Colostrum Immunoglobulin G Concentration Research Articles

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

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

Difructose Anhydride and Passive Immunity Effects on Passive Immune Transfer and Performance of Feeding Difructose Anhydride to Neonatal Calves.

The objective of this study was to assess the potential effects of supplementing difructose anyhdride III (DFAIII) during the first days of life on the absorption of immunoglobulin G (IgG) and growth performance of calves early in life fed colostrum with a high IgG concentration. Sixty-six healthy new-born Holstein calves were randomly assigned to three treatments consisting of no supplementation (control), supplementation of 12 g/d (DFA12), or 36 g/d (DFA36) of DFAIII during the first 7 d of life via colostrum and milk replacer (MR). Calves were separated from dams at birth and bottle-fed colostrum in two meals, each targeting 2.5 L within the first 18 h of birth. Colostrum had been previously collected from other dams (and preserved frozen) within the first 2 h of calving and had a Brix value ≥32%. Daily consumption of starter concentrate and MR (and colostrum on the first day) were individually monitored. Calves were body weighed using an electronic scale at birth and on a weekly basis thereafter until the end of study at 42 d of age. A sample of colostrum fed to each calf and a blood sample from the jugular vein of the calves were collected at 12 and 24 h of life to determine the IgG concentration. The mean colostrum IgG concentration fed in the current study was 110 ± 33.7 g/L (mean ± SD). No differences in animal performance were found among the treatments. Calves on all treatments consumed the same amount of colostrum with a similar concentration of IgG, and thus the amount of IgG consumed was also similar. Serum IgG concentrations were greater at 24 than at 12 h but did not differ among treatments. However, the apparent efficiency of absorption of colostral immunoglobulins was greater in DFA12 and DFA36 at 12 h of life than in control calves, with no differences observed at 24 h. Even when feeding high-quality colostrum, in terms of IgG concentration, supplementation with difructose anhydride III may pose an additional advantage in promoting the passive transfer of immunoglobulins in neonatal Holstein calves during the first 12 h of life.

PSIV-1 Effects of Poor Maternal Nutrition During Gestation on F0 and F1 Ewe Colostrum and Milk Composition and Colostrum Igg

Abstract High-quality colostrum and milk are critical for proper neonatal growth and immune system development. Immunoglobulin G (IgG) is the predominant antibody class in colostrum and is vital for passive immune transfer in sheep. There is limited understanding of how poor maternal nutrition during gestation (restricted- and over-feeding) might influence colostrum and milk composition and colostrum IgG concentrations and how F1 offspring colostrum and milk are impacted as a result of F0 maternal diet. The objective of this experiment was to determine if poor maternal nutrition during gestation impacts F0 and F1 colostrum and milk composition, including IgG concentrations. We hypothesized that maternal restricted-feeding would decrease, and maternal over-feeding would increase total solids, fat, and protein during early and transitional lactation and that restricted-feeding would increase IgG concentrations and over-feeding would decrease IgG concentrations in F0 and F1 ewe colostrum. Multiparous Dorset ewes pregnant (n = 46) with twins were fed 100% (control; n = 13), 60% (restricted; n = 17) or 140% (over; n = 16) of National Research Council (NRC) requirements. After birth and during lactation, dams were fed 100% NRC for lactating ewes, so the nutritional insult only occurred during gestation. Resulting ewe offspring (n = 32) were raised on control diets and were bred between 16 and 19 mo of age. Colostrum samples were collected within 24 h of parturition and milk samples were collected at d 3 and d 21 postpartum. Colostrum and milk composition were evaluated using Brix Refractometry (total solids, g/dL) and spectrophotometry (crude fat, %; crude protein, %). Additionally, a radial immunodiffusion assay was used to determine IgG concentrations (mg/dL) in colostrum. A treatment by time interaction was observed for F0 colostrum crude fat where restricted-fed ewes had less fat than control-fed ewes (P ≤ 0.024). No interaction was detected for all other F0 and F1 composition variables (P ≥ 0.16). We did not detect a main effect of diet on F0 or F1 total solids, crude fat, and crude protein of colostrum nor milk (P ≥ 0.24). A main effect of time was observed for all variables where colostrum had greater total solids, crude fat, and crude protein compared with milk at d 3 and d 21 (P ≤ 0.0001). No effect of maternal diet on IgG concentrations were detected in F0 or F1 ewe colostrum (P ≥ 0.46). These data indicate that poor maternal diet has minimal effects on F0 and F1 ewe colostrum composition and IgG concentrations, and d 3 and d 21 milk composition. In addition, the impact of F0 diet on colostrum fat composition did not persist into the F1 generation.

