Immunity transfer in mule foals fed with good IgG quality colostrum.

While the passive transfer of immunity in horse and donkey foals has been extensively studied, there is limited information for mule foals. Immunoglobulin type G (IgG) and serum total protein concentration (TP) were assessed at different sampling times to evaluate the correlation between serum radial immunodiffusion (SRID) with electrophoresis, refractometry, and dry chemistry analyzer (Biuret), and to estimate serum IgG concentrations using serum TP in mule foals. We analyzed a total of 30 samples collected at birth, and at 6, 12, 24, and 48 h of life from 6 mule foals by SRID, electrophoresis TP, biuret TP, and refractometry TP. The SRID IgG concentration significantly increased from birth until T6 (p < 0.001). Serum TP analyzed with refractometry revealed differences between T0 and T12, T24 and T48 (p < 0.05), while a significant difference was observed with the biuret method between T0 and all the other sampling times (p < 0.001). A strong correlation was found between IgG SRID and biuret TP (r = 0.69, p < 0.001), and a good correlation existed between IgG SRID, refractometry TP, and electrophoresis TP (r = 0.44, p < 0.01 and r = 0.39, p < 0.05, respectively). All methods can be used to estimate the passive transfer of immunity in mule foals. TP refractometry and biuret TP values can be used to determine serum IgG concentrations in the blood of mule foals on their first day of life through the application of a specific equation.

Efficacy of a single-dose albendazole against lancet liver fluke Dicrocoelium dendriticum and liver enzymes activity in naturally infected sheep.

Infections with D. dendriticum are distributed worldwide and mostly associated with ruminant livestock. Depending on the length and strength of the infection it can be manifested with losses in milk production, reductions in milk and wool quality, decreased weight gains, reproductive performance and poor carcass quality. The objective of this study was to determine the efficacy of albendazole (ABZ) against the lancet liver fluke Dicrocoelium dendriticum in naturally infected sheep using parasitological methods. Twenty-four sheep were divided into four groups: two untreated control groups (C1, C2) and two treated groups (T1, T2), with six animals in each group. The sheep in the treated groups were administered a single oral dose (15 mg/kg bwt) of ABZ suspension. After ABZ treatment the animals were slaughtered on Day 14 (groups C1, T1) and Day 30 (groups C2, T2) and were necropsied. Coprological therapeutic ABZ efficacy reached 92.4% on Day 14 (P < 0.001) and 88.5% on Day 30 (P < 0.001). On Day 30, the serum activities of hepatic and cholestatic enzymes including serological analysis of total protein concentration (TP) and protein fractions were evaluated. Significant decrease of aspartate aminotransferase (AST) (P < 0.01) and gamma-glutamyltransferase (GGT) (P < 0.05) activity by 36.9% and 34.6%, respectively, were detected for sheep in T2 group. These enzymes showed a strong positive correlation to fluke burden: AST (r = 0.654) and GGT (r = 0.768), respectively (P < 0.05). Additionally, the electrophoretic analysis of serum total protein and protein fraction concentrations revealed minimal hypoproteinemia and hyperalbuminemia after ABZ treatment. The decrease of liver enzyme activities and their correlation with fluke burden may indicate recovery of hepatocellular and biliary damage following the reduction of fluke burdens after ABZ therapy. A decline in AST and GGT activity could serve as a valuable adjunct bioindicator of liver damage and fluke reduction after treatment of dicrocoeliosis in naturally infected sheep.

Serum total protein-to-albumin ratio predicts risk of death in septic acute kidney injury patients: A cohort study.

OBJECTIVE: Sepsis is the leading cause of acute kidney injury (AKI). Increasing evidence shows that serum total protein-to-albumin ratio (TAR) could serve as an inflammation- and nutrition-based prognostic marker in various diseases. The purpose of this study was to assess the prognostic value of TAR in predicting the clinical outcomes of septic AKI patients. METHODS: We retrospectively enrolled septic AKI patients between August 2015 and August 2022 at West China Hospital of Sichuan University. Patients admitted between August 2015 and August 2021 were defined as the original cohort. The primary outcomes were 30-day and 90-day all-cause mortality of septic AKI patients. The secondary outcomes were septic shock, transfer to the intensive care unit, mechanical ventilation, requirement for renal replacement therapy, and stage 3 AKI. The utility of TAR was further verified in a validation cohort of septic AKI patients admitted between September 2021 and August 2022. RESULTS: In the original cohort, a total of 309 eligible patients with a median age of 58 years were enrolled, of which 70.2 % were males. In multivariate Cox analysis, after adjustments for age, sex, and other confounding factors, higher TAR at admission was associated with an increased risk of 30-day and 90-day all-cause mortality in septic AKI patients (HR 1.91, 95 % CI 1.18-3.09, P = 0.008; HR 1.54, 95 % CI 1.01-2.34, P = 0.043, respectively). Subgroup analysis revealed no significant interactions in most strata. TAR at AKI diagnosis or discharge was not significantly related to 30-day (P = 0.120 and 0.153, respectively) or 90-day mortality (P = 0.147 and 0.124, respectively). We found no relationship between baseline TAR and septic shock, transfer to the intensive care unit, mechanical ventilation, requirement for renal replacement therapy, or stage 3 AKI (all P > 0.05). In the validation cohort of 81 septic AKI patients, TAR at admission remained a significant prognosticator for 30-day and 90-day mortality (HR 4.367, 95 % CI 1.20-15.87, P = 0.025; HR 4.237, 95 % CI 1.59-11.27, P = 0.004). CONCLUSIONS: TAR at admission is an independent risk factor for 30-day and 90-day mortality in septic AKI patients and could be used as a convenient and economic septic AKI prognostic indicator.

