Illinois beef cow handbook : management, health, pastures, economics / 1068

Cover title

Lipid Sources in Finishing Diets for Yearling Steers

Adding Synergy2 to a corn-based finishing diet to provide 1.12% lipid did not significantly increase steer performance in this trial or in pooled results between this trial and one reported in 1995. However, numerical increases were observed in daily gain and feed dry matter intake for Synergy when compared to control values. Pooled results for additions of pork fat (white grease) to provide 1.12 or 2.24% lipid were intermediate to those for the control and Synergy treatments. Any performance benefit attributed to Synergy may be as much from its effect on dry matter intake as it is from nutrient addition

Cull Dry Edible Beans in Growing Calf Rations

Including cull dry edible beans into diets for steer calves in two yearly trials produced slightly different results. In the first year, calculated net energy levels were higher in diets with 5 or 10% dry beans and daily gains were equal or better than for the no-bean diets. In the second year, with equal net energy values in rations containing 0, 7.5 or 15% dry beans, daily gains and feed intake decreased linearly with dry bean additions. Feed efficiency was improved as bean level increased

Cull Dry Edible Beans in Growing Calf Rations

Including cull dry edible beans into diets for steer calves in two yearly trials produced slightly different results. In the first year, calculated net energy levels were higher in diets with 5 or 10% dry beans and daily gains were equal or better than for the no-bean diets. In the second year, with equal net energy values in rations containing 0, 7.5 or 15% dry beans, daily gains and feed intake decreased linearly with dry bean additions. Feed efficiency was improved as bean level increased

The Effect of Feeding Pressed Sugar Beet Pulp in Beef Cattle Feedlot Finishing Diets

When the two trials were analyzed together, average daily gain was higher in the corn silage treatment compared to the two levels of beet pulp. However, feed to gain conversions between the treatments were not different. Beet pulp can serve as a substitute for corn silage and even though dry matter intake may be slightly affected, feed efficiency will be equal

Short-term associations between particle oxidative potential and daily mortality and hospital admissions in London.

BACKGROUND: Particulate matter (PM) from traffic and other sources has been associated with adverse health effects. One unifying theory is that PM, whatever its source, acts on the human body via its capacity to cause damaging oxidation reactions related to its content of pro-oxidants components. Few epidemiological studies have investigated particle oxidative potential (OP) and health. We conducted a time series analysis to assess associations between daily particle OP measures and numbers of deaths and hospital admissions for cardiovascular and respiratory diseases. METHODS: During 2011 and 2012 particles with an aerodynamic diameter less than 2.5 and 10μm (PM2.5 and PM10 respectively) were collected daily on Partisol filters located at an urban background monitoring station in Central London. Particulate OP was assessed based on the capacity of the particles to oxidize ascorbate (OP(AA)) and glutathione (OP(GSH)) from a simple chemical model reflecting the antioxidant composition of human respiratory tract lining fluid. Particulate OP, expressed as % loss of antioxidant per μg of PM, was then multiplied by the daily concentrations of PM to derive the daily OP of PM mass concentrations (% loss per m(3)). Daily numbers of deaths and age- and cause-specific hospital admissions in London were obtained from national registries. Poisson regression accounting for seasonality and meteorology was used to estimate the percentage change in risk of death or admission associated with an interquartile increment in particle OP. RESULTS: We found little evidence for adverse associations between OP(AA) and OP(GSH) and mortality. Associations with cardiovascular admissions were generally positive in younger adults and negative in older adults with confidence intervals including 0%. For respiratory admissions there was a trend, from positive to negative associations, with increasing age although confidence intervals generally included 0%. CONCLUSIONS: Our study, the first to analyse daily particle OP measures and mortality and admissions in a large population over two years, found little evidence to support the hypothesis that short-term exposure to particle OP is associated with adverse health effects. Further studies with improved exposure assessment and longer time series are required to confirm or reject the role of particle OP in triggering exacerbations of disease

Estimating risk of emergency room visits for asthma from personal versus fixed site measurements of NO2

Background: We examined the impact of data source and exposure measurement error for ambient NO2 on risk estimates derived from a case-crossover study of emergency room visits for asthma in Windsor, Canada between 2002 and 2009. Methods: Paired personal and fixed-site NO2 data were available from an independent population (47 children and 48 adults) in Windsor between 2005 and 2006. We used linear regression to estimate the relationship and measurement error variance induced between fixed site and personal measurements of NO2, and through a series of simulations, evaluated the potential for a Bayesian model to adjust for this change in scale and measurement error. Finally, we re-analyzed data from the previous case-crossover study adjusting for the estimated change in slope and measurement error. Results: Correlations between paired NO2 measurements were weak (R2≤0.08) and slopes were far from unity (0.0029≤β≤0.30). Adjusting the previous case-crossover analysis suggested a much stronger association between personal NO2 (per 1 ppb) (Odds Ratio (OR)=1.276, 95% Credible Interval (CrI): 1.034, 1.569) and emergency room visits for asthma among children relative to the fixed-site estimate (OR=1.024, 95% CrI 1.004–1.045). Conclusions: Our findings suggest that risk estimates based on fixed-site NO2concentrations may differ substantially from estimates based on personal exposures if the change in scale and/or measurement error is large. In practice, one must always keep the scale being used in mind when interpreting risk estimates and not assume that coefficients for ambient concentrations reflect risks at the personal level

Trace Metal Exposure is Associated with Increased Exhaled Nitric Oxide in Asthmatic Children

Background Children with asthma experience increased susceptibility to airborne pollutants. Exposure to traffic and industrial activity have been positively associated with exacerbation of symptoms as well as emergency room visits and hospitalisations. The effect of trace metals contained in fine particulate matter (aerodynamic diameter 2.5 μm and lower, PM2.5) on acute health effects amongst asthmatic children has not been well investigated. The objective of this panel study in asthmatic children was to determine the association between personal daily exposure to ambient trace metals and airway inflammation, as measured by fractional exhaled nitric oxide (FeNO). Methods Daily concentrations of trace metals contained on PM2.5 were determined from personal samples (n = 217) collected from 70 asthmatic school aged children in Montreal, Canada, over ten consecutive days. FeNO was measured daily using standard techniques. Results A positive association was found between FeNO and children’s exposure to an indicator of vehicular non-tailpipe emissions (8.9 % increase for an increase in the interquartile range (IQR) in barium, 95 % confidence interval (CI): 2.8, 15.4) as well as exposure to an indicator of industrial emissions (7.6 % increase per IQR increase in vanadium, 95 % CI: 0.1, 15.8). Elevated FeNO was also suggested for other metals on the day after the exposure: 10.3 % increase per IQR increase in aluminium (95 % CI: 4.2, 16.6) and 7.5 % increase per IQR increase in iron (95 % CI: 1.5, 13.9) at a 1-day lag period. Conclusions Exposures to ambient PM2.5 containing trace metals that are markers of traffic and industrial-derived emissions were associated in asthmatic children with an enhanced FeNO response