Impact of volume, immunoglobulin G concentration, and feeding method of colostrum product on neonatal nursing behavior and transfer of passive immunity in beef calves.

One-third of beef calves fail to achieve adequate transfer of passive immunity (TPI) through timely ingestion of colostrum, which substantially increases their risk of preweaning morbidity and mortality. Two randomized clinical trials were designed to assess the impact of volume, immunoglobulin G (IgG) concentration, and feeding method of colostrum product on neonatal nursing behavior and TPI. In Trial 1, 47 calves were randomly assigned to receive one of three colostrum interventions by oro-esophageal tube feeder (OET): 1 L with 100 g/L IgG, 1.4 L with 70 g/L IgG, or 2 L with 100 g/L IgG. In Trial 2, 29 calves were randomly assigned to be fed 1 L of colostrum product with 100 g/L IgG by either nipple bottle (NB) or OET. Colostrum intervention (i.e. feeding of colostrum product) occurred within 60 minutes of birth. Cow-calf pairs were monitored by video surveillance in individual stalls for 24 h. Dam colostrum was collected at 10 minutes and calf serum was collected at 24-36 h after birth to assess IgG concentration. Differences among colostrum intervention groups on latency to stand and nurse were analyzed using Kaplan-Meier survival curves and Cox proportional hazard models. The impact of colostrum intervention group on TPI was assessed using multivariable linear regression modeling. In Trial 1, calves fed 1.4 L with 70 g/L IgG by OET nursed from their dams statistically significantly earlier compared to calves fed 1 L with 100 g/L IgG (P = 0.003) and calves fed 2 L with 100 g/L IgG (P = 0.008). Six of the 15 calves in the NB group in Trial 2 refused to consume part of the colostrum feeding offered by bottle and required follow-up tube feeding of the remaining volume. These calves were analyzed as a separate group (NB + OET). Calves fed 1 L by NB stood and nursed statistically significantly earlier than calves fed by OET (P = 0.005) or a combination of NB + OET (P = 0.003). Calf serum IgG concentrations were not statistically significantly different among colostrum intervention groups (P > 0.1). Overall, the colostrum interventions assessed in this study led to only one calf with failed TPI. While statistically significant differences in serum IgG concentrations were not detected in this study, subsequent nursing behavior did vary and was improved by feeding a moderate volume (1.4 L with 70 g/L IgG) of colostrum when using an OET, and by using the NB when feeding a smaller volume (1 L with 100 g/L IgG).

Feeding colostrum or a 1:1 colostrum:whole milk mixture for 3 days after birth increases serum immunoglobulin G and apparent immunoglobulin G persistency in Holstein bulls.

Conflicting reports exist on whether prolonged IgG consumption can further increase serum IgG in neonatal calves. Given that higher serum IgG in neonates has lifelong benefits, our objective was to determine whether serum IgG can be increased by providing multiple meals containing IgG to neonatal calves. Twenty-seven Holstein bulls were all fed 1 colostrum meal (7.5% body weight; 62 g of IgG/L) at 2 h after birth and randomly assigned to be fed (5% body weight) colostrum (COL; n = 9), whole milk (WM; n = 9), or a 1:1 colostrum:whole milk mixture (MX; n = 9) every 12 h from 12 to 72 h. Serum IgG was measured at 1, 2, 3, 6, 9, 11, and 12 h after birth. After the 12-h meal, IgG was determined at 0.5-h intervals until 16 h and then at 1-h intervals from 16 to 24 h. Serum IgG was then measured at 27 h, then every 6 h from 30 to 60 h. From 60 to 64 h, IgG was measured every 0.5 h, then at 65 and 66 h, and then every 2 h until 72 h. Serum IgG increased rapidly between 2 and 12 h for all calves. A treatment × time interaction occurred as serum IgG began to diverge between treatments after they were fed at 12 h; the interaction was greatest over the entire period for COL compared with both MX and WM and was greater for MX than for WM. Maximum IgG concentrations (Cmax) were 30.4 ± 0.8, 27.2 ± 0.8, and 23.9 ± 0.8 g/L for COL, MX, and WM, respectively. Although MX Cmax was equivalent to both COL and WM Cmax, COL Cmax was greater than WM Cmax. Feeding COL and MX also prolonged the time to reach Cmax. Respectively, these calves achieved Cmax at 29.5 and 27.0 ± 3.4 h, whereas WM IgG peaked at 13.4 ± 3.4 h. No differences were observed for apparent efficiency of absorption between treatments from 0 to 12 h and 0 to 24 h. Immunoglobulin G area under the curve (AUC) was the same for COL and MX calves over the entire experimental period and from when treatments were fed. The IgG AUC for 0 to 72 h for WM calves was 27.4% lesser than that for COL calves but not different from MX calves. However, the IgG AUC for 12 to 72 h for WM calves differed relative to that for both COL (30.8% less) and MX (19.6% less) calves. Serum IgG concentrations were more persistent when COL (88.2 ± 2.4%) and MX (91.2 ± 2.4%) were fed rather than WM (75.3 ± 2.4%). Prolonged IgG consumption increased serum IgG concentrations, corresponding to the mass of IgG fed, and improved apparent IgG persistency in Holstein bulls. Neonatal calves should be fed at least 62 g of IgG at 12 h after birth to further increase serum IgG concentrations.

