Case study : evaluation of annual cultivated peanut as a forage crop for grazing by growing beef cattle

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Case study : evaluation of annual cultivated peanut as a forage crop for grazing by growing beef cattle
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2009 Florida Beef Report
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Myer, Bob
Gorbet, Dan
Blount, Ann
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Institute of Food and Agricultural Sciences, University of Florida
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Case Study: Evaluation of Annual Cultivated Peanut as a Forage Crop for
Grazing by Growing Beef Cattle

Bob Myert
Dan Gorbet
Ann Blount



Annual peanut forage like other forage legumes has excellent nutritional quality. However, it lacked
adequate re-growth during the grazing season when grazed by growing beef cattle.


Summary
The annual cultivated peanut (Arachic hypogaea
L.) was evaluated as a possible high quality
pasture forage crop for grazing by growing beef
cattle. A 10.2 ac field that was originally
planted to annual peanut in 1999 was used.
Since 1999, the peanut reseeded (self-seeded)
annually. The forage initially was harvested for
hay, and the seeds were left in the soil. In 2002,
a 2-yr demonstration grazing study was
initiated. Early weaned calves were used each
year 25 (442 lb avg. wt.) for yr 1 and 20 (402
lb) for yr 2. The peanut field was rotationally
grazed each year ,',,, i/,g mid July (yr 1) or
early August (yr 2). The relatively late start was
to ensure the peanut set seed for the next year's
forage crop. The grazing season lasted 88 dfor
yr 1 and 55 d for yr 2. Estimated average
forage yield was 5406 lb ac and 3915 lb ac for
yr 1 and 2, respectively. At the start of each
year, forage amount and quality was high;
however, both declined as grazing season
progressed. Estimated calf gain per ac was 165
and 94 lb for yr 1 and 2, respectively. The
annual peanut initially was an excellent forage
crop for grazing by early weaned beef calves,
but the lack of re-growth and declining forage
quality resulted in poor performance late in the
grazing periods.

Introduction
High quality forage legumes that can be grown
during the warm season are scarce in the lower


southeastern USA. Temperate perennial forage
crops such as alfalfa (Medicago sativa) do not
grow well in this region (Prine and French,
1999). Perennial (rhizome) peanut for forage
(Arachis glabrata) can be grown in this area but
is planted from rhizomes and is hard and slow to
establish, taking two to three years to establish a
stand (Hill, 2002; French and Prine, 2006). The
cultivated or annual peanut (A. hYpogIueLa) is
well adapted to this region and is established by
seed, and unlike the perennial peanut, forage
would be available the first year (Gorbet et al.,
1994).

Recent development of annual peanut cultivars
with resistance to late leaf spot may allow the
production of a quality, high yielding forage
crop without the use of fungicides. Fungicides
are commonly used in peanut production to
inhibit the development of late leaf, a common
foliar disease. Late leaf spot can decrease
amount of leaves and thus decrease forage
amount and nutritional quality. Also, there is an
inherent liability in feeding annual peanut forage
to livestock because many of the pesticides, in
particular, fungicides, used in peanut production
are not cleared for the feeding of forage and
crop residue (Gorbet et al., 1994; Hill, 2002).
Previous Florida research have obtained forage
dry matter yields of up to 7200 lb/ac using
disease resistance lines and without the use of
fungicides (Gorbet et al., 1994). In that study,


2009 Florida BeefReport










the forage was harvested for hay 75 to 85 d after
planting and then the seed pods were harvested
at plant maturity. Defoliation of the canopy,
however, resulted in decreased seed pod yields.

With changes in the USA peanut program, there
has been interest in growing the annual peanut
strictly as a forage crop. Since the pods are not
harvested, the peanut plant may be able to self-
seed (re-seed) and the plants would emerge the
next growing season to produce a subsequent
forage crop. Thus it would be possible to obtain
several years of forage from one planting.
Anecdotal evidence suggests that this may be
possible as annual peanut will readily emerge
(volunteer) the next spring from seed left after
harvest the previous fall. A 2-yr demonstration
study was conducted to evaluate the suitability
of annual peanut as a forage crop for grazing by
beef cattle.