[Determination of human serum total protein via electrophoresis titration and capacitively coupled contactless conductivity detection].

Serum total protein refers to the sum of all proteins in the serum, and its content determination is relevant to human health monitoring and disease diagnosis. However, existing detection techniques present a number of limitations; for example, the Kjeldahl method suffers from the negative effects of interfering substances such as non-protein nitrogen (NPN). Although the electrophoresis titration (ET) method has solved interference problems to some extent, the current ET technique relies on optical detection methods, which increases the tediousness of the operation. This study addresses the challenge of accurate serum total protein detection by combining the traditional ET technique with capacitively coupled contactless conductivity detection (C4D). The research contributions of this work are multifold. First, it presents the first development of an ET-C4D detection system, which consists of six components: an ET power module, an ET chip, a C4D sensing module, a detection module, a data acquisition card, and software. The developed system can capture the conductivity of substances in the channel using the software developed by our laboratory during ET. The detection system can be used to quantify the total protein content in human serum without the addition of specific labeling reagents or using optical detection equipment, and its running time is approximately 300 s. Second, this research proposes the corresponding principle of the system. Under an electric field, ion migration results in different pH levels before and after the boundary, leading to a protein surface charge difference. The maintenance of the electrical neutrality of the substances in the detection channel is related to the protein surface charge; therefore, the ion concentration distribution of the substances in the detection channel changes as the protein surface charge varies. A plot of conductivity as a function of running time showed an "inverted clock shape", first falling and then rising. Owing to the addition of different types and concentrations of proteins, the microenvironment of the entire system changes, resulting in different changes in conductivity. Third, the performance of the detection system was tested using human serum albumin (HSA) standard protein, which was mixed with polyacrylamide gel (PAG) mother liquor, riboflavin, etc., and irradiated under ultraviolet light for 10 min to form a gel. The ET experiments were then carried out. The shape of the conductivity curve was consistent with the proposed principle, and the higher the HSA concentration, the lower the conductivity curve trough, followed by a lagged time of the trough. Quantitative analysis of the conductivity signals showed that the linear range was 0.25-3.00 g/L, with a linearity of up to 0.98. The limit of detection (LOD) was 0.01 g/L, the relative standard deviation (RSD) was 1.90%, and the relative error of the test values was <7.20%, indicating the good detection stability and sensitivity of the system. Clinical samples collected from healthy volunteers were used as target blood samples for serum total protein content measurement using our detection system. Blood samples from a volunteer were used to obtain a standard curve, and the serum samples of other four volunteers were selected for ET-C4D and biuret detection. The results showed that the relative errors between the two methods were within 4.43%, indicating the accuracy and reliability of the detection system. The advantages of the ET-C4D detection system proposed in this paper are as follows: (i) ET-C4D realizes the rapid detection of total serum protein content based on the ET technique; (ii) compared with the traditional protein ET technique, the ET-C4D method does not rely on specific labeling components or optical detection equipment, thereby reducing the complexity of the operation; and (iii) the output signal of ET-C4D can be used for quantitative analysis with excellent analytical performance and high accuracy. These merits highlight the potential of the developed system for clinical application and biochemical analysis.

Assessing failure of transfer of passive immunity by gamma-glutamyl-transferase activity and serum refractometry in holstein-friesian calves affected by neonatal diarrhea.

Hardly published data are available to diagnose the failure of transfer of passive immunity (FTPI) in calves affected by neonatal calf diarrhea (NCD). This study evaluated the diagnostic performance and differences among optical serum total protein (STP) concentration and gamma-glutamyl-transferase (GGT) activity for assessing FTPI in diarrheic Holstein Friesian calves. 72 diarrheic and 19 healthy Holstein Friesian calves aged 1 to 10 days were enrolled. Each calf underwent a complete clinical examination and dehydration assessment. The effect of dehydration status and age on the correlation between the two methods under study (STP and GGT) and the gold standard (Immunoglobulin G [IgG] measured with RID) was investigated with Spearman's correlation index R for ranks. Serum total protein concentration and GGT activity were analyzed by receiver operating characteristic (ROC) curve analysis to identify the optimal cut-off point to distinguish between diarrheic calves with or without FTPI, also considering the effects of dehydration and age. The results show that GGT activity was affected by the age of calves, while STP was influenced by dehydration. The cut-offs to distinguish calves with IgG < 10 g/L were < 52 g/L of STP in normohydrated calves, < 58 g/L of STP in dehydrated calves, and < 124 IU/L of GGT in calves with aged between 3 and 10 days. In nondehydrated diarrheic calves, the STP refractometer showed better diagnostic accuracy.In dehydrated calves aged between 3 and 10 days, however, its accuracy drops, and it is advisable to use GGT activity.

