Supporting intensively managed commercial beef cows on crop residues and processing co-products

V. L. Anderson

Carrington Research Extension Center

North Dakota State University

Introduction

North Dakota has been and will continue to be a cow/calf state regardless of the emphasis on the feedlot enterprise. Native range and pastures are occupied by beef cows in relatively uniform east to west distribution across the state (Figure 1). It is apparent that the arable acres in the state support intensive crop production as well as substantial numbers of beef cows by means of deliberate forage and feed production or through use of cropping system biomass in the form of residues, grain screenings, or processing co-products. Livestock manure contributes substantially to the value of integrating a crop farm with ruminants by reducing fertilizer costs and adding organic matter.

The concept of processing grains and oilseeds in the state continues to grow with mainstream processors (ADM, Cargill, and the ND Mill) and cooperative or specialty companies (Dakota Growers, and AgGrow Oils). As a result, the region has an abundance of good quality natural protein sources (sunflower meal, soybean meal, canola meal, crambe meal, safflower meal, linseed meal, wheat midds, corn gluten feed, corn gluten meal, distillers grains, barley malt pellets, edible bean splits, field peas, and alfalfa) with relatively few high energy feeds (corn, barley, and hulless oats). A very high percentage of the co-products are exported to other regions for use in feedlot diets, dairy rations, or commercial feeds. A much greater proportion of these co-products could be used in the region to supplement low quality forages for increased beef cow-calf production.

To explore the concept of enhancing crop-livestock integration and enterprise diversity, a long term study was initiated in 1996 to compare performance and economics of intensively managed beef cows fed conventional vs alternative feeds. This project will evaluate supporting beef cows throughout the year on cropping system residues, co-products, and limited amounts of conventional forage and grain. First calf heifers were used as they are the most difficult phase in a cow herd to keep growing, rebreed on time, and wean a reasonable calf. The first phase of this project will attempt to achieve or exceed typical commercial production levels using large amounts of crop residue (small grain straw and corn stover) and supplemental protein sources (wheat midds and corn gluten feed) during lactation, breeding season and up to weaning. If this concept proves successful, alternative feeds can be used in balanced and palatable rations in virtually all phases of beef cow/calf production.

Materials and Methods

After calving in the spring of 1996, thirty first calf heifers and their calves were allotted to a control treatment or an alternative feeds treatment. Control diets used chopped alfalfa hay and corn silage as the primary ingredients. The alternative diet used small grain straw and wheat middlings as the primary ingredient. Rations are presented in Table 1 along with nutrient content of the primary ingredients. Wheat middlings are the bran, germ and shorts remaining after milling hard wheat or durum for flour or semolina.

The randomly allotted Red Angus x Limousin and reciprocal cross cow/calf pairs were maintained in two adjacent pens and fed a mixed ration once daily in fenceline feedbunks. The fixed rations were established based on NRC Nutrient Requirements for Beef Cattle (1984). Calves were allowed access to creep feed from approximately June 1 to weaning in late September. A concurrent creep feeding trial was conducted after breeding season with the 30 pairs allotted to four pens of 7 or 8 pairs respectively. Wheat midds were the primary creep feed ingredient. Cows and calves were weighed at the start of the trial on May 2, at the end of breeding season on August 1, and at weaning on September 28. Cow condition scores were assigned at the same time. One pair was removed in each treatment early in the study due to calf health problems unrelated to the study. Natural service sires were penned with the cows on June 13 and removed on August 2 for a 50 day breeding season. Bulls in both treatment groups performed normally. Pregnancy diagnosis was determined on November 7. Many of the pregnant cows in the study were marketed in the fall preventing a good sampling of calving dates the following spring.

Results and Discussion

Feed data is reported in Table 1 with dry matter intakes for the two treatments being very close. The animal performance results reported in Table 2 are from the first year of the study.

Cow weight change pattern was similar for both treatment groups during the trial, losing weight during early lactation and gaining during the post breeding season period. Condition score was identical for both treatments at the start, at 5.19 on a 9 point scale with the alternative diet cows tending to improve over the control cows by weaning. Two cows were open in the alternative diet and only one in the control diet group. Calving dates the succeeding year were not available due to the sale of many of the test animals.

Calf performance on both treatments was nearly identical suggesting milk production was not altered by diet. Results reinforce what other trials have suggested, that beef cows perform to their genetic potential on a wide variety of feedstuffs provided the ration is balanced to the cows' needs and is palatable.

Table 1. Rations formulations and ingredient analysis for supporting intensively managed first calf heifers.

Control

Diets

Alternative

Feeds



DM



Cr Prot



ADF

------(as fed/hd/day)------

%

---%(DM basis)---

Corn silage, lb

36.58

-.-

37.3

8.1

25.8

Alfalfa/grass hay, lb

12.42

5.51

85.8

17.5

39.7

Straw, lb

4.16

10.48

83.3

6.1

51.4

Wheat midds,

-.-

16.79

86.8

18.2

8.8

Mineral

.34

.34

95.1

-.-

-.-

Dry Matter intake/hd

28.08

28.36


Table 2. Performance of intensively managed first calf heifers on conventional vs alternative feeds during breeding season and late summer lactation.

Control

Diets

Alternative

Feeds

St Err

Number of pairs

15

15

Initial weight, lb

1094

1059

25.38

Intermediate weight, lb

1085

1039

28.82

Final weight, lb

1108

1094

30.78

Breeding season wt change, lb

-9.2

-19.9

8.60

Late summer wt change, lb

+22.8

+54.6

6.46

Overall wt change, lb

+13.6

34.7

9.54

Number pregnant

14

13

-

Number open

1

2

-

Initial cond score

5.19

5.19

.16

Intermediate cond score

5.00

4.93

.15

Final cond. score

5.00

5.27

.12

Breeding season CS change

-.19

-.26

.08

Late summer CS change

0

+.34

.13

Overall CS change

-.19

+.08

.09

Table 3. Performance of nursing calves from first calf heifer fed conventional vs alternative feeds during lactation.



Control

Diets

Alternative

Feeds

 

St Err

Birth date, Julian

77.63

77.87

2.02

Birth weight, lb

88.63

85.75

2.92

Sex, 2=F, 3=M

2.44

2.38

.13

Initial weight, lb

164.2

158.9

5.94

Intermediate weight, lb

350.1

351.3

13.97

Final weight, lb

502.9

500.7

19.74

Breeding season wt change, lb

185.9

192.4

8.87

Late summer wt change, lb

152.8

149.4

12.45

Overall wt change, lb

338.7

341.8

15.01




1997 Beef and Bison Contents