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.
|
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|
DM |
Cr Prot |
ADF |
|
|
|
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| ||
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|
Corn silage, lb |
|
|
|
|
|
|
Alfalfa/grass hay, lb |
|
|
|
|
|
|
Straw, lb |
|
|
|
|
|
|
Wheat midds, |
|
|
|
|
|
|
Mineral |
|
|
|
|
|
|
Dry Matter intake/hd |
|
|
|
|
|
Table 2. Performance of intensively managed first calf
heifers on conventional vs alternative feeds during breeding season
and late summer lactation.
|
|
Control Diets |
|
|
|
Number of pairs |
15 |
|
|
|
|
| ||
|
Initial weight, lb |
1094 |
|
|
|
Intermediate weight, lb |
1085 |
|
|
|
Final weight, lb |
1108 |
|
|
|
| |||
|
Breeding season wt change, lb |
-9.2 |
|
|
|
Late summer wt change, lb |
+22.8 |
|
|
|
Overall wt change, lb |
+13.6 |
|
|
|
| |||
|
Number pregnant |
14 |
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|
Number open |
1 |
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|
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|
Initial cond score |
5.19 |
|
|
|
Intermediate cond score |
5.00 |
|
|
|
Final cond. score |
5.00 |
|
|
|
| |||
|
Breeding season CS change |
-.19 |
|
|
|
Late summer CS change |
0 |
|
|
|
Overall CS change |
-.19 |
|
|
Table 3. Performance of nursing calves from first calf
heifer fed conventional vs alternative feeds during
lactation.
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Birth date, Julian |
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Birth weight, lb |
|
|
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Sex, 2=F, 3=M |
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| |||
|
Initial weight, lb |
|
|
|
|
Intermediate weight, lb |
|
|
|
|
Final weight, lb |
|
|
|
|
| |||
|
Breeding season wt change, lb |
|
|
8.87 |
|
Late summer wt change, lb |
|
|
12.45 |
|
Overall wt change, lb |
|
|
15.01 |