Analysis of the influence of selected protein markers as markers of nutritional status and inflammation on the occurrence of eventration after laparotomy.

<b><br>Introduction:</b> Eventration is a fairly rare complication after laparotomy, which consists of postoperative wound dehiscence and protrusion of the viscera outside the abdominal cavity. This complication is associated with a higher mortality rate. The known risk factors for this condition include malnutrition and the coexistence of inflammation or cancer.</br> <b><br>Aim:</b> The main aim of the study was to investigate the relationship between the occurrence of eventration after laparotomy and the patient's nutritional status with the intensity of inflammatory processes, expressed using selected protein markers.</br> <b><br>Material and method:</b> The study was based on the analysis of patients treated at our own center from January 2014 to December 2020. It included a group of patients who underwent laparotomy and who experienced eventration, as well as a control group of patients who underwent laparotomy but did not experience eventration after the procedure.</br> <b><br>Results:</b> The analysis showed that a lower serum albumin concentration is associated with a greater risk of eventration in patients who have undergone laparotomy due to acute abdominal disease. The study group and the control group differed significantly in the levels of: Hgb, serum total protein, CRP, lymphocytes, albumin, PCT, NRS.</br>.

Evaluation of 2 refractometers to estimate different passive immunity status in Simmental dairy calves.

Inadequate transfer of passive immunity (ITPI) is major risk for mortality, morbidity and decreased growth performance in dairy and beef calves. Refractometry method is used in estimating ITPI in dairy and beef calves but studies evaluating refractometers for Simmental dairy calves are limited. The objectives of this study were determining the accuracy of digital serum total protein refractometer (STP-REF) and digital Brix refractometer (BRIX-REF) in the estimating of different passive immunity status (<10, <18, <25 and <32 g/L) in Simmental dairy calves. Serum samples were collected from apparently healthy Simmental dairy calves aged 1-8 days (n = 291). Serum total solid percentages were measured using BRIX-REF, serum total protein concentrations were measured using STP-REF and serum IgG concentrations were measured using radial immunodiffusion (RID) assay as a reference test. Correlation coefficients were calculated between RID test and refractometers results, and each other. The diagnostic test performance of the refractometers at IgG concentrations of < 10, < 18, < 25 and < 32 g/L was measured by performing a receiver operating characteristics (ROC) analysis. The optimal thresholds of the refractometers were determined based on Youden's J statistics and after accounting for different costs between false positive and false negative cases using misclassification cost term analysis. The overall test performance and the agreement of the refractometers were assessed using area under the ROC curve and Cohen's kappa analysis. Optimal thresholds were determined as < 7.9, < 8.3, < 8.7, < 9.4% for the BRIX-REF, and < 4.6, < 5.2, < 5.4, < 5.8 g/dL for the STP-REF in estimating IgG concentrations of < 10, < 18, < 25, < 32 g/L, respectively. Se and Sp of BRIX-REF were 88.8% and 89.1% for < 7.9% Brix, 81.6% and 94.2% for < 8.3% Brix, 77.9% and 97.4% for < 8.7% Brix and 81.7% and 91.2% for < 9.4% Brix, respectively. Se and Sp of STP-REF 92.5% and 88.2% for < 4.6 g/dL; 92.1% and 87.1% for < 5.2 g/dL; 81.7% and 93.6% for < 5.4 g/dL; 79.0% and 94.1% for < 5.8 g/dL, respectively. Both, digital Brix and STP refractometers performed well to estimate the status of passive immunity in dairy Simmental calves.

Evaluation of refractometry methods for estimating passive immunity status in neonatal foals.

