Evidence for transfer of maternal antigen specific cellular immunity against Mycobacterium avium ssp. paratuberculosis via colostrum in a goat twin model.

Colostrum intake is one of the most important factors in neonatal health in ruminants, mainly because of its unique immunological properties. Both in practice as well as in research, the attention of lactogenic immunity is focused on the importance of colostral antibodies and less attention is given to the functional role of maternal cells in colostrum. Here we study the transfer of maternal leukocytes via colostrum and the functionality in goat kids. In experiment 1, twenty twin pairs of goat kids from dams previously immunized with an inactivated Mycobacterium avium subsp. paratuberculosis (MAP) vaccine were fed maternal colostrum from their dam (kid 1) or pasteurized and frozen/thawed bovine colostrum (kid 2). The presence of cell mediated immune response (CMIR) against Mycobacterium avium antigens in the kids was assessed using intradermal skin testing with PPD-A tuberculin. Linear mixed effect models showed an increase in skin thickness in response to intradermal PPD-A injection in maternal colostrum fed kids compared to bovine colostrum fed kids. After intradermal PPD-A application, serum concentration of MAP specific antibodies increased in kids fed maternal colostrum, indicating antigen specific activation of the adaptive immune system. We did not detect a similar increase in antibodies in the kids fed bovine colostrum. In experiment 2, a more reductionistic approach was applied to specifically study the effects of the transfer of maternal colostral leukocytes on CMIR in goat kids. Similar to experiment 1, twin kids from MAP immunized dams were randomly divided over two groups. The experimental group received colostrum replacer supplemented with fluorescently labelled colostral cells of the dam and the control group received colostrum replacer only. No difference in skin response following intradermal PPD-A injection was observed between both groups of kids. Histologic examination of the skin at the intradermal injection site did not show fluorescently labelled cells. In conclusion, in our initial experiment we observed an antigen specific CMIR in goat kids fed fresh colostrum with colostral leukocytes from vaccinated dams. The lack of a DTH response in kids fed colostrum replacer supplemented with maternal colostrum derived leukocytes indicated that the complete colostral matrix is probably required for colostrum leukocytes to transfer across the intestinal epithelial barrier and modulate the neonatal immune response. In line with earlier studies, our results indicate that caprine maternal leukocytes present in colostrum can functionally contribute to the newborns' early adaptive immune responses adding to the importance of colostrum feeding in ruminant neonates.

Large inter-individual variation in isoflavone plasma concentration limits use of isoflavone intake data for risk assessment.

BACKGROUND/OBJECTIVES: Isoflavones are present in soy foods and soy-based supplements. Despite low plasma isoflavone concentrations in the general Western population, concentrations in supplement users exceed those suggested to be beneficial for health in Asian populations, raising concerns for adverse effects. To aid risk assessment, quantification of the relation between isoflavone intake and plasma concentrations is essential. SUBJECTS/METHODS: Plasma samples were collected from postmenopausal women in three placebo-controlled crossover studies with 8-week periods for supplements (two studies, ~100 mg isoflavones/day, n=88) or 4-week periods for soy foods (one study, ~48 mg isoflavones/day, n=15). Plasma isoflavone concentrations (daidzein, equol, genistein and glycitein) were quantified using high-performance liquid chromatography and electrochemical detection. The association between plasma concentrations and isoflavone intake, equol producer status, intake-producer interaction and background dietary intake was assessed based on the assumption of a log-linear relation. RESULTS: Median plasma total isoflavone concentrations after the soy food and supplement interventions were respectively 2.16 and 3.47 µmol/l for equol producers and 1.30 and 2.39 µmol/l for non-producers. Regression analysis showed that doubling isoflavone intake increased plasma concentrations by 55-62% (±s.e. 1-2%, R(2)>0.87) for daidzein, genistein, equol (only for producers) and total isoflavones; for glycitein the association was weaker (15±1%, R(2)=0.48). Adjustments for energy, carbohydrate and fat intake did not affect these estimates. Inter-individual variation, estimated based on repeated measures in one of the studies, was 30-96%. CONCLUSIONS: Although the relation between isoflavone intake and plasma concentrations was adequately quantified, the use of isoflavone intake data for risk assessment needs caution due to large inter-individual variation in plasma concentrations.

The effects of three-month oral supplementation with a nutraceutical and exercise on the locomotor pattern of aged horses.

