2002 Unified Beef Cattle and Range Research Report (continued)
Effect of field pea-based creep feed on intake and
digestibility of nursing beef calves grazing native range in western North Dakota
A. A. Gelvin1, G. P. Lardy1, J. S. Caton1,
and D. G. Landblom2
Supplemental creep feed increased total feed intake of nursing calves,
without affecting forage or milk intake. Grazed diets of nursing calves declined
in crude protein and digestibility with advancing season.
Effects of pea-based creep feed on intake of nursing calves grazing native
range in western North Dakota was investigated using eight ruminally cannulated
Angus-Hereford cross nursing steer calves (320 ± 96 lb initial BW). A completely
randomized design was used with two treatments: 1) no creep feed control and
2) supplemented. Supplemented calves received 0.45% BW (DM basis) creep feed
daily of the field pea-based creep feed (19% CP, 0.6% Ca, 0.4% P). Total feed
intake was higher (P = 0.09) for the supplemented compared with the control
calves. No differences were observed in forage (P = 0.40) or milk intake
(P = 0.90). Supplemented calves tended to consume forage higher (P
= 0.07) in CP compared with controls. Data indicate that supplementation of
nursing calves with a pea-based creep increases total intake without altering
forage or milk consumption.
Introduction
Supplemental creep feed can increase weaning weights of nursing
calves (Faulkner et al., 1994, Lardy et al., 2001, Loy et al., 2002). Lardy et
al. (2001) reported metabolizable protein to be the first limiting nutrient
for nursing calves, while Loy et al. (2002) reported energy to be the first
limiting nutrient. This could be due to different forage quality available to
the calves. Forage diet samples from Lardy et al. (2001) averaged
12.5% CP and 54.8% in vitro organic matter digestibility (IVOMD). Loy et
al. (2002) had forage that averaged 10.2% CP and 53.0% IVOMD.
Potential value of creep feed in a cow/calf operation is dependant
upon increased weaning weight, ability to stretch tight forage supplies,
and improved feed intakes at weaning. Research by Lardy et al. (2001)
shows that forage intake as a percent of BW tended
(P = 0.09) to be higher in the non-supplemented calves than
calves receiving supplemental undegraded intake protein (UIP) in the form
of sulfite liquor-treated soybean meal and feather meal. However, Loy et
al. (2002) found no differences in forage intake between supplemented
and non-supplemented calves. Milk intake did not differ between
supplemented and non-supplemented calves in either study. Krysl et al. (1989) found
that small amounts of soybean meal or steam-flaked sorghum grain had
little effect on forage intake, but both increased total tract OM digestion
in steers. However, increased starch intake may lead to depressions
in forage digestibility when starch-based creep feeds are fed at high levels.
Our objective was to determine the effect of pea-based creep feed on
forage intake, supplement intake and ruminal fermentation of
nursing calves grazing native range.
Procedure
Research was conducted at North Dakota State University Dickinson Research
Extension Center and used eight ruminally cannulated Angus-Hereford cross nursing
steer calves (320 ± 96 lb initial BW). Calves were allotted randomly to
two treatment groups: 1) no creep feed control and 2) supplemented . Supplemented
calves received 0.45% BW of a 19% CP (DM basis) field pea-based creep feed (Table
1). Previous research conducted at Dickinson Research and Extension Center shows
that this creep feed formulation is optimum for calf performance.
Table 1. Supplement composition
(dry matter basis).
----------------------------------
Ingredient %
----------------------------------
Field peas 62.10
Wheat middlings 31.05
Molasses 5.00
Limestone 1.80
Trace mineral & vitamin
premix 0.05
----------------------------------
Laboratory Analysis
CP 19.11
IVOMD 88.10
----------------------------------
All calves grazed native pasture with their dams from July 1 to Nov. 5.
Salt and mineral was available on a continuous basis. Measures of
calf responses to treatment were taken July, August, September, and
October and included BW, fecal output, milk consumption, diet composition,
and digestion. Grazed forage quality was analyzed for organic matter
(OM), neutral detergent fiber (NDF), acid detergent fiber (ADF), crude
protein (CP), in vitro organic matter digestibility (IVOMD), and acid
detergent insoluble nitrogen (ADIN).