Consensus recommendations on calf- and herd-level passive immunity in dairy calves in the United States.

Passive immunity in calves is evaluated or quantified by measuring serum or plasma IgG or serum total protein within the first 7 d of age. While these measurements inform about circulating concentrations of this important protein, they are also a proxy for evaluating all of the additional benefits of colostral ingestion. The current individual calf standard for categorizing dairy calves with successful passive transfer or failure of passive transfer of immunity are based on serum IgG concentrations of ≥10 and <10 g/L, respectively. This cutoff was based on higher mortality rates in calves with serum IgG <10 g/L. Mortality rates have decreased since 1991, but the percentage of calves with morbidity events has not changed over the same time period. Almost 90% of calves sampled in the USDA National Animal Health Monitoring System's Dairy 2014 study had successful passive immunity based on the dichotomous standard. Based on these observations, a group of calf experts were assembled to evaluate current data and determine if changes to the passive immunity standards were necessary to reduce morbidity and possibly mortality. In addition to the USDA National Animal Health Monitoring System's Dairy 2014 study, other peer-reviewed publications and personal experience were used to identify and evaluate potential standards. Four options were evaluated based on the observed statistical differences between categories. The proposed standard includes 4 serum IgG categories: excellent, good, fair, and poor with serum IgG levels of ≥25.0, 18.0-24.9, 10.0-17.9, and <10 g/L, respectively. At the herd level, we propose an achievable standard of >40, 30, 20, and <10% of calves in the excellent, good, fair, and poor categories, respectively. Because serum IgG concentrations are not practical for on-farm implementation, we provide corresponding serum total protein and %Brix values for use on farm. With one-third of heifer calves in 2014 already meeting the goal of ≥25 g/L serum IgG at 24 h of life, this achievable standard will require more refinement of colostrum management programs on many dairy farms. Implementation of the proposed standard should further reduce the risk of both mortality and morbidity in preweaned dairy calves, improving overall calf health and welfare.

Feeding colostrum or a 1:1 colostrum:milk mixture for 3 days postnatal increases small intestinal development and minimally influences plasma glucagon-like peptide-2 and serum insulin-like growth factor-1 concentrations in Holstein bull calves.

This study evaluated how feeding colostrum- or a colostrum-milk mixture for 3 d postnatal affects plasma glucagon-like peptide-2 (GLP-2), serum insulin-like growth factor-1 (IGF-1), and small intestinal histomorphology in calves. Holstein bulls (n = 24) were fed colostrum at 2 h postnatal and randomly assigned to receive either colostrum (COL), whole milk (WM), or a 1:1 COL:WM mixture (MIX) every 12 h from 12 to 72 h. A jugular venous catheter was placed at 1 h postnatal to sample blood frequently for the duration of the experiment. Samples were collected at 1, 2, 3, 6, 9, 11, and 12 h. Following the 12-h meal, blood was collected at half-hour intervals until 16 h and then at 1-h intervals from 16 to 24 h. A 27-h sample was taken, then blood was sampled every 6 h from 30 to 60 h. Again, blood was taken at half-intervals from 60 to 64 h, then at 65 and 66 h, following which, a 2-h sampling interval was used until 72 h. Plasma GLP-2 (all time points) and serum IGF-1 (at time points: 1, 6, 12, 18, 24, 36, 48, and 72 h) were both analyzed. Duodenal, jejunal, and ileal tissues were collected at 75 h of age to assess histomorphology and cellular proliferation. Feeding COL, rather than WM, increased plasma GLP-2 by 60% for 2 h and tended to increase GLP-2 by 49.4% for 4 h after the 60-h meal. Insulin-like growth factor-1 area under the curve (from 12 to 72 h) tended to be 27% greater for COL than WM calves but was otherwise unaffected by treatment. Ileal crypts tended to proliferate more with MIX than WM, whereas ileal crypt proliferation did not differ for COL compared with MIX or WM and was not different between treatments in the proximal jejunum. Villi height was increased 1.8 and 1.5× (COL and MIX vs. WM) in the proximal and distal jejunum, respectively, whereas MIX duodenal and ileal villi height tended to be 1.5 and 1.4× that of WM. Crypt depth did not differ in any region. Surface area of the gastrointestinal tract was reduced for WM by 60 and 58% (proximal jejunum) and 38 and 52% (ileum) relative to COL and MIX and was 54% less than MIX in the distal jejunum. Overall, extended COL feeding minimally increased plasma GLP-2 and serum IGF-1 compared with WM feeding. As COL and MIX similarly promoted small intestinal maturation, feeding calves transition milk to promote intestinal development could be a strategy for producers.

