9. ANEXOS
9.1. ANEXO 1: MATERIALES PARA IMPRESIÓN 3D
Where: ˆP
j= exogenous price crop j
ˆ
j
Y
= average yield of crop j
YI
j= yield index of crop j on plot
mult
Y
= yield multiplier of farm agent
A
j= total acres of crop i on the plot
4.2.2 Forage and Livestock Production
Livestock producers (mixed farms) require forage production as a primary source of feed. Grain
farms do not produce livestock and consequently must sell annual hay production and rent
pasture land in their control to other farming agents.
4.2.2.1 Livestock Income
Mixed farms will generate income annually from the sale of the calves. Livestock production
income is the value of the calves less the costs. Note that raised feed and labour costs are
excluded (equation 4.3).
75
This allows the land quality to have a different impact on each crop included in the model based on historical
records.
6
Zentner et al. (2002) found that many crops had higher yields when seeded using no-till technology in the black soil
zone of Saskatchewan.
7
Feed costs are the annual cost of pasture and hay production in addition to any purchased feed. Labour costs are
(
cow)
l
LI
=
P W VC⋅ −
⋅NC
4.3
Where: LI = livestock income
P
l= price per pound of calf
W= average weight of calf
cow
VC
= variable cost of cow and calf, excluding feed and labour
NC = total cows of the farm operator
4.2.2.2 Hay and Pasture Production
Livestock production requires an adequate supply of feed for the entire year. Although feeds
sources (such as barley) other than forage could be used, it is assumed that livestock are fed only
forages in the form of hay or pasture. In the winter months, cattle are fed hay and in the summer
pasture is grazed. Pasture production is often greater early in the summer months and lower later
in the year, therefore pasture production is divided into two periods: 1) early pasture and 2) late
pasture, each with its own yield. The first period forage yield corresponds to early pasture or in
the case of hay production, the first cutting of hay. The second period forage production is the
subsequent re-growth for both hay land and pasture, which is assumed to only be used as late
pasture. Total energy production of each feed type, hay, early pasture, and late pasture is the sum
of the feed type production from all plots (equation 4.4).
, 1 n j i j i
TP
P
==∑
4.4
Where: TP
j= the total energy production of feed type j of the farm agent
P
i,j= the energy production of feed type j on plot i
The production of hay and each period of pasture production is the sum of the production of all
categories of land used in that method of forage production (equation 4.5). Each land category
may potentially have a different quality and therefore the yields may differ.
, , , 1 n ton i j j k j k j k
P
A
Y
E
==∑
⋅
⋅
4.5
Where: P
i,j= the total energy production feed type j on plot i
, j k
A
= acres of land category k used for feed type j on the plot i
, j k
Y
= the yield of forage on land category k in tons
8ton j
E
= energy in a ton of forage j
4.2.2.3 Hay and Pasture Usage
Farmers must have an adequate inventory of feed for the year. Pasture shortages can be offset by
feeding summer hay. If a farmer has excess early pasture, pasturing can be delayed until late
summer pasture; however there is nutrient loss due to over maturity. The total quantity of excess
early pasture that can be delayed for late pasture usage is:
1 1 1
EP TP E NC=
− ⋅
4.6
Where:EP
1= excess early pasture energy
TP
1= total early pasture production
E
1= energy required per cow of early pasture
NC = total cows of the farm operator
Excess late pasture is assumed to be unavailable for hay; as it increases the risk and extent of
winter kill and regrowth potential (Belanger et al. 1999). All the excess early pasture energy is
carried over to late pasture increasing the total late pasture production (equation 4.7). Late
pasture production has not occurred at the time of early pasture and therefore late pasture cannot
be transferred to early pasture. Early pasture shortages are offset by feeding hay. Therefore, if
excess early pasture is less than zero and there is no transfer of early pasture to late pasture and
the late pasture available is simply equal to late pasture production.
2 2
(1
)
1new
TP
=TP
+ −L EP⋅
4.7
Where: TP
2new= the new total late pasture energy available for farmer
TP
2= total late pasture production
L = the loss from delaying early pasture to late pasture
Hay is fed in winter months and to supplement pasture, if short in summer months. The total
quantity of hay fed is the sum over the summer and winter (equation 4.8).
s H ton H
H
NC E
HF
E
+
⋅
=
4.8
Where: HF = total hay fed in tons for the farm agent
H
s= hay fed in summer in energy units
E
H= total energy required over the winter months
ton H
4.2.2.4 Hay Reserves, Sales, and Purchases
Farm operators put hay in reserves (inventories) from years of high forage yields to avoid
purchasing hay when production is low. The quantity of hay in reserves is the sum of the current
hay reserves, new production, and hay purchases less hay fed and sold (equation 4.9).
1
(1
)
H t t ton HTP
HR
HR
SP
HP HF HS
E
−=
⋅ −
+
+
−
−
4.9
Where: HR
t= hay reserves at time t in tons
SP = spoilage to hay reserves
HP = hay purchases in tons
HS = hay sales in tons
Farmers adjust their hay reserves based on a minimum, maximum, and target level of hay
reserves through purchasing and selling hay.
9If a farmers hay reserves go below a minimum
threshold level, the farmer purchases hay to raise the hay reserves back to the threshold level.
When hay reserves exceed a maximum threshold level hay is sold to lower the hay reserves to the
target reserves level.
The net hay income is the sales value of hay less purchase cost (equation 4.10). A fixed
transaction fee for all hay sales is included to cover the cost of finding a buyer and transportation
expenses.
(
H)
HNHI
=
P
−TF HS P HP⋅
−
⋅
4.10
Where: NHI = net hay income
P
H= the market price of hay per ton
TF = the transaction fee when selling hay
Although in reality hay quality can vary within a region, it is not easily determined visually and
therefore it is assumed that all hay produced is of similar quality.
9
These levels are a percentage of the farmer’s expected annual hay requirement, therefore farmers who produce hay
In document
Elaboración de un plan de negociación para una empresa especializada en sistemas de impresión 3D
(página 68-73)