Effects of Feeding Selenium-Enriched Alfalfa Hay on Immunity and Health of Weaned Beef Calves

Abstract

Previously, 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, 22.5, 45.0, or 89.9 g Se/ha. All calves were immunized with J-5 Escherichia coli bacterin. Serum was collected for antibody titers 2 weeks after the third immunization. Whole-blood neutrophils collected at 6 or 7 weeks were evaluated for total antioxidant potential, bacterial killing activity, and expression of genes associated with selenoproteins and innate immunity. Calves fed the highest versus the lowest level of Se-enriched alfalfa hay had higher antibody titers (P = 0.02), thioredoxin reductase-2 mRNA levels (P = 0.07), and a greater neutrophil total antioxidant potential (P = 0.10), whereas mRNA levels of interleukin-8 receptor (P = 0.02), L-selectin (P = 0.07), and thioredoxin reductase-1 (P = 0.07) were lower. In the feedlot, calves previously fed the highest-Se forage had lower mortality (P = 0.04) and greater slaughter weights (P = 0.02). Our results suggest that, in areas with low-forage Se concentrations, feeding beef calves Se-enriched alfalfa hay during the weaning transition period improves vaccination responses and subsequent growth and survival in the feedlot.

Organic selenium supplementation improves growth parameters, immune and antioxidant status of newly received beef cattle

“…(Hogan et al, 1990). Moreover, Hall et al (2013) reported that dietary Se supplementation increases antibody titre, neutrophils killing activity and reduces morbidity and mortality in beef cattle. Se improves phagocytosis in white blood cell populations (Hogan et al, 1990).…”

Supranutritional dietary selenium depressed expression of selenoprotein genes in three immune organs of broilers

“…Oxidative stress is a primary mechanism by which ROS influences biological processes and may contribute to the pathogenesis of disease by modifying the expression of proinflammatory genes (Hall et al . ,). We compared the effect of supranutritional dietary Se on antioxidant capacity in immune organs of the chicken and the results showed increased ( P < 0.05) activities of GSH‐Px, T‐AOC and SOD mainly occurred in early stages (at days 14 and 28) (Table ).…”

“…Feeding Se‐enriched forage improves antibody titers in mature beef cows (Hall et al . ,), and elevates whole‐blood Se concentrations in weaned beef calves (Hall et al ).…”

Effect of Selenium Yeast Supplementation on Naturally Acquired Parasitic Infection in Ewes

“…We previously showed in beef cows and recently weaned beef calves that feeding Se-enriched hay improves vaccination responses [24,25,58]. Studies are warranted to determine whether other forms of organic Se, such as Se-fortified forage, are as effective as Se yeast in reducing parasite infection.…”

“…Fertilizing crops and pastures with Se is one option to increase the Se content in ruminant livestock feeds that can be used in parts of the world, including Oregon [24,25]. To prevent Se deficiency, the Food and Drug Administration (FDA) permits Se supplementation [26].…”