The objective of this cross-sectional study was to determine the accuracy of the digital Brix and serum total protein (TP) refractometers for estimating different passive immunity status in neonatal foals. In total, 18- to 40-h old purebred Arabian foals (n = 185) were used. Serum TP concentrations, total solid percentages and IgG concentrations were measured with a digital serum TP refractometer, digital Brix refractometer and the gold standard radial immunodiffusion (RID) assay, respectively. Correlation coefficients were calculated between the refractometer and RID assay results. A receiver operating characteristic analysis was used to select the optimal cut-offs for both refractometers. Test performance and agreement were evaluated using diagnostic test characteristics at optimal thresholds and areas under the ROC curve, and by calculating Cohen's kappa coefficient. The sensitivity and specificity of the digital Brix refractometer at optimal cut-offs (≤7.8%, ≤7.9%, ≤8.2%, ≤8.3%, ≤9.0%) were 100 and 69.3%; 100% and 68.5%; 70.5% and 71.0%; 88.3% and 85.5%; 88.1% and 76% to estimate RID-IgG of <400 mg/dL, <800 mg/dL, <1500 mg/dL, <2500 mg/dL and < 3000 mg/dL, respectively. The sensitivity and specificity of the digital serum TP refractometer at optimal cut-off (≤4.6 g/dL, ≤4.6 g/dL, ≤4.8 g/dL, ≤5.0 g/dL, ≤5.4 g/dL) were 100 and 69.3%; 100% and 72.8%; 90% and 72.8%; 72.9% and 83.9%; 84.4% and 88% to estimate RID-IgG of <400 mg/dL, <800 mg/dL, <1500 mg/dL, <2500 mg/dL and < 3000 mg/dL, respectively. In conclusion, the refractometers showed a good potential as screening tools for the estimation of different IgG concentrations in neonatal foals.

Genetic parameters for dairy calf and replacement heifer wellness traits and their association with cow longevity and health indicators in Holstein cattle.

High mortality and involuntary culling rates cause great economic losses to the worldwide dairy cattle industry. However, there is low emphasis on wellness traits in replacement animals (dairy calves and replacement heifers) during their development stages in modern dairy cattle breeding programs. Therefore, the main objectives of this study were to estimate genetic parameters of wellness traits in replacement cattle (replacement wellness traits) and obtain their genetic correlations with 12 cow health and longevity traits in the Chinese Holstein population. Seven replacement wellness traits were analyzed, including birth weight, survival from 3 to 60 d (Sur1), survival from 61 to 365 d (Sur2), survival from 366 d to the first calving (Sur3), calf diarrhea, calf pneumonia, and calf serum total protein (STP). Single and bivariate animal models were employed to estimate (co)variance components using the data from 189,980 Holstein cattle. The genetic correlations between replacement wellness traits and cow longevity, health traits were calculated by employing bivariate models, including 6 longevity traits and 6 health traits (clinical mastitis, metritis, ketosis, displaced abomasum, milk fever, and hoof health or hoof disease). The estimated heritabilities (± SE) were 0.335 (± 0.008), 0.088 (± 0.005), 0.166 (± 0.006), 0.102 (±0 .006), 0.048 (± 0.003), 0.063 (± 0.004), and 0.170 (± 0.019) for birth weight, Sur1, Sur2, Sur3, pneumonia, diarrhea, and STP, respectively. The majority of the genetic correlations among the 7 replacement wellness traits were negligible. The genetic correlations among Sur1, Sur2, and Sur3 ranged from 0.112 (Sur1 and Sur3) to 0.445 (Sur1 and Sur2) when fitting a linear model (estimates in the observed scale), and from 0.560 (Sur1 and Sur3) to 0.773 (Sur1 and Sur2) when fitting a threshold model (estimates in the liability scale). The genetic correlations between replacement wellness and cow longevity were low (absolute value lower than 0.30), but some of them were significantly different from zero. Compared with other replacement wellness traits, Sur3 and STP had relatively high genetic correlations with cow longevity. Replacement wellness traits are heritable and can be improved through direct genetic and genomic selection. The results from the current study will contribute for better balancing dairy cattle breeding goals to genetically improve dairy cattle wellness in the period from birth to first calving.

Serum protein and electrolyte imbalances are associated with chemotherapy induced neutropenia.

Introduction: Cancer and its treatment using various chemotherapeutic agents can have many adverse side effects. These side effects often result in significant changes in haematological and biochemical composition of blood. As a result, the regular monitoring of serum biochemical and haematological changes plays an important role in management of disease. The present study aimed to determine the relationship between haematological and biochemical changes in neutropenic cancer patients following chemotherapy. Specifically we evaluated the association between neutrophil count and serum proteins and electrolytes. Methods: For this purpose we analysed retrospectively collected laboratory results from two independent patient cohorts. Each cohort was divided into a control group consisting of patients with normal haematological parameters and a study group which included patients with reduced neutrophil counts. Neutropenic patients (study group) were cancer patients on chemotherapy. Results and conclusion: Blood samples of cancer patients in study group showed reduction in haemoglobin, neutrophils and platelets. Neutropenic group showed a significant reduction in serum albumin, total protein, calcium, and potassium. Our results show that patients with severe neutropenia had pronounced changes in serum protein and electrolytes and increased incidence of abnormal serum protein and electrolyte level. The changes in the neutrophil counts showed a positive correlation with the changes in serum protein and electrolyte levels. A similar trend was seen in both the patient cohorts: the discovery set (176 patients) and the validation set (200 patients). Taken together our results suggest that chemotherapy-induced neutropenia is associated with dysregulation in haemoglobin, platelets, serum proteins and electrolytes.

