nutrient and vegetation management in outdoor hog production systems

7/21/2019 Nutrient and Vegetation Management in Outdoor Hog Production Systems

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Outdoor swine enterprises represent an

opportunity for small producers, who could benet

from the growing consumer interest in pork

produced locally, in a more natural way. Outdoor

hog producon systems allow producers to meet

these consumer needs and to do so in smaller scale

enterprises that can be economically feasible.

Despite these opportunies, outdoor hog

operaons can create environmental damagerelated to the phosphorous (P) and nitrogen (N)

contained in hog manure and urine. Also, the

natural behavior of hogs outdoors can damage

vegetaon and cause soil compacon. Unless

managed correctly, high concentraons of nutrients

can accumulate in the soil and cause nutrient losses

to ground water, surface waters and into the

atmosphere. However, if properly managed,

outdoor operaons provide an opportunity for

producers to earn a prot, improve their quality of

life, sustain natural resources and support local

communies.

Knowing the amount of nutrients passing through

hogs during the various producon phases can be

useful to managers who want to capture that

valuable “ferlizer” for crop producon while

minimizing the potenal for contaminang surface

and ground waters. Nutrient loading is strongly

dependent on the stocking density and the length

of me animals occupy specic land areas.

Nutrient and Vegetaon Management inOutdoor Hog Producon Systems

Jim Green, Geo Benson and Silvana Pietrosemoli, 2014

Integrating hogs to crop rotation allows soil nutrient removal



2

Table 1. Nutrient loading for farrow to nish

operaon with 1 sow and 14 pigs per acre

stocking rate when site is used for 1 to 5 years

connuously

Crop response to P application does not change when P-I from

NCDA Soil Test is above 80 (which is equal to about 390 lbs of

available P2O5/acre (based on Mehlich-3 extractant

procedure}). Plant available N is for 1st year and is 0.4 of total

output; Plant available P2O5 and K 2O are 0.9 of total output.

Table 2. Nutrient loading from Feeder to Finish operaon at various stocking rates (14 to 5

head/ac/ yr) when same site is used connuously for 1 or 5 years.

Table 1 provides some esmates for the annual

nutrient loading when one sow and her 14

nished pigs are kept on one acre of land for one

to ve years. Note that the increase in the NCDA

Soil Test P-Index goes from 15 to 74 if there is no

removal of P from the site during those years.

Similarly, Table 2 shows esmates of the eect of

stocking density of nishing hogs over a ve-year

period on soil nutrient loads of P. These

esmates show that P buildup can be managed

with animal density, but would be strongly

related to the soil type and landscape and crop

removal. Eecve buers alongside streams

would be needed to help control runo and the

movement of soil parcles and nutrients fromthe land area used by hogs.

Crop response to P application does not change when P-I from NCDA Soil Test is above 80 (which is equal to about 390

lbs of available P2O5/acre based on Mehlich-3 extractant procedure). Plant available N is for 1st year and is 0.4 of total

output; Plant available P2O5 and K 2O are 0.9 of total output.

YR N P205 K20 P-I

1 72 72 94 15

2 143 144 188 29

3 215 217 282 44

4 287 289 377 59

5 358 361 471 74

Plant Available

Nutrients excretedonto the site

lbs/acre

Change in Soil

Test P-Index withno crop removal

fom site.

Years of

continuoususe

Change in Soil

Test P-Index with

no crop removal

from site

N

PAN

P205

PAP

K20

PAKP-I

14 1 56 49 67 10

28 1 112 98 133 20

56 1 224 196 266 40

14 5 280 245 333 50

28 5 560 490 665 100

56 5 1120 981 1330 200

Years

on same

site

Plant Available

Nutrients excreted

onto the site,

lbs/acre

Feeder-

Finishers,

Hd/acre

(based on

220 Mkt wt.)



To minimize the potenal environmental impacts

outdoor hog enterprises need to consider how to

prevent a build-up of nutrients in the soil and how

to prevent soil, water and nutrients from being

transported to nearby streams. To prevent a

nutrient build up there must be a balance

between the nutrients deposited on the soil bythe hogs’ manure and urine and those removed as

meat and crops. The amount of vegetave cover

on the hog lots and the use of buer strips

between the hog enterprise and streams aects

the loss of soil and nutrients from the hog lots.

Dierent strategies can be used to reduce these

environmental impacts including: maintaining

moderate animal stocking rates, reducing the

length of stay of the animals in a pen or paddockand removing harvested crops or forage from the

sites. Moving shelters, shades, waterers and

feeders periodically will prevent high

concentraons of nutrients from building up in

small areas of the hog lots.