Procedure
The 2-yr demonstration study was conducted at
the University of Florida's North Florida
Research and Education Center (NFREC)
Marianna Beef Unit located in northwest Florida
(30.50N). A 10.2 ac field that was originally
planted with annual peanut (cultivar 'Florida
MDR 98') in 1999 was used. Each year the
peanut plants emerged in April from seed of the
previous year's crop. For the first 3 yr, the
forage was harvested as hay. In 2002, a beef
cattle grazing study was started. The study was
conducted for two consecutive years without
replanting the annual peanut.

The peanut seeding rate in 1999 was 85 lb/ac.
Prior to the start of the grazing trial in 2002,
lime (dolomite, 1000 lb/ac) was applied to the
field in February. Fertilizer was applied (350
lb/ac of 9-24-16 + minor elements) during
March. Also during March, the field was treated
with herbicide (Sonalan, Dow AgroServices,
Indianapolis, IN, USA) and then disc harrowed.
The plants emerged in April. In May, the field
was sprayed with another herbicide (Cadre,
BASF Corp., Research Triangle, NC, USA).
During July, the field was divided into four
equal sized sections using temporary electric
fencing. A narrow section, 12 ft wide, through
the middle of the field was fenced off to provide


an un-grazed check area. The four sections were
rotationally grazed starting in late July. This
rather late starting time was chosen to insure that
the peanut plants have "pegged" (seed set) for
re-seeding of the next year's forage crop. For the
first year, 25 early weaned heifers and steers
with an average initial weight of 442 72 lb
were used. While grazing, the calves had free
access to water, mineral mix, and shade. Each
section was grazed for 7 d then allowed to
recover for 21 d and than grazed again. Three
complete cycles were completed. After the three
rotations, the cattle were allowed to graze all
sections for an additional 5 d.

Before grazing each section, the forage in two
representative one meter (1.2 sq. yd) square
areas was hand clipped to a stubble height of
about 5 in. Samples were taken to estimate
forage dry matter (DM) yield and determine
crude protein (CP) and in vitro organic matter
digestibility (IVOMD). The samples were dried,
ground (1 mm) and saved for future analyses.
Also, 7 d before the start in 2002 (yr 1) only, a
composite sample was taken from four
representative one meter square areas within the
entire field. This sample was dried, ground and
sent to commercial laboratory for the
determination of CP, phosphorus (P), calcium
(Ca), ash, acid detergent fiber (ADF), neutral
detergent fiber (NDF) and lignin. The
individual section samples were dried, ground
and analyzed for CP and IVOMD.

The above forage management and sampling,
and grazing procedures were repeated for the
second year (2003) except no lime was applied
to the field. Only 20 calves were used (avg.
initial weight of 402 62 lb) for the second
year. For both years, calf weights were taken
after an overnight fast (no feed/pasture and
water) at start and end of grazing period, and at
an approximate midpoint (d 41 for yr 1 and d 32
for yr 2). For each year, the calves were
gradually adjusted to grazing of peanut forage
for 5 d prior to weighing and starting of the
grazing periods using a small section across the
ends of the four grazing sections. For the first
year, an initial cattle stocking density of 2.5
head/ac was chosen based on estimated available
forage. For the second year, the stocking rate


2009 Florida BeefReport










was lowered to 2.0 head/ac and time spent
grazing each section was also lowered to 4 d.

The annual peanut was grown without fungicide
and under dry land conditions. Rainfall data
during each year's growing-grazing period was
obtained from the Florida Automated Weather
Network Station at NFREC Marianna.

Results
Initial analyses of the annual peanut forage
(Table 1) indicated very good nutritional value,
similar to that of alfalfa (NRC, 2000) and
perennial peanut (Prine and French 1999; Hill,
2000). Forage samples taken during the grazing
periods also indicated good nutritional value;
however, a noticeable decline occurred as the
grazing periods progressed, especially the first
year (Table 2).