Defining optimal thresholds for digital Brix refractometry to determine IgG concentration in ewe colostrum and lamb serum in Scottish lowland sheep flocks.

This research aimed to define thresholds for ewe colostrum and lamb serum Brix refractometer measurements in lowland Scottish sheep. This would facilitate the use of this convenient, sheep-side test, enabling quick and accurate identification of poor quality colostrum and prevention of failure of transfer of passive immunity (FTPI) in lambs. Secondary aims were to identify risk factors for poor colostrum quality and FTPI in lambs. Serum samples (n=233) were collected from lambs between 24 and 48hrs after birth, from four lowland Scottish meat sheep farms. Pre-suckle colostrum samples (n=112) were also collected from ewes on two of these farms. Farmers provided information on litter size, ewe body condition score, ewe breed and dystocia. Duplicate digital Brix refractometer measurements were compared with immunoglobulin G (IgG) radial immunodiffusion (RID) testing for all colostrum and serum samples. Receiver operating characteristic (ROC) curves were used to redefine thresholds for Brix testing in colostrum and serum. Linear regression models were constructed with colostrum and serum IgG concentration as the outcomes of interest. Colostrum and serum IgG concentrations were highly variable. The prevalence of inadequate colostrum quality (using <50g/L IgG on RID) was 4.5% (95% CI = 1.5 - 10.1) and the prevalence of FTPI (using <15g/L IgG in serum on RID) was 7.73% (95% CI = 4.64-11.93). A ewe's colostrum IgG concentration was significantly and positively associated with the serum IgG concentration of her lamb(s) (p=0.02). ROC analysis defined a Brix threshold for adequate colostrum quality of >22.10% (sensitivity 80% (95%CI=28.4-99.5), specificity 90% (95%CI=82.3-94.8)). ROC analysis defined a Brix threshold for serum of >8.65% for adequate passive transfer of immunity in Scottish lambs (sensitivity 94% (95%CI=72.7-99.8), specificity 82% (95%CI=76.6-87.2)). To optimise passive transfer of immunity in lambs, we suggest that ewe colostrum Brix measurements be defined as 'poor' (<22%); 'fair' (22-26%) and 'good' (>26%); and lamb serum as 'poor' (<8%); 'fair' (8-9%) and 'good' (>9%). It is recommended that these tests are used as for flock screening, using samples from multiple animals.

Comparison of turbidometric immunoassay and brix refractometry to radial immunodiffusion for assessment of colostral immunoglobulin concentration in beef cattle.

Colostral immunoglobulin G (IgG) concentration is critical to the attainment of adequate transfer of passive immunity in cattle, however, studies comparing available tools for measurement of colostral IgG concentration in beef cattle are limited. To report the agreement between 3 commercially available tests for evaluating IgG concentration in beef colostrum. Two hundred six beef-breed cows hospitalized for calving management or dystocia. Retrospective study to assess IgG of whole colostrum measured stall-side via turbidimetric immunoassay (TI) and brix refractometry (BRIX), compared to fat separated (FS) analysis via single radial-immunodiffusion (RID; reference standard), TI-FS and BRIX-FS. Test performance was assessed using Passing Bablock regression, Bland-Altman analysis, and area under the curve to determine optimal thresholds. Correlation between RID and TI-FS, BRIX-FS, or BRIX was similar (Spearman's ρ = 0.717, 0.715, 0.716, respectively) but correlation for TI was poor (ρ = 0.586). Regression analysis identified a substantial constant (-214.75 [CI: -272.03 to -178.07]) and proportional (13.24 [CI: 11.81-15.37]) bias between the RID and TI-FS which was similar for TI. TI-FS concentrations of 28.47, 38.75, and 50.62 g/L, BRIX-FS of ≤21.9%, ≤24.0%, and ≤27.4%, and BRIX of ≤21.3%, ≤23.8%, and ≤26.4% indicated IgG concentrations <50, <100, and <150 g/L, respectively; appropriate cutoffs for TI could not be generated. Both TI and TI-FS demonstrated a large constant and proportional bias compared to RID; BRIX and BRIX-FS were well correlated with RID and remain a reliable method for estimation of colostral IgG concentration in beef cattle.

Transfer of passive immunity and survival in Jersey heifer calves fed heat-treated pooled colostrum.