Diagnostic accuracy of digital Brix and serum total protein refractometers in estimating different passive immunity levels in dairy calves.

The aim of this study was to determine the diagnostic accuracy of digital serum total protein (TP) and digital Brix refractometers in estimating different passive immunity levels (<10, <18, <25 mg/mL) in dairy calves. Blood samples were collected from 260 apparently healthy Holstein calves, aged 2-7 days. Serum IgG concentrations were measured using digital Brix and TP refractometers and the radial immunodiffusion (RID) assay, as the gold standard. Data were analyzed by a receiver operating characteristics (ROC) analysis, the area under the ROC curves (AUC) and Cohen's kappa (κ). Optimal thresholds were determined as < 8.4, < 9.0 and < 9.4% for the digital Brix refractometer, and < 5.0, < 5.4 and < 5.8 g/dL for the serum TP refractometer in estimating IgG concentrations of < 10, < 18, < 25 mg/mL, respectively. The sensitivity (Se) and specificity (Sp) of the Brix refractometer were 96.3% and 88.8% for < 8.4% Brix, 97.0% and 83.4% for < 9.0% Brix, and 85.5% and 77.8% for < 9.4% Brix, respectively. The Se and Sp of the serum TP refractometer were 96.3% and 90.1% for < 5.0 g/dL, 91.0% and 89.6% for < 5.4 g/dL, 79.6% and 85.2% for < 5.8 g/dL, respectively. The discriminant ability of the refractometers was moderately accurate in estimating IgG concentrations of < 10 and < 18 mg/mL, and highly accurate in estimating IgG concentrations of < 25 mg/mL. Both refractometers substantially agreed with RID-IgG results and almost perfectly agreed with each other. In conclusion, the digital Brix and digital serum TP refractometers offer a good utility for determining different passive immunity levels in dairy calves.

Prevalence of failure of passive immunity transfer in Australian non-replacement dairy calves.

Failure of passive immunity transfer (FPIT) increases the risk of morbidity and mortality in dairy calves. The prevalence of FPIT in dairy calves has generally been reported to be high, with FPIT estimated to occur in 38%-42% of Australian dairy calves. However, the focus of previous studies has been on replacement heifer calves. Our aim was to assess the prevalence of FPIT in Victorian bobby calves (non-replacement dairy calves). We collected blood samples from 3608 bobby calves at three abattoirs at exsanguination, and measured serum total protein as an indicator of passive transfer. We found that 36% of bobby calves showed evidence of FPIT (serum total protein ≤52 g/L), and 50% of calves had poor or fair passive transfer (<58 g/L). When a subset of calves (from farms with more than five calves in the dataset) was analysed using a linear mixed model, Jersey calves and crossbred/other calves had an estimated 5.3 g/L and 5.1 g/L higher serum total protein concentration, respectively, than Holstein-Friesian calves (P < 0.001). Our results suggest that the prevalence of FPIT in bobby calves at abattoirs is similar to that reported in dairy heifer calves sampled on farms. A high prevalence of FPIT has implications for bobby calf morbidity and mortality, as well as calf viability and profitability for dairy-beef production.

Protein Nutritional Status and Frailty: A Mendelian Randomization Study.

BACKGROUND: Observational studies have suggested that better protein nutritional status may contribute to prevention of frailty. OBJECTIVE: We sought to examine this hypothesis using a Mendelian randomization (MR) analysis. METHODS: We conducted a two-sample MR study using GWAS summary statistics data of the UK Biobank. We applied genetically predicted serum albumin as a primary exposure measure and serum total protein as a secondary exposure measure. The outcome measure was the Rockwood frailty index (FI) based on 49 deficits from 356,432 individuals (53.3% of them were women, with a mean ± SD age of 56.7 ± 8.0 y. The association between serum protein measures and FI was mainly analyzed by use of the inverse variance weighted method. RESULTS: A genetically predicted serum albumin concentration was not statistically significantly associated with FI in the full sample. However, in women, we observed a preventive association between genetically predicted serum albumin and FI (ß = -0.172 per g/L; 95% CI: -0.336, -0.007; P = 0.041). In the full sample, genetically predicted serum total protein was inversely associated with FI (ß: -0.153 per g/L; 95% CI: -0.251, -0.056; P = 0.002). In both women and men, higher serum total protein was significantly inversely associated with FI; regression coefficients were -0.148 per g/L (95% CI: -0.287, -0.009; P = 0.037) for women, -0.154 per g/L (95% CI: -0.290, -0.018; P = 0.027) for men. CONCLUSIONS: The present MR study implies that better protein nutritional status modestly contributes to reducing the risk of frailty.