Results
Supplementation did not alter grazed forage NDF, but tended to decrease ADF
(P = 0.09) and tended to increase CP (P = 0.07; Table 2). Grazed
forage ADIN and IVOMD were not altered by supplementation. There were no seasonal
effects for grazed forage NDF or ADF (P > 0.10; Table 2). Crude protein
and ADIN decreased linearly with advancing season (P less than or equal
to 0.03). In vitro organic matter digestibility decreased (P < 0.01)
from July (58.5%) to October (41.3%). Calf weight was similar (P = 0.51)
between treatments at the beginning of the trial (control = 310 lb; supplemented
= 331 lb); however in October supplemented calves were heavier (P = 0.05;
control = 497 lb; supplemented = 569 lb).
Forage intake was not different (P = 0.89) between treatments, but increased
linearly with advancing season (P = 0.025; Table 3). Milk intake was
similar (P = 0.55) between control and supplemented calves, but decreased
linearly (P = 0.001) over time when expressed as a percentage of calf
BW. Supplement intake (lb/d) increased linearly (P = 0.002) over time.
This was due to the research protocol. Calves were fed at a percent of BW, consequently
creep intake (lb/d) increased as calves grew. Supplemented calves had greater
total intake (forage + milk + creep; P = 0.05) than control calves.
Organic matter and CP digestibilities of the grazed forage were higher (P
= 0.004; Table 4) for the supplemented calves than the control calves. With
advancing season, NDF, ADF, and OM digestibilities decreased linearly (P <
0.01; Table 4).
Table 2. Effects of season on grazed forage diet quality (OM basis).
------------------------------------------------------------------------------------------
Treatment Season Contrast
------------- ------------------------- ------------------
Item CON SUP SEMa P July Aug Sept Oct SEMa Lb Qc Cd
------------------------------------------------------------------------------------------
OM 84.8 86.2 1.38 0.49 88.4 81.4 87.5 84.6 1.96 0.84 0.32 0.02
- - - - - - - - - - - - - %, OM basis - - - - - - - - - - - - - - - - - - -
NDF 67.9 66.4 0.96 0.32 68.6 66.6 68.6 64.9 1.41 0.24 0.55 0.10
ADF 40.8 39.2 0.57 0.09 40.0 40.2 41.1 38.7 0.92 0.56 0.17 0.27
CP 8.6 9.8 0.36 0.07 9.7 10.3 8.1 8.6 0.57 0.03 0.92 0.08
ADIN 0.23 0.25 0.015 0.54 0.25 0.29 0.21 0.21 0.020 0.02 0.30 0.08
IVOMD 52.7 53.4 1.51 0.76 58.5 57.1 55.3 41.3 1.28 <0.001 <0.001 0.003
------------------------------------------------------------------------------------------
aSEM=standard error of the mean
bL=linear contrast
cQ=quadratic contrast
dC=cubic contrast
Table 3. Effect of treatment and period on intakes of nursing calves (DM Basis).
-------------------------------------------------------------------------------------
Treatment Season Contrast
----------- ------------------------ ----------------
CON SUP SEMa P July Aug Sept Oct SEMa Lb Qc Cd
-------------------------------------------------------------------------------------
Intake, lb, DM/day
Milk 2.23 2.29 0.32 0.90 2.60 2.26 2.11 2.07 0.31 0.23 0.62 0.83
Forage 5.10 5.99 0.68 0.40 3.69 4.18 6.86 7.44 0.48 <0.001 0.93 0.30
Total 7.33 10.26 1.03 0.09 7.02 7.32 10.05 10.78 0.57 <0.001 0.71 0.36
-------------------------------------------------------------------------------------
Intake, % BW
Milk 0.58 0.54 0.04 0.55 0.81 0.58 0.50 0.39 0.075 <0.001 0.31 0.45
Forage 1.28 1.31 0.127 0.89 1.18 1.08 1.50 1.42 0.117 0.025 0.94 0.12
Total 1.86 2.29 0.125 0.05 2.21 1.88 2.18 2.02 0.139 0.88 0.54 0.09
-------------------------------------------------------------------------------------
aSEM=standard error of the mean
bL=linear contrast
cQ=quadratic contrast
dC=cubic contrast
Table 4. Total tract digestibilites (% OM basis) of nursing calves
grazing native range.