Oligosaccharide concentrations in colostrum, transition milk, and mature milk of primi- and multiparous Holstein cows during the first week of lactation.

The objective of this study was to characterize the oligosaccharide (OS) profile of colostrum and transition milk from primiparous (Pp, n = 10) and multiparous (Mp, n = 10) Holstein cows. The experiment was conducted on a commercial dairy farm, where cows were assigned to the study at calving. Colostrum (milking 1) was collected at 5.3 ± 0.7 h after parturition, followed by collection of milkings 2 through 6, milkings 8, 10, 12, and 14 at 0500 and 1600 h each day. Samples were analyzed for OS concentrations using liquid chromatography-mass spectrometry and for IgG and milk components. Concentration of IgG was highest in colostrum and milking 2. Colostral IgG concentration was less in Pp cows than in Mp cows (82.1 ± 3.1 vs. 106.1 ± 16.2 mg/mL). Colostrum and milkings 2 and 3 had 3'-sialyllactose and 6'-sialyllactose concentrations greater than those of mature milk (milkings 8+). For colostrum and milking 2, 6'-sialyllactosamine concentrations were higher than all other milkings, while disialyllactose was only higher in colostrum. In addition, 3'-sialyllactose was the most abundant OS in colostrum and milkings 2 and 3 compared with all other OS. A parity difference was observed for 6'-sialyllactosamine, with Mp having a higher concentration over the first 7 d in milk than Pp (46.4 ± 8.7 vs. 16.9 ± 3.2 µg/mL). Similar results were observed between milkings for OS yields. Parity differences were detected for 3'-sialyllactose, 6'-sialyllactose, and 6'-sialyllactosamine yield, with Mp yield being greater than Pp over the first 7 d in milk. These findings demonstrate that colostrum and transition milk contain elevated concentrations of certain OS compared with mature milk and suggest further research should be conducted regarding the potential benefits of OS in colostrum and transition milk when fed to newborn calves.

Preweaned heifer management on US dairy operations: Part II. Factors associated with colostrum quality and passive transfer status of dairy heifer calves.

Passive transfer of immunity is essential for the short- and long-term health of dairy calves. The objective of this study was to evaluate factors associated with colostrum quality and passive transfer status of US heifer calves. This study included 104 operations in 13 states that participated in the calf component of the National Animal Health Monitoring System's Dairy 2014 study. This 18-mo longitudinal study included 1,972 Holstein heifer calves from birth to weaning. Multivariable mixed linear regression models were selected using backward elimination model selection after univariate screening to determine which factors were associated with colostrum IgG and serum IgG concentrations. The mean colostrum IgG concentration was 74.4 g/L with 77.4% of colostrum samples having IgG concentrations >50 g/L. The final model for colostrum IgG included colostrum source and a categorized temperature-humidity index value (cTHI) for the month before calving. Mean colostrum IgG concentrations were highest for dams in third and higher lactations (84.7 g/L) and lowest for commercial colostrum replacers (40.3 g/L). Colostrum IgG concentrations were highest for cTHI ≥70 (72.6 g/L) and lowest for cTHI <40 (64.2 g/L). The mean serum IgG concentration was 21.6 g/L, with 73.3% of calves having serum IgG concentrations >15 g/L. The final model for serum IgG concentration included region, heat treatment of colostrum, colostrum source, timing to first feeding, volume of colostrum fed in the first 24 h, age of the calf at blood sampling, and colostrum IgG concentration. Mean serum IgG concentrations were highest for calves that received colostrum from first-lactation dams (25.7 g/L) and lowest for calves fed commercial colostrum replacer (16.6 g/L). Serum IgG concentrations were higher for calves fed heat-treated colostrum (24.4 g/L) than for calves fed untreated colostrum (20.5 g/L). Serum IgG concentration was positively associated with the volume of colostrum fed in the first 24 h and colostrum IgG concentration, and negatively associated with the number of hours from birth to colostrum feeding and age (days) at blood collection. Dairy producers should be encouraged to measure the quality of colostrum before administering it to calves and to measure serum IgG or a proxy such as serum total protein or Brix to evaluate passive immunity and colostrum management programs.