The estimated total DM yield of annual peanut
forage obtained during yr 1 was within the range
of forage yields obtained by Gorbet et al. (1994)
for the annual peanut (Table 3). Forage DM
yield; however, was lower than commonly
obtained (4 to 8 t/ac) for established perennial
peanut (Prine and French, 1999). Estimated
peanut forage DM yield declined noticeably as
each year's grazing period progressed,
especially in the first year (Figure 1). The
declines indicated a lack of re-growth.

Due to the declining peanut forage yield as the
grazing period progressed during yr 1, 11 calves
were removed after 41 d and the trial continued
with just 14 calves. For yr 2, all 20 were kept on
for the duration of the grazing period; however,
the grazing period lasted only 55 d vs. 88 d for
yr 1(Table 3).

The grazing season length each year was rather
short, especially the in yr 2 (Table 3). In
comparison, established perennial peanut can be
grazed for 110 to 140 d (June to mid-October)
per yr (Blount, A. R., personal communication).
Estimated forage DM yield overall was lower in
yr 2 and appeared to be negatively affected by
grazing in yr 1. Evidence for this negative affect
was that estimated DM forage yield obtained in
the un-grazed check strip was higher than
obtained in grazed areas during yr 2 (4,784


506 vs. 3,915 285 lb/ac). Rainfall, however,
was more plentiful for yr 1 (Figure 2) which
may have resulted in the difference in forage
yield and also for the difference in length of
grazing period for each year.

Average daily gain (ADG) of the cattle was
consistent for the two yr and overall averaged
0.92 lb/d (Table3). However, during yr 1, an
ADG of 1.96 0.601b/d was obtained for the
first 41 d. A slightly negative gain was obtained
for the last 48 d. The decrease in performance
was probably due to the low forage yield and
poorer nutritional quality as the grazing period
progressed (Table 2; Figure 1).

Even though annual peanut was initially an
excellent forage source in each yr, its lack of re-
growth was quite evident in each year's trial.
The strategy of lower initial cattle stocking
density and shorter grazing times per rotation
used during the second year appeared to be
somewhat successful. For the first yr, very few
leaves on the peanut plants were noted in a
section when the cattle were rotated to the next
section even though stubble height was 5 to 10
in. More leaves were evident in yr 2 with the
shorter rotations. Even though forage re-growth
declined as the grazing period progressed, the
decline noted for yr 2 was not as steep as noted
for yr 1 (Figure 1).

Total calf weight gain per acre averaged 129
lb/yr in this study. Estimated costs for annual
peanut for pasture would be higher than value of
gain in calf weight. Even though some peanut
establishment costs can be spread out over 2 yr
or longer, estimated pasture costs still would be
about $120 to $140/ac per yr (Hewitt, 2006).
Since it appears that grazing may have a
negative impact on the following year's forage
yield, the probability of profitably would decline
with subsequent years.

In conclusion, the lack of re-growth limits the
annual peanut as a pasture crop for grazing at
this time. Progress via plant breeding may
produce high yielding, persistent, seeded peanut
cultivars that can be used for grazing over
several grazing seasons from a single planting.
Thus in the future, the annual peanut may be


2009 Florida BeefReport










viable high quality summer legume forage for
grazing in the southeastern USA.


















Literature Cited
French, E.C. and G.M. Prine. 2006. UF-IFAS EDIS Publ. No. AA183.
Gorbet, D.W., et al. 1994. Peanut Sci. 21:112-115.
Hewitt, T. D. 2006. http://nfrec.ifas.ufl/hewitt/budgets.htm.
Hill, G.M. 2002. Vet. Clin. Food Anim. 18:295-315.
National Research Council (NRC). 2000. Nutrient Requirements of Beef Cattle, 7th Revised Ed.
National Academy Press. Washington, DC.
Prine, G. M., and E. C. French. 1999. Perspectives on New Crops and Uses. ASHS Press,
Alexandria, VA, USA. pp. 60-65.