-------------------------------------------------------------------------------
Treatment Season Contrast
---------- ---------------------- -----------------
Item CON SUP SEMa P July Aug Sept Oct SEMa Lb Qc Cd
-------------------------------------------------------------------------------
NDF 46.0 45.6 1.82 0.88 53.0 53.1 41.0 36.0 2.85 <0.001 0.31 0.37
ADF 44.3 41.7 1.92 0.35 49.0 51.7 38.6 32.7 3.01 <0.001 0.10 0.25
OM 45.4 57.7 2.07 0.004 58.2 56.4 46.0 45.5 2.96 <0.001 0.80 0.34
CP 25.1 48.3 4.40 0.004 36.2 44.2 27.2 39.2 4.98 0.42 0.65 0.03
-------------------------------------------------------------------------------
aSEM=standard error of the mean
bL=linear contrast
cQ=quadratic contrast
dC=cubic contrast
Discussion
Forage intake did not differ between the two treatment groups, which
is similar to the findings of Lardy et al. (2001) and Loy et al. (2002),
but contradictory to the findings of Faulkner et al. (1994). Milk
intake was not different between the two treatment groups, and, as a
percentage BW, decreased over time. Lardy et al. (2001) and Loy et al.
(2002) reported similar findings. Total intake of the supplemented calves was
higher than the total intake of control calves, which also agrees with data
from Lardy et al. (2001) showing that nursing calves receiving
supplement had greater total intakes than control calves.
There was no treatment effect on total tract digestibility of NDF and ADF
of the forage, but treatment effects were present for OM and
CP digestibilities, which were similar findings as Krysl et al. (1989).
Calves that received supplement had similar forage intake compared
to control calves, with total intake being higher, resulting in greater
weight gains and weaning weights for the supplemented calves.
Supplemented calves had higher total tract digestibilities of OM and CP
compared to control calves.
Implications
Forage quality declines with advancing season in western North Dakota.
A field pea-based creep feed may be used to increase total energy
intake and improve nutrient status in nursing calves. More research is necessary
to define optimum creep feed level and economics under southwestern
North Dakota conditions.
References
Faulkner, D. B., D. F. Hummel, D. D. Buskirk, L. L. Berger, D. F. Parrett,
and G. F. Cmarik. 1994. Performance and nutrient metabolism by nursing calves
supplemented with limited or unlimited corn or soyhulls. J. Anim. Sci. 72:470-477.
Krysl, L. J., M. E. Branine, A. U. Cheema, M. A. Funk, and M. L. Galyean.
1989. Influence of soybean meal and sorghum grain supplementation on intake,
digesta kinetics, ruminal fermentation, site and extent of digestion and microbial
protein synthesis in beef steers grazing blue grama rangeland. J. Anim. Sci.
67:3040-3051.
Loy, T. W., G. P. Lardy, M. L. Bauer, W. D. Slanger, and J. S. Caton. 2002.
Effects of supplementation on intake and growth of nursing calves grazing
native range in southeastern North Dakota. J. Anim. Sci. 80:2717-2725.
Lardy, G. P., D. C. Adams, T. J. Klopfenstein, R. T. Clark, and J. Emerson.
2001. Escape protein and weaning effects on calves grazing meadow regrowth.
J. Range Manage. 54:233-238.
Merchen, N. R. 1988. Digestion, absorption and excretion in ruminants. In:
D. C. Church (Ed.) The Ruminant Animal: Digestive Physiology and Nutrition.
P 189. Prentice-Hall, Englewood Cliffs, NJ.
1Animal
and Range Sciences Department, North Dakota State University
2Dickinson Research
and Extension Center
INDEX
Effects of supplement type on intake and growth in
suckling calves grazing native range in southeastern North Dakota
T. D. Maddock1 and G. P.
Lardy1
Creep feeding nursing beef calves to increase weaning weights and stretch
limited forage resources is a common practice in North Dakota. Two trials
were conducted to evaluate differences in creep feed. Trial 1 investigated
the differences in performance and supplement intakes between grain-based
and fiber-based creep feeds and Trial 2 evaluated total intakes of nursing
calves supplemented with a grain-based creep feed while grazing native range
in southeastern North Dakota.
