Supranutritional Se supplementation may improve immune responses in beef cattle. Immunity is compromised in beef cattle during the periparturient period. This study aims to determine the best time during pregnancy to supplement beef cows with Se-yeast to optimize humoral immunity at parturition.
View Article and Find Full Text PDFIntestinal absorption of immunoglobulins is critical for health and survival of newborn calves because there is no transfer of immunoglobulins in utero. The objective of this study was to determine if feeding beef cows Se-enriched alfalfa hay during the last trimester of gestation improves passive transfer of ovalbumin (OVA), a surrogate protein marker for IgG absorption. Control cows (n = 15) were fed non-Se-fortified alfalfa hay (5.
View Article and Find Full Text PDFThe prevalence of asthma has increased in recent decades, which may be related to higher dietary intake of (n-6) polyunsaturated fatty acids (PUFA) and lower intake of (n-3) PUFA, e.g., those contained in fish oil.
View Article and Find Full Text PDFGastrointestinal parasites cause substantial economic losses in pasture-based sheep production systems. Supranutritional organic selenium (Se) supplementation may be beneficial because it improves immune responses to pathogens. To evaluate the effect of Se-yeast supplementation on gastrointestinal parasite load, 30 ewes per treatment group were drenched weekly with no Se, 4.
View Article and Find Full Text PDFDairy cows have increased nutritional requirements for antioxidants postpartum. Supranutritional organic Se supplementation may be beneficial because selenoproteins are involved in regulating oxidative stress and inflammation. Our objective was to determine whether feeding Se-yeast above requirements to Se-replete dairy cows during late gestation affects blood micronutrients, antioxidants, metabolites, and inflammation biomarkers postpartum.
View Article and Find Full Text PDFSelenium (Se) is an essential micronutrient for ruminant animals affecting both performance and immune functions. Adding 3 mg of Se/L (in the form of Na selenite) to colostrum has been shown to improve IgG absorption in Se-deficient newborn dairy calves. The objective of our study was to determine the effect of supranutritional maternal and colostral Se supplementation on IgG status of Se-replete dairy calves.
View Article and Find Full Text PDFDietary selenium (Se) alters whole-blood Se concentrations in sheep, dependent upon Se source and dosage administered, but little is known about effects on immune function. We used footrot (FR) as a disease model to test the effects of supranutritional Se supplementation on immune function. To determine the effect of Se-source (organic Se-yeast, inorganic Na-selenite or Na-selenate) and Se-dosage (1, 3, 5 times FDA-permitted level) on FR severity, 120 ewes with and 120 ewes without FR were drenched weekly for 62 weeks with different Se sources and dosages (30 ewes/treatment group).
View Article and Find Full Text PDFPreviously, we reported that feeding selenium (Se)-enriched forage improves antibody titers in mature beef cows, and whole-blood Se concentrations and growth rates in weaned beef calves. Our current objective was to test whether beef calves fed Se-enriched alfalfa hay during the transition period between weaning and movement to a feedlot also have improved immune responses and slaughter weights. Recently weaned beef calves (n = 60) were fed an alfalfa-hay-based diet for 7 weeks, which was harvested from fields fertilized with sodium selenate at 0, 22.
View Article and Find Full Text PDFFootrot (FR) is a common, contagious bacterial disease of sheep that results in lameness and significant economic losses for producers. We previously reported that sheep affected with FR have lower whole-blood (WB) selenium (Se) concentrations and that Se supplementation in conjunction with routine control practices accelerates recovery from FR. To determine whether oral Se-yeast administered at supranutritional levels (>4.
View Article and Find Full Text PDFReference genes are essential for studying mRNA expression with quantitative PCR (qPCR). We investigated 11 potential neutrophil reference genes (RPL19, GAPDH, ACTB, B2M, HPRT, G6PD, TFRC, PGK1, YWHAZ, SDHA and GYPC) for sheep under disease conditions of foot rot (FR) and with or without Se supplementation. Initial screening was based on gene expression level (<28 Cq cycles) and variability (SD < 1.
View Article and Find Full Text PDFSelenium (Se) is an essential micronutrient in cattle, and Se-deficiency can affect morbidity and mortality. Calves may have greater Se requirements during periods of stress, such as during the transitional period between weaning and movement to a feedlot. Previously, we showed that feeding Se-fertilized forage increases whole-blood (WB) Se concentrations in mature beef cows.
View Article and Find Full Text PDFWe reported previously that sheep affected with footrot (FR) have lower whole-blood selenium (WB-Se) concentrations and that parenteral Se-supplementation in conjunction with routine control practices accelerates recovery from FR. The purpose of this follow-up study was to investigate the mechanisms by which Se facilitates recovery from FR. Sheep affected with FR (n = 38) were injected monthly for 15 months with either 5 mg Se (FR-Se) or saline (FR-Sal), whereas 19 healthy sheep received no treatment.
View Article and Find Full Text PDFDietary (n-3) fatty acids from fish oil have been used to modulate immune function in many mammalian species. Together, dietary antioxidants and behavioral enrichment have been shown to enhance neutrophil phagocytosis in geriatric Beagle dogs. The purpose of this study was to further investigate the effects of vitamins E and C, in combination with dietary fish oil, on neutrophil mediated bacterial killing, and on transcript levels of selected neutrophil mRNA.
View Article and Find Full Text PDFInformation on aging and the innate immune response in dogs is needed in order to understand the impact of age on the innate immune system and to design diets that might improve age-associated changes in innate immunity. The purpose of this study was to investigate the effects of age on phagocytosis and antibacterial activity of peripheral blood neutrophils, and on expression levels of selected mRNA specific for neutrophil migration or killing functions. Three groups of Beagle dogs were evaluated in a cross-sectional study design: puppies less than 1 year of age (n=15), adults 1-7 years of age (n=37) and senior adults over 8 years of age (n=25).
View Article and Find Full Text PDFAlthough the effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) are mediated through binding and activation of the aryl hydrocarbon receptor (AhR), the subsequent biochemical and molecular changes that confer immune suppression are not well understood. Mice exposed to TCDD during an acute B6-into-B6D2F1 graft-vs-host response do not develop disease, and recently this has been shown to correlate with the generation of CD4(+) T cells that express CD25 and demonstrate in vitro suppressive function. The purpose of this study was to further characterize these CD4(+) cells (TCDD-CD4(+) cells) by comparing and contrasting them with both natural regulatory CD4(+) T cells (T-regs) and vehicle-treated cells.
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