Acquisition of adequate transfer of passive immunity (ATPI) by calves depends on the absorption of sufficient mass of colostral immunoglobulin G (IgG). Several studies report conflicting evidence regarding the ability of feeding pooled colostrum to achieve ATPI. Pooling colostrum is practical and efficient for some dairies, and recommendations are required to prevent failure of transfer of passive immunity (FTPI) in calves following pooling. This study aimed to determine the effect of pooling colostrum on serum IgG concentrations, FTPI, and preweaning mortality in calves. A prospective study was performed on two conventional Jersey dairy farms where heat treatment of colostrum occurred in the same colostrum processing kitchen. Four to 10 cows contributed to colostrum pools. A sample of the colostrum pool fed to the calves and serum from calves at 24-72 h was collected for IgG concentration determination by single radial immunodiffusion assay. Multivariable and logistic regression analyses were performed to evaluate factors that predicated serum IgG concentrations and the probability of FTPI, respectively. A Cox proportional hazard model analysis was performed to determine risk factors for mortality over the preweaning period. A total of 164 calves fed 28 colostrum pools were enrolled. Birth weight, number of colostrum feedings and pool IgG concentrations were significant predictors of calf serum IgG concentrations at 24-72 h, whereas the number of colostrum feedings and age at bleeding to determine passive transfer status were not significant predictors of calf serum IgG concentrations at 24-72 h. The prevalence of FTPI was 4.9%. Birth weight, pool IgG concentrations, number of colostrum feedings, and age at bleeding to check for passive transfer status were not significant predictors of the probability of FTPI at 24-72 h. The incidence of mortality was 4.3%. Passive transfer status was not a predictor of mortality. Our study demonstrates the effect of pooling colostrum on serum IgG concentrations even in herds where colostrum with higher median colostrum IgG concentrations is fed to calves. The results emphasize the recommendations to assess pooled colostrum IgG concentrations before feeding calves.

PSII-A-6 Evaluation of Maternal Plane of Nutrition and Selenium Supplementation on the Neonatal Fragment Crystallizable Receptor (Fcrn) in ewe Mammary Tissue

Abstract Maternal immunoglobulin G (IgG) in livestock species is transferred to the offspring exclusively through colostrum. In ruminants, a highly selective mammary barrier allows only immunoglobulin G1 to enter colostrum in substantial amounts. The neonatal fragment crystallizable receptor (FcRn) is responsible for the bidirectional transport of IgG; however, its role in concentrating IgG into colostrum is not well described. The objective of this study was to evaluate maternal nutrition and supranutritional selenium (Se) supplementation on FcRn abundance in mammary tissue. Pregnant Rambouillet ewes (n = 80) were used in a 2 x 3 factorial treatment arrangement which included the main effects of dietary Se [adequate Se (9.5 µg/kg of BW) vs. high Se (81.8 µg/kg of BW)] and plane of nutrition [60%, 100%, and 140% of requirements]. After parturition, ewe mammary glands were collected, and tissue samples were fixed in 10% NBF before paraffin embedding and sectioning. Cross-sections (5 μm) were mounted onto glass slides, deparaffinized, stained for FcRn, and counterstained with DAPI. Areas of tissue cross-sections were captured with Plan-Apochromat 20x/0.8 NA lens using the tiling module of Zeiss software. Images were analyzed using ImagePro Premiere software. Relative fluorescence within the areas of interest was used as an indicator of FcRn abundance with data presented as receptor abundance per glandular tissue area. Data were analyzed using the general linear model procedure of SAS. High Se supplementation increased FcRn abundance per glandular area (P = 0.01). Abundance of mammary FcRn was not influenced by maternal plane of nutrition. Mammary FcRn was positively correlated (r2 = 0.25; P = 0.02) with IgG concentration in colostrum. Results indicate the presence of FcRn in ewe mammary tissue and correlation with colostral IgG. Further evaluation of the role of supranutritional Se and the FcRn is needed.

PSIII-15 Effect of Saccharomyces Cerevisiae Boulardii CNCM I-1079 Supplementation to Sows on Colostrum igG Concentration

Abstract The transmission of passive immunity from the sow to the neonate piglets through colostrum is crucial for their future development. The aim of this experiment was to demonstrate that feeding the live yeast Saccharomyces cerevisiae boulardii CNCM I-1079 (SCB) increases the immunoglobulin G (IgG) concentration in colostrum. In total, 620 colostrum samples were taken from mixed-parity sows (1-9) in 11 farms in Colombia. There were 2 treatments: control (CON; standard feed in gestation and lactation), and SCB (CON + 1 × 109 colony forming units (CFU)/kg, fed from 3 weeks before the expected farrowing date). The samples were taken within the first 4 hours after the birth of the first piglet, from both sides of the teats of the sow, and immediately analyzed with a MA871 refractometer to obtain a °Brix value. Furthermore, each value was attributed to 1 of the 4 following categories regarding IgG concentration: Very good, Adequate, Limited, and Poor. Data were analyzed with SPSS Statistics 26.0 (IBM) and submitted to an analysis of variance with farm as random effect, parity rank and treatment as fixed effects, and their interactions. However, no interaction was found between any of the variables studied. Colostrum from sows in the SCB treatment displayed a higher °Brix value (P &amp;lt; 0.001) than the 1 from sows in the CON treatment. Additionally, the percentage of sows fitting the categories Very good and Adequate was greater in the SCB treatment than in the CON, and the one fitting the categories Limited and Poor was greater in the CON treatment than in the SCB. It is concluded that supplementing sows with Saccharomyces cerevisiae boulardii CNCM I-1079 from 3 weeks before farrowing increases IgG concentration in colostrum, helping the neonate piglets to acquire the passive immunity necessary to improve later performance.

