Ascophyllum nodosum (Tasco-14) decreased the prevalence of enterohemorrhagic Escherichia coli (EHEC) O157:H7 in animals fed prior to harvest. Tasco-14 was supplemented on a 2% dry matter basis 14 days prior to harvest to determine its effects on EHEC and Salmonella spp. prevalence. Two hundred mixed crossbred steers and heifers (Bos indicus x Bos taurus), in a large commercial finishing facility, served as experimental units. Treatment (TRT, n = 100) animals received a steam-rolled corn-based diet containing 2% Tasco-14 on a dry matter basis, and control (CON, n = 100) animals received only the steam-rolled corn-based diet. Hide swabs and fecal samples were obtained for EHEC and Salmonella spp. evaluations. Animals were sampled 1 day prior to (d - 1) the feeding of Tasco-14 and immediately following exsanguinations. The prevalence of EHEC O157 on hide swabs and in fecal samples (P = 0.0001 and P < 0.0001, respectively) and the prevalence of EHEC O157:H7 on hide swabs and in fecal samples (P < 0.0001 and P < 0.0001, respectively) was reduced by 33 and 36% from d - 1 levels on TRT hide swabs and by 9 and 11% in TRT fecal samples. The prevalence of EHEC O157 and EHEC O157:H7 was reduced by 33 and 36% from d - 1 levels on TRT hide swabs and by 9 and 11% in TRT fecal samples. The prevalence of Salmonella spp. on hide swabs did not change for TRT animals (P = 0.64). CON animals showed an increase in Salmonella spp. prevalence (P < 0.0001) from d - 1 feeding levels on hide swabs. The prevalence of Salmonella spp. increased in both TRT and CON fecal samples when compared to d - 1 levels (P = 0.002). However, TRT samples exhibited a lower (P < 0.05) postfeeding prevalence of Salmonella spp. in fecal samples than did CON samples. Results from this study indicate that 2% Tasco-14 supplementation in feedlot cattle diets reduces EHEC O157 and EHEC O157:H7 prevalence on hide swabs and in fecal samples and may suppress increases in Salmonella spp.

The mixed-models procedure (MMP) was used to analyze pooled data sets from 12 independent studies conducted during the last 13 yr at nine locations in seven states to provide combined estimates of daily gains by beef steers (Bos taurus) grazing tall fescue (Festuca arundinacea Schreb.) pastures free of (E-) or infested (E+) at different levels with the endophytic fungus Acremonium coenophialum. Treatments included low-infestation (< or = 5% E+), moderate-infestation (> or = 20 to < or = 35% E+), and high-infestation (> or = 50 to < or = 97% E+) tall fescue pastures, and, in tall fescue-clover (Trifolium spp.) mixtures, pastures at the same E+ levels with approximately 25 and 10% clover in spring and summer stands, respectively. Spring, summer, and combined spring+summer data were analyzed separately. The MMP permitted estimation of the fixed effects of treatments over a broad inference space of future years and different tall fescue pastures over a wide geographic range; detected relationships that had not been apparent in the individual studies, such as the interactions between clover presence and E+ infestation levels; and provided a more coherent body of information than did the results obtained from each discrete study. Logistical and financial constraints that force undesirable compromises in the conduct of future grazing and other expensive or time-consuming research may be avoided by using MMP within the context of cooperative projects.