Evaluation of Different Methods to Estimate the Transfer of Immunity in Donkey Foals Fed with Colostrum of Good IgG Quality: A Preliminary Study.

The aims of the present study were to evaluate the correlation between IgG Serum Radial Immunodiffusion (SRID), Electrophoresis Gamma Globulins (EGG), Electrophoresis Total Protein (ETP) and the serum total protein (TP) analyzed by refractometry and by a dry chemistry analyzer (Biuret) and to estimate serum IgG concentrations using serum TP. A total of 36 samples collected at four different times (birth, 6, 12, 24 h after birth) from nine Amiata donkey foals were evaluated with SRID, EGG, ETP, serum TP Biuret and refractometry. SRID IgG concentration increased significantly over time until T12. Serum TP analyzed with refractometry, electrophoresis and Biuret showed a statistically significant difference between T0 and T6 vs. T12 and T24. A good or strong correlation was found between different tests performed. Equations to quantify serum IgG were created and can be used for estimating the donkey foals' serum IgG in the first day of life. Serum TP refractometry showed a high correlation with SRID IgG (0.91) which may be a particularly useful and economic instrument to estimate the transfer of immunity in donkey foals during the first day of life. Further studies evaluating a high number of animals are needed in order to set specific cut-off values.

Genetic parameters of passive transfer of immunity for US organic Holstein calves.

Passive transfer of immunity is important for calf health and survival. The objectives of this study were to estimate genetic parameters for calf passive transfer of immunity through producer-recorded serum total protein (STP) and to determine associations with other routinely evaluated traits in organic Holstein calves (n = 16,725) that were born between July 2013 to June 2018; a restricted subset (n = 7,518) of calves with known Holstein maternal grandsires was analyzed separately. Producers measured STP on farm, and STP was extracted from farm management software. Failure of passive transfer of immunity (FPT) was declared for calves with STP ≤5.2 g/dL. Calves that had the opportunity to reach 1 yr of age were recorded as either staying in the herd or leaving the herd (STAY365). Univariate and threshold models were fitted for STP and FPT, respectively, and included the fixed effects of herd-year-month of birth, calf age in days at STP measurement, dam age in years, and random effects of animal and birthdate within herd. Model effects for STAY365 included the fixed effects of herd-year-month of birth and random effects of animal and birthdate within herd. Multivariate analyses of STP with FPT or STAY365 were conducted to determine the genetic correlation between traits and STP was also regressed on gestation length. Heritability estimates of STP were 0.06 and 0.08 for full and restricted data, respectively. Heritability estimates for FPT were 0.04 and 0.06 for full and restricted data, respectively. The genetic correlation between STP and FPT was near unity. Heritability estimates for STAY365 ranged from 0.08 to 0.11 with genetic correlation estimates between STP and STAY365 ranging from 0.19 and 0.25. Approximate genetic correlations were estimated for sires (n = 302 and n = 256 for full and restricted data, respectively) with at least 10 daughters for STP and predicted transmitting abilities for health, calving traits, and production. Positive approximate genetic correlations were estimated for STP with cow livability, productive life, net merit dollars, and milk yield; favorable approximate genetic correlations were observed for daughter and sire calving ease, and sire stillbirth. Longer gestation length was associated with reduced STP genetically and phenotypically. These results suggest that passive transfer as measured through STP is heritable and favorably correlated with current measures of health, calving, and production.

Evaluation of 3 refractometers to determine transfer of passive immunity in neonatal beef calves.

BACKGROUND: Refractometry is used to assess transfer of passive immunity (TPI), but studies evaluating different refractometers and appropriate thresholds for recommended target immunoglobulin G (IgG) concentrations for beef calves are limited. OBJECTIVES: To evaluate test performance of digital (DSTP) and optical (OSTP) serum total protein (STP) refractometers and a digital Brix (DBRIX) refractometer for assessment of passive immunity in beef calves. ANIMALS: A total of 398 beef calves from 6 herds, 1 to 7 days of age. METHODS: Serum IgG concentration was estimated by DSTP, OSTP, and DBRIX, and measured by radial immunodiffusion (RID). Correlation coefficients (r) among results were calculated. Optimal STP and Brix thresholds for identification of IgG <10, <16, and <24 g/L were determined using interval likelihood ratios. Refractometer performance and agreement were assessed using areas under the curve (AUC), diagnostic test characteristics, Cohen's kappa (κ), and Bland-Altman analysis. RESULTS: Refractometer results were highly correlated with RID (r = 0.82-0.91) and with each other (r = 0.91-0.95), and overall test performance was excellent (AUC = 0.93-0.99). The STP concentrations of ≤5.1, ≤5.1, and ≤5.7 g/dL and Brix percentages of ≤7.9%, ≤8.3%, and ≤8.7% indicated IgG concentrations <10, <16, and <24 g/L, respectively. Agreement of refractometers with RID was variable (κ = 0.46-0.80) and among refractometers was substantial (κ = 0.62-0.89). CONCLUSIONS AND CLINICAL IMPORTANCE: All refractometers showed good utility as monitoring tools for assessment of TPI in beef calves.