Detection of nucleotide variants in FCGRT (Fc fragment of IgG, receptor, transporter, alpha) gene and their influence on colostral IgG concentration in Indian water buffalo (Bubalus bubalis).

The neonatal Fc receptors (FcRn) mediate the transfer of immunoglobulin G (IgG) molecules from a dam's circulation to the colostrum produced by it immediately after parturition. In ruminants, the calves born are agammaglobulinemic therefore, ingestion of colostrum with high concentration of IgG imparts passive immunity to the newborn. The FcRn molecule is a heterodimer, coded by FCGRT (Fc fragment of IgG Receptor Transporter neonatal) and B2M (Beta 2 microglobulin) genes. Present study attempted to identify single nucleotide polymorphisms (SNPs) in the FCGRT gene in 40 buffaloes of Murrah breed and evaluated the association of these nucleotide variations and haplotypes with IgG concentration in their colostrum. Animals producing colostrum with high IgG and low IgG levels were identified by indirect ELISA and selected. SNPs were detected in the FCGRT gene sequence of selected animals by amplifying it in nine fragments covering all exons (with flanking introns) followed by PCR-single strand conformational polymorphism (PCR-SSCP). A total of nine SNPs were observed of which seven were present in flanking introns and two in exon 4 of the gene. The SNP A75G was non-synonymous and produced an amino acid change from isoleucine to valine. The exonic SNPs and corresponding haplotypes were found to be significantly (P < 0.01 and 0.05 respectively) associated with colostral IgG concentration based on Odds ratios at 95% confidence interval. Polymorphism in FCGRT gene is found to be associated with IgG concentration in colostrum and identification of females with desirable variations may prevent failure of passive transfer in neonatal ruminants.

Cow-level factors associated with colostrum yield and quality of Holstein dairy cows

Context Colostrum feeding and hence transfer of sufficient immunoglobulin G (IgG) is vital for protecting against disease in the neonatal calf. A wide range of variations exists in colostrum yield, IgG concentration and many factors that affect colostrum quality. Aims The current study aimed to determine the cow-level factors associated with colostrum yield, IgG concentration, and somatic cell score (SCS) in dairy cows. Methods Colostrum weight from 152 Holstein dairy cows from a commercial dairy herd was recorded, and SCS and IgG concentration were analysed. Cow-level factors were obtained from the on-farm computer software. The mixed linear model (PROC MIXED) was used to analyse the colostrum quality and production. Key results A calving body condition score (BCS) of &lt;3 was associated with higher colostrum production and a lower colostrum IgG concentration. Furthermore, cows that lost their BCS during the dry period (DP) produced less colostrum IgG concentration than did cows that maintained or gained BCS. Cows with BCS of &gt;3.5 at dry-off and calving had greater colostrum SCS. Cows that gained or lost BCS during the DP had the greatest and lowest colostrum SCS. Moreover, colostrum yield was highest in second-lactation cows, and cows with &lt;45 day DP length (DPL) produced more colostrum with a higher IgG concentration. Higher-parity cows produced higher IgG-concentration colostrum. Colostrum SCS increased with increasing parity, and cows with &gt;75 day DPL had the greatest SCS. Cows with &gt;12 500 kg energy-corrected milk in previous lactation produced colostrum with the greatest IgG concentration and lowest SCS. Also, colostrum production was greater in singleton cows than in twinning cows, while colostrum SCS was lower. Moreover, cows that experienced clinical mastitis in the previous lactation had greater colostrum SCS than did cows without mastitis. Conclusions The results indicated that cow-level factors affect colostrum yield, quality, and SCS and highlighted the importance of routine colostrum testing. Finally, these results may help producers and advisers make decisions to improve colostrum production and quality. Implications Future research should focus on the effect of BCS change during the DP on colostrum yield and quality.

Validation of Brix refractometer to estimate immunoglobulin G concentration in goat colostrum.