REASONS FOR PERFORMING STUDY: Multiple in vitro studies assessing articular tissues have indicated that glucosamine and chondroitin sulphate may possess anti-inflammatory effects, but little is known of their clinical effects in vivo. Many old horses have stiff joints, which is likely to be attributable to inflammation and therapy with these nutraceutical compounds could improve joint function. OBJECTIVES: To assess the clinical effects of a mixed supplement on the improvement of stiff gait in aged horses. STUDY DESIGN: Randomised, blinded, placebo-controlled study. METHODS: A group of 24 geriatric equids (age 29 ± 4 years; mean ± s.d.) received either 3 months oral supplementation with a test compound (containing glucosamine, chondroitin sulfate and methyl sulfonyl methane), or a placebo. Kinematic outcome criteria (primary: stride length; secondary: carpal flexion, fore fetlock extension and tarsal range of motion) were objectively quantified on a treadmill at a walk and trot before and after treatment. RESULTS: Stride length did not change significantly in the treated horses at the end of the trial. In the control group, carpal flexion and fore fetlock extension were significantly increased (P<0.05). CONCLUSIONS: There were no indications of effect of the supplement on gait characteristics. The observations in the control group may have been due to a habituation or exercise effect. This study does not support the use of a glucosamine/chondroitin sulfate/methyl sulfonyl methane supplement to improve stiff gait in geriatric horses because of the lack of a sizeable effect. The significant changes in gait parameters in the control group may indicate the usefulness of exercise regimens in older horses.

Sports doping: emerging designer and therapeutic ß2-agonists.

Beta2-adrenergic agonists, or ß2-agonists, are considered essential bronchodilator drugs in the treatment of bronchial asthma, both as symptom-relievers and, in combination with inhaled corticosteroids, as disease-controllers. The use of ß2-agonists is prohibited in sports by the World Anti-Doping Agency (WADA) due to claimed anabolic effects, and also, is prohibited as growth promoters in cattle fattening in the European Union. This paper reviews the last seven-year (2006-2012) literature concerning the development of novel ß2-agonists molecules either by modifying the molecule of known ß2-agonists or by introducing moieties producing indole-, adamantyl- or phenyl urea derivatives. New emerging ß2-agonists molecules for future therapeutic use are also presented, intending to emphasize their potential use for doping purposes or as growth promoters in the near future.

Vitamin E supplementation during the dry period in dairy cattle. Part I: adverse effect on incidence of mastitis postpartum in a double-blind randomized field trial.

A randomized, controlled field trial with dairy cows demonstrated an adverse effect of vitamin E supplementation during the dry period on mastitis incidence in early lactation. This study was conducted on farms with historically high rates of mastitis to investigate the benefit of vitamin E supplementation on udder health; however, the outcome showed an adverse effect. The aim of the study was to evaluate whether daily supplementation of 3,000 IU of vitamin E to dairy cows during the dry period could improve udder health in commercial herds with a high incidence of mastitis. On 5 dairy farms, dry cows were randomly divided into 2 experimental groups: a high and a low group. Both groups received a dry cow mineral mix providing 3,000 or 135 IU of vitamin E/cow per day, respectively, between dry-off and calving for a mean period of 8 wk. Providing 3,000 IU of vitamin E exceeds NRC standards, but this amount has been used in previous studies. The experiment, as well as the majority of the statistical analysis, were carried out blinded. Blood was sampled 3 times before calving and on calving day. Serum was analyzed for vitamin E and cholesterol. Vitamin E and the vitamin E:cholesterol ratio were analyzed as dependent variables in mixed models and Student's t-tests to study trends in time and differences between groups. Relative risk calculation and survival analysis were used to study the effect of supplementation on mastitis incidence in the first 3 mo of lactation. The results showed that vitamin E supplements increased both absolute vitamin E and the ratio of vitamin E to cholesterol in blood. In the high group, significantly more subclinical and clinical cases occurred, showing the same trend on all farms. In this study, an initial vitamin E level at dry off above 14.5 µmol/L was a risk factor for clinical mastitis, suggesting that the vitamin E status at the start of the dry period is important. It is recommended to work out exactly at what threshold vitamin E is harmful for udder health before new trials with high dosages of vitamin E are started. Additionally, further research is required to investigate the mechanism by which vitamin E affects udder health.

Vitamin E supplementation during the dry period in dairy cattle. Part II: oxidative stress following vitamin E supplementation may increase clinical mastitis incidence postpartum.

