pigs. In experiment 2 diarrhea, typhlocolitis, and pancreatic degeneration developed in 4 of the STARTER-COL pigs after weaning. In both experiments all the pigs fed mainly bovine colostrum before weaning survived until termination. All pigs tested free of swine influenza virus H1N1 and H3N2, Porcine reproductive and respiratory syndrome virus, and Porcine parvovirus. In experiment 2 all the pigs tested free of Porcine circovirus type 2 (PCV2), but some in both groups tested positive for Torque teno virus genogroups 1 and 2. In conclusion, with the use of snatch-farrowing and bovine colostrum, pigs can be raised in the absence of porcine maternal antibodies with 100% survival and freedom from most porcine pathogens of biologic relevance. This model is potentially suitable for animal disease research.

La présente étude visait à tester l'avantage du colostrum bovin déshydraté disponible commercialement pour élever des porcs captés à la misebas et privés de colostrum porcin (SF-pCD). Dans l'expérience 1, 12 porcs SF-pCD ont reçu une diète liquide composée principalement de colostrum bovin de la naissance au jour 10; 6 sont demeurés sur la même diète liquide (COL), et les 6 autres étaient nourris avec une diète composée principalement de substitut de lait (RPL) jusqu'au sevrage. Dans l'expérience 2, 12 porcs SF-pCD étaient nourris principalement avec du colostrum bovin avant le sevrage; après le sevrage, 6 étaient nourris avec une diète de début contenant 20 % (poids/poids) de poudre de colostrum bovin (STARTER-COL), et les 6 autres étaient nourris avec une diète de début mais sans le colostrum bovin (STARTER-CTRL) jusqu'à la fin de l'expérience (jour 42 ou jour 49). Dans l'expérience 1, les porcs COL avaient significativement moins de jours avec fièvre que les porcs RPL. Dans l'expérience 2, de la diarrhée, une typhlocolite et une dégénération du pancréas s'est développée chez 4 des porcs STARTER-COL après le sevrage. Dans les 2 expériences tous les porcs nourris principalement avec du colostrum bovin avant le sevrage ont survécu jusqu'à la fin de l'expérimentation. Tous les porcs se sont avérés négatifs pour les virus H1N1 et H3N2 de l'influenza porcin, le virus du syndrome reproducteur et respiratoire porcin, et le parvovirus porcin. Dans l'expérience 2, tous les porcs ont testé négatif pour le circovirus porcin de type 2 (PCV2), mais quelques-uns dans les 2 groupes ont testé positif pour le virus Torque teno des génogroupes 1 et 2. En conclusion, avec l'utilisation de la mise-bas avec captation et de colostrum bovin, les porcs peuvent être élevés en absence d'anticorps maternels porcins avec un taux de survie de 100 % et l'absence des principaux agents pathogènes porcins d'importance biologique. Ce modèle est potentiellement approprié pour la recherche sur les maladies animales.(Traduit par Docteur Serge Messier).

A randomized controlled trial on preweaning morbidity, growth and mortality in Holstein heifers fed a lacteal-derived colostrum replacer or pooled maternal colostrum.

BACKGROUND: The objective of this randomized controlled trial was to determine the effect of feeding a commercial lacteal-derived colostrum replacer (CR) or pooled maternal colostrum (MC) on preweaning morbidity, growth and mortality in Holstein heifer calves. A total of 568 calves were randomly assigned to be fed either 3.8 L of pooled MC or two doses (200 g IgG) of a CR. Calves were monitored daily for preweaning morbidity until weaning at 60 d old. Birth and weaning weights were measured to estimate growth rates. RESULTS: Calves fed CR were significantly less likely to be affected with a diarrhea event (OR = 0.58; 95% CI, 0.38 to 0.88; P value = 0.011) and had a higher rate of daily weight gain (0.051 kg/day; 95% CI, 0.03 to 0.08; P value <0.001) compared to calves fed pooled MC. Use of lacteal-derived colostrum replacer was not significantly associated with respiratory disease (OR = 1.01; 95% CI 0.67 to 1.51; P value = 0.974 ), omphalitis (OR = 0.93; 95% CI 0.06 to 14.86; P value = 0.956), or mortality (HR = 0.71; 95% CI 0.27 to 1.92; P value = 0.505) in the study calves. CONCLUSIONS: The lacteal-derived CR fed at the study dose was a viable colostrum alternative in the event of poor quality pooled MC for the prevention of preweaning diarrhea and resulted in higher growth rates in comparison to calves fed pooled MC in the study herd.

Efficacy of feeding a lacteal-derived colostrum replacer or pooled maternal colostrum with a low IgG concentration for prevention of failure of passive transfer in dairy calves.