Introduction
Creep feeding has been used successfully to increase preweaning
gain (Stricker et al., 1979; Prichard et al., 1989). As many cow-calf
producers sell their calf crop at weaning time, weaning weight can be highly
correlated with gross income (Martin et al., 1981). Grain-based feeds
generally include corn and/or oats which, while higher in energy, can disrupt
fiber digestion in the rumen, while fiber-based feeds using wheat
middlings, soybean hulls, or corn distillers by-products are lower in energy, but
can help maintain rumen health (Wright, 2002). Faulkner et al. (1994)
investigated the performance of non-supplemented calves versus
calves supplemented with either soyhulls or corn while grazing
endophyte-infected fescue, and found no difference
in performance or feed efficiency, but did report calves supplemented
with soyhulls had higher NDF, ADF, and CP intakes. Trial 1
investigated performance and feed efficiency of supplementing suckling calves
either grain-based or fiber-based creep feeds. Trial 2 evaluated forage,
milk supplement and total intakes of calves supplemented grain-based creep feed.
Procedures
These trials were conducted at the Albert Ekre Grassland Preserve
near Walcott, ND, which is characterized as sandhills tallgrass prairie,
comprised of approximately 60% cool- season and 40% warm-season
grasses. Primary species include Poa pratensis (Kentucky bluegrass),
Agrostis stolonifera (redtop bent), Bouteloua gracilis (blue grama), and
various sedges (Carex spp.). Cow/calf pairs grazed a 160-acre pasture that
was split into four subunits for the duration of the study. Each
subunit was grazed 21 days in a twice-over rotation. Salt and trace minerals
were offered free choice.
Trial 1 consisted of 24 Angus and Angus cross cows (initial BW 1405
± 165 lb) and non-implanted suckling steer calves (initial BW 355.5 ±
57 lb). Calves were assigned randomly to one of three treatments.
Treatments (Table 1) were control, grazing only (CONTROL; n=8); fiber-based
creep feed (soyhulls and wheat middlings combined; FIBER; n=8); or
starch-based creep feed (corn and oats; STARCH; n=8). Both
supplements were pelleted and formulated to have equal crude protein. Calves
were allowed a 10-day adaptation period to feed. Once all calves were
consuming feed, calves were offered creep feed at 0.68 % of BW (DM).
Supplemented calves were sorted from cows, penned, and individually fed daily
for the duration of the trial (71 days). Feed refusals were collected
and weighed following each feeding. Cows and calves were weighed every
21 days during the trial.
Trial 2, which was conducted at the same place and during the same
time frame as Trial 1, utilized seven ruminally cannulated suckling
steer calves (initial BW = 350.9 ± 31.4 lb). Calves were assigned randomly
to either CONTROL (n = 4) or STARCH (n = 3). Calves in Trial
2 were supplemented the same as those in Trial 1. Collections occurred July
1 through 6 and Aug. 13 through 19. Forage intake was estimated
through total fecal collections. Total fecal output was collected for a
minimum of five days. Feces were collected once daily, weighed and then
subsampled for analysis. Diet samples were collected by evacuating
ruminal contents of the calves and allowing them to graze for approximately
30 minutes. Using in-vitro digestion of the diet samples and average
daily fecal outputs, total forage intake was determined (fecal output /
in-vitro digestibility = intake of forage). Milk intake was measured July 7 and
Aug. 16, using the weigh-suckle-weigh method (Boggs et al., 1980)
where cows were suckled dry, separated from their calves for 6 to 12
hours, and then calves were weighed, allowed to suckle the cows and then
reweighed. The difference in weight was considered milk production of
the cow.
Results and discussion
Trial 1. An interaction between period and treatment existed
for supplement intake (P < 0.001). This was expected, as calves in the
control group received no supplement, and calves ate more in August than in
July. In Table 2, cow and calf performance is given for the entire creep
feeding period. No differences were found in change in cow weight or calf
ADG due to treatment (P > 0.10).
Trial 2. Table 3 summarizes the intake data expressed on an OM basis
in lb/d and as a percentage of BW. Treatment did not affect forage or milk intake.
Calves consumed more (P = 0.004) forage in August than in July, but when
expressed as a percentage of BW, there were no differences (P = 0.30).
Milk intake increased (P < 0.01) from July to August, but this may
be due to the different weigh-suckle-weigh methods. In July calves were separated
from their dams for six hours. It was observed that some calves did not nurse,
so in August, calves were separated from their dams 12 hours. There was a period
x treatment interaction for supplement intake and total intake (lb/d; P
< 0.10). This was not unexpected, since CONTROL calves received no supplement.