There are two basic outdoor hog producon

systems. Dry-lot systems have a high density of

animals on a relavely small area of land with a

lower priority for maintaining vegetave cover on

that land. Pasture-based systems are designed

to maintain soil cover by rotang animals through

a series of paddocks using a low stocking rate andother management pracces. Within these two

basic approaches there are many alternave

layout designs for managing the animals.

The distribuon of the nutrients on the land area

used by the hogs will depend on how the system

is designed and how the hogs are managed. We

will provide two examples, each showing the

annual nutrient loading over the land area based

on output from the various hog producon

phases. One example is for hogs managed on a

dry lot system and one is for a pasture-based

operaon.

To prevent nutrients build up there must a balance between imported and exported nutrients



4

3. The size of the dry-lot relave to the number of

animals is based on animal welfare or behavioral

needs, the numbers of animals in a specied

producon phase and the length of me animals

spends in a specic producon phase.

4. Each year the acreage used by hogs is subdivided

so that about 31% is used for sows and boars and

about 69% is used for the growing and nishing

animals. The color coded parts of Table 3 show the

acreage of each area allocated to each type of

animal and producon phase with the esmated

amounts of nutrients (N, P and K) produced during

the year.

a. Boars use about 0.2 acres

b. Breeding area is about 0.45 acres

c. Gestaon period uses about 2.10 acres and

this area may be divided into early and late

gestaon to facilitate sow group management.

d. Lactaon period uses about 2.26 acres which

may be divided into early and late lactaon

areas to beer facilitate sow groups and pig

management.

e. Finishing pens are about 1.83 acres each and are

used for two feed-out periods of about 4-5 months

each; this means there will be a two- to four-month

Excessive algae growth results as excess nutrien

entering surface water from runoff or nutrien

Common assumpons to both examples:

Both producon systems are designed to have the

same number of sows producing the same number

of hogs. Each system produces an equal number of

market hogs each month to meet consumer

demand. The land area required for producon

diers between the two systems.

Each system has 24 sows producing 2 liers per sow

per year with 7 pigs weaned per lier. There are 2

boars.

Sows farrow in groups of four every month of the

year and weaned pigs are placed in growing and

nishing groups for 4-5 months.

I. Hogs on Dry-lot or Pens followed by Crop

Rotaon for Nutrient Management

Assumpons and consideraons for the dry-lot

example:

1. The basic goal in designing this example is that

nutrient loading on the land should remain constant

over a long period of me. In other words,

nutrients harvested through cropping should equalthe nutrient coming from hog manure and urine.

There are many alternaves to this example that

could meet the soil nutrient loading goal, depending

on the soil type, water table, slope, crop selecon,

and crop management.

2. The producon system requires a total of 48

acres, with one third (16 acres) used each year for

hogs and the remaining two-thirds being cropped to

remove nutrients. Each year the hogs move to 16

acres that were cropped the previous two years,

creang a rotaon of one year of hogs and two

years of crops. A buer acreage is provided to

prevent nutrients from migrang from the farmed

area into a stream and this is in addion to the 48

acres needed for the hog-crop rotaon.



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8. Each separate lot (paddock) has a watering point,

feeders and shelter/shade.

The suggested farm layout (Table 3) provides some

guidelines on the nutrient loading of specic

paddocks based on the hog producon phase using

the paddock. Each year, the 24-sow farrow-to-

nish operaon produces about 1738, 1764 and

2290 lbs of plant available N, P2O5, and K2O

respecvely (Figure 1). Well over 70% of the

nutrients are from the nishing phase of the

operaon. The total ferlizer value of the output is

more than $2,000 at 2013 esmated prices for

commercial ferlizer.

period between nishing groups when vegetaon

can recover or when annual crops could be grown

to provide vegetave cover.

5. This system stocks animals on 1/3 of the farmed

acreage for one year followed by the growing of

crops for two years, to be harvested to remove

nutrients deposited by the hogs. Each year the hog

enterprise is moved to land previously cropped for

two-years.

6. The annual nutrient loads are of plant available

nutrients based on the coecients shown in the

Figure 1.

7. Fences are electried 3-wire that can be moved

relavely easily.

Figure 1. Annual nutrient loading from a farrow-to-nishing operaon with the following animal numbers:

24 sows weaning 14 pigs (7 pigs/farrowing) and 2 boars. Availability coecients: N=.4; P & K = .9

1343

172 204

18

1738

1177

250 305

32

1764

1596

315 348

31

2290

0

500

1000

1500

2000

2500

Grow -finish pig gestating sow lactating sow boar, mature Total

L b s .