The aim of this study was to evaluate, retrospectively, which physiological states influenced the effect of vitamin E supplements during the dry period on the level of oxidative stress at 2 wk antepartum. Furthermore the effect of oxidative stress at 2 wk antepartum on the risk of clinical mastitis in early lactation was investigated. Cows experience oxidative stress around calving. Vitamin E is able to decrease oxidative stress by scavenging free radicals. Normally, vitamin E radicals formed when vitamin E reacts with free radicals are regenerated by a network of other antioxidants, termed the "vitamin E regeneration system" (VERS). In case of vitamin E supplementation, VERS should be sufficient to regenerate formed vitamin E radicals; if not, oxidative stress might increase instead of decrease. Additionally, the level of oxidative stress and vitamin E might be important physiological states to evaluate before supplementation. In a clinical trial, 296 cows on 5 farms were randomly divided into 2 groups, supplemented with a mineral mix between dry off and calving that supplied 3,000 or 135 IU/d, respectively. Blood samples collected at dry off and 2 wk antepartum were analyzed for vitamin E, reactive oxygen metabolites, ferric-reducing ability of plasma, glutathione peroxidase, and malondialdehyde. Cows were allocated retrospectively into 8 subgroups based on the level of oxidative stress, vitamin E, and VERS status at dry off. To evaluate whether differences in physiological states at dry off influenced the effect of vitamin E supplementation on the level of oxidative stress, group effects (supplemented vs. control) were studied with Student's t-test for all 8 subgroup at 2 wk antepartum. Differences in physiological states at dry off influenced the effect of vitamin E supplements. In 2 insufficient VERS subgroups, the supplemented group had higher levels of free radicals at 2 wk antepartum compared with the control group. Relative risk calculation was used to study the effect of oxidative stress at 2 wk antepartum on the incidence of mastitis in the first 100 d of lactation. Higher levels of oxidative stress at 2 wk antepartum were related to higher risk of clinical mastitis. In conclusion, not every dry cow responded well to high vitamin E supplementation. This subgroup analysis provides a possible explanation for the unexpected adverse effects observed in the clinical trial.

Comparison of the oxidative status of vitamin E-supplemented and non-supplemented cows under field conditions.

The effect of oral vitamin E supplementation during the dry period on serum biomarkers of oxidative status was evaluated in an observational field study. Ninety-eight cows were selected from 26 herds in the Netherlands. On 15 farms dry cows were supplemented with a dry-cow mineral mix containing 1000 IU vitamin E (vitamin E+ group, n = 52), and on 11 other farms dry cows did not receive the supplement (control group, n = 48). A blood sample was taken from all cows between 0 and 28 days before calving. Serum levels of alpha-tocopherol, cholesterol, triacylglycerol, superoxide dismutase (SOD), glutathione peroxidase (GSHpx), uric acid, albumin, protein sulphydryl oxidation level, reactive oxygen metabolites (ROM), iron, the ferric reducing ability (FRAP), and malondialdehyde (MDA) were measured. Alpha-tocopherol levels were significantly higher in the vitamin E+ group, as was the alpha-tocopherol:cholesterol ratio. MDA levels were significantly lower in the vitamin E+ group, suggesting that levels of lipid peroxidation were lower with vitamin E supplementation. In conclusion, vitamin E supplementation increases alpha-tocopherol and lowers MDA serum levels.

Evidence of the indirect hormonal activity of prohormones using liver S9 metabolic bioactivation and an androgen bioassay.

Prohormones such as dehydroepiandrosterone (DHEA) are steroid precursors that do not show hormonal activity by themselves. Abuse of these prohormones in cattle fattening is hard to prove because of strong in vivo metabolism and the difficulty to detect metabolites which are not significantly above endogenous levels. The aim of the present work was to develop an in vitro assay capable of detecting the indirect hormonal activity of prohormones that might be present in feed supplements and injection preparations. Sample extracts were incubated with a bovine liver S9 fraction in order to mimic the in vivo metabolic activation. Subsequently incubated extracts were exposed to a highly androgen-specific yeast bioassay to detect hormonal activity. Metabolic activation of DHEA, 4-androstene-3,17-dione (4-adione) and 5-androstene-3,17-diol (5-adiol) resulted in an increased androgenic activity caused by the formation of the active androgen 17beta-testosterone (17beta-T), as shown by ultra-performance liquid chromatography and time-of-flight mass spectrometry with accurate mass measurement. The developed in vitro system successfully mimics the hydroxysteroid dehydrogenase (HSD)- and cytochrome P450-mediated in vivo metabolic transitions, thus allowing assessment of both bioactivity and chemical identification without the use of animal experiments. Screening of unknown supplement samples claimed to contain DHEA resulted in successful bioactivation and positive screening results according to the androgen yeast biosensor.