However, when measured as a percentage of BW, no interaction is present. Main
effects of treatment existed (P < 0.001) for supplement and total
intake as a percent of BW, with supplemented calves consuming more than nonsupplemented
controls. A period effect is also present for total intake as a percent of BW,
with calves consuming more total OM in August than July.
Table 1. Composition of supplements
used in Trial 1 and Trial 2.
-----------------------------------
Starch Fiber
-----------------------------------
%, DM basis
Corn 40.6 --
Oats 40.0 --
Soy Hulls -- 38.7
Wheat Midds -- 55.0
Soybean Oil Meal 13.0
Molasses 4.2 5.0
Limestone 1.1 1.3
Dicalcium Phosphate 1.1
Analyzed
nutrient content
NDF 20.7 45.1
ADF 8.7 23.9
CP 15.6 16.5
-----------------------------------
Table 2. Effect of supplement type on cow and calf performance
during creep period (Trial 1)a.
-------------------------------------------------------------------
Treatment P-value
------------------------ -----------
Control Fiber Starch SE Trt
-------------------------------------------------------------------
Initial Cow Wt. (lbs) 1412.0 1394.8 1409.4 60.9 0.98
Final Cow Wt. (lbs) 1397.4 1351.9 1368.5 59.3 0.86
Change in Cow Wt. (lbs) -14.6 -42.9 -40.9 15.8 0.39
Initial Calf Wt. (lbs) 340.9 360.1 365.2 20.8 0.69
Final Calf Wt. (lbs) 445.7 469.6 478.9 24.2 0.61
Calf ADG c 1.48 1.54 1.60 0.11 0.71
-------------------------------------------------------------------
aPeriod reflects changes across entire creep feeding period (71 d).
bP - value of contrast for nonsupplemented vs supplemented.
cCalf ADG = total weight gain / d on creep.
Table 3. Effect of supplement type and period on forage OM,
milk OM, supplement OM, and total OM intakes on weight and
% BW basis (Trial 2).
------------------------------------------------------------------
Period P - values
------------- ----------------------
July August SE Trt Per Per*trt
------------------------------------------------------------------
Forage OM intake - lb/d, OM -
Control 3.01 5.04 0.48 0.84 0.004 0.58
Starch 2.65 5.20
-- % BW --
Control 0.85 0.84 0.09 0.64 0.30 0.20
Starch 0.67 0.93
Milk OM intake - lb/d, OM -
Control 0.13 0.51 0.06 0.19 0.001 0.72
Starch 0.02 0.45
-- % BW --
Control 0.04 0.08 0.01 0.22 0.007 0.35
Starch 0.01 0.08
Supplement OM intake lb/d, OM
Control 0.00 0.00 0.19 <0.001 0.06 0.04
Starch 2.70 3.65
-- % BW --
Control 0.00 0.00 0.04 <0.001 0.68 0.68
Starch 0.69 0.65
Total OM intake - lb/d, OM -
Control 3.14 5.55 0.39 <0.001 <0.001 0.09
Starch 5.38 9.30
-- % BW --
Control 0.89 0.92 <0.001 <0.001 0.09 0.16
Starch 1.36 1.66
------------------------------------------------------------------
Implications
Supplementing calves with starch-based creep feed does not
increase weight gains when compared to fiber-based creep feeds
or nonsupplemented controls. Starch-based supplements did not
increase forage OM or milk OM intakes when compared to
nonsupplemented controls. Supplemented calves did consume more total OM,
however this did not translate into an advantage in performance.
References
Boggs, D. L., E. F. Smith, R. R. Schalles, B. E. Brent, L. R. Corah, and
R. J. Pruitt. 1980. Effects of milk and forage intake on calf performance.
J. Anim. Sci. 51:550-553.
Faulkner, D. B., D. F. Jummel, D. D. Buskir, L. L. Berger, D. F. Parrett,
and G. F. Cmarik. 1994. Performance and nutrient metabolism by nursing calves
supplemented with limited or unlimited corn or soyhulls. J. Anim. Sci. 72:470-477.
Loy, T. W., G. P. Lardy, M. L. Bauer, W. D. Slanger, and J. S. Caton. 2002.
Effects of supplementation of intake and growth of nursing calves grazing
native range in southeastern North Dakota. J. Anim. Sci. 80:2717-2725.