PA N

PA P2O5

PA K2O



T a b l e 3 . E s t i m a t e d

a c r e a g e a n d a n n u a l n u t r i e n t l o a d i n g f o r a n O u t d o o r D R Y L O T h o g o p e r a t i

o n s t o c k e d a t 2 4

s o w s + f i n i s h e d p i g s p e r 1 6 a c r e s i n c o m b i n a

t i o n w i t h 3 2 a c r e s o f c r o p l a n d . H o g s a n d c r o p s w

i l l b e o n a 3 y e a r

r o t a t i o n ( 1 y r h o g s

f o l l o w e d b y 2 y e a r s o f c r o p s ( 4 8 t o t a l a c r e s ) .

S O W # = 2 4

5 . 0

1 1 . 0

l b s P A N / a c = 7 9

l b s P 2 O 5 / a c = 1 1 7

l b s K 2 O / a c = 1 3 9

1 2 2 l b s P

A N / a c r e / y r

1 0 7 l b s P 2 O 5 / a c r e

1 4 5 l b s K 2 0 / a c r e

A c r e s / p e n

1 . 8 3

h d / p e n = 2 8

h d / a c r e = 1 5

0 . 4 5

a c r e s

1 . 1 3 a c r e s

1 . 0 5 a c r e s

J a n - A p r

J l y - O c t

F e b - M a y

A u g - N o v

M a r - J u n

S e p - D e c

0 . 2 0 a c r e s

1 . 1 3 a c r e s

1 . 0 5 a c r e s

A p r - J l y

O

c t - J a n

M a y - A u g

N o v - F e b

J u n - S e p

D e c - M a r

T h e s i z e o f t h e b u f f e r d e p e n d s o n m a n y t h i n g s s

u c h a s , s l o p e , p r o x m i t y t o w a t e r c o u r s e , s o i l , n u t r i e n t l o a d i n g , w i d t h ,

v e g e t a t i o n t y p e a n d m

a n a g e m e n t o f t h e v e g e t a t i o n .

T h e b l o c k a b

o v e s h o w s t h e s u b d i v i s i o n s o f t h e 1 6 - a c r e b l o c k d u r i n g t h e y e a r t h a t h o g s a r e o

n t h e s i t e .

R u n o f f B u f f e r

A c r e a g e , s t o c k i n g r a t e a n d n u t r i e n t l o a d i n g

f o r e a

c h f i n i s h i n g g r o u p o f

f e e d e r t o f i n i s h i n

g p i g s f r o m

2 4 s o w s . S i x f e e d i n g

l o t s a r e u s e d

t w i c e

p e r y e a r w i t h a t w o m o n t h r e s t p e r i o d b e t w e e n f i n

i s h i n g g r o u p s .

A c r e s f o r S o w s , p r e w e a n p i g s a n d b o

a r =

A c r e s f o r F e e d e r t o F i n i s h i n g h o g s =

A s s u m i n g a 6 y e

a r p r o d u c t i o n t i m e - l i n e t h i s 1 6 - a c r e b l o c k

w o u l d h a v e h o g s d u r i n g y e a r s 3 , &

6 a n d h a r v e s t e d

c r o p s i n y e a r s 1 , 2 , 4

, & 5 .

A c r e a g e f o r e a c h p r o d u c t i o n p h a s e w h e n 5 a c e s a r e u s e d f o

r 2 4 s o w s & 2

b o a r s p r o d u c i n g t w o l i t t e r s

o f 7 p i g s e a c h . S o w s f a r r o w

i n g r o u p s o f 4 e v e r y

m o n t h . N u t r i e n t l o a d i n g i s

a n n u a l t o t a l f o r a l l p r o d u c t i o n p h a s

e s .

A c r e s f o r e a c h p h

a s e o f s o w / b o a r a n d p r e w e a n i n g p r o d

u c t i o n

A s s u m i n g a 6 y e

a r p r o d u c t i o n t i m e - l i n e t h i s 1 6 - a c r e b l o c k

w o u l d h a v e h o g s d u r i n g y e a r s 2 &

5 a n d h a r v e s t e d

c r o p s i n y e a r s 1 , 3 , 4

& 6 .

B o a r

P e n 2 f i n i s h 2 g r o u p s

B r e e d i n g - p o s t w e a n



L a t

e G e s t a t i o n

E a r

l y G e s t a t i o n

E a r l y L a c t a t i o n

L a t e L a c t a t i o n

P e n 1 f i n i s h 2

g r o u p s

P e n 4 f i n i s h 2

g r o u p s




Potenal Crops for pens or dry-lots

The example presented here provides a reasonable

chance for maintaining some ground cover under

normal growing condions. The suggested example

design for the nishing hogs provides for 2 to 4

months of “rest” between nishing groups, and there

are annual forage crops that could be used to

produce cover for the soil during that period. The

annual forage crops listed in Table 4 provide quick

germinaon and seedling development during the

very short period between feed-out groups. One

would not expect high forage producon during most

seasons, but high seeding rates can improve the plant

density and reduce runo during this period. Many

of these forage crops also could be used as cover

crops following the harvest of row-crops used in the

rotaon. In addion, the early spring growth could

be harvested for hay thereby removing addional

nutrients from the site. Perhaps other grazing

animals, such as cale, could be used to control

some of the cover crop, but not many nutrients are

removed from the land.