Acknowledgment
The assistance of Mary Chambliss, Harvey Standland, Todd Matthews, Tina Gwin, John Crawford,
Wayne Branch, and Richard Fethiere is gratefully acknowledged. Partial funding was from Florida
Peanut Check-Off funds.





1Bob Myer, Professor, Dan Gorbert, Professor Emeritus, and Ann Blount, Associate Professor; UF-
IFAS, North Florida Research and Education Center, Marianna, FL.


2009 Florida BeefReport














Table 1. Composition of annual peanut forage a

Item
Crude protein
Neutral detergent fiber
Acid detergent fiber
Lignin
Ash
Calcium
Phosphorus
a'Average of analyses of samples taken just prior to grazing in yr 1.
bDry matter basis.


17.8
32.8
26.8
8.6
8.2
0.85
0.21


Table 2. Crude protein (CP) and in vitro organic matter digestibility (IVOMD) of annual
peanut forage during grazing trials.a

Year Sampling period CP,% IVOMD,%
1 First 28 d 20.5 72
Second 28 d 15.6 66
Last 33 d 14.7 61

2 First 16 d 18.8 71
Second 16 d 17.8 68
Last 23 d 16.2 64
aAverage analyses of four samples per period per year; dry matter basis.


2009 Florida BeefReport











Table 3. Animal grazing days, forage dry matter (DM) yield, and performance of growing cattle grazing
annual peanut forage.a

Year 1 Year 2
Grazing period:
Start 12 Jul 5 Aug
End 8 Oct 29 Sep
Days 88 55
Grazing d/ac 167 113
Forage DM, lb/ac 5406 148b 3915 285b
Stocking density, head/ac 1.72 2.00
Avg. daily gain, lb 0.99 + 0.42c 0.86 0.29d
Gain, lb/ac 165 95
aYr 1, 25 head for first 41 d of grazing and 14 head for last 48 d of grazing. Yr 2, 20 head for entire
grazing period.
bN = 4.
CN = 19 (weighed average).
dN = 20.



4000

3500

3000

2500

2000 Year 1

Year 2
1500



500

0
First Second Last



Figure 1. Estimated annual peanut forage yield, lb dry matter/ac (First = first 28 d period of
grazing for yr 1 and first 16 d for yr 2; Second = second 28 d for yr 1 and second 16 d for yr 2;
and Last = last 33 d for yr 1 and last 23 d for yr 2; S.D. = 102, 112 and 46, and 73, 57 and 72 lb
DM/ac for each of the three periods for each yr, respectively).


