4 2013 North Dakota Beef Report

Corn stover and distillers grains for lactating drylot beef cowsV.L. Anderson1, B.R. Ilse2 and C.L. Engel1

This project evaluated the use of corn stover and distillers grains as the primary ingredients in lactating beef cow diets. The control diet included corn silage, wheat middlings, barley hulls and straw as the primary feeds. Cow performance and calf growth appear to be similar for both diets in this nonreplicated field study. The daily feed cost was lower for the stover-distillers grain diet at $1.71/head vs. $2.22 for the control diet.

research is needed to understand the value of corn stover and give producers confidence in using corn stover-distillers grain rations for lactating cows.

IntroductionNorth Dakota livestock enter-

prises are primarily beef cow-calf operations. Cow numbers continue to decrease here and nationally as a result of drought and the fact that more grazing land is being farmed for corn, soybeans and other profit-able crops. The high cost of conven-tional feed ingredients also has been a factor in reducing cow numbers, yet underutilized and undervalued feed resources are available to live-stock producers in North Dakota.

Feed resources in the region include crop residues, grains and nearly 3 million tons of a variety of coproducts produced each year in North Dakota. The market price for many coproducts may decrease in the summer due to reduced demand as more cattle are grazing vs. fed in confinement.

Distillers grain often is very competitively priced as an energy and protein source. Corn stover is increasing in availability with corn production migrating north, and it is becoming a primary forage for beef

cow production. The preferred uti-lization of stover is by postharvest grazing in the fall and early winter. Harvesting corn stover in large bales is highly weather dependent but makes year-round use of stover for feed possible.

Drylot cow-calf production is a new concept in beef production that is increasingly viewed as an option as the cost of rental pastures or purchasing grazing land escalate beyond economic thresholds. A separate article in this publication addresses drylot vs. pasture beef production.

An integrated crop-livestock production system has the advan-tages of maximizing biological efficiencies such as stover and straw used as feed or bedding, and return-ing manure to the fields. Ruminant animals help diversify the North Dakota agricultural economy and can add to the net profit of an appro-priately managed integrated crop-livestock farming operation.

Experimental ProceduresCrossbred spring-calving Red

Angus x Red Simmental mature beef cow-calf pairs (n = 42) were allotted to one of two drylot ration treat-ments based on calf birth date. The treatments were: 1) corn stover and distillers grains as the primary feed ingredients and 2) corn silage, straw, wheat middlings and barley hulls as the control diet (T able 1), with nu-trient composition listed in Table 2.

The two diets were balanced to meet or exceed the nutrient require-ments of lactating beef cows of average milking ability according to NRC (National Research Council, 1996), specifically a 0.56 megacalo-

1Carrington Research Extension Center, NDSU 2Big Horn County Extension office, Montana State University

SummaryBeef cows can be fed a variety

of feeds as long as nutrient require-ments are met. With the increase in corn acres, corn stover is more available and may be a useful feed for beef cows. Distillers grain is produced at several ethanol plants in North Dakota and has been a very competitively priced energy and protein source for livestock. Spring-calving, mature crossbred beef cows managed in drylot during the summer were fed a ration of primarily corn stover and distillers grain compared with corn silage, wheat middlings, barley hulls and straw. Cows fed the control diet lost 57 pounds while cows fed the stover-distillers grain diet lost 90 pounds during the 92-day study. Calves gained 2.57 and 2.73 pounds, respectively, for the control and sto-ver-distillers grain diets. Condition score decreased by 1 for the control and 1.1 for the stover-distillers grain cows during the summer feeding period. The daily ration cost was $1.71 per head for the stover-distill-ers grain treatment and $2.22 for the control ration with corn silage. More

2013 North Dakota Beef Report 5

rie (Mcal)/pound of net energy for maintenance (NEm) and 9.27 per-cent crude protein requirement for cows during the months of lactation in this trial.

The control diet contained ap-proximately 0.56 Mcal NEm per pound and 9.87 percent crude pro-tein, with the stover-distillers grain ration providing 0.57 Mcal NEm per pound and 10.82 percent crude pro-tein. These values are based on feed delivered to the bunk and estimated intake (and waste) of the free-choice forages.

Ration ingredients were mixed in a truck-mounted Knight “Little Augie” three-auger mixer wagon and delivered to fence-line bunks once daily. A portion of the straw and stover was ground and mixed with other ingredients fed in the bunk line. Cows were allowed 3 feet of fence-line bunk space per head. Free-choice straw or stover was offered as large, round bales placed in ring feeders in respective treat-ments.