Martin, T. G., R. P. Lemenager, G. Srinivasan, and R. Alenda. 1981. Creep
feed as a factor influencing performance of cows and calves. J. Anim. Sci.
53:33-39.
Prichard, D. L., D. D. Hargrove, T. A. Olson, and T. T. Marshall. 1989. Effects
of creep feeding, zeranol implants and breed type on beef production: 1. Calf
and cow performance. J Anim. Sci. 67:609-616.
Stricker, J. A., A. G. Matches, G. B. Thompson, V. W. Jacobs, F. A. Martz,
H. N. Wheaton, H. D. Currance, and G. F. Krause. 1979. Cow-calf production
on tall fescue-ladino clover pastures with and without nitrogen fertilization
of creep feeding spring calves. J. Anim. Sci. 48:13.
Wright, C. 2002. Creep Feeding May Reduce Grazing Pressure on Drought-Stressed
Pastures. Available: http://agbionews.sdstate.edu/articles/creepfeed.html.
Accessed Jan. 30, 2003.
1Dept.
of Animal and Range Sciences
North Dakota State University
INDEX
Utilization of field pea and sunflower meal as dietary
supplements for beef cows — progress report
C. Smith¹, T.J.Transtrom¹, W.W. Poland², L.J.Tisor² and J.
Nelson2
Summer calving cows can be managed on stockpiled perennial forages in
southwestern North Dakota. Weight loss during grazing can be reduced with
supplementation. Supplemental energy appeared to be the first limiting nutrient
for beef cows grazing this type of forage. Field pea and sunflower meal appear
to be effective feed ingredients in the formulation of supplements for beef
cows grazing stockpiled perennial forage in late fall and early winter.
The objectives of this study were to determine if 1) field pea and sunflower
meal can be used effectively as dietary supplements and 2) energy or protein
is the first-limiting nutrient for beef cows grazing stockpiled perennial forage
in the late fall/early winter. Twenty-one summer calving cows grazed a pasture
of stockpiled predominately native range in western North Dakota from November
14, 2001 until January 23, 2002. Stockpiling refers to the practice of allowing
forage to accumulate in the absence of grazing for use at a later time. Cows
were randomly allotted into four groups and groups were then assigned one of
four supplemental treatments. Treatments included an unsupplemented control
(CON) and three supplemented groups. Supplemental treatments were a barley (BAR)-,
field pea (PEA)- and sunflower meal (SFM)-based pellet provided to individual
cows in respective treatments three times a week. At the end of grazing, all
cows were combined into one group and managed similarly for 28 days. Body weight
(BW) did not differ among treatments throughout the trial. With the exception
of days 28 and 42, body condition score (BCS) did not differ consistently among
treatments. Treatment did not affect BW loss on day 14. On this day, cows had
lost an average of 126 lbs. Supplementation reduced BW loss compared to CON
on days 42 and 70. Overall, supplementation reduced weight loss during grazing
by 63 lbs BCS loss was reduced by supplementation on day 42. Under common management
for 28 days post-grazing, overall BW, BW change, BCS and BCS change did not
differ among treatments. In general during late fall and early winter, BW increased
75 lbs and BCS decreased .3 units with 70 days of grazing and 28 days of recovery.
Cattle grazing stockpiled perennial forages in southwestern North Dakota from
mid-November to late-January lost body weight and condition score. Weight loss
during this grazing period was reduced with supplementation. Energy appeared
to be the first limiting nutrient, and source of supplemental energy (barley,
field pea or sunflower meal) did not affect body weight change. Most of the
body weight and condition lost during grazing had been recovered by 28 days
post-grazing.
Introduction
Narrow profit margins in the cow/calf sector of the beef industry
require careful attention to production costs and associated levels of
output. Extended grazing periods have been shown to decrease winter feed costs
(a major component of overall cow/calf expenses). Management of
pre-calving cow weight and condition change can enhance overall reproductive
efficiency. Nutritional supplementation regimes may be necessary to
manage cow weight and condition during extended fall/winter grazing
periods. Dietary protein has been suggested to be the first-limiting nutrient in
cattle grazing winter range. There are alternative crops and processing
co-products that are higher in crude protein than typical feed grains
that might be used effectively in protein supplements formulated for
cattle grazing stockpiled perennial forage.
Objectives
- Determine whether field pea and sunflower meal can be used effectively as
dietary supplements for beef cows grazing stockpiled perennial forage in the
late fall/early winter.