Lactating beef cows (16 Hereford and 34 Angus, 430 kg average body weight, aged 8 to 10 yr) were fed a basal diet containing 200 micrograms/g Al alone or supplemented with Al-citrate, citric acid, soil or soil plus citric acid for 56 d. Diets containing Al-citrate, soil and soil plus citric acid contained 1,730, 1,870 and 1,935 micrograms/g Al, dry-basis, respectively. Adding soil to the diet also increased Mg and Fe content of the diet. Aluminum values in ruminal contents of beef cows fed the basal alone or supplemented with citric acid, Al-citrate, soil or soil plus citric acid were 800, 990, 2,930, 3,410 and 2,910 micrograms/g, air-dry basis, respectively. Serum Mg and inorganic P declined (P less than .01) and urinary Ca concentration increased (P less than .01) for cows fed Al-citrate. By d 56, serum Mg was 1.5 and 2.2 mg/dl, and serum P was 3.8 and 6.8 mg/dl, for cows fed Al-citrate and basal diets, respectively. Calcium concentrations in urine were 281 and 11 micrograms/g for cows fed Al-citrate and basal diets, respectively. Citric acid, soil and soil plus citric acid had no detrimental effects on serum Mg and inorganic P, or urinary Ca concentration. By d 56, serum Ca was higher (P less than .06) in cows fed Al-citrate, compared with cows on the other four diets. Bone Ca, P, Zn and percent ash were not significantly affected by treatment but bone Mg tended to be slightly lower (P less than .07) for cows fed Al-citrate.(ABSTRACT TRUNCATED AT 250 WORDS)

Fall weaned Angus calves grazed stockpiled 1) tall fescue (Festuca arundinacea Schreb.), 2) tall fescue-red clover (Trifolium pratense L.), or 3) tall fescue-alfalfa (Medicago sativa L.) or were barn-fed, 4) tall fescue hay, 5) orchardgrass (Dactylis glomerata L.)-alfalfa hay, or 6) tall fescue silage from late October to early April during each of 5 yr. Infection of the fescue with Acremonium coenophialum ranged from 0 to 55%. There were two replications each of steers and heifers for each forage system in a completely random design. Each replicate was grazed by three Angus stockers, except for System 1, which was grazed by six stockers, for a total of 420 stockers. Each pasture replicate contained .8 ha (except System 1, which was 1.6 ha), and the stocking rate was one stocker per .27 ha. Fescue hay and silage were harvested each spring for barn-fed systems from the area stockpiled for grazing by cattle in System 1. Nitrogen fertilizer (90 kg/ha) was applied in early spring and again in early August, before stockpiling; no N was applied to stockpiled fescue grown with legumes. Daily gains by calves grazing stockpiled fescue-alfalfa were greater (P less than .01) than by calves grazing stockpiled fescue-red clover or N-fertilized stockpiled fescue (.50, .33, and .34 kg/d, respectively), but fescue-alfalfa calves required more days (P less than .01) of supplemental hay feeding (105, 60, and 36, respectively). Calves fed fescue hay in the barn gained more (P less than .01) than those fed fescue silage.(ABSTRACT TRUNCATED AT 250 WORDS)

Background: Incidence of syphilis continues to increase among HIV-positive men who have sex with men (MSM) in Ontario. Our objective was to determine the effect of acute syphilis on virologic failure (VF) among virally suppressed HIV-positive MSM taking antiretroviral therapy (ART) and determine if the relationship is confounded by drug use. Setting: The OHTN Cohort Study is a voluntary cohort of people receiving HIV care in Ontario. Syphilis and viral load (VL) data were retrieved via linkage with the provincial laboratory. Methods: Analyses included 2632 MSM from 2008 to 2015, on ART, with ≥1 questionnaire and 2 consecutive VL of <50 copies per milliliter 6 months apart. VF was defined as (1) VL of ≥1000 copies per milliliter or (2) 2 consecutive VLs of ≥200 copies per milliliter ≥1 month apart. We modeled acute syphilis as a time-varying covariate on VF using Poisson regression. Time-varying drug use was assessed for confounding using an iterative process where potential confounders were removed and then reintroduced into the model. Our model allowed for repeat observations using generalized estimating equations. Results: VF incidence was 3.5 per 100 person-years [95% confidence interval (CI): 3.4 to 4.2]. The rate ratio for VF for acute syphilis was 1.5 (95% CI: 0.9 to 2.4) in the unadjusted model; 1.6 (95% CI: 1.0 to 2.4) in the model adjusted for age, education, region, and income; and 1.2 (95% CI: 0.7 to 1.9) in the final model with additional adjustment for drug use. Conclusions: Acute syphilis was not associated with VF among virologically suppressed MSM on ART. Consequently, ART may still reduce HIV transmission risk to sexual partners.