Corn Silage: What's New?

This information was presented at the 2012 Cornell Nutrition Conference for Feed Manufacturers, organized by the Department of Animal Science in the College of Agriculture and Life Sciences at Cornell University. Softcover copies of the entire conference proceedings may be purchased at http://www.ansci.cornell.edu/dm/proceedings_orders.html or by calling (607)255-4285

Effects of chemical additive and packing density on the fermentation profile and nutrient composition of ensiled cocktail forage mix

Recently, the use of cocktail forage mixes in dairy cattle rations has become more common because the mixtures are low-cost, fit well in rotation after a cereal grain forage, and can have similar yield and energy value compared with alfalfa silage. This experiment evaluated the effects of a chemical additive and packing density on the fermentation profile and nutrient composition of cocktail mix silage. The cocktail forage mix (brown-midrib sorghum-sudangrass, Italian ryegrass, red clover, berseem clover, and hairy vetch) was harvested, ensiled in laboratory silos (3.79-L plastic buckets), and allowed to ferment for 30 d. The experiment consisted of 6 treatments, 2 chemical additives [CON (30 mL of distilled water) or ADD (sodium sulfite, sodium metabisulfite, and fungal amylase)], and 3 packing densities [D100, D75, and D50 (100%, 75%, or 50% of the maximum material in laboratory silos, respectively)], for a total of 24 silos (4 replications per treatment combination). No interactions of additive by density were detected for any parameters evaluated. The addition of the chemical additive influenced fermentation profile, with reduced concentrations of total acids, lactic acid, acetic acid, and ethanol in ADD-treated silages. Moreover, D50 reduced concentrations of total acids, lactic acid, and acetic acid compared with D100, but had greater pH and yeast and mold counts. Minimal changes in nutrient composition were detected regardless of treatment. Overall, this study corroborates the importance of a well-packed silage during the ensiling process. Poorly packed cocktail mix silages may be more prone to spoilage based on yeast and mold counts

Simulated atmospheric disperison of radioactive material released in an urban area

A combination of Gaussian plume and particle-in-cell techniques is used to simulate the atmospheric transport and dispersion of a puff release of radioactive material. The release is caused by an accident that is assumed to occur during the shipment of the radioactive material through central New York City. The simulation provides estimates of volumetric and surface concentrations of the dispersed material that are used to predict radiation doses incurred by the City's population in the event of an accidental release. In the simulation, the release point is arbitrary and the material is assumed to be either a gas or fine particles. The Gaussian plume model follows cloud concentrations from the release time until times when transport over distances up to 500 m has been achieved. The released cloud may stabilize at street level or above the mean buildings height; at a street intersection or in the middle of the block. The possibility of the formation of multiple clouds, owing to circumstances of wind flow direction and street geometry, is allowed

Effect of feeding a reduced-starch diet with or without amylase addition on lactation performance in dairy cows

The objective of this study was to determine lactation performance responses of high-producing dairy cows to a reduced-starch diet compared with a normal-starch diet and to the addition of exogenous amylase to the reduced-starch diet. Thirty-six multiparous Holstein cows (51 +/- 22 DIM and 643 +/- 49 kg of body weight at trial initiation) were randomly assigned to I of 3 treatments in a completely randomized design: a 3-wk covariate adjustment period during which the cows were fed the normal-starch diet, followed by a 12-wk treatment period during which the cows were fed their assigned treatment diets. The normal-starch TMR did not contain exogenous amylase (NS-). The reduced-starch diets, formulated by partially replacing corn grain with soy hulls, were fed without (RS-) and with (RS+) exogenous amylase added to the TMR. Starch and NDF concentrations averaged 27.1 and 30.6%, 21.8 and 36.6%, and 20.7 and 36.6% (dry matter basis) for the NS-, RS-, and RS+ diets, respectively. Dry matter intake for cows fed the RS- diet was 2.4 and 3.2 kg/d greater than for cows fed the NS- and RS+ diets, respectively. Intake of NDF ranged from 1.19 to 1.52% of body weight among the treatments, with the RS- diet being 28% greater than the NS- diet and 13% greater than the RS+ diet. Milk yield averaged 50.4 kg/d and was unaffected by treatment. Fat-corrected milk yield was 2.9 kg/d greater for cows fed the RS- diet than for cows fed the NS- diet. Body weight and body condition score measurements were unaffected by treatment. Fat, solids-, and energy-corrected milk feed conversions (kilograms/kilogram of DMI) were 12 to 13% greater for cows fed the RS+ diet than for cows fed the RS-diet. Dry matter and nutrient digestibilities were lowest for cows fed the NS- diet and greatest for cows fed the RS+ diet, and were greater for cows fed the RS+ diet than for cows fed the RS- diet, with the exception of starch digestibility, which was similar. Greater conversion of feed to milk for dairy cows fed reduced-starch diets that include exogenous amylase may offer potential for improving economic performance