Background and Aim:Immunoglobulin G (IgG) concentration is high in goat colostrum, particularly in the first few hours after parturition, and this is important for the kid’s immunity and growth. IgG levels vary depending on several factors, including breed, disease status, colostrum management, handling, and collection time postpartum. A handheld optical refractometer, an affordable instrument that is simple to use in the field, is used widely in dairy farms to measure total solids. However, it can also be applied to estimate colostrum IgG content on the basis of comparison with standard measurement methods, usually radial immunodiffusion. Studies comparing %Brix values in relation to IgG concentration measured using enzyme-linked immunosorbent assay (ELISA) in goats are limited. The present study aimed to evaluate the use of a handheld optical Brix refractometer for the measurement of IgG concentration in goat colostrum, compare results with those using ELISA, and estimate the %Brix cutoff value equating to low-quality colostrum.Materials and Methods:Colostrum samples were collected on day 0 from 21 goats (nine Black Bengal, six Saanen, and six of their crossbred offspring) and were frozen. Subsequently, they were analyzed for IgG concentration using a goat-specific ELISA test and Brix percentage using a handheld refractometer. The optimum %Brix cutoff value for the evaluation of colostrum quality was evaluated.Results:The mean IgG concentration and %Brix in colostrum were 10.60±0.64 mg/mL and 25.0±0.9, respectively. There was a significant (p<0.01) correlation between %Brix and IgG concentration. For an IgG concentration of 6.9 mg/dL, the cutoff value for %Brix was 18.5, equating to high specificity (100%) but low sensitivity (50%). A higher %Brix cutoff value of 21.5 showed high specificity (95%) and high sensitivity (100%).Conclusion:A Brix refractometer can be used to estimate goat colostrum quality with a proposed %Brix cutoff value of <18.5%-21.5% for poor-quality colostrum.

Suitability of Protein Content Measured by MilkoScan FT-Plus Milk Analyzer to Evaluate Bovine and Ovine Colostrum Quality.

Simple SummaryA rapid and reliable method for assessing colostrum quality is needed to ensure enough immunoglobulins available to offspring in order to avoid the failure of the passive transfer of immunity. This study evaluates MilkoScan FT-plus as a rapid tool for the evaluation of immunoglobulin content indirectly by protein content measurement and thus colostrum quality with a particular focus on bovine and ovine colostrum. The results indicate that MilkoScan FT-plus has good agreement with the reference method for the measurement of immunoglobulin concentration in colostrum represented by the radial immunodiffusion method.The objective of this study was to evaluate MilkoScan FT-plus for the estimation of the immunoglobulin G (IgG) content in bovine and ovine colostrum. Between April and May 2016, a total of 94 colostrum samples (54 from Simmental dairy cows and 39 from Sarda ewes) were collected within 6 h (T0) and after 24 h (T24) from parturition. Colostrum samples were subjected to the radial immunodiffusion (RID) assay for the quantification of IgG and to MilkoScan FT-plus for the estimation of protein content (TP, %), which was then used as an indirect method for the evaluation of colostrum quality. To compare the two methods, correlation and regression analysis of IgG quantification by RID and protein (%) content estimation by MilkoScan FT-plus data was performed using Procedure CORR and Procedure REG of SAS, respectively (version 9.3, SAS Institute Inc., Cary, NC, USA). Thresholds for the classification of good colostrum quality (as determined by RID assay, the gold standard method) were set at 50 g of IgG/L in cows and 20 g of IgG/L in ewes. The concentration of IgG in bovine colostrum assayed by RID showed a variation ranging from 41.45 to 199.97 g/L with an average of 99.85 ± 40.84 g/L at T0, and from 2.83 to 75.93 g/L with an average of 19.76 ± 19.01 g/L at T24. Regarding ovine colostrum, the concentration of IgG assayed by RID ranged from 34.45 to 156.32 g/L with an average value of 77.82 ± 37.58 g/L at T0, and from 5.6 to 69.74 g/L with an average of 27.90 ± 19.81 g/L at T24. Colostrum TP ranged from 3.70 to 23.96% for bovine colostrum and 6.32 to 22.88% for ovine colostrum using MilkoScan FT-plus. MilkoScan FT-plus and RID data were highly and significantly correlated (r = 0.91 for bovine and r = 0.94 for ovine colostrum), and regression analysis showed a strong relationship between IgG concentration provided by RID assay and TP provided by MilkoScan FT-plus (R2 = 0.84 and 0.88 for bovine and ovine, respectively). Optimal cut-off points for the greatest accuracy of TP (%) determined by MilkoScan FT-plus were 12.8% in cows [with 88.9% sensitivity (Se) and 100% specificity (Sp)] and 9% in ewes (with 96.7% Se and 100% Sp). In conclusion, these outcomes indicate that MilkoScan FT-plus as an indirect method may be a reliable tool for the estimation of the total IgG concentration and quality in bovine and ovine colostrum. Moreover, the cut-off levels of 12.8% for bovine and 9% for ovine of TP, seem sufficient to ensure that all poor-quality colostrum can be classified as such, with only a low proportion of good-quality colostrum being misclassified as poor-colostrum, thereby increasing the probability of delivering good-quality colostrum to new-born calves and lambs.