Effect of delaying colostrum feeding on passive transfer and intestinal bacterial colonization in neonatal male Holstein calves.

The objective of this study was to investigate the effect of time of first colostrum feeding on the passive transfer of IgG and on bacterial colonization in the intestine of neonatal dairy calves. Twenty-seven male Holstein calves were randomly assigned to 1 of 3 treatments at birth: calves were fed colostrum at 45 min (0 h, n = 9), 6 h (n = 9), or 12 h after birth (n = 9). Calves were fed pooled, heat-treated colostrum (62 g of IgG/L) at their respective feeding times at 7.5% of birth body weight and fed milk replacer at 2.5% of birth body weight per meal every 6 h thereafter. Blood samples were taken every 3 h using a jugular catheter and were analyzed for determination of serum IgG by radial immunodiffusion. At 51 h after birth, calves were euthanized for collection of tissue and digesta of the distal jejunum, ileum, and colon. Quantitative real-time PCR was used to estimate the prevalence of Bifidobacterium spp., Lactobacillus spp., Fecalibacterium prausnitzii, Clostridium cluster XIVa, and total Escherichia coli. Delaying colostrum feeding by 6 h (35.6 ± 1.88%) and 12 h (35.1 ± 3.15%) decreased the maximum apparent efficiency of absorption of IgG compared with feeding colostrum immediately after birth (51.8 ± 4.18%) and delayed the time to maximum serum IgG concentration (24 h vs. 15 h, respectively). Moreover, 12-h calves tended to have a lower prevalence of Bifidobacterium spp. (0.12 ± 0.017%) and Lactobacillus spp. (0.07 ± 0.019%) associated with the colon mucosa compared with 0-h calves (1.24 ± 0.648% and 0.26 ± 0.075%, respectively). In addition, 6-h (0.26 ± 0.124%) and 12-h (0.49 ± 0.233%) calves had a lower prevalence of total E. coli associated with ileum mucosa compared with 0-h calves (1.20 ± 0.458%). These findings suggest that delaying colostrum feeding within 12 h of life decreases the passive transfer of IgG and may delay the colonization of bacteria in the intestine, possibly leaving the calf vulnerable to infections during the preweaning period.

The effect of tube versus bottle feeding colostrum on immunoglobulin G absorption, abomasal emptying, and plasma hormone concentrations in newborn calves.

The objective of this study was to determine if feeding colostrum to newborn calves through an esophageal tube, compared with a nipple bottle, would delay abomasal emptying, which would in turn decrease passive transfer of IgG and plasma glucose, insulin, and glucagon-like peptide (GLP) 1 and GLP-2 concentrations. Twenty newborn Holstein bull calves were fed 3 L of colostrum replacer (200 g of IgG) through either an esophageal tube or nipple bottle at 2 h after birth followed by feeding pooled whole milk every 12 h after birth. Acetaminophen was mixed into the colostrum meal as a marker for abomasal emptying. A jugular catheter was inserted 1 h after birth and blood was sampled frequently to analyze serum for IgG and acetaminophen and plasma for glucose, insulin, GLP-1, and GLP-2. Feeding method did not affect abomasal emptying, and as a result no treatment effect was present on serum IgG concentrations. Maximum concentration of serum IgG was 24.4 ± 0.40 mg/mL (± standard error), which was reached at 14.6 ± 1.88 h after the colostrum meal for both groups. Apparent efficiency of absorption at maximum concentration of IgG was 52.9%, indicating high efficiency of passive transfer of IgG for both treatments. Tube feeding increased glucose and insulin area under the curve before the first milk meal, most likely due to the decreased time to consume the colostrum meal. In addition, tube-fed calves consumed 0.5 ± 0.13 L more milk in their first milk meal than bottle-fed calves. No treatment effect on plasma concentrations of GLP-1 or GLP-2 was present, but both hormones increased after colostrum feeding. These findings confirm that there is no effect on absorption of IgG from colostrum when feeding good-quality colostrum at a volume of 3 L through either an esophageal tube or nipple bottle.

Effects of prepartum stocking density on innate and adaptive leukocyte responses and serum and hair cortisol concentrations.