- Determine whether either energy or protein is the first-limiting nutrient
for beef cows grazing stockpiled perennial forage in late fall/early winter.
Materials and Methods
Twenty-one summer calving cows (BW = 1386 ± 142 lbs; BCS = 6.8 ±
.64 units) grazed a pasture of stockpiled predominately native range in western
North Dakota from November 14, 2001 until January 23, 2002. Stockpiling refers
to the practice of allowing forage to accumulate in the absence of grazing for
use at a later time. Cows were randomly allotted into four groups and groups
were then assigned one of four supplemental treatments. Treatments included
an unsupplemented control (CON; six head) and three supplemented groups (five
head/group). Supplemental treatments were a barley (BAR)-, field pea (PEA)-
and sunflower meal (SFM)-based pellet. Supplemental treatments were chosen to
supply additional energy and gradient levels of rumen-degradable protein (Table
1). Supplements were provided to individual cows in the supplemental treatments
three times a week. Supplemental intake was limited to 3.0 lbs/hd per day or
7.0 lbs/hd per feeding. Adjustments to supplement delivery based on adverse
environmental conditions were not necessary during the study period.
Table 1. Composition of total digestible
nutrients (TDN), crude protein (CP) and
ruminally degraded crude protein (DIP) in
stockpiled perennial forage, barely, field
pea and sunflower meal.
-----------------------------------------------
Sunflower
Forage Barley Field Pea meal
-----------------------------------------------
TDN (% DM) 53 84 87 74
CP (% DM) 4.9 13 25 45
DIP (% DM) - 10.3 19.5 34.2
DIP (% CP) - 79 78 76
-----------------------------------------------
Sources: NRC, 1984, 1985; Hicking, 1994;
Transtrom, et al., 2002.
Cows were weighed (BW) and condition scored (BCS; Encinias and Lardy, 2000)
at 14-day intervals throughout the course of the winter grazing period and at
28-d post-grazing. Herbage available for grazing was also sampled at 14-day
intervals to detect changes in dry matter available for grazing. For sampling
purposes, the pasture was divided into two halves (east and west) and 5 sample
sites were chosen per pasture half to represent major range types. Two .25 m2
areas were clipped per site per sampling date. At clipping, forage was physically
separated into grasses (G) and others (forbs; F). All forage was dried (55°
C) to a constant weight. Dry weights of G and F were then used to calculate
forage production per acre. Total forage available for grazing (T) was the sum
of G and F.
At the end of grazing, all cows were combined into one group and
managed similarly. Cows were moved to an unharvested corn field that
had been previously grazed by beef heifers and supplied with approximately
23 lbs/hd per day of dry hay. Cows remained at this facility until
grazing commenced the following spring.
Animal data were analyzed utilizing a completely random design with
four treatments replicated across cows. Treatment represented a fixed
effect and animal within treatment served as the experimental unit. Means
were separated using orthogonal contrasts. Specific contrasts include 1) CON
vs supplemental treatments, 2) BAR vs PEA and SFM and 3) PEA vs
SFM. Forage yields were analyzed utilizing a randomized complete block
design where pasture half was the blocking factor and sampling date was the
main effect.
Results
Body weight and BCS are depicted in figures 1 and 2, respectively. Live weight
did not differ among treatments (P > .30) throughout the trial. With the
exception of days 28 and 42, BCS did not differ among treatments (P > .20).
On day 28 (P < .10) and 42 (P < .05), PEA reduced BCS compared to SFM.
Also on day 42 (P = .01), CON reduced BCS compared to other treatments.
Figure 1. Effects of supplemental treatment and grazing days
on body weight (BW). Supplemental treatments were an unsupplemented control
(CON) and a barley (BAR)-, field pea (PEA)- and sunflower meal (SFM)-based
pellet. (Click here for a 12KB black and
white graph.)
Figure 2. Effects of supplemental treatment and grazing days on body
condition score (BCS). Supplemental treatments were an unsupplemented
control (CON) and a barley (BAR)-, field pea (PEA)- and sunflower meal
(SFM)-based pellet. (Click here for a 12KB black
and white graph.)
Supplemental treatment (P > .30; Table 2) did not affect BW loss on
day 14. On this day, cows had lost an average of 126 lbs.
