Substituting Wet Distillers Grains or Condensed Distillers Solubles for Corn Grain in Finishing Diets for Yearling Heifers

A feeding trial was conducted with 790-lb yearling heifers fed an average of 121 days to evaluate replacing cracked corn and supplemental urea with wet distillers grains or condensed distillers solubles. Wet distillers grains were evaluated at 16%, 28% and 40% of diet dry matter. Condensed distillers solubles were added at 6.5% of diet dry matter. Control diets were supplemented with urea or a combination of urea and soybean meal. Feeding 16% wet distillers grains or condensed distillers solubles increased gain of heifers compared with those fed the control urea diet. Increasing the amount of wet distillers grains tended to decrease feed intake and reduce gain. The calculated apparent net energy based on gain of the heifers was greatest for the heifers fed 16% wet distillers grains. The apparent energy of the wet distillers grains declined as the quantity fed was increased. The calculated net energy values were 1.09 and 1.35 Mcal/lb of dry matter for the average of the three concentrations of wet distillers grains and condensed distillers solubles. These results confirm the high energy values of wet distillers grains relative to cracked corn as observed in a previous steer feeding trial.

Evaluation of Wet Distillers Grains in Finishing Diets for Yearling Steers

A feeding trial was conducted with 940-lb yearling steers fed 113 days to determine the feeding value of distillers grains relative to corn grain. Replacing corn and urea with wet distillers grains for 20% of the diet dry matter tended to increase gain with no increase in feed consumption, resulting in improved feed conversion. Replacing 40% of diet dry matter with wet distillers grains decreased feed intake without affecting gains, and improved feed efficiency. The overall average estimated net energy value of wet distillers grains was 1.20 Mcal NEg per pound dry matter. This experiment confirmed the observations in previous cattle feeding experiments, that for finishing cattle wet distillers grains have a high energy value compared with cracked corn grain. Another objective of the study was to determine if cattle being fed wet distillers grains could be suddenly changed to a different diet if the supply of wet feed was suddenly disrupted. It was found that if intake is managed during the change, that distillers grains portion of the diet can be suddenly changed from wet to dry and then changed back to wet after a week, without sacrificing performance of the cattle.

Effects of Supplementing High or Low Quality Forages with Corn or Corn Processing Co-Products Upon Digestibility of Dry Matter and Energy by Steers

A digestibility trial, utilizing eight crossbred steers weighing initially 741 lbs. was conducted in an 8 x 8 Latin square design. High-fiber corn by-products were compared with corn as energy sources when fed in mixed diets with either lowor high-quality forage. Ground, dry corn stover and ground alfalfa hay were both fed alone or with corn grain, dried corn gluten feed (CGF), and dried corn distillers grains plus solubles (DDG) in a 1:1 ratio (dry basis). Total tract dry matter digestibility (DMD) was increased for both forages when fed with concentrates. Total tract DMD was similar in stover-based and alfalfa-based diets fed with CGF and DDG. However, stover+corn was lower in DMD than either stover+CGF and stover+DDG. Conversely, alfalfa+corn was higher in DMD than alfalfa+CGF or alfalfa+DDG. Feeding stover with corn tended to decrease digestibility of neutral detergent fiber (NDF), while feeding stover with CGF or DDG increased NDFD. There was no effect upon NDF digestion of alfalfa-based diets when fed with any of the concentrates. Feeding either forage with a concentrate increased digestible energy (DE). Stover+CGF and stover+DDG were similar in DE and were both higher in DE than stover+corn. Alfalfa+DDG tended to be higher than alfalfa+CGF and was similar to alfalfa+corn in DE. Alfalfa+CGF was lower in DE compared with alfalfa+corn. Results are interpreted to indicate that stover is more susceptible to negative feed interactions caused by corn grain than is alfalfa. Additionally, highfiber corn co-products fed with stover resulted in a positive associative effect but essentially had no associative effect when fed with alfalfa.

Evaluation of a Mixture of Corn Steep Liquor and Distillers Solubles as a Replacement for Corn and Supplement in Cattle Finishing Diets

Finishing yearling steers fed a corn-based diet containing steep liquor had statistically similar live performance as steers fed the control diet. Numerically steers fed the steep containing diet were 6% more efficient. Steers fed steep liquor tended to contain less carcass fat (as measured by intramuscular marbling) less kidney, heart and pelvic fat, and less backfat thickness. When priced at $50/ton adding steep liquor at 10% of diet dry matter reduced feed cost for gain 9%.

An Evaluation of Effective Fiber in Beef Feedlot Finishing Diets

A study was designed to collect a database of Iowa feedlot rations for determination of effective neutral detergent fiber (NDF) in complete diets from fiber analysis and particle size determination of individual feed ingredients and compare this with particle size determination of mixed wet rations. Seventy-one beef finishing total mixed rations were collected by ISU Extension Beef Field Specialists across Iowa. Producers were asked to complete a form assessing the acidosis risk associated with each ration. The average NDF of these diets was 25.9%. Of the total mixed rations 1.33 % remained in the top tray (>.75 in.), 47.27 % remained in the middle tray (>.31 in.), and 50.88 % was smaller than the .31 in screen. The effective NDF (eNDF) calculated from the eNDF of the ingredients averaged 10.56%. Estimated eNDF from total diet NDF and the percentage of the total diet in the top and middle trays averaged 12.47%. The calculated eNDF from non-grain sources alone averaged 3.6%. The percentage of digestive deads was weakly related to the percentage of the ration in the bottom tray (r=.19), the percentage in the top tray (r=- .46) and the effective NDF of the ration (r=-.23). The percentage of bloat was related to the total NDF of the diet (r=.28) and the effective fiber from non-grain sources (r=-.23). The number of off-feed incidences was related to the dry matter of the ration (r=.38), the apparent eNDF (r=-.28) and the percentage of ration in the bottom tray (r=.24). This study confirms that there is some relationship between effective NDF of the diet, effective NDF from non-grain sources or diet particle size; and acidosis indicators. These relationships are weak, however, indicating that other factors such as feedbunk management, feed processing, feed presentation and feed mixing likely also play a role in the incidence of acidosis in feedlot cattle.