Evaluation of Brix Refractometry for the Estimation of Colostrum Quality in Jennies

Donkey placenta does not allow the passage of immunoglobulins; thus, foals are born hypogammaglobulinemic and an adequate intake of high-quality colostrum in the first 24 hours of life is crucial for the surviving. The study aims to assess the relation between colostrum immunoglobulin G (IgG) concentration evaluated by the single radial immunodiffusion (SRID) test and the Brix refractometer in donkeys to establish a cutoff value for high quality of colostrum based on Brix refractometry. Colostrum was collected at foaling, and at 6, 12, and 24 hours after foaling from the left and the right half of nine Amiata jennies. A total of 72 colostrum samples were analyzed. A Friedman test with a Dunn’s test for multiple comparisons was used for assessing the differences between the left and right half at each sampling time. No differences were found between the left and right halves; the average value was used to analyze the effect of sampling time on the IgG concentrations and Brix values. The relationship between colostrum IgG concentrations (SRID test) versus Brix value and Brix value versus time was analyzed using two different mixed linear models. A strong statistically significant relation has been found between IgG concentrations and Brix values (R2 = 0.84). The relation between IgG concentrations and Brix refractometer showed a cutoff point of 17% Brix score for the identification of high-quality colostrum. The Brix value (%) decreased continuously from 16.29 by 0.29 × hour. Jennies’ and donkey foals’ management may be greatly improved using this simple and cheap device.

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

BackgroundBrix 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.ObjectivesEvaluate 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.AnimalsBeef cows (n = 416) from 11 cow‐calf operations in Alberta, Canada.MethodsColostral 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.ResultsBrix 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 ImportanceBrix 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.

Supplementing protein and starch combined to ewes in good body condition may not improve colostrum in ewes

Context Lamb survival can be compromised by twin-bearing ewes being unable to produce enough colostrum and immunoglobulins following parturition. Without sufficient colostrum production, newborn lambs are at risk of death due to starvation, mismothering, exposure and infection. These deaths can be reduced by altering the ewe’s nutrition in the final weeks of pregnancy. Starch, a glucose precursor, has increased colostrum production; however, the digestibility of starch can be increased with protein supplement, which may increase colostrum production. Aims Two separate experiments evaluated if protein supplementation, to a high-starch diet could improve colostrum production and immunoglobulin G (IgG) concentration in twin-bearing ewes. It was hypothesised that the addition of protein to a high-starch diet would have a cumulative effect on colostrum production and IgG. Methods Ewes in both experiments were randomly allocated to one of two treatments –control and protein (120 g/day canola meal) – with both treatments receiving 600 g/head.day barley grain. Feeding began from Day 130 of gestation until 2–10 days post-lambing. Key results Colostrum IgG concentration at 2–10 days old did not differ between treatments (P > 0.05) in both experiments. In Experiment 2, colostrum (3–7 h post-lambing) and milk production (2 days post-lambing) did not differ between treatments (P > 0.05), although metabolisable energy intake was affected by treatment (P = 0.018) with protein supplemented ewes consuming 12.91 ± 0.612 MJ ME/day and control ewes consuming 10.78 ± 0.854 MJ ME/day. Conclusions Supplementation of ewes with protein when consuming high-starch diets did not increase colostrum production nor the IgG concentration of colostrum in ewes with pre-lambing body condition scores above industry recommendations. Implications Supplementation of protein and starch combined has limited commercial viability and would not be recommended for late gestation ewes to increase colostrum production. However, supplementation of ewes on low-quality feed with canola meal can increase metabolisable energy intake, which may have other production benefits.