Table 4. Potential vegetative cover crops to provide temporary soil cover during the“rest period” between groups of finishing animals

Cereal rye and ryegrass mixture that could be harvested for nutrient removal or provide cover during

the subsequent feed out period.



Many factors aect the vegetave cover that can be

maintained and the desirable level of cover. Cover

may be less of a priority if sucient buers are in

place to manage nutrient run-o. However, it may

be necessary or desirable to plant a cover crop or

use crop residue to provide some cover from the

me the hogs are moved to or from the site at the

beginning or end of each rotaon cycle.

When the crop to be rotated with the hogs is a

perennial grass it should be possible to maintain

cover in the nishing paddocks because the

stocking rate is less than 20 head/acre.

The hog area will need to be planted to forage cropswhen the crop rotaon is based on row-crops.

There is a possibility of maintaining some cover in

Stocking density and length of stay in the paddock are factors that impact soil nutrient loading

Other Consideraons

As noted above, this is one example of a dry-lot

producon system and the specic characteriscs of a

site will aect the system design. Soil types,

landscape and crop choices aect both the hog

operaon and the cropping rotaon. The cropping

systems to be used in the rotaon with the hogs

could include any crop that is marketable in the

region. It may be possible to keep hogs on the same

site for two years and meet the nutrient balance goal

by following the hogs with 3 or 4 years of crops.

Maintaining animals on the same site for two years

would reduce the number of mes the fences would

have to be move but the nutrient loading would be

greater aer 2 years than 1.

Planng a quick growing “cover crop” between

harvested crops can be helpful in controlling erosion

and nutrient loss.



the nishing paddocks, especially early in the nishing

phase of each group. If over-seeding or re-planng is

required aer a group leaves a paddock, the crop

should planted immediately following the removal of

the previous nished hog group. Table 4 contains

some of the annual crops that might be grown.

Consider increasing seeding rates by 50% to 100% ascompared to normal forage planng guidelines for

establishing new pastures. Seedling density will be

crical to eecve soil cover when the growth period

is limited between nishing groups. For cover crop

planng following row-crop harvest the normal

seeding rates should suce.

Lack of vegetative ground cover can lead to nutrient and

soil movement with runoff and erosion.

Cereal rye and ryegrass mixture paddock at the end of the finishing production cycle (30 pigs/ac), almost no vegetative ground

cover is left. Notice the crop buffer surrounding the pen



The Cropping Rotaon

The goal of the cropping rotaon is to use most, If

not all, of the nutrients recycled through the hogs

as a way to minimize soil buildup. The actual

choice of crops in the rotaon will be governed by

soil type, landscape and climate as well as thenutrient needs. Esmates of the nutrient uptake

by various crops at specic yield levels are found

in Table 5. This informaon can be useful in

determining the cropping systems to use for

nutrient harvesng from the hog producon sites.

Table 6 shows the nutrient producon from the

example dry-lot hog operaon and the nutrient

uptake from corn and Bermuda grass. The

assumed corn yield is 123 bushels/acre and the

Bermuda grass yield is 4 tons/acre during the two

cropping years of the three-year rotaon with

hogs. Corn at this yield level potenally removes

more P than Bermuda grass hay at 4 tons/acre.

Note that about 90% to 115% of the P deposited

Table 5. Nutrient (N and P205) uptake estimates for selected crops at specific

yield levels.

by the nishing hogs is taken up in the hay and

corn grain crop respecvely, but the uptake levels

in the boar and sow areas ranged from 61% to

373% of that deposited. The post weaning sites

have the least amount of nutrients deposited.



%Removal

Soil Test

P-Index

Change

%Removal

Soil Test

P-Index

Change

Post wean/breeding 33 373% -18 291% -13

Gestation, Early 106 117% -4 91% 2

Gestation, Late 105 118% -4 92% 2

Farrowing/lactation, 1/2 of area 135 91% 3 71% 8

Farrowing/lactation, 1/2 of area 135 91% 3 71% 8

Boar number= 2 158 78% 7 61% 13

105% -1 82% 4

115% -3 90% 2

110% -2 86% 3

Sows & Boar avg based on weighted acres

Finishing hogsAverages for sows and finishers, but not a

weighted over acres

For every 4.931 lbs of P 2 O 5 added to the land that is not removed through crop

harvest or animal product the NC Soil Test P Index increases by one point.