The relationship between oxidative damage and vitamin E concentration in blood, milk, and liver tissue from vitamin E supplemented and nonsupplemented periparturient heifers.

This study investigated the relationship between oxidative damage and the effect of vitamin E supplementation in blood, milk, and liver tissue in 16 periparturient heifers. The question is whether measurements of oxidative and vitamin E status in blood of a periparturient cow are representative of the total body, given that blood concentrations of both vitamin E and oxidative stress products change around this period. The daily vitamin E intake of the vitamin E-supplemented Holstein-Friesian heifers (n = 8) was 3,000 international units and was started 2 mo before calving; the control heifers (n = 8) were not supplemented. Oxidative damage was determined on the basis of malondialdehyde (MDA) concentrations. Blood was sampled 9 times before calving, on calving day, and twice after calving. Liver biopsies were taken at wk -5, -1, and 2 relative to calving day. Milk was obtained from all heifers immediately after calving, the first 2 milkings and on d 3, 7, and 14 at 0600 h. Serum and liver tissue were analyzed for vitamin E, cholesterol, and MDA; and milk samples were analyzed for vitamin E, MDA, fat, protein, and somatic cell count. The results showed that vitamin E supplements increased both absolute vitamin E concentrations and the ratio of vitamin E to cholesterol in blood and liver tissue. Absolute vitamin E concentration in milk tended to be greater in supplemented cows. Based on the increased MDA blood concentrations at calving, it seems that dairy heifers experience oxidative stress. The effect of vitamin E on MDA differs between the blood, liver, and mammary gland. Vitamin E supplementation could not prevent the increase in blood MDA at calving, but the significantly lower MDA blood concentrations of supplemented cows in the 2 wk after calving suggest that vitamin E has a role in recovery from parturition-related oxidative stress. Vitamin E supplementation reduced oxidative damage in liver, whereas no obvious effect was found on milk MDA concentrations. A strong relationship was found between blood and liver vitamin E and the ratio of vitamin E to cholesterol. Concentrations of MDA in blood and milk were also strongly related. The results show that the relationship between oxidative damage and vitamin E differs within blood, liver tissue, and milk. This implies that oxidative and vitamin E status calculated on the basis of blood values alone should be interpreted with caution and cannot be extrapolated to the whole animal.

An untargeted metabolomics approach to contaminant analysis: pinpointing potential unknown compounds.

This study deals with an automated data analysis strategy to pinpoint potential unknown compounds in full scan mass spectrometry (MS) experiments. Three examples of an untargeted metabolomics approach to contaminant analysis are given. By comparing a plant-oil based hormone cocktail to 90 plant oil samples ca. 25 compounds specific to the hormone cocktail could be detected. Five of these compounds were confirmed as steroid hormones. A comparison of a drink water sample from a farm to distillated water showed the presence of contaminants specific to this drink water sample. A grass sample, which was known to give a false positive result in a DR-CALUX bioassay, was unexpectedly shown to contain an abnormal level of chrysene, which was obviously not eliminated during clean-up.

A concept for a decision support system based on practical experiences from a national disease emergency. The Dutch experience.

In 1997-1998, the Netherlands experienced a large epidemic of classical swine fever (CSF). The magnitude of this epidemic stressed the role information systems could play in supporting the management during an eradication campaign. The enforcement of an eradication strategy can become very complicated, especially with large epidemics, due to time pressure and many different procedures that have to be executed at the same time. The application of comprehensive information systems may result in more control over the process and in a relief of the operational management. After a brief description of the Dutch epidemic the authors provide an overview and the general application of four different types of information systems, classified as decision support systems. The application of these information systems in animal disease control is illustrated by providing concepts for a system architecture for transaction processing, management and executive information support and decision support. The application of a data warehouse as part of this systems architecture is explained. The eradication of CSF from the Netherlands was complicated by several factors. It is important to notice that information systems cannot prevent these factors. However, information systems can support disease control authorities in controlling these factors.