Objectives were to evaluate the effects of prepartum stocking density on innate and adaptive leukocyte responses, serum cortisol and haptoglobin concentrations and hair cortisol concentration of Jersey cows. The cows (254 ± 3d of gestation) were balanced for parity (nulliparous vs. parous) and previous lactation projected 305-d mature equivalent milk yield and assigned to one of two treatments: 80SD=80% stocking density (38 animals/48 headlocks) and 100SD=100% stocking density (48 animals/48 headlocks). Pens (n=4) were identical in size and design and each pen received each treatment a total of 2 times (4 replicates; 80SD: n=338; 100SD: n=418). A sub-group of cows (n=48/treatment per parity) was randomly selected on week 1 of each replicate from which blood was sampled weekly from d -14 to 14 (d 0=calving) to determine polymorphonuclear leukocyte (PMNL) phagocytosis, oxidative burst, and expression of CD18 and L-selectin, and hemogram. The same sub-group of cows was treated with chicken egg ovalbumin on d -21, -7, and 7 and had blood sampled weekly from d -21 to 21 for determination of serum IgG anti-ovalbumin concentration. Blood was sampled weekly from d -21 to 21 to determine glucose, cortisol, and haptoglobin concentrations in serum. Hair samples collected at enrollment and within 24h of calving were analyzed for cortisol concentration. The percentage of leukocytes classified as granulocyte and the granulocyte to the lymphocyte ratio were not affected by treatment. Treatment did not affect the percentage of PMNL positive for phagocytosis and oxidative burst or the intensity of phagocytosis and oxidative burst. Similarly, treatment did not affect the percentage of PMNL expressing CD18 and L-selectin or the intensity of expression of CD18 and L-selectin. Concentration of IgG anti-ovalbumin was not affected by treatment. Serum concentrations of haptoglobin and cortisol were not affected by treatment. Similarly, hair cortisol concentration at calving was not affected by treatment. According to the current experiment, a target stocking density of 80% did not improve leukocyte responses compared with 100% target stocking density.

Supplementing fresh bovine colostrum with gut-active carbohydrates reduces passive transfer of immunoglobulin G in Holstein dairy calves.

High concentrations of coliform bacteria in maternal colostrum (MC) have been associated with reduced IgG absorption in calves. Mannan-oligosaccharide, a gut-active carbohydrate (GAC) derived from yeast cell wall, has been shown to adsorb pathogens expressing type-1-fimbriae, reducing their ability to colonize the gastrointestinal tract. The objective of this study was to investigate if addition of a GAC to colostrum would result in increased IgG absorption in newborn calves. Newborn Holstein heifer and bull calves were enrolled in summer 2012 at a commercial transition cow facility in western Wisconsin. Each day, 7.6-L pools of fresh, first milking MC were created, split into 3.8-L aliquots, and refrigerated until feeding. Eligible newborn calves were removed from the dam 30 to 60min after birth, weighed, and randomly assigned to be fed either 3.8 L of the MC pool (control) or 3.8 L of the MC pool with 30 g of GAC mixed in immediately before feeding. Duplicate 10-mL samples of colostrum were collected and frozen at -20°C before feeding (and before addition of GAC) for bacterial culture and IgG determination. A 10-mL venous blood sample was collected from calves before feeding colostrum and 24 h after colostrum feeding, for laboratory determination of serum IgG using radial immunodiffusion analysis. Colostrum and calf characteristics, including colostrum IgG concentration (g/L), colostrum bacteria counts (log10, cfu/mL), calf dystocia scores (1 to 4), birth weights (kg), and age at first feeding (min) were not different between the group fed GAC (n=47) and the control group (n=48). Mixed linear regression analysis showed that calves fed colostrum supplemented with 30 g of GAC had lower mean (standard error) apparent efficiency of absorption of IgG and lower serum IgG concentrations at 24 h [23.9% (1.0); IgG=24.0 (1.1) g/L] than did control calves [30.4% (1.0); IgG=30.8 (1.0) g/L]. Given the negative effect observed in this study, it is not recommended that fresh colostrum be supplemented with 30 g of GAC.

Addition of gut active carbohydrates to colostrum replacer does not improve passive transfer of immunoglobulin G in Holstein dairy calves.