Supplementation reduced BW loss compared to CON on days 42 (P = .10) and 70 (P <
.01). Overall, supplementation reduced weight loss during grazing by 63 lbs.
Loss of BCS (P < .10; Table 3) was reduced by supplementation on day 42.
Among supplemental treatments, BCS loss tended to be reduced by SFM compared
to PEA on day 42 (P < .15) and by BAR on day 70 (P < .15) (Table 3).
Under common management for 28 days post-grazing (day 96),
overall BW and BCS and BW and BCS change did not differ among
treatments (P > .15). In general during late fall and early winter, BW
increased 75 lbs and BCS decreased .3 units with 70 days of grazing and
28 days of recovery (Tables 2 and 3).
Forage available for grazing (T), grass (G), and nongrass (F) yield and change
in yield was not affected by grazing date (P >.15; data not shown). Nonetheless,
yields of T, G and F were numerically reduced 368, 301 and 67 lbs/ac, respectively,
over the grazing season.
Table 2. Effect of supplementation treatment on body
weight change (lbs).
------------------------------------------------------------
Treatmenta Probabilityb
Day of -------------------------- ----------------
trial CON BAR PEA SFM SE 1 2 3
------------------------------------------------------------
14 -128 -132 -140 -102 29.4 .90 .76 .37
42 -182 -102 -135 -106 35.9 .10 .68 .57
70 -164 -110 -97 -95 24.0 .03 .63 .96
96 65 64 95 76 22.1 .59 .44 .55
------------------------------------------------------------
aTreatments included an unsupplemented control (CON) and
three supplemented groups. Supplemental treatments were a
barley (BAR)-, field pea (PEA)- and sunflower meal
(SFM)-based pellet.
bProbability of a significant orthogonal contrast. Specific
contrasts include 1) CON vs supplemental treatments,
2) BAR vs PEA and SFM and 3) PEA vs SFM.
Table 3. Effect of supplementation treatment on body
condition score change.
----------------------------------------------------------
Treatmenta Probabilityb
Day of ----------------------- ----------------
trial CON BAR PEA SFM SE 1 2 3
----------------------------------------------------------
14 -.3 -.4 -.6 -.4 .24 .62 .74 .56
42 -1.2 -.6 -1.0 -.4 .25 .08 .74 .11
70 -1.0 -.4 -1.0 -.8 .27 .37 .14 .60
96 -.3 0.0 -.4 -.4 .26 .81 .23 1.00
----------------------------------------------------------
aTreatments included an unsupplemented control (CON) and
three supplemented groups. Supplemental treatments were
a barley (BAR)-, field pea (PEA)- and sunflower meal
(SFM)-based pellet.
bProbability of a significant orthogonal contrast. Specific
contrasts include 1) CON vs supplemental treatments,
2) BAR vs PEA and SFM and 3) PEA vs SFM.
Conclusion
Cattle grazing stockpiled perennial forages in southwestern
North Dakota from mid November to late January lost body weight and
condition score. Weight loss during this grazing period was reduced
with supplementation. Energy appeared to be the first limiting nutrient,
and source of supplemental energy (barley, field pea or sunflower
meal) did not affect body weight change. Most of the body weight and
condition lost during grazing had been recovered by late- February.
Literature cited
Encinias, A.M. and G. Lardy. 2000. Body condition scoring I: managing your
cow herd through body condition scoring. Ext. Publ. AS-1026. North Dakota
State University. (/pubs/ansci/beef/as1026w.htm,
January 27, 2003).
Hickling, D. 1994. Canadian peas: feed industry guide. Canadian Special Crops
Assn. (Winnipeg, Manitoba) and Western Canada Pulse Growers Assn. (Regina,
Saskatchewan).
NRC. 1984. Nutrient requirements of beef cattle (6th Ed.). National Academy
of Science. National Research Council, Washington, DC.
NRC. 1985. Nutrient requirements of sheep (6th Ed.). National Academy of
Science. National Research Council, Washington, DC.
Transtrom, T.J., C. Smith, W.W. Poland and L.J. Tisor. 2003. Diet composition
of beef cows grazing stockpiled native range in southwestern North Dakota.
ND Unified Beef Report pp17-20.
¹ Department of
Agriculture and Technical Studies, Dickinson State University
² Dickinson Research Extension
Center, North Dakota State University
INDEX | NEXT
|