OBJECTIVE: To compare the efficacy of a lacteal-derived colostrum replacer (LDCR) for the prevention of failure of passive transfer of immunity (FPT) in calves with that of pooled maternal colostrum (MC). DESIGN: Randomized field trial. ANIMALS: 568 heifer calves from 1 California dairy. PROCEDURES: Calves were randomly allocated to 1 of 2 treatment groups and fed 2 doses (200 g of IgG) of an LDCR or 3.8 L of pooled MC. From each calf, blood samples were collected before and approximately 24 hours after treatment. Serum IgG and total protein (TP) concentrations were quantified with standard methods, and the apparent efficiency of IgG absorption was calculated. RESULTS: At 24 hours after treatment, mean serum TP and IgG concentrations were significantly lower for calves fed pooled MC (TP, 4.77 g/dL; IgG, 7.50 g/L), compared with those for calves fed the LDCR (TP, 5.50 g/dL; IgG, 15.15 g/L). Calves fed the LDCR were 95% less likely to develop FPT (OR, 0.05; 95% confidence interval, 0.03 to 0.08) than were calves fed pooled MC. However, the mean IgG concentration in the pooled MC fed during the study (21.1 g/L) was substantially lower than that (64.3 g/L) determined for representative samples of pooled MC from other southwestern US dairies during a national survey. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that, on this particular dairy, calves fed an LDCR were at less risk of developing FPT than were calves fed pooled MC. The LDCR evaluated was a viable alternative for the prevention of FPT in calves.

Validation of an immunohistochemical assay for bovine cysticercosis, with comparison to a standard histological method.

The larval stage (syn Cysticercus bovis) of the human tapeworm Taenia saginata causes cysticercosis in cattle, which has both aesthetic and food safety implications to consumers of beef. A monoclonal antibody-based immunohistochemical (IHC) assay developed to improve postmortem diagnosis of this parasite and a standard histological method were assessed to determine their fitness for intended use. Sections from 169 known-positive specimens of T. saginata from experimentally or naturally infected cattle, and from 30 known-negative specimens and lesions of various etiologies from non-infected cattle, were tested. The IHC assay identified significantly more known positive bovine cysticerci than the histological method (91.7% and 38.5%, respectively). Positive IHC staining occurred on sections from other cestode species, but should not affect the diagnostic specificity of this assay for bovine cysticercosis, due to the different host and/or tissue preferences amongst these parasites. Use of the IHC assay should improve the reliability of diagnosing lesions caused by degenerated cysticerci, facilitating more effective and efficient control of bovine cysticercosis.

Immunohistochemical expression of vascular endothelial growth factor and vascular endothelial growth factor receptor-2 in canine simple mammary gland adenocarcinomas.

The expression of 5 markers associated with angiogenesis, proliferation, and apoptosis was studied in 26 canine simple mammary gland adenocarcinomas (SMGAs). The adenocarcinomas were graded histologically, and tissue sections were immunohistochemically stained for the expression of vascular endothelial growth factor (VEGF), VEGF receptor-2 (VEGFR-2), intra-tumor microvessel density, and tumor proliferation (PI) using antibodies against VEGF, VEGFR-2, von Willebrand factor, and Ki-67 antigen, respectively. Apoptotic indices (AI) were determined by an apoptosis assay. Markers VEGF and VEGFR-2 were detected in 96% and 100% of SMGAs, respectively. A high correlation between histologic grade and PI (r = 0.73), a moderate correlation between VEGF and histologic grade (r = 0.33), and between VEGF and PI (r = 0.42) were found. There was a significant difference in median PI among the 3 histologic grade groups (r < 0.05). Vascular endothelial growth factor may stimulate tumor cell proliferation through an autocrine loop, since VEGF and VEGFR-2 were expressed in most tumors.

The effect of bovine viral diarrhea virus infections on health and performance of feedlot cattle.

The aim of this study was to investigate the effect of bovine viral diarrhea virus (BVDV) infections (unapparent acute infections and persistent infections) on the overall health and performance of feedlot cattle. Calves from 25 pens (7132 calves) were enrolled in the study. Overall and infectious disease mortality rates were significantly higher (P < 0.05) in pens categorized at arrival as positive for type I BVDV and lower in pens that were positive for type II BVDV than in negative pens. Mortality attributed to BVDV infection or enteritis was significantly more common (P < 0.05) in the pens containing persistently infected (PI) calves than in pens not containing PI calves (non-PI pens). There were no statistically detectable (P > or = 0.05) differences in morbidity, overall mortality, average daily gain, or the dry matter intake to gain ratio between PI and non-PI pens. Although type-I BVDV infections in feedlots appear to contribute to higher mortality rates, the presence of PI calves alone does not appear to have a strong impact on pen-level animal health and feedlot performance.

Immune mediated neutropenia and thrombocytopenia in 3 giant schnauzers.

Neutropenia, thrombocytopenia, and splenomegaly were recognized in 3 adult female giant schnauzers. Antineutrophil antibodies were demonstrated in 2 dogs. Following splenectomy, administration of prednisone and azathioprine resulted in normalization of neutrophil and platelet numbers in all dogs.