The primary objective of this study was to investigate the effects of supplementing a commercial colostrum replacer (CR) with gut active carbohydrates (GAC) on passive transfer of IgG in commercial dairy calves. A secondary objective was to evaluate the effect of treatment on preweaning health and growth. A total of 240 newborn Holstein dairy calves on a commercial dairy farm were enrolled in this study. Newborn heifer and bull calves were weighed and then randomly assigned to either the treated group [GAC: 30g of GAC mixed into 1.5 doses (150g of IgG) of commercial colostrum replacer; n=119] or the control group [CON: 1.5 doses (150g of IgG) of CR; n=121]. The assigned CR treatment was fed within 3.5h of birth using an esophageal tube feeder. Venous blood samples were collected at 0 and 24h of age and used to measure serum IgG (mg/mL) and serum total protein (g/dL) concentrations and to estimate the apparent efficiency of absorption of IgG (%). The 129 heifers calves enrolled (CON=60; GAC=69) were also followed until weaning to assess the effect of GAC addition on preweaning health and growth. Multivariable linear regression showed that the addition of GAC to CR did not influence passive transfer of IgG, as measured by apparent efficiency of absorption at 24h of age (CON=54.0 vs. GAC=54.3%), serum IgG (CON=20.3 vs. GAC=20.2mg/mL), and serum total protein (CON=5.69 vs. GAC=5.68g/dL). Although study sample sizes were not originally derived to evaluate health outcomes, treatment had no effect on weight gain or incidence of health events (diarrhea, pneumonia, mortality) for heifer calves between birth and 7 wk of age.

Application of low-background gamma-ray spectrometry to monitor radioactivity in the environment and food.

The results are described of an upgrade of the low-background gamma-ray spectrometry laboratory at New York State Department of Health by acquiring sensitivity to low-energy gamma rays. Tuning of the spectrometer and its low-energy response characteristics are described. The spectrometer has been applied to monitor the environment by measuring aerosols and water in New York State contaminated by the 2011 Fukushima accident plume. In addition, the spectrometer has been used to monitor radioactivity in food by performing a study of cesium in Florida milk.

Evaluation of a Brix refractometer to estimate serum immunoglobulin G concentration in neonatal dairy calves.

The objective of this study was to evaluate the utility of a digital Brix refractometer for the assessment of success of passive transfer of maternal immunoglobulin compared with the measurement of serum total protein (STP) by refractometry. Blood samples (n = 400) were collected from calves at 3 to 6d of age. Serum IgG concentration was determined by radial immunodiffusion (RID), and STP and percentage Brix (%Brix) were determined using a digital refractometer. The mean IgG concentration was 24.1g/L [standard deviation (SD) ± 10.0] with a range from 2.1 to 59.1g/L. The mean STP concentration was 6.0 g/dL (SD ± 0.8) with a range from 4.4 to 8.8 g/dL. The mean %Brix concentration was 9.2% (SD ± 0.9) with a range of 7.3 to 12.4%. Brix percentage was highly correlated with IgG (r = 0.93). Test characteristics were calculated to assess failure of passive transfer (FPT; serum IgG <10 g/L). The sensitivity and specificity of STP at 5.5 g/dL were 76.3 and 94.4%, respectively. A receiver operating characteristic curve was created to plot the true positive rate against the false positive rate for consecutive %Brix values. The optimal combination of sensitivity (88.9%) and specificity (88.9%) was at 8.4% Brix. Serum total protein was also positively correlated with %Brix (r = 1.00) and IgG (r = 0.93). Dairy producers can successfully monitor their colostrum management and the overall success of passive transfer using a digital Brix refractometer to estimate IgG concentration of colostrum and calf serum.

Colostrum replacer feeding regimen, addition of sodium bicarbonate, and milk replacer: the combined effects on absorptive efficiency of immunoglobulin G in neonatal calves.

Eighty Holstein and Holstein cross dairy calves were blocked by birth date and randomly assigned to 1 of 8 treatments within each block to examine the effect of a colostrum replacer (CR) feeding regimen, supplementation of CR with sodium bicarbonate (NaHCO3), and provision of a milk replacer (MR) feeding on IgG absorption. Calves were offered a CR containing 184.5g/L of IgG in either 1 feeding at 0h (within 30 min of birth), with or without 30g of NaHCO3, with or without a feeding of MR at 6h of age, or 2 feedings of CR (123g of IgG at 0h with or without 20g of NaHCO3 and 61.5g of IgG at 6h with or without 10g of NaHCO3), with or without a MR feeding at 12h. Therefore, treatments were (1) 1 feeding of CR; (2) 2 feedings of CR; (3) 1 feeding of CR + 30g of NaHCO3; (4) 2 feedings of CR + 30g of NaHCO3; (5) 1 feeding of CR + MR feeding; (6) 2 feedings of CR + MR feeding; (7) 1 feeding of CR + 30g NaHCO3 + MR feeding; and (8) 2 feedings of CR + 30g NaHCO3 + MR feeding. Blood samples were obtained at 0, 6, 12, 18, and 24h after birth and were analyzed for IgG via radial immunoassay. Results indicated that CR feeding schedule, MR feeding, and the interactions CR × Na, CR × MR, and CR × Na × MR were similar for 24-h serum IgG, apparent efficiency of absorption, or area under the curve. Serum IgG at 24h, apparent efficiency of absorption, and area under the curve were decreased with addition of NaHCO3 compared with calves not supplemented with NaHCO3. These data indicate that supplementation of CR with NaHCO3 is not beneficial to IgG absorption and feeding MR within 6h of CR feeding does not affect IgG absorption.