Short communication: Use of a digital refractometer in assessing immunoglobulin G concentrations in colostrum and the first 5 transition milkings in an Irish dairy herd

Transition milk is a source of immunoglobulin G (IgG) and could potentially be used to provide calves with passive immunity, when the IgG concentration is ≥50 g/L. Assessment of IgG concentrations in transition milk would be required before feeding and could be conducted using cow-side tests such as refractometers. Currently, limited information is available on the ability of refractometers to assess transition milk quality. We hypothesized that digital refractometry could be used to provide an accurate cow-side assessment of IgG concentrations in colostrum and transition milk, and IgG concentration in colostrum and one or more transition milking in an Irish herd is >50 g/L. The objectives of this study were to determine the IgG concentrations in colostrum and first, second, third, fourth, and fifth transition milk, and determine the utility of a digital refractometer in assessing quality of colostrum and transition milk produced by cows in a pasture-based dairy production system. A convenient sample of 75 dairy cows were enrolled. Colostrum and transition milk IgG concentrations were determined by radial immunodiffusion and refractometry. Sensitivity and specificity of the refractometer were determined and cut-off points that maximized sensitivity and specificity were determined using receiver operating characteristic curves. Median (range) IgG concentrations in colostrum and first, second, third, fourth, and fifth milking were 99.6, 43.5, 12.5, 5.3, 1.9, and 1.8 g/L, respectively. The sensitivity (0.8-1) of digital refractometry in identifying samples with low IgG concentrations in colostrum, first, second, and third transition milk was acceptable. In contrast, digital refractometry was not useful for assessing IgG concentrations in the fourth and fifth milking due to low IgG concentrations.

L-arginine supplementation in sow diet during late gestation decrease stillborn piglet, increase piglet birth weight and increase immunoglobulin G concentration in colostrum

The fetal growth is rapid during the last trimester of gestation in sows and hence sow nutrition during this period is important for fetal growth and development. During the last decade, studies reported that l-arginine HCl supplementation during gestation increased sow and piglet performances. However, clinical studies concerning the association between l-arginine HCL supplementation and some neonatal piglet characteristics as well as colostrum and milk yield of sow are still lacking. The present study aims to determine the effect of l-arginine HCl supplementation in sow diet during late gestation on piglet characteristics at birth, colostrum consumption (CC), concentration of immunoglobulin G (IgG) in colostrum, milk yield, average daily gain at d 7 and 21 and piglet mortality at d 7 and 21 of life. In total, 166 sows were allocated into four groups, i.e., CON (n = 66), ARG-0.5 (n = 42), ARG-1.0 (n = 41) and ALA (n = 17). The sows in each group were fed with a conventional gestation diet (CON) or the same diet supplemented with 0.5% l-arginine HCl (ARG-0.5), 1.0% l-arginine HCl (ARG-1.0) or 1.7% l-alanine (ALA, isonitrogenous with ARG-1.0). The feeding protocol was carried out from 85 days of gestation until farrowing. The proportion of live-born piglets, piglet birth weight (BWB), within-litter variation of BWB, proportion of piglets with BWB above 1.35 kg, proportion of growth-restricted piglets (defined as BWB below 1.0 kg), blood oxygen saturation (SatO2) and heart rate were determined in 2292 newborn piglets from 166 litters. Colostrum consumption of each individual piglets and the colostral concentration of IgG was determined. The milk yield between d 0–7 and 7–21 and relative backfat loss were estimated in each individual sow. The piglet mortality and body weight was determined at d 7 and 21 of life. On average, the number of piglet born alive per litter was 12.4. The proportion of stillborn piglets, piglets with BWB above 1.35 kg and growth-restricted piglets were 6.9%, 62.7% and 14.0%, respectively. Piglet preweaning mortality at d 7 and 21 were 8.5% and 12.4%, respectively. Compared to the ALA group, ARG-0.5 increased the proportion of live-born piglets per litter (+9.8%, P < 0.001), reduced stillborn (−8.3%, P < 0.001) and tended to increase the proportion of piglets with BWB above 1.35 kg (+6.4%, P = 0.08). Compared to the CON group, ARG-0.5 increased BWB (+7.0%, P < 0.001), increased SatO2 (+3%, P < 0.001) and reduced heart rate (−20%, P < 0.001) and tended to reduce the relative backfat loss (−4.4%, P = 0.06). No difference between ARG-1.0 and ARG-0.5 was observed among these traits. Other traits including within-litter variation of BWB, growth-restricted piglets, average daily gain, piglets preweaning mortality and CC and milk yield were not affected by treatment (P > 0.05). The colostral concentration of IgG at 1 h after onset of farrowing in ARG-1.0 sows (116 mg/ml) was higher than CON, ARG-0.5 and ALA sows (85, 74 and 78 mg/ml, respectively; P < 0.05). In conclusions, dietary l-arginine HCl supplementation in late gestating sows favourably increased proportion of live-born piglets, BWB, SatO2 and IgG concentration in the sow colostrum.

Factors associated with colostrum immunoglobulin G concentration in northern-Victorian dairy cows.