2009 Florida BeefReport




Full Text

PAGE 1

Case Study: Evaluation of Annual Cultivated Peanut as a Forage Crop for Grazing by Growing Beef Cattle Bob Myer 1 Dan Gorbet Ann Blount Summary The annual cultivated peanut (Arachic hypogaea L.) was evaluated as a possible high quality pasture forage crop for grazing by growing beef cattle. A 10.2 ac field that was originally planted to annual peanut in 1999 was used. Since 1999, the peanut reseeded (self-seeded) annually. The forage initially was harvested for hay, and the seeds were left in the soil. In 2002, a 2-yr demonstration grazing study was initiated. Early weaned calves were used each year 25 (442 lb avg. wt.) for yr 1 and 20 (402 lb) for yr 2. The peanut field was rotationally grazed each year starting mid July (yr 1) or early August (yr 2). The relatively late start was forage crop. The grazing season lasted 88 d for yr 1 and 55 d for yr 2. Estimated average forage yield was 5406 lb/ac and 3915 lb/ac for yr 1 and 2, respectively. At the start of each year, forage amount and quality was high; however, both declined as grazing season progressed. Estimated calf gain per ac was 165 and 94 lb for yr 1 and 2, respectively. The annual peanut initially was an excellent forage crop for grazing by early weaned beef calves, but the lack of re-growth and declining forage quality resulted in poor performance late in the grazing periods. Introduction High quality forage legumes that can be grown during the warm season are scarce in the lower southeastern USA. Temperate perennial forage crops such as alfalfa ( Medicago sativa ) do not grow well in this region (Prine and French, 1999). Perennial (rhizome) peanut for forage ( Arachis glabrata ) can be grown in this area but is planted from rhizomes and is hard and slow to establish, taking two to three years to establish a stand (Hill, 2002; French and Prine, 2006). The cultivated or annual peanut ( A. hypogaea ) is well adapted to this region and is established by seed, and unlike the perennial peanut, forage would be available the first year (Gorbet et al., 1994). Recent development of annual peanut cultivars with resistance to late leaf spot may allow the production of a quality, high yielding forage crop without the use of fungicides. Fungicides are commonly used in peanut production to inhibit the development of late leaf, a common foliar disease. Late leaf spot can decrease amount of leaves and thus decrease forage amount and nutritional quality. Also, there is an inherent liability in feeding annual peanut forage to livestock because many of the pesticides, in particular, fungicides, used in peanut production are not cleared for the feeding of forage and crop residue (Gorbet et al., 1994; Hill, 2002). Previous Florida research have obtained forage dry matter yields of up to 7200 lb/ac using disease resistance lines and without the use of fungicides (Gorbet et al., 1994). In that study, Annual peanut forage like other forage legumes has excellent nutritional quality. However, it lacked adequate re growth during the grazing season when grazed by growing beef cattle.

PAGE 2

the forage was harvested for hay 75 to 85 d after planting and then the seed pods were harvested at plant maturity. Defoliation of the canopy, however, resulted in decreased seed pod yields. With changes in the USA peanut program, there has been interest in growing the annual peanut strictly as a forage crop. Since the pods are not harvested, the peanut plant may be able to selfseed (re-seed) and the plants would emerge the next growing season to produce a subsequent forage crop. Thus it would be possible to obtain several years of forage from one planting. Anecdotal evidence suggests that this may be possible as annual peanut will readily emerge (volunteer) the next spring from seed left after harvest the previous fall. A 2-yr demonstration study was conducted to evaluate the suitability of annual peanut as a forage crop for grazing by beef cattle. Procedure The 2-yr demonstration study was conducted at Research and Education Center (NFREC) Marianna Beef Unit located in northwest Florida (30.5N). A 10.2 ac field that was originally peanut plants emerged in April from seed of the forage was harvested as hay. In 2002, a beef cattle grazing study was started. The study was conducted for two consecutive years without replanting the annual peanut. The peanut seeding rate in 1999 was 85 lb/ac. Prior to the start of the grazing trial in 2002, lime (dolomite, 1000 lb/ac) was applied to the field in February. Fertilizer was applied (350 lb/ac of 9-24-16 + minor elements) during March. Also during March, the field was treated with herbicide (Sonalan, Dow AgroServices, Indianapolis, IN, USA) and then disc harrowed. The plants emerged in April. In May, the field was sprayed with another herbicide (Cadre, BASF Corp., Research Triangle, NC, USA). During July, the field was divided into four equal sized sections using temporary electric fencing. A narrow section, 12 ft wide, through the middle of the field was fenced off to provide an un-grazed check area. The four sections were rotationally grazed starting in late July. This rather late starting time was chosen to insure that re-seeding of the next ye first year, 25 early weaned heifers and steers with an average initial weight of 442 72 lb were used. While grazing, the calves had free access to water, mineral mix, and shade. Each section was grazed for 7 d then allowed to recover for 21 d and than grazed again. Three complete cycles were completed. After the three rotations, the cattle were allowed to graze all sections for an additional 5 d. Before grazing each section, the forage in two representative one meter (1.2 sq. yd) square areas was hand clipped to a stubble height of about 5 in. Samples were taken to estimate forage dry matter (DM) yield and determine crude protein (CP) and in vitro organic matter digestibility (IVOMD). The samples were dried, ground (1 mm) and saved for future analyses. Also, 7 d before the start in 2002 (yr 1) only, a composite sample was taken from four representative one meter square areas within the entire field. This sample was dried, ground and sent to commercial laboratory for the determination of CP, phosphorus (P), calcium (Ca), ash, acid detergent fiber (ADF), neutral detergent fiber (NDF) and lignin. The individual section samples were dried, ground and analyzed for CP and IVOMD. The above forage management and sampling, and grazing procedures were repeated for the second year (2003) except no lime was applied to the field. Only 20 calves were used (avg. initial weight of 402 62 lb) for the second year. For both years, calf weights were taken after an overnight fast (no feed/pasture and water) at start and end of grazing period, and at an approximate midpoint (d 41 for yr 1 and d 32 for yr 2). For each year, the calves were gradually adjusted to grazing of peanut forage for 5 d prior to weighing and starting of the grazing periods using a small section across the ends of the four grazing sections. For the first year, an initial cattle stocking density of 2.5 head/ac was chosen based on estimated available forage. For the second year, the stocking rate