Acute and Long-Term Impact of Chemical Weapons: Lessons from the Iran-Iraq War.

Chemical weapons have given the human experience of warfare a uniquely terrifying quality that has inspired a general repugnance and led to periodic attempts to ban their use. Nevertheless, since ancient times, toxic agents have been consistently employed to kill and terrorize target populations. The evolution of these weapons is examined here in ways that may allow military, law enforcement, and scientific professionals to gain a perspective on conditions that, in the past, have motivated their use - both criminally and as a matter of national policy during military campaigns. Special emphasis is placed on the genocidal use of chemical weapons by the regime of Saddam Hussein, both against Iranians and on Kurdish citizens of his own country, during the Iran-Iraq War of 1980-88. The historical development of chemical weapons use is summarized to show how progressively better insight into biochemistry and physiology was adapted to this form of warfare. Major attributes of the most frequently used chemical agents and a description of how they affected military campaigns are explained. Portions of this review describing chemical-casualty care devote particular focus to Iranian management of neurotoxic (nerve) agent casualties due to the unique nature of this experience. Both nerve and blistering "mustard" agents were used extensively against Iranian forces. However, Iran is the only nation in history to have sustained large-scale attacks with neurotoxic weapons. For this reason, an understanding of the successes and failures of countermeasures to nerve-agent use developed by the Iranian military are particularly valuable for future civil defense and military planning. A detailed consideration of these strategies is therefore considered. Finally, the outcomes of clinical research into severe chronic disease triggered by mustard-agent exposure are examined in the context of the potential of these outcomes to determine the etiology of illness among US and Allied veterans of the 1991 Persian Gulf War.

Effects of weekly regrouping of prepartum dairy cows on innate immune response and antibody concentration.

Objectives were to evaluate the effects of a stable prepartum grouping strategy on innate immune parameters, antibody concentration, and cortisol and haptoglobin concentrations of Jersey cows. Cows (253±3 d of gestation) were paired by gestation length and assigned randomly to the stable (all-in-all-out; AIAO) or traditional (TRD) treatment. In the AIAO treatment, groups of 44 cows were moved into a pen where they remained for 5 wk, whereas in the TRD treatment, approximately 10 cows were moved into a pen weekly to maintain stocking density (44 cows for 48 headlocks). Pens were identical in size and design and each pen received each treatment a total of 3 times (6 replicates; AIAO, n=259; TRD, n=308). A subgroup of cows (n=34/treatment) was selected on wk 1 of each replicate from which blood was sampled weekly from d -14 to 14 (d 0=calving) to determine polymorphonuclear leukocyte (PMNL) phagocytosis, oxidative burst, and expression of CD18 and L-selectin, hemogram, cortisol and glucose concentrations, and haptoglobin concentration. Another subgroup of cows (n=40/treatment) selected on wk 1 of each replicate was treated with chicken egg ovalbumin on d -21, -7, and 7 and had blood sampled weekly from d -21 to 21 for determination of immunoglobulin G anti-ovalbumin. All cows (n=149) had blood sampled weekly for nonesterified fatty acid (NEFA) and ß-hydroxybutyrate (BHBA) concentrations from d -21 to 21. Treatment did not affect percentage of PMNL positive for phagocytosis and oxidative burst (AIAO=64.3±2.9 vs. TRD=64.3±2.9%) and intensity of phagocytosis [AIAO=2,910.82±405.99 vs. TRD=2,981.52±406.87 geometric mean fluorescence intensity (GMFI)] and oxidative burst (AIAO=7,667.99±678.29 vs. TRD=7,742.70±682.91 GMFI). Similarly, treatment did not affect the percentage of PMNL expressing CD18 (AIAO=96.3±0.7 vs. TRD=97.8±0.7%) and L-selectin (AIAO=44.1±2.8 vs. TRD=45.1±2.8%) or the intensity of expression of CD18 (AIAO=3,496.2±396.5 vs. TRD=3,598.5±396.9 GMFI) and L-selectin (AIAO=949.8±22.0 vs. TRD=940.4±22.3 GMFI). Concentration of immunoglobulin G anti-ovalbumin was not affected by treatment (AIAO=0.98±0.05 vs. TRD=0.98±0.05 OD). The percentage of leukocytes classified as granulocyte (AIAO=38.9±1.5 vs. TRD 38.2±1.5%) and the granulocyte:lymphocyte ratio (AIAO=0.75±0.04 vs. TRD=0.75±0.04) were not affected by treatment. Concentrations of cortisol (AIAO=14.95±1.73 vs. TRD=18.07±1.73 ng/mL), glucose (AIAO=57.6±1.5 vs. TRD=60.0±1.5 ng/mL), and haptoglobin (AIAO=3.09±0.48 vs. TRD=3.51±0.49 OD) were not affected by treatment. According to the current experiment, a stable prepartum grouping strategy does not improve innate immune parameters or antibody concentration compared with weekly prepartum regrouping.