To determine the proportion of first-milking colostrum samples produced on four northern-Victorian dairy farms that meet industry standards in terms of immunoglobulin G (IgG) concentration and to identify risk factors that affect colostrum quality. Colostrum IgG concentrations from 442 dairy cows on four farms were estimated using a Brix refractometer and risk factors for colostrum IgG concentration were determined using multivariable logistic regression. Only 39% of samples met the definition of high quality. The strongest predictor for colostrum quality was the interval from calving to colostrum harvesting. Colostrum harvested from cows within 12 h of calving was 6-fold more likely to be high quality compared with colostrum harvested later. Colostrum from cows in ≥ 4th lactation was nearly twice as likely to be high quality compared with cows entering their 1st lactation. If the calf was not allowed to suckle from the dam prior to colostrum harvesting, the odds of producing high-quality colostrum were nearly 4-fold greater. If the cow had not leaked colostrum prior to harvesting, it was more than 3-fold more likely to produce high-quality colostrum. The majority of samples assessed were below industry standard. Herd, lactation number, calf suckling or cow leaking colostrum prior to harvesting and time between calving and colostrum harvesting were factors that influenced colostrum IgG concentration. The results support current industry recommendations of harvesting colostrum shortly after parturition (ideally within 12 h of calving) and testing the quality of all colostrum prior to feeding to dairy calves.

The effect of farrowing induction on colostrum and piglet serum immunocrits is dependent on parity.

Farrowing induction is a common practice among swine producers to manage timing of farrowing and the labor associated with farrowing. In this experiment, the effect of induction of labor using cloprostenol on Day 114 of gestation ( = 88) was compared to our standard farrowing protocol at USMARC (natural farrowing with induction using cloprostenol on Day 116 if needed, = 82) in gilts and sows up to fourth parity. In a subset of dams ( = 10 each treatment), colostrum was collected within 30 min of birth of the first piglet, and at 4, 8, 12, and 24 h. Colostrum samples were measured for immunoglobulin G (IgG) using the immunoglobulin immunocrit and porcine IgG specific ELISA, and for total protein. Blood samples were collected from each live piglet on d 1 of age and measured using the immunocrit assay, and average immunocrit was calculated for each litter. Total piglets born and born alive, birth and weaning weights, and the stillbirth rate and preweaning mortality rate were also recorded for each litter. Results indicated that induction of farrowing by cloprostenol treatment on d 114 reduced average gestation length by 0.5 to 1 d depending on parity ( < 0.05), and reduced overall colostrum immunocrit, IgG and total protein ( < 0.05). Colostrum immunocrits and IgG concentrations were well correlated ( = 0.89; < 0.01) but IgG was curvilinearly related to total protein. Litter average immunocrits were similar in gilts between treatments, but were reduced in later parity sows induced to farrow using cloprostenol on d 114 of gestation. Total born, born alive, birth and weaning weights, and stillbirth and preweaning mortality rates were unaffected by treatments. In conclusion, induction of farrowing using cloprostenol injection on d 114 reduced colostrum IgG concentrations in dams, but this was reflected in a reduction in litter average immunocrit only in later parity sows. This reduction in litter average immunocrit was not sufficient to influence preweaning mortality, but other effects are possible given the reported influence of colostrum on growth and reproductive traits.

The effect of cow-level factors on colostrum quality, passive immunity and health of neonatal calves in a pasture-based dairy operation

A study of 95 cows (19 primiparous and 76 multiparous) and their offspring was performed on a pasture-based dairy in the coastal region of South Africa. Collected data included weight changes during the dry period, colostrum immunoglobulin G (IgG) and calf serum IgG at 24–48 h after birth. Colostrum and serum IgG concentrations were measured using radial immunodiffusion and colostrum was regarded as having adequate IgG concentration if the amount was ≥50 g/L. Calf serum IgG concentration of ≥10 g/L was considered an adequate transfer of passive immunity. The median (range in parentheses) colostrum quality for cows with weight loss during the dry period was 23.1 g/L (9.0, 108.1) compared with 61.9 g/L (10.9, 200.0) in cows without weight loss. The median serum IgG of calves from cows with weight loss was 9.9 g/L (0.5, 44.6) compared with 14.0 g/L (0.5, 76.3) in calves from cows that did not lose weight during the dry period. Cows experiencing weight loss were four times more likely to have colostrum with lower concentrations of IgG (OR = 0.25; 95% CI, 0.07–0.88; P = 0.030). Lactation number was also significantly associated with colostrum IgG concentration (P &lt; 0.001), with younger cows tending to have higher IgG concentrations. Failure of passive transfer did not have a significant effect on any calf-health or production variables measured in the study. The effect of dry-cow feeding on colostrum IgG concentration is poorly understood and inadequate pasture management could have an impact on colostrum quality in pasture-based dairy herds.