美國的指數定義

Roselu

Formulas for STAGES Indexes
Revised October 2005


Traits in the postweaning analysis are Days to 250 lbs, Backfat, and Loin Eye Area. Traits in the reproductive analysis are Number born alive, Number weaned (number at 21 days), and Litter weight at 21 days. Other EPDs are calculated from these.

STAGES indexes are economic indexes. EPDs are combined with the economic values to calculate the indexes. A constant is added to the indexes so they will average 100.



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First, here are the names of the EPDs and Indexes, and the Economic Values currently being used.

EPDs:
   DAYS
Days to 250 lbs

   BACK
Backfat, in.

   LEA
Loin Eye Area, in2

   LBLEAN
Pounds of Fat-Free Lean adjusted to a 250 lb live weight

   FUG
Feed/lb of gain

   NBA
Number Born Alive

   NW
Number Weaned

   LW
Litter Weight at 21 days, lbs

   LBW
Litter Birth Weight, lbs

   DW
Days to Weaning ( to reach a specific target BW )

   DWTB
Days from Weaning to Breeding

   MBW
Mean birth weight ,lbs


Indexes:
   PWI
PostWeaning Index for a terminal sire line

   PWIMAT
PostWeaning Index for a maternal line

   TSI
Terminal Sire Index

   MLI
Maternal Line Index

   SPI
Sow Productivity Index


Economic Values and Constants:
   NLPF
4
Number of litters per female

   CNPD
1.65
Cost of nonproductive sow days

   RBMP
$.45
Base market price/lb live weight for a 48% fat-free lean carcass

   RLFCST
$.17
Labor and facilities cost/day

   RFDCST
$.07
Feed cost/lb of feed

   ZMNDX
$30.00
Value of a pig at weaning

   SLWT
265
Target slaughter weight (lbs)

   WTGAIN
250
Weight gained from weaning to slaughter

   ZDAYS
170
Average days to 250 lbs

   ZFUG
3.25
Average feed/lb gain (lbs)

   VPW
$30.00
Value of a pig at weaning

   VPB
$22.00
Value of a pig at birth

   CPB
$.35
Cost to process newborn pig

   CLD
$2.00
Cost/day for sow in farrowing and lactation

   CLW
$.035
Extra feed cost/pig

   DWBAR
22.637
Average days to weaning (15 lb pigs weaned)

   XST
10.4
Average size of standardized litter

   WNM
.11
Average preweaning mortality

   XSTWNM
9.256
XST(1-WNM) = Average litter size at weaning

   TWW
15
Target weaning weight (lbs)

   XBW
3.2
Average birth weight (lbs)

   ZLW
130.94
Average litter weight at 21 days (lbs)

   ZPWI
4.80
Average PWI

   ZPWIMAT
6.928
Average PWIMAT

   ZSPI
66.48
Constant for SPI (used so SPI will average 100)

   ZMLI
66.48
Constant for MLI (used so MLI will average 100)




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Formulas used:
Let:

   ZLBLEAN
Average pounds of lean

   VALITS
Value index for terminal sire line

   VALIML
Value index for maternal line

   PIGVALTS
Value of a pig at 265 lbs for a terminal sire line

   PIGVALML
Value of a pig at 265 lbs for a maternal line

   X and VI
Intermediate variables


Postweaning EPDs output from the analysis are DAYS, BACK, and LEA. Then:

LBLEAN = -14.95*BACK + 1.5*LEA

FUG = .0146*DAYS - .02083*LBLEAN

For a maternal line, ZLBLEAN = 92
X = ZLBLEAN+LBLEAN
If X  94 then X = 94.
If X  76.2 then VI = .918507 + .0068621*(X-76.2)
If X > 76.2 then VI = 3.433454 - (.112831*X) + (.001572*X2 ) - (.000006882*X3 )
VALIML = VI*1.0324

For a terminal sire line, ZLBLEAN = 87
X = ZLBLEAN+LBLEAN
If X  94 then X = 94.
If X  76.2 then VI = .918507 + .0068621*(X-76.2)
If X > 76.2 then VI = 3.433454 - (.112831*X) + (.001572*X2 ) - (.000006882*X3 )
VALITS = VI*1.0324

PIGVALTS = SLWT*RBMP*VALITS

PIGVALML = SLWT*RBMP*VALIML

Reproductive EPDs output from the analysis are NBA, NW, LBW, DWTB, and LW. Then:

MBW = ((33.28 + LBW+ 2.5 NBA)/(XST + NBA)- XBW

NW = NW + .77 *MBW

DW = [(XSTWNM+NW)*21.*(TWW-(XBW+2.2*MBW))/(ZLW+LW-(XSTWNM+NW)*(MBW+XBW))]-DWBAR



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Indexes are:
SPI = (XSTWNM+NW)*VPW+(VPB-CPB)*NBA

-(DWBAR+DW)*(CLD+CLW*(XSTWNM+NW))

-[(NLPF-1)/NLPF] x (DWTB x CNPD)

taiwanp

豬頭，妳不會好人做到底喔 ∼ 順便翻譯一下會死喔 ∼ 反正晚上嫌嫌沒事做，又不用服伺公婆、相夫教子 ...  造福一下平凡百姓吧 ∼∼

frankyen

我不喜歡用young boar
他只不過是父母的平均
真正的好豬是靠後裔的追蹤
如 seed stock 的前幾名
多少後代分布在多少個牧場
如sgi395 396.............
美國豬的育種叉乳牛差太多了
美國的豬就像美國人一樣
一 個大熔爐