Hot topic: investigating the risk of violative meat residues in bob veal calves fed colostrum from cows treated at dry-off with cephapirin benzathine.

The objective was to conduct a study to investigate if violative meat residues are detected in very young bob veal calves that are fed first-milking colostrum harvested from cows that were dry treated, on-label, with cephapirin benzathine. First-milking colostrum was collected from cows that were given intramammary treatment at dry off, on-label, with cephapirin benzathine (ToMORROW, Boehringer Ingelheim Vetmedica Inc., St. Joseph, MO). Newborn bull calves meeting study inclusion criteria were removed from their dams shortly after birth and before suckling, and assigned to 1 of 2 trials. For the first trial, 6 treated calves were fed 3.8L of fresh maternal colostrum and 1 control calf was fed 1.5 doses of a plasma-derived colostrum replacer (Secure Calf Colostrum Replacer, VitaPlus Inc., Madison, WI) within 1h after birth. For the second trial, 5 treated calves were fed 3.8L of fresh maternal colostrum and 1 control calf was fed 1.5 doses of Secure Calf Colostrum Replacer within 1h after birth. All calves were humanely euthanized at 24h (trial 1) or 48h (trial 2) of age, and tissues were harvested for antimicrobial residue testing. Samples of maternal colostrum and colostrum replacer were also submitted for antimicrobial residue testing. Kidneys collected from all study calves tested negative for cephapirin benzathine residues when using both the KIS assay (Charm Sciences, Lawrence, MA) and liquid chromatography-tandem mass spectrometry analysis. The potential transfer of cephapirin from cows treated on-label at dry off to calves via colostrum may not be a significant source of cephapirin residues in veal tissues.

In vitro suppression of lymphocyte activation in patients with seasonal allergic rhinitis and pollen-related asthma by cetirizine or azelastine in combination with ginkgolide B or astaxanthin.

Novel strategies are evaluated for management of allergic rhinitis and asthma in patients co-afflicted with both disorders. It is hypothesized that the platelet activating factor receptor antagonist ginkgolide B (GB) and the carotenoid antioxidant astaxanthin (ASX) interact with antihistamines cetirizine dihydrochloride (CTZ) and azelastine (AZE) to potentiate their ability to downregulate potentially pathological immune activation. Peripheral blood mononuclear cells from asthmatics and healthy subjects, cultured 24 hours with 50 µg/ml phytohemaglutinin (PHA) or PHA plus each drug are analyzed by flow cytometry for expression of CD25+ or HLA-DR+ by CD3+ (T cells). Results are reported as stimulation indices for CD3+CD25+ (SICD3+CD25+) and CD3+HLA-DR+ (SICD3+HLADR+) cells in cultures treated with PHA alone, versus cultures treated with both PHA and drugs. Optimal suppression of activated cells was observed in cultures stimulated with ASX 10-6 M + CTZ 10-6 M (SICD3+CD25+, p = 0.016; SICD3+HLADR, p = 0.012); ASX 10-6 M + AZE 10-6 M (SICD3+CD25+, p = 0.012; SICD3+HLADR, p = 0.015); GB 10-6 M + CTZ 10-6 M (SICD3+CD25+, p = 0.024, SICD3+HLADR+, p = 0.019). Results demonstrate improved activity of antihistamines by 2 phytochemicals, suggesting dosing strategies for animal trials of ASX- or GB-augmented formulations for seasonal allergic rhinitis and asthma.