Monitor Sulfur Content In Diet When Feeding Distillers Grains To Cattle; Feeder Bull Discounts Studied

Research shows sulfur content varies greatly between distillers grains; feeder bull discounts were more closely evaluated.

Monitor DGs for sulfur

Composition and consistency of wet or dry distillers grains (DG) should be of concern to all cattlemen feeding this common and readily available byproduct.

A nutrient survey of DG production from six ethanol plants conducted by University of Nebraska researchers revealed that dry matter (DM) content varied from plant to plant and large variations in sulfur (S) content exist within and between plants. A total of 1,200 samples (200/plant) were assayed for DM, crude protein, fat, phosphorus and S over a 12-month period.

The average S content of all samples was 0.77% on a dry matter basis (DMB). However, average results for S can be deceiving. Two plants had individual samples assay at 1.72% and 1.26% DMB, potentially lethal levels for cattle consuming diets containing greater than 30% DMB of DG. Rations should not exceed 0.4% S.

Over 4,000 health records from cattle finished in byproduct experiments were summarized by Nebraska researchers for the incidence of polioencephalomalacia (polio). A baseline for polio was established at about 0.13% for cattle consuming diets containing 0.46% DMB of S or less. When dietary S levels rose to between 0.47 and 0.56% DMB, the polio incidence increased to 0.35%; and to 6.06% when dietary S exceeded 0.56% DMB.

High S levels have been reported to reduce feedlot performance of finishing steers (BEEF, August 2010, “Research Roundup”). Daily gain and DM intake of steers consuming 0.65% S were reduced 11.8% and 8.9%, respectively. Carcass weight was decreased by 39 lbs.

DM content of all samples averaged 32.5% and 45.2% for wet DGs plus solubles and modified DGs plus solubles, respectively. Regardless of the DG type, DM content varied between plants, emphasizing how important it is for producers to monitor DM in the products they purchase.

Crude protein, fat and phosphorus averaged 31.0, 11.9 and 0.84% DMB, respectively, and were more consistent between and within the plants than S and DM. Crude protein, fat and phosphorus do not create the daily nutritional concerns of S and DM.

Feedlots utilizing multiple loads of DG per day are at less risk of a single load being high in S than are small feedlots utilizing only several loads per week. Mixing of DG product from different loads in the feeding process will lessen high S risks.

Feeder bull discounts >>

Feeder bull discounts. How much?

Determining the appropriate purchase price discount for bulls can be challenging. In a Kansas and Missouri auction market survey, bulls were discounted $5-$6/cwt. compared to steers of similar weight (BEEF, August 2010, “Research Roundup”).

Production records on 2,200 bull and 1,200 steer calves purchased from Kentucky and Tennessee sale barns, and received at the Kansas State University Beef Stocker Unit, were evaluated to determine appropriate discounts for bulls owned through a 44-day backgrounding period or retained through slaughter.

Bulls and steers were fed and managed the same. Off-truck weight averaged 460 lbs. for all calves and ranged from 320 to 640 lbs. At processing, bulls were surgically castrated and all calves received a metaphylactic antibiotic injection.

Daily gain during the backgrounding period was 15% greater for steers than bulls. Overall backgrounding morbidity was 28%. Bulls were 30% more likely to need treatment once or more than once than were steers.

Based on health and performance parameters, average weight bulls (460 lbs.) should be discounted 4.3 or 5.6% compared to average weight steers if owned through backgrounding or finishing, respectively. Lighter (370 lbs.) and heavier (550 lbs.) bulls should be discounted 4.3 or 1.6%, and 3.5 or 6.9%, if owned through backgrounding or finishing, respectively.

For more information: – page 79 – page 126