In this study, actual feed costs were used for purchased ingredi-ents, including delivery and farm-raised feeds, and the feeds were valued according to production costs reported in the North Dakota Farm Business Management Pro-gram (Metzger and Hanson, 2012). Feed costs used include: corn si-lage,$50/ton; straw, $35/ton; barley hulls, $80/ton; wheat midds, $234/ton; corn stover, $40/ton for ground stover and $35/ton for bales fed; modified distillers grain, $116/ton; and grass hay, $85/ton.

Cows and calves were moni-tored daily at feeding for any health issues, with no unusual problems observed. Cows were bred by natural-service sires for 45 days. Bulls were tested for fertility and passed a breeding soundness exam prior to use. Creep feed (16 percent crude protein) was offered to all calves starting in late June at equal

Table 1. Rations for lactating drylot beef cows with stover and distillers grain.

Diet treatments Diet Treatments

Stover/ Stover/ Distillers Distillers Control Grain Control Grain

Lb/hd/day, as fed Percent, DM basis

Bunk fed as mixed ration Corn silage 24.23 30.31 Wheat/pea straw, ground 6.77 18.86 Barley hulls 7.71 24.78 Wheat midds 7.71 23.93 Ionophore/min supplement 0.52 0.47 2.12 2.28 Corn stover, ground 10.35 43.71 Modified distillers grains 11.35 30.47 Mixed hay, ground 5.21 23.54Offered free choice, estimate of intake Wheat/pea straw 8.38 Corn stover 28.34

Total 55.32 55.72 100 100

Table 2. Ration specifications for lactating drylot beef cows fed a control ration vs. corn stover and distillers grain.

Diet Treatments

Control Stover/Distillers Grain

NEm, Mcal/lb. 0.56 0.57Crude protein, % 9.87 10.82Feed cost/hd/day, $ 2.22 1.71

Table 3. Performance of drylot cow-calf pairs fed a control ration vs. corn stover and distillers grain.

Diet Treatments

Control Stover/Distillers Grain

Cow weight, lb. Initial wt., June 21 1,540 1,500 Final wt., Sept. 20 1,483 1,410 Weight change -57 -90Cow condition score Initial 6.2 5.9 Final 5.3 4.8 Change -1.0 -1.1Percent pregnant 86 86Calf weight, lb. Initial wt., June 21 287 304 Final wt., Sept. 20 521 552 Gain 234 248 Avg. daily gain 2.57 2.73

6 2013 North Dakota Beef Report

amounts per head daily. The study started on June 21 (80 days post-partum) and concluded on Sept. 20, 2012, when all drylot calves were weaned.

Results and DiscussionFeed intake and nutrient content

appear to be similar for both diets and meet the nutrient requirements for lactating beef cows in this study. Cows fed the stover-distillers grain diet lost 90 pounds during the trial period, while control cows lost only 57 pounds. Condition score changes reflect weight loss with a decrease of 1 and 1.1, respectively, for control and stover-distillers grain treat-ments.

The weight loss and decrease in condition score are not unusual for this stage of production. Cows were still in adequate condition at wean-ing. Calf gains were numerically

higher for the stover-distillers grain treatment at 2.73 vs. 2.57 pounds per head daily for the control ration. The small numerical increase may be a result of bypass protein from distill-ers grain, but greater weight loss suggests milk production potential might have been greater than “aver-age,” as described in NRC (1996). Meeting nutrient requirements to ensure breeding success and subse-quent performance is critical.

Feed cost favored the stover-distillers grain diet, but ingredient costs can vary widely. Eighty-six percent of cows in both groups were diagnosed as pregnant at palpation in the fall. From this field trial data, feeding a ration of primarily corn stover and distillers grain appears to support satisfactory cow perfor-mance and calf growth. Pregnancy rates were relatively low but similar between treatments.

More replications of this trial and other nutrition and manage-ment studies with corn stover and distillers grains are needed to give cow-calf producers confidence in the use of these ingredients for drylot management of lactating beef cows.

AcknowledgmentsThe authors thank the technical

and administrative staff for their contributions to this study. Appreci-ation is also expressed to the North Dakota Corn Utilizations Council for funding to support this study.

Literature CitedMetzger, Steve, and Jory Hanson. 2012.

North Dakota Farm Business Man-agement Report.

National Research Council. 1996. Nutri-ent Requirements of Beef Cattle. 7th Revised Edition. National Academy of Science. Washington, D.C.