PAGE 3

was lowered to 2.0 head/ac and time spent grazing each section was also lowered to 4 d. The annual peanut was grown without fungicide and under dry land conditions. Rainfall data -grazing period was obtained from the Florida Automated Weather Network Station at NFREC Marianna. Results Initial analyses of the annual peanut forage (Table 1) indicated very good nutritional value, similar to that of alfalfa (NRC, 2000) and perennial peanut (Prine and French 1999; Hill, 2000). Forage samples taken during the grazing periods also indicated good nutritional value; however, a noticeable decline occurred as the grazing periods progressed, especially the first year (Table 2). The estimated total DM yield of annual peanut forage obtained during yr 1 was within the range of forage yields obtained by Gorbet et al. (1994) for the annual peanut (Table 3). Forage DM yield; however, was lower than commonly obtained (4 to 8 t/ac) for established perennial peanut (Prine and French, 1999). Estimated peanut forage DM yield declined noticeably as especially in the first year (Figure 1). The declines indicated a lack of re-growth. Due to the declining peanut forage yield as the grazing period progressed during yr 1, 11 calves were removed after 41 d and the trial continued with just 14 calves. For yr 2, all 20 were kept on for the duration of the grazing period; however, the grazing period lasted only 55 d vs. 88 d for yr 1(Table 3). The grazing season length each year was rather short, especially the in yr 2 (Table 3). In comparison, established perennial peanut can be grazed for 110 to 140 d (June to mid-October) per yr (Blount, A. R., personal communication). Estimated forage DM yield overall was lower in yr 2 and appeared to be negatively affected by grazing in yr 1. Evidence for this negative affect was that estimated DM forage yield obtained in the un-grazed check strip was higher than obtained in grazed areas during yr 2 (4,784 506 vs. 3,915 285 lb/ac). Rainfall, however, was more plentiful for yr 1 (Figure 2) which may have resulted in the difference in forage yield and also for the difference in length of grazing period for each year. Average daily gain (ADG) of the cattle was consistent for the two yr and overall averaged 0.92 lb/d (Table3). However, during yr 1, an ADG of 1.96 0.60lb/d was obtained for the first 41 d. A slightly negative gain was obtained for the last 48 d. The decrease in performance was probably due to the low forage yield and poorer nutritional quality as the grazing period progressed (Table 2; Figure 1). Even though annual peanut was initially an excellent forage source in each yr, its lack of reThe strategy of lower initial cattle stocking density and shorter grazing times per rotation used during the second year appeared to be somewhat successful. For the first yr, very few leaves on the peanut plants were noted in a section when the cattle were rotated to the next section even though stubble height was 5 to 10 in. More leaves were evident in yr 2 with the shorter rotations. Even though forage re-growth declined as the grazing period progressed, the decline noted for yr 2 was not as steep as noted for yr 1 (Figure 1). Total calf weight gain per acre averaged 129 lb/yr in this study. Estimated costs for annual peanut for pasture would be higher than value of gain in calf weight. Even though some peanut establishment costs can be spread out over 2 yr or longer, estimated pasture costs still would be about $120 to $140/ac per yr (Hewitt, 2006). Since it appears that grazing may have a yield, the probability of profitably would decline with subsequent years. In conclusion, the lack of re-growth limits the annual peanut as a pasture crop for grazing at this time. Progress via plant breeding may produce high yielding, persistent, seeded peanut cultivars that can be used for grazing over several grazing seasons from a single planting. Thus in the future, the annual peanut may be