Hot topic: Accuracy of refractometry as an indirect method to measure failed transfer of passive immunity in dairy calves fed colostrum replacer and maternal colostrum.

Serum total protein (STP) refractometry is a widely used indicator of failed transfer of passive immunity (FTPI), defined as serum IgG concentrations of <10 mg/mL or STP levels <5.2 g/dL measured at 24 h of life. However, recent reports have demonstrated that refractometry could be inaccurate at estimating serum IgG concentrations and FTPI when calves are fed colostrum replacer (CR). The objective of this study was to evaluate the accuracy of STP measurements to estimate FTPI in calves fed CR compared with calves fed maternal colostrum. Blood was collected from dairy calves fed maternal colostrum (n = 927) or colostrum-derived CR (n = 1,258) and analyzed for STP and serum IgG. Serum total protein was measured with a digital refractometer, whereas radial immunodiffusion was used to determine IgG concentrations. Calves fed maternal colostrum had a mean STP of 5.80 ± 0.72 (standard deviation) g/dL and a mean IgG concentration of 22.81 ± 10.14 mg/mL, respectively, whereas calves fed CR had a mean STP and IgG concentration of 5.14 ± 0.50 g/dL and 12.78 ± 4.60 mg/mL, respectively. Rates of FTPI for calves fed maternal colostrum or CR were 4.2% and 27.26%, respectively. Calves were considered to have FTPI if their IgG postcolostrum feeding was <10 mg/mL. Logistic and linear regression analyses were performed to determine cutoff points and existent relationships between STP and IgG. Serum total protein and IgG for calves fed maternal colostrum were highly correlated. In contrast, STP and IgG for calves fed CR were lowly correlated. A receiver operator characteristic curve analysis demonstrated that an STP cutoff point that could predict FTPI when calves are fed CR would be 4.9 g/dL (sensitivity = 0.68; specificity = 0.75). This study suggests that current cutoff points used for STP inflates the number of calves estimated to have FTPI when they are fed CR.

Passive immunity and colostrum management practices on Ontario dairy farms and auction facilities: A cross-sectional study.

Failed transfer of passive immunity (FTPI) in dairy calves has substantial health consequences, but there have been no recently published estimates of the prevalence of FTPI on Ontario dairy farms. The major objectives of this cross-sectional study were to determine the level of FTPI in dairy calves across the province of Ontario and to determine colostrum management practices used. A convenience sample of 109 dairy farms in Ontario were visited from June to August 2019, along with 4 auction facilities from January to February 2019. At the single visit to each dairy farm, an in-person questionnaire was administered, and all calves between 24 h and 9 d of age had a blood sample collected to determine the levels of serum total protein (STP). At the auction facility, a blood sample was collected on all calves that arrived on the day of the visit. The dairy farms were distributed throughout Ontario, and the farms milked on average 151 dairy cows. Of the 444 calves sampled on Ontario dairy farms, 46% were male, 54% were female, and the mean weight and age at sampling were 46.3 kg and 4.4 d, respectively. The mean STP of calves sampled on the dairy farm was 5.69 g/dL (standard deviation = 0.78), and 107 calves (24%) had FTPI. The likelihood of FTPI was not associated with sex (female vs. male, risk ratio = 0.89, 95% confidence interval = 0.64-1.24), age (per day, risk ratio = 1.02, 95% confidence interval = 0.94-1.11), or weight (per kg, risk ratio = 0.98, 95% confidence interval = 0.96-1.01). In contrast, at the auction facilities, 386 male dairy calves were sampled and had a mean STP of 5.79 g/dL (standard deviation = 0.83). Using a cut point of ≥5.2 g/dL, 91 calves (24%) had FTPI. From the in-person questionnaire administered on the dairy farms, it was reported that the median time to first feeding of colostrum was 2.5 h (range = 0-12 h). The farms reported providing a mean of 3.3, 2.9, and 3.4 L of colostrum from 0 to 6 h after birth, 6 to 12 h after birth, and 12 to 24 h after birth, respectively. Ninety-one farms (83%) fed colostrum from the dam of the calf as their predominant source of colostrum. The most common method used to deliver the first feeding of colostrum was a nipple bottle (89 farms, 82%). Twenty-seven farms (25%) reported managing colostrum differently for male calves, which included a different colostrum source, use of poorer quality colostrum, a smaller quantity of colostrum, a longer time from birth to feeding, and generally having a lower focus on colostrum management for male calves. The prevalence of FTPI on Ontario dairy farms appears to have decreased since previous estimates, and substantial room for improvement remains. Although no overall differences were found in FTPI between male and female calves, differential reported colostrum management by sex indicates this may be a risk for male calves on a proportion of Ontario dairy farms.