Yield, Corn Grain,

123 bu/acre/ r

Yield, Bermuda Hay,

4 Tons/acre/yr

Animal Production Phase

Nutrients

Deposited,

lbs/acre/yr

Hay cropping is an effective way to remove nutrients

Table 6. Crop removal of P205 from corn or Bermuda hay during 2 years of harvests in

a 3 -yr rotation with 24 sows farrow to finishing operation on 48 acres. Hogs occupy

1/3 of the acreage every year and crops occupy two-thirds.



Matching crop nutrient needs and the nutrient

producon by the hogs is a challenge and an exact

match is unlikely. The problem of variaons in thenutrient distribuon across the site could be

migated by changing the locaon of the various

pen types over successive three-year rotaons, by

planng parts of the area to dierent crops or by

applying supplemental ferlizer in some areas.

Based on data from the NC Department of

Agriculture and Consumer Services soil tesng

Appropriate site selection and use of grassed buffer areas

minimize runoff potential

Corn crop besides N and P2O5 can remove other macronutrients as K2O, MgO, CaO, and S, and micronutrients as Fe,

Zn, Mn, B, Cu, Mo and Cl

services the overall P Index would remain fairly

stac (range from -18 to 13) over mulple crop

rotaon cycles. Considering that many soils inNorth Carolina currently have P indices below 100,

the stocking rate and crop rotaon in this example

could operate for many years before P levels would

be of concern. There are implicaons that higher

stocking rates could be used without overloading

phosphorus. We conclude that this example dry-lot

operaon can achieve the desired nutrient goals.

Implementing periodic movements of waterers, feeders and

shelter/shade structures help improving nutrient distribution



e. Finishing pastures are about 1.33 acres

and will be used for one feed out period

of about 4-5 months each year; this

means there will be a seven to eight

month period between nishing groups

where perennial vegetaon can recover

or perennial and/or annual grass cropscould be over sown to provide improved

ground cover.

4. On average 20% of the acreage is renovated

with permanent vegetaon each year.

5. Fences are electried 3-wire that can be

moved if design changes are needed. .

6. Each paddock has a watering point, feedersand shelter/shade. The infrastructure can be

managed exibly to help control nutrient

distribuon and heavy use areas.

The example farm layout 7) uses esmated nutrient

producon by the hogs to esmate the nutrient

loading of the acreage based on the hog producon

phase using the specic paddocks.

Rotational grazing management improves nutrient distribution along the paddock and provides a “rest” period to the grass

II. Nutrient Management in Pasture based Farrow

to Finish Hog operaons

Assumpons and consideraons for this example:

1. Total acreage is 24. with 24 sows & 2 boars.

2. Paddock size is based on potenal nutrientloading, animal welfare or behavioral needs,

and length of me in the producon phase.

3. The acreage used by hogs is subdivided so that

about 33% is used for sows and boars and

about 67% is used for nishing (see Table 7

for example layout).

a. Boars use about 0.24 acres

b. Breeding area is about 0.8 acres

c. Gestaon period uses about 3.6 acres and

it may be divided into early and late

gestaon to facilitate sow group

management.

d. Lactaon period uses about 3.36 acres

which may be divided into early and late

lactaon to beer facilitate sow groups

and pig management.



T a b l e 7 . L a y o u t , a c r e a g e o f p e r m a n e n t p a s t u

r e a n d e s t i m a t e o f a n n u

a l n u t r i e n t l o a d i n g f o r a

h o g o p e r a t i o n

s t o c k e d a t o n e s o w +

1 4 f i n i s h e d p i g s p e r a c r e / y r . T h e s y s t e m i s f o r 2 4 s o w s a n d p i g s o n 2 4 a c r e s .

S O W

# =

2 4

8 . 0

1 6 . 0

4 9 l b s P A N / a c

7 3 l b s P 2 O 5 / a c

8 7 l b s K 2 O / a c

8 4 l b s P A N / a c r e /

7 4 l b s P 2 O 5 / a c r e

1 0 0 l b s K 2 0 / a c r e

A c r e s / p e n =

1 . 3 3

H e a d / p e n = 2 8

H

e a d / a c r e = 2 1

J a n - A p r

F e b - M a

y

M a r - J u n

A p r - J l y

M a y - A u g

J u n - S e p

0 . 8

a c r e s

1 . 6 8 a c r e s

1 . 8 a c r e s

P e n 1

P e n 2

P e n 3

P e n 4

P e n 5

P e n 6

J l y - O c t

A u g - N o

v

S e p - D e c

O c t - J a n

N o v - F e b

D e c - M a r

0 . 2 4 a c r e s

1 . 6 8 a c r e s

1 . 8 a c r e s

P e n 7

P e n 8

P e n 9

P e n 1 0

P e n 1 1

P e n 1 2

T h e s i z e o f t h e b u f f e r

d e p e n d s o n m a n y t h i n g s

s u c h a s s l o p e , p r o x m i t y

t o w a t e r c o u r s e , s o i l t y p e , n u t r i e n t

l o a d i n g , w i d t h , v e g e t a

t i o n t y p e a n d m a n a g e m e

n t a n d u s e o f t h e v e g e t a t i o n .