PAGE 4

viable high quality summer legume forage for grazing in the southeastern USA. Literature Cited French, E.C. and G.M. Prine. 2006. UF IFAS EDIS Publ. No. AA183. Gorbet, D.W., et al. 1994. Peanut Sci. 21:112 115. Hewitt, T. D. 2006. http://nfrec.ifas.ufl/hewitt/budgets.htm Hill, G.M. 2002. Vet. Clin. Food Anim. 18:295 315. National Research Council (NRC). 2000. Nutrient Requirements of Beef Cattle, 7 th Revised Ed. National Academy Press. Washington, DC. Prine, G. M., and E. C. French. 1999. Perspectives on New Crops a nd Uses. ASHS Press, Alexandria, VA, USA. pp. 60 65. Acknowledgment The assistance of Mary Chambliss, Harvey Standland, Todd Matthews, Tina Gwin, John Crawford, Wayne Branch, and Richard Fethier e is gratefully acknowledged. Partial funding was from Florida Peanut Check Off funds. 1 Bob Myer, Professor, Dan Gorbert, Professor Emeritus, and Ann Blount, Associate Professor; UF IFAS, North Florida Research and Education Center, Marianna, FL.

PAGE 5

Table 1. Composition of annual peanut forage a Item % b C rude protein 17.8 N eutral detergent fiber 32.8 A cid detergent fiber 26.8 Lignin 8.6 Ash 8.2 C alcium 0.85 P hosphorus 0.21 a Average of analyses of samples taken just prior to grazing in yr 1. b Dry matter basis. Table 2. Crude protein (CP) and in vitro organic matter digestibility (IVOMD) of annual peanut forage during grazing trials. a Year Sampling period CP,% IVOMD,% 1 First 28 d 20.5 72 Second 28 d 15.6 66 Last 33 d 14.7 61 2 First 16 d 18.8 71 Second 16 d 17.8 68 Last 23 d 16.2 64 a Average analyses of four samples per period per year; dry matter basis.

PAGE 6

Table 3. Animal grazing days, forage dry matter (DM) yield, and performance of growing cattle grazing annual peanut forage. a Year 1 Year 2 Grazing period: Start 12 Jul 5 Aug End 8 Oct 29 Sep Days 88 55 Grazing d/ac 167 113 Forage DM, lb/ac 5406 148 b 3915 285 b Stocking density, head/ac 1.72 2.00 Avg. daily gain, lb 0.99 0.42 c 0.86 0.29 d Gain, lb/ac 165 95 a Yr 1, 25 head for first 41 d of grazing and 14 head for last 48 d of grazing. Yr 2, 20 head for entire grazing period. b N = 4. c N = 19 (weighed average). d N = 20. 0 500 1000 1500 2000 2500 3000 3500 4000 First Second Last Year 1 Year 2 Figure 1 Estimated annual peanut forage yield, lb dry matter/ac (First = first 28 d period of grazing for yr 1 and first 16 d for yr 2; Second = second 28 d for yr 1 and second 16 d for yr 2; and Last = last 33 d for yr 1 and last 23 d for yr 2; S.D. = 102, 112 an d 46, and 73, 57 and 72 lb DM/ac for each of the three periods for each yr, respectively).