Risk factors associated with failed transfer of passive immunity in male and female dairy calves: A 2008 retrospective cross-sectional study.

This retrospective cross-sectional study was designed to identify risk factors associated with failed transfer of passive immunity (FTPI) and to determine differences in colostrum management between male and female dairy calves. Research technicians visited a total of 16 commercial dairy farms weekly. For each calf born on these farms, the farm personnel completed a birth record to document the colostrum management practices provided, level of calving assistance, calf sex, and time of birth. On the weekly visits to the farms, the technicians collected blood from calves that were 1 to 7 d of age. Serum was separated via centrifugation and the concentration of serum total protein (STP) was determined using a digital refractometer. Failed transfer of passive immunity was defined as calves having an STP of <5.2 g/dL. Data were available for 1,778 calves aged 1 to 7 d. Several differences were observed with respect to how male and female calves were managed. Male calves were more likely to receive a lower volume of colostrum, have colostrum delivered using a nipple bottle followed by an esophageal tube feeder, be fed pooled colostrum, and receive fresh colostrum rather than frozen colostrum relative to female calves. Serum total protein (STP) ranged from 3.6 to 9.7 g/dL with a mean of 5.7 g/dL (standard deviation, 0.7 g/dL) and 21.1% of the calves had FTPI. Using a mixed linear regression model, we identified that a calf being male (-0.14 g/dL), being delivered by a hard pull (-0.23 g/dL), and receiving the first feeding colostrum from a combination of a nipple bottle followed by an esophageal tube feeder (-0.12 g/dL) were associated with a lower concentration of STP. Feeding 6 L or more of colostrum in the first 24 h of life was associated with a 0.14 g/dL higher concentration of STP compared with feeding <3.9 L of colostrum. For FTPI, being delivered by a hard pull [odds ratio (OR) 2.21] and receiving the first feeding colostrum from a nipple bottle followed by an esophageal tube feeder (OR 1.83) were associated with higher odds of FTPI. Feeding >6 L of colostrum in the first 24 h of life was associated with a reduced odds (OR 0.65) of FTPI compared with feeding <3.9 L of colostrum. This study highlights the importance of certain management practices in reducing FTPI incidence and identifies discrepancies in colostrum management between male and female dairy calves.

Protein metabolic changes and nucleolus organizer regions activity in the lymphocytes of neonatal calves during the development of respiratory diseases.

BACKGROUND AND AIM: Calfhood disease is an important problem in dairy farming that could cause significant effects on heifer survival and productivity and has economic and welfare effects. Total protein concentration in the blood serum could be one of the predictors of bovine respiratory disease (BRD) in newborn calves. The number of active nucleolus organizers could be used to assess the viability of the protein synthesis system in cells and tissues. We aimed for a comparative assessment of the dynamics of the main indicators of protein metabolism and nucleolus organizer regions (NORs) activity in the lymphocytes of healthy calves (Group I) and calves with BRD (Group II) during the 1st month after birth. MATERIALS AND METHODS: This study included 30 calves of the red-motley Holstein breed. Venous blood samples were taken from all calves on the 1st, 7th, 14th, and 28th days after birth. Quantitative analysis of total protein (Serum total protein [STP]), immune globulin (Serum immune globulin [SIg]), urea, and creatinine in serum and transcriptionally active chromosome NORs in the interphase nuclei of lymphocytes was conducted using receiver operating characteristic analysis and factor analysis. RESULTS: In Group I, the STP levels decreased during the 1st month of life, and in Group II, the STP levels were variable. The STP levels in both groups remained within the reference intervals. During the first 2 weeks after birth, the calves' SIg fluctuated within the statistical error limits and did not significantly differ between the groups. On the 28th day, SIg increased in both the groups (by 42.8% for Group I and 33.7% for Group II). The creatinine concentration showed a decrease but did not go beyond the range of reference values. Urea concentration in Group I markedly decreased and remained below the reference values; it did not change in Group II over the entire observation period. The number of NORs in 1-day-old calves did not significantly differ between the groups and amounted to 2.43 in Group I and 2.59 in Group II. A significant increase in the number of active NORs was found in calves in both groups at the ages of 14 and 28 days. Early BRD predictors (at 1-14 days) could not be identified among the studied indicators. The urea and creatinine concentrations and the NOR activity on day 28 after birth could be late BRD predictors. Protein metabolism in the newborn calves' organisms is regulated by three types of factors: Maintenance of a constant protein concentration in the plasma, protein decomposition, and de novo synthesis. CONCLUSION: There were no observed significant differences in the protein metabolism values and dynamics of indicators between healthy calves and calves with developed BRD. Alterations in the studied characteristics are the result, but not the cause of BRD. The increase in active NORs under BRD could be a favorable forecasting indicator. Protection against foreign protein and genetic material is a more important task for the organism than ensuring growth processes during the neonatal period.