A c r e

s f o r F e e d e r t o F i n i s h i n g h o g s =

B U F F E R

A c r e a g e f o r e a c h p r o d u c t i o n p h a s e

w h e n

2 4 a c r e s a r e u s e d f o r 2 4 s o w s p r o

d u c i n g t w o

l i t t e r s o f 7 p i g s e a c h . S o w s f a r r o w i n g r o u p s o f 4 e v e r y m o n t h . N u t r i e n t l o a d i n

g i s t o t a l f o r

a l l p r o d u c t i o n p h a s e s e a c h y e a r .

A c r e a g e , s t o c k i n g d e n s i t y a

n d t h e a s s o c i a t e d n u t r i e n t l o a d i n g f o r f e e

d e r t o f i n i s h i n g f o r t w o l i t t e r s

o f 7 p i g s e a c h / y e a r . E a c h

o f t h e 1 2 f e e d l o t s o r p a d d o c k s a r e u s e d

f o r o n e f e e d o u t g r o u p p e r

y e a r .

A c r e s f o r e a c h p h a s e o

f s o w / b o a r a n d p r e w e a n i n g p r o d u c

t i o n

A

c r e s f o r s o w s , p r e w e a n a n d b o a r =

B r e e d i n g - p o s t w e a n

E a r l y G e

s t a t i o n

L a t e G e s t a t i o n

E a r l y L a c t a t i o n

L a t e L a c t a t i o n

B o a r



Consideraons for Perennial Species

Since it is important to maintain vegetave cover to

reduce environmental impacts, there is juscaon for

using endophyte containing tall fescue because of its

improved persistence. Non-toxic endophyte types are

available, but they generally are not as persistent as

the toxic types found in KY 31 fescue. Since animals

are being fully fed, the toxic endophyte will not likely

cause any adverse eects on animal performance.

Bermudagrass, with its rhizomes and stolons, has the

potenal to spread and recover even following

extensive roong and trampling in heavy use areas.

The hybrid types will be more expensive to establish,

but they have the advantage of potenally producing

more pasture and they are easier to control if there isa desire to rotate the pastures into some other

cropping system. Seeded types of bermuda are

cheaper to establish but their reseeding capability will

ensure that the soil is full of seed for future

generaons, and this may become a disadvantage if

cropping systems change. If spreading of seed around

the farm is of lile concern, then this opon is a viable

one.

Nutrient Removal.

Nutrient removal, especially for P, from pastured sites

is nil when a crop is not harvested and removed from

the site. Very few nutrients are removed from a

pasture-based system because the vegetaon is rarely

harvested and removed from the site, and the amount

of nutrients removed through the sale of animals is

relavely low. Table 9 illustrates the change in NCDA

soil test P index based on the nutrient loading by 1

sow with 14 pigs farrow-to-nish per acre when no

crop is harvested. The length of me hogs can remain

on the same site will be directly related to hog density

and soil capability for capturing and holding nutrients

from manure and urine. Depending on the inial soil

test P level, soil type, landscape, duraon of use, and

the amount and type of any periodic harvesng of

Pasture Crops for Outdoor Hog Producon

The system outlined here uses perennial grasses,

(mainly tall fescue or bermudagrass) for providing

soil cover, but depending on stocking rate and the

length of me hogs will occupy the paddock

several annual crops may be useful for renovaon

and temporary cover when perennial vegetaon is

poor (Table 8). In this example the nishing

pastures are used at a relavely low stocking rate

and with up to eight months rest between nishing

groups it is likely that vegetave cover will be

sasfactory and renovaon needs may be minimal.

However, Under North Carolina condions 20% of

the land used by hogs may need to be renovated in

a typical year and it may be useful to consider

some of the annual forage crops as companion

crops for temporary cover. Depending on the

seasons of the year, it may be possible to renovate

only porons of the pastures with the base

perennial crops (bermuda and tall fescue). With a

total of 12 nishing pastures it is possible to use

some pastures twice per year while renovang

other pastures.

Periodical soil sampling helps monitor soil nutrient

levels.



T a b l e 8 . P o t e n t i a l p a s t u r e c r o p s t o p r o v i d e

d s o i l c o v e r f o r t h e f i n i s h i n g p h a s e o f o u t d o o r h

o g p r o d u c t i o n .

F i n i s h i n g h o g s o n p a s t u r e c o n t i n u o u s l y f o r 4

m o n t h s f o l l o w e d b y 8 m

o n t h s o f r e s t o n e a c h p a s

t u r e . A f t e r o n e

y e a r l y c y c l e o f f i n i s h i n g , i t m i g h t b e p r a c t i c

a l t o a l t e r t h e s e q u e n c e

o f p a d d o c k u s e , e s p e c i a l l y i f t h e r e a r e

s i g n i f i c a n t d i f f e r e n c e s i n v e g e t a t i o n s u r v i v a l .

P o t e n t i a l r e n o v a t i o n c

r o p s f o l l o w i n g a f i n i s h i n g c y c l e

M o n t h s

o n

p a s t u r e

M o n t h s

o f

n o h o g s

B a s e C r o p s i n e a c h p a s t u r e ( c h o o s e

g r a s s e s w i t h r h i z o m e s , s t o l o n s )

M o n t h s

o n

p a s t u r e

M o n t h s

o f

n o h o g s

P o s s i b l e r e n o v a t i o n n e e d

s f o l l o w i n g 4 m o n t h s o f

f i n i s h e r s

A n n u a l c r o p s t h a t w o u l d

c o v e r t h e s o i l q u i c k l y f o l l o w i n g 4

m o n t h s o f h o g s , b u t m a

y n o t b e t h e r e 8 m o n t h s l a t e r w h e n

h o g s r e t u r n

1

2 8

2 1

J a n - A p

r

M a y - D e c

M o s t l y F e s c u e m i x e d w i t h s o m e B e r m u d

a

J a n - A p r

M a y - D e c

R e n o v a t e w i t h B e r m u d a i n M a y o r F e s c u e i n A u g .

b e r m u d a ; c r a b g r a s s , s o

r g h u m , s u d a n , m i l l e t , t e f f , l o v e g r a s s

2

2 8

2 1

F e b - M a

y

J u n - J a n


a

F e b - M a y

J u n - J a n

R e n o v a t e w i t h B e r m u d a i n J u n e o r F e s c u e i n A u g



3

2 8

2 1

M a r - J u n

J u l y - F e b . M o s t l y F e s c u e m i x e d w i t h s o m e B e r m u d

a

M a r - J u n

J u l y - F e b . R e n o v a t e w i t h B e r m u d a i n J l y o r F e s c u e i n A u g



4

2 8

2 1

A p r - J l y

A u g - M a r

M o s t l y B e r m u d a w i t h s o m e F e s c u e

A p r - J l y

A u g - M a r

R e n o v a t e w i t h B e r m u d a a n d F e s c u e i n A u g

f e s c u e , r y e g r a s s , r a p e

5

2 8

2 1

M a y - A u

g

S e p - A p r


M a y - A u g

S e p - A p r

R e n o v a t e w i t h F e s c u e i n

S e p t a n d B e r m u d a i n M a r c h


6

2 8

2 1

J u n - S e p

O c t - M a y

M o s t l y B e r m u d a ; P e r h a p s f a l l o v e r s e e d e d

w i t h S m a l l g r a i n

J u n - S e p

O c t - M a y


O c t a n d B e r m u d a i n M a r c h


7

2 8

2 1

J l y - O c t

N o v . - J u n



J l y - O c t

N o v . - J u n


N o v a n d B e r m u d a i n M a r c h

f e s c u e , r y e , r a p e

8

2 8

2 1

A u g - N o

v

D e c - J l y



A u g - N o v

D e c - J l y

R e n o v a t e w i t h C e r e a l R y e & F e s c u e i n D e c a n d

B e r m u d a i n M a r c h

f e s c u e , r y e

9

2 8

2 1

S e p - D e

c

J a n - A u g



S e p - D e c

J a n - A u g

R e n o v a t e w i t h C e r e a l R y e & F e s c u e i n J a n a n d


r y e

1 0

2 8

2 1

O c t - J a n

F e b - S e p


O c t - J a n

F e b - S e p

R e n o v a t e w i t h C e r e a l R y e & F e s c u e i n F e b a n d


f e s c u e , r y e

1 1

2 8

2 1

N o v - F e b

M a r - O c t


a

N o v - F e b

M a r - O c t

R e n o v a t e w i t h F e s c u e a n

d B e r m u d a i n M a r c h

b e r m u d a , r a p e , c r a b g r a s s

1 2

2 8

2 1

D e c - M a

r

A p r - N o v


a

D e c - M a r

A p r - N o v

R e n o v a t e w i t h F e s c u e a n

d B e r m u d a i n A p r i l

b e r m u d a , c r a b g r a s s , s o


# o f

p a d d o c k s

#

p i g s / g r o u p

o f 4 s o w s

H e a d / a c r e

w h i l e o n

p a s t u r e

1 s t y e a r

2 n d y e a r



T a b l e 9 . N u

t r i e n t s d e p o s i t e d i n v a r i o

u s p h a s e s o f a f a r r o w t o

f i n i s h p a s t u r e s y s t e m a n

d t h e c h a n g e

i n P - I n d e x w

h e n n o c r o p s a r e r e m o v e d f r o m t

h e p a s t u r e s . B a

s e d o n 2 4 s o w s h a v i n g 1 4 p i g s / y r i n

f a r r o w t o f i n

i s h o p e r a t i o n o n 2 4 a c r e s .

% R e m o v a l

n o h a r v e s t

S o i l

T e s t P -

I n d e x

C h a n g e

P o s t w e a n / b r e e d i n g

1 9

0 %

4

G e s t a t i o n , E a r l y

6 2

0 %

1 2

G e s t a t i o n , L a t e

6 1

0 %

1 2

F a r r o w i n g / l a c t a t i o n , 1 / 2 o f a r e a

9 1

0 %

1 8

F a r r o w i n g / l a c t a t i o n , 1 / 2 o f a r e a

9 1

0 %

1 8

B o a r n u m b e r = 2

1 3 2

0 %

2 7

S o w s & B o a r a v g b a s e d o

n w e i g h t e d a c r e s

7 3

0 %

1 5

F i n i s h i n g h o g s

7 4

0 %

1 5

A v e r a g e s f o r s o w s a n d f i n i s h e r s , b u t n o t a

w e i g h t e d o v e r a c r e s

7 3

0 %

1 5

A n i m a l P r o d u c

t i o n P h a s e

N u t r i e

n t s

D e p o s i t e d ,

l b s / a c r

e / y r

Y i e l d , B e r m u d a H a y , 4

T o n s / a c r e / y r

F o r e v e r y 4 . 9

3 1 l b s o f P 2 O

5

a d d e d t o t h e l a n d t h a t i s n o t r e m o v e d t h r o u g h c r o p

h a r v e s t o r a n i m a l p r o d u c t t h e N C S o i l T e s t P I n d e x i n c r e a s

e s b y o n e p o i n t .



crop or crop residue it could take several years to

see signicant build up.

Extending the length of me hogs can be grown on

a parcular land area before nutrient loading

reaches problem levels requires the periodic

removal of nutrients in harvestable crops. At some

point the soils in a pasture-based operaon cannot

remain below the target levels necessary to meet

environmental goals and the land must be

converted to other uses that will extract some of

the nutrients.

Economics

Creang a producve and environmentally sound

outdoor hog operaon presents many produconchallenges. Making money from the enterprise

represents an addional challenge. Costs of

producon are likely to be higher for an outdoor

hog operaon than for hogs produced by large-

scale intensive producon systems. Therefore, a

higher selling price is necessary to recoup these

higher costs and make a prot. Fortunately, there

are markeng opportunies to earn this higher

price. Specialty or niche markets oer higherprices for market hogs. There are direct markeng

opportunies but these come with added work and

expense. Producers interested in outdoor hog

operaons are advised to rst assess the market

for their products of interest, design a producve

and environmentally sound system for producing

and markeng the animals, and then evaluate the

costs and returns for producing and markeng

these hogs. Enterprise budget spreadsheets for

producing market-weight hogs are available at //ag

-econ.ncsu.edu/extension/outdoor -hogs-budgets.

These budgets were developed for the example

producon systems described here but the

spreadsheet entries can be customized for other

outdoor hog producon systems. These budget

spreadsheets can and should be used for

evaluang alternave producon scenarios before

any money is invested.

Conclusions

Outdoor hog producon provides opportunies

and challenges. Environmental damage resulng

from nutrients produced by the hogs can be

reduced or eliminated when the producon systemis designed carefully. Phosphorus and nitrogen

produced in the hog manure and urine are the

nutrients of concern. Maintaining a nutrient

balance over the long term is feasible when hogs

are raised in a dry-lot system in combinaon with a

crop rotaon. Vegetave cover can be maintained

at acceptable levels in a dry-lot system. Vegetave

cover can be maintained at high levels in a pasture-

based system, minimizing the loss of soil and

nutrients through run-o. A nutrient balance is

unlikely to be achieved or maintained over the

long term but the rate of increase in the nutrient

load on the land can be slowed by appropriate

management strategies. Stocking rate is a key

factor in maintaining sasfactory control over the

environmental impact of outdoor hog operaons.

Producers are advised to design their producon

systems carefully and to evaluate both the

environmental and economic outcomes.

nutrient and vegetation management